CLINICAL OPHTHALMOLOGY Flashcards

Question

Which feature below would increase the suspicion of an ischaemic aetiology for a third nerve palsy? neurology and pupils

Answer 1

The majority of ischaemic nerve palsies will recover within 3 months. Features of aberrant regeneration such as pupil constriction on eye movements or lid retraction should ring alarm bells, as this can be a sign of compression from space occupying lesions e.g. meningioma. Features of partial third cranial nerve palsies such as pupil sparing, or single muscle weakness may be a sign of a compressive lesion.

Answer 2

This child has a high accommodative convergence/accommodation (AC/A) ratio esotropia: Also called non-refractive accommodative esotropia There is an excessive convergence response for the amount of accommodation needed to focus while wearing their full cycloplegic correction Deviation present only at near or is much larger at near Refractive error normally averages around +2.25D, but can occur at normal or high level of hyperopia, emmetropia or even with myopia Management: (1) Executive bifocals plus full hypermetropic correction, (2) Surgery: Controversial, (3) Observation: Many have reduction in near deviation with time, and binocular vision at both distance/near fixation eventually develops The other options are wrong as: Refractive fully accommodative esotropia would have equal distance and near deviation and esotropia resolves with full hypermetropic correction Refractive partially accommodative esotropia would have equal distance and near deviation and esotropia partially resolves with full hypermetropic correction Infantile esotropia would have an earlier onset before 6 months of age, and is a constant non-accommodative esotropia

Answer 3

This patient has features most consistent with myasthenia gravis (MG). MG should be considered a possibility when there is intermittent diplopia. Methods for investigating for MG include: ice-pack test serum antibodies - anti-acetylcholine (anti-ACh) receptor antibody present in >95% of patients with generalised myasthenia but only 50% of ocular myasthenia; anti-skeletal muscle is present in 85% of patients with thymoma single fibre electromyography (EMG) As MG is associated with other autoimmune diseases, e.g. Graves’s disease in 4–10%, thyroid function test may help to detect associated thyroid disease but will not diagnose MG. Skeletal muscle biopsy assessing for mitochondrial myopathic changes is used to diagnose chronic progressive external ophthalmoplegia (CPEO). Whilst double vision can possibly occur, most CPEO patients do not have double vision due to the symmetric and diffuse nature of the weakness of extraocular muscles.

Answer 4

internal hordeolum Any active ocular or periocular infection is a contraindication to intravitreal injections. Another contraindication is an allergy to any ingredient/component of the intravitreal injection. An IOP of 26 should raise suspicion on post-injection IOP spikes. Consideration should be given to administer IOP-lowering medication as per local guidelines. A non-iodine based antiseptic should be used in all cases of iodine allergies. An only seeing eye is not a contraindication to intravitreal injections but risks and benefits should be thoroughly discussed with the patient before proceeding.

Answer 5

5 / 6 5) The parent of a newborn was enquiring about future surgery for their child with bilateral congenital cataracts. Which of the following is the most appropriate tiime to remove both cataracts? Your Answer: C Correct Answer: C Mark this question as 'Not Tried Before'. This tells the algorithm to treat this question as not seen before, thus higher chance to reappear in future tests. Chapters Tested 2 Clinical Ophthalmology 2.3 Glaucoma 2.7 Paediatrics Overall Result 1 / 1 Question Statistics 68.8% of users got it right on the first try. 75.0% of users got it right after multiple attempts. Explanation ID #00wf Timing of surgery in congenital cataract should be performed when risk of glaucoma is lowest, but before visual deprivation leads to intractable amblyopia. This is typically 6 weeks for unilateral and 10 weeks for bilateral cataracts Congenital cataract Lamellar cataracts are the most common form in congenital/infantile cataracts Characterised by opacification within specific lens zones Causes Isolated; usually autosomal dominant Chromosomal Trisomies: Downs (21), Edwards (18), Patau (13) Turners Craniosynotosis: premature closer of 1 or more cranial sutures Apert AKA acrocephalosyndactyly Crouzon The most common craniosynotosis Autosomal dominant Mutation in FGFR2 gene on chromosome 10 The most common strabismus in craniosynotosis syndrome is V-pattern exotropia often with inferior oblique overreaction Incontinentia pigmenti Myotonic dystrophy Christmas tree cataract and associated with low IOP (?ciliary body detachment) Marfan’s Alports Typically X-linked recessive mutation in basement membrane synthesis by COL4A5 gene Only males tend to develop renal failure Glomerulonephritis, sensorineural deafness, eye abnormalities Dot and fleck retinopathy Anterior lenticonus: oil droplet appearance on retinoscopy Posterior polymorphous dystrophy Oil droplet cataract Posterior lenticonus can be X-linked dominant presenting with cataract in childhood, often unilateral and tends to affect males more than females; associated with Alport’s, Duanes, Lowe’s syndrome Anterior segment dysgenesis Metabolic disorders: Fabry disease, Wilson disease, Lowe’s syndrome (thin disciform cataract) Lowe syndrome: rare X-linked disease caused by reduced activity of phosphatidylinositol (4,5) bisphosphate 5 phosphatase. Associated with glaucoma, corneal/conjunctival keloids, hypotonia at birth, renal tubular acidosis (Fanconi syndrome) Endocrine: diabetes mellitus, hypoparathyroidism (Christmas tree cataract) TORCH infections: toxoplasma, rubella, CMV/herpes, syphilis, measles, polio, influenza Trauma, drugs Timing of congenital cataract surgery Aim for lowest glaucoma risk, but before visual deprivation leads to intractable amblyopia 6 weeks for unilateral, 10 weeks for bilateral The Infant Aphakia Treatment Study (IATS) Sample Unilateral congenital cataract in 1-6 month olds who underwent cataract surgery, either receiving IOL or no IOL implantation Main findings Risk factor of glaucoma at 4.8 years after surgery was 17% Risk factor of glaucoma and/or glaucoma suspect at 4.8 years was 31% No difference in glaucoma (or glaucoma suspect) outcome between the IOL and no IOL groups Younger age at time of surgery caused higher risk of glaucoma Smaller corneal diameter caused higher risk of glaucoma + glaucoma suspect 95% of glaucoma cases were open angle is

Answer 6

High myopia is the commonest cause of CNV in young patients, accounting for >60% of CNV in <50y

Answer 7

Traumatic optic neuropathy The sudden VA loss, RAPD and health disc suggest traumatic optic neuropathy Traumatic optic neuropathy Acute VA loss Reduced optic nerve function and RAPD present Optic nerve appears healthy The most common cause of TON is indirect injury to the optic nerve, causing transmitted shock from an orbital impact to the intracanalicular (formed by lesser wing of sphenoid) portion of optic nerve Direct TON can result from penetrating injury or from bony fragments in the optic canal or orbit piercing the optic nerve. Orbital haemorrhage (orbital compartment syndrome) and optic nerve sheath haematoma can also cause TON by direct compression. No evidence for high dose steroids

Answer 8

chloramphenicol Chloramphenicol is the least effective in pseudomonas keratitis. Pseudomonas aeruginosa is usually intrinsically resistant towards chloramphenicol. The treatment regimes for pseudomonas keratitis tends to vary, but may either be monotherapy or combination therapy with topical fluoroquinolones e.g. ofloxacin, aminoglycosides, e.g. gentamicin, cephalosporins e.g. cefuroxime and carbapenems.

Answer 9

Polycythaemia, where there is an increase in red cell mass is a cause of low ESR. Other causes of low ESR include: Congestive heart failure Sickle cell anaemia Leukocytosis Cryoglobulinaemia The other options given are causes of high ESR. High ESR can occur from any conditions causing inflammation such as rheumatoid arthritis and other autoimmune conditions. Pregnancy causes an elevated ESR.

Answer 10

lateral wall decompression You should not be tested on the details of orbital decompression. But the purpose of this question is to test your understanding that newer techniques in orbital decompressions has a lower morbidity compared to the older technique used (lateral wall decompression). less: swinging eyelid endoscopic decompression trans- blepharoplasty

Answer 11

topical steroids This patient most likely has stromal keratitis caused by varicella zoster virus. She probably had shingles 2 weeks ago which would’ve been treated by his GP with oral antivirals. The most important treatment to start the patient on would be topical steroids. Care should be taken to ensure there is no risk of perforation. If risk is present, prevention is required with glue, BCL or tectonic grafting. Herpes zoster ophthalmicus Reactivation of dormant VZV virus in the sensory ganglion with involvement of ophthalmic branch of CN V 15% of shingles Risk factors Immunosuppression: chronic illness, drugs, HIV Age > 60 Caucasian Clinical features Pre-herpetic neuralgia: intermittent tingling to severe constant electric pain Rash (papules to vesicles to pustules to scabs) Hutchinson’s sign (cutaneous involvement of tip of nose indicating nasociliary nerve involvement, indicating high likelihood of ocular complications) Beware of dissemination in immunocompromised May cause neurotrophic cornea Epithelial Acute and common (2-3d after rash, resolves in a few weeks) Superficial punctate keratitis Pseudodendrites Anterior stromal infiltrate Stromal Early and uncommon (10d after rash) Nummular keratitis with anterior stromal granular deposits Necrotising interstitial keratitis with stromal infiltrates, thinning, perforation (rare and occurs late 3m-years) Disciform Late and uncommon (3m-years) Endotheliitis with disc of corneal oedema DM folds Mild AC activity KPs Neurotrophic May cause corneal nerve damage causing persisted ED, thinning, perforation Treatment Treat with systemic anti-viral acyclovir 800mg 5x/day for 5 days or valaciclovir 1g 3x/day for 7 days or famciclovir 750mg once a day for 7 days If immunosuppressed, acyclovir IV 10mg/kg 3x/day Then to consider: Epithelial Topical lubricants Stromal and disciform Topica steroid Consider BCL, glue and tectonic grafting in risk of perforation Neurotrophic Topical lubrication Tarsorrhaphy Amniotic membrane or conjunctival flap Monitor IOP Corneal scarring Penetrating keratoplasty Complications Conjunctivitis, microbial keratitis, glaucoma, anterior uveitis, necrotising retinitis (ARN, PORN), episcleritis, scleritis, optic neuritis, cranial nerve palsies Strokes, neuralgia Herpetic Eye Disease study main points Effectiveness of topical steroids in stromal keratitis (on topical antivirals): safe and effective Effectiveness of oral acyclovir in stromal keratitis: no benefit Effective of oral acyclovir in herpetic uveitis: effective Effectiveness of oral acyclovir in recurrent HSV: decreased recurrence rate by 50% Oral acyclovir does not prevent progression from epithelial to stromal disease Differences between HSV and VZV Zoster Consider demographic: normally elderly or immunocompromised Dermatome: complete More painful and more likely to develop post-herpetic neuralgia Nummular stormal infiltrates Raised plaque like lesions stain with Rose-Bengal Mucous epithelial plaques Sectoral iris atrophy No terminal bulbs (dendrites) HSV Incomplete dermatome Patchy iris atrophy Terminal bulbs ChatGPT said: ChatGPT This statement refers to the pattern of skin involvement (dermatomal distribution) seen in infections caused by Varicella Zoster Virus (VZV) and Herpes Simplex Virus (HSV). Zoster Dermatome: Complete VZV causes Herpes Zoster (Shingles), which typically follows a complete dermatome. This means the rash and associated symptoms (like pain and tingling) strictly follow the distribution of the affected sensory nerve (dermatome) from the dorsal root ganglion. The pattern is usually well-defined, respecting the midline, and does not "skip" areas within the dermatome. This is because the reactivation of VZV involves the entire nerve segment. HSV Dermatome: Incomplete HSV infections (e.g., Herpes Simplex) can sometimes involve the skin in a dermatomal distribution but often show an incomplete pattern. This means the rash may not strictly follow the full distribution of the nerve or may involve patchy areas within a dermatome. HSV infections typically occur due to reactivation of the virus in the sensory ganglia (commonly the trigeminal or sacral ganglia), but the involvement tends to be less well-defined compared to VZV. Key Takeaways Complete dermatome (VZV): More consistent, contiguous involvement within the entire dermatome due to localized reactivation in the nerve root. Incomplete dermatome (HSV): Patchy or partial involvement, as the reactivation of HSV does not necessarily involve the entire dermatome.

Answer 12

Atopy and eye-rubbing are associated with keratoconus. Keratoconus causes irregular astigmatism. This patient will need collagen cross-linking, which has been shown to stabilise astigmatism. It is however limited to use to corneas with >400microns in thickness to avoid endothelial toxicity. His allergic conjunctivitis will also need to be stabilised following which a corneal referral is highly warranted in this case. Keratoconus Bilateral paracentral thinning of cornea at the apex of the cone Apex of the cone is usually just below the visual axis of the cornea Fragmentation of Bowman’s layer with bowing forward of cornea Steep corneas (>50D) and high astigmatism should raise suspicion for keratoconus Topographic abnormalities usually at a young age (puberty) Corneal hydrous, scarring and Fleisher-rings (deposition of haemosiderin within basal corneal epithelial cells; this is seen at the base of the cone), Vogt striae Treatment Counselling e.g. disease stabilises at mid 30s, collagen cross-linking for progression Mild astigmatism: spectacle or CL Moderate astigmatism: collagen cross-linking, RGP lens, scleral lens, intracorneal ring segments can flatten cornea to improve vision and CL tolerance Severe astigmatism: deep anterior lamellar keratoplasty or PK Hydrops: topical steroids, lubricants and cycloplegia. Intracameral air for Descemet’s break

Answer 13

impaired abilith to initiate saccade Louis-Bar syndrome Autosomal recessive, ATM gene mutation which also affects BRCA1 One of earliest sign is oculomotor apraxia such as impaired ability to initiate saccades Conjunctival telangiectasia Cerebellar ataxia, dysarthria, dystonia, choreoathetosis Reduced IQ Immunodeficiency Increased risk of breast cancer in heterozygous females

Answer 14

Variants within the complement factor H gene (CFH) have been found to be associated with significantly increased risk for AMD. CFH codes for complement factor H which regulates the complement pathway. Variations in the age-related maculopathy susceptibility 2 (ARMS2) gene have also been found to be associated with AMD. The other options are associated with other conditions: TIMP3: Sorsby macular dystrophy RDH5: Fundus albipunctatus OAT: Gyrate atrophy

Answer 15

This patient is likely to have blebitis. Blebitis is said to classically look "white-on-red", where there is an opacified bleb surrounded by hyperaemic conjunctiva. It is important to differentiate blebitis from bleb-associated endophthalmitis but many would say this is a continuum. Bleb-associated enophthalmitis tends to present with poorer vision, severe pain and on examination typically there is significant vitritis and a hypoyon. However in many institutions, there is a low threshold for treatment with tap and injection of intravitreal antibiotics, even if all of these features are not present. In this case as there is only a possible minor visual acuity loss (we are not told what the previous visual acuity is), ocassional cells in the anterior chamber, and no vitritis, this is likely to be a case of blebitis. Therefore in most institutions, this would be treated with topical antibiotics such as moxifloxacin, after a conjunctival swab is taken for microscopy, culture and sensitivity.

Answer 16

Oil red O Recurrent chalazia and unilateral blepharitis should raise suspicions of sebaceous cell carcinoma and trigger investigations. This neoplasm arises from sebaceous glands such as those in the meibomian glands, gland of Zeis, the caruncle and the skin of the eyebrow. The upper eyelid is the most common site for sebaceous cell carcinoma. It is an aggressive neoplasm and can metastasise, and can spread in a pagetoid pattern so there is often involvement of both the eyelid and the conjunctiva. On a slide without special stains, the stain may contain foamy cells or cells with vacuolated cytoplasm. The reason why the cytoplasm is vacuolated is because the fat in the cytoplasm has been removed by alcohol during paraffin fixation. This is why it is important pathologists are contacted prior to sending the slides over. Tissue left in formaldehyde for prolonged periods or paraffin fixed will have intracytoplasmic lipids removed. Special stains can help the pathologist diagnose sebaceous cell carcinoma because it mimic squamous cell carcinoma. Traditionally, oil red O or Sudan black are dyes that can be used. Oil red O are often used on frozen-sections. On slide stained with oil red O, the red areas represent tumour cells that contain fat. However, in more recent times, various immunohistochemistry stains are used, which we will not go into detail here.

Answer 17

Descemet membrane Kayser-Fleischer ring is a feature of Wilson's disease, where there is build up of copper due to an autosomal recessive copper metabolic disorder. In Kayser-Fleischer ring, copper is deposited in the descemet's membrane of the cornea. Do not confuse Kayser-Fleischer ring with Fleischer ring, which is a feature that be found in patients with keratoconus. The ring is made from iron deposit often present within the epithelium around the base of the cone, giving it a brown colour. It may be best seen using a cobalt blue filter.

Answer 18

This patient is experiencing an anaphylactic reaction. The most appropriate next step is to administer 0.5ml of 1:1000 adrenaline intramuscularly immediately. 0.3ml is for children 6-12 years old. Any children >12 years and adults should be given 0.5ml. Intravenous (IV) adrenaline must be given by experienced specialists in an appropriate setting, and it is likely that the day ward in an eye centre is not an appropriate setting. Steroids should not be used as a first line treatment in place of adrenaline as the benefit of corticosteroids in anaphylaxis is unproven.

Answer 19

This patient will require urgent IV corticosteroids. There should not be any delay to treatment. Head and orbital imaging can be arranged while treatment has been commenced. Orbital decompression can be considered if the patient does not respond to treatment. Thyroid eye disease is an EXTREMELY high yield topic. There will always be at least 2-3 questions on this. Notes below highlights relevant points needed to know for the exam. Thyroid eye disease (TED/TAO/Grave’s ophthalmopathy) 30-50% of people with Grave’s disease develop TED, 3-5% are severe, most are mild 90% related to Grave’s, 3% related to Hashimoto’s 90% of TED will develop hyperthyroid, only 30% of hyperthyroid has TED Pathogenesis Target antigen (on orbital fibroblasts) shared between orbital tissues (extraocular muscles and adipose tissue) and thyroid gland causing inflammatory response Risk factors 6x more common in females HLA-DR3, HLA-B8, genes for CTLA4 and the TSH receptor Smoking Family history Stress Clinical features Ocular irritation, injection and chemosis (conj, caruncle) Reduced VA Painful eye movement Diplopia Proptosis Lid retraction (upper>lower, lateral>medial) Lid lag Lagophthalmos Orbital fat prolapse Keratopathy (exposure/superior limbic/KCS) Restrictive myopathy Optic neuropathy General features of hyper/hypothyroidism Hyper: weight loss, heat intolerance, restlessness, diarrhoea, poor libido, amenorrhea, poor concentration, irritable, warm peripheries, hair loss, tachy, AF, proximal myopathy, tremor, osteoporosis Hypo: weight gain, cold intolerance, fatigue, constipation, poor libido, menorrhagia, poor memory, depression, coarse and thin hair, bradycardia, pericardial/pleural effusions, muscle cramps, slow reflexes, deafness Grave’s Anti-TSH receptor antibodies cause overproduction of T4 and/or T3 Goitre, TED, finger clubbing (acropachy), pretibial myxoedema Hashimoto’s May have transient hyperthyroid stage Firm lobulated goitre from lymphocytic infiltration Acute progressive optic neuropathy Reduced VA, colour, VF, RAPD Due to compression of optic nerve by tissues, mainly recti muscles or proptosis induced stretch Treat with oral or IV corticosteroids Assess over 1-2 weeks Repeat doses if needed Risk of exceeding 8g - acute liver damage in 0.8% Consider urgent surgical decompression if failure of medical treatment Exposure keratopathy As a result of proptosis and lid retraction Treat as per usual exposure keratopathy Taping/Tarsorraphy if needed EUGOGO classification classifies TED into categories according to impact on QOL and need for immunosuppresion/surgery Mild: clinical features are mild and have little impact on QOL; no need for immunosuppression/surgery Moderate/severe: not sight-threatening but presence of impact on QOL; immunosuppression for active disease, surgery for inactive Sight threatening: optic neuropathy and/or corneal breakdown; urgent immunosuppression and/or surgery CAS score (clinical activity score by Mourits et al) Scores 1 each Pain pain on or behind globe pain on eye movement Redness eyelid redness conjunctival redness Swelling swelling of lids chemosis caruncle swelling proptosis (2mm or more in 1-3m) Impaired function (eye movements and vision) decreasing eye movements (5 or more degrees in 1-3m) decreasing vision (1 or more line pinhole VA on snellen chart in 1-3m) Investigations Bloods TFTs: TSH, T4 (T3 is an active metabolite and is only checked if strong clinical suspicion Anti-TSH receptor >95% in Grave’s, 40-95% in TED Anti-TPO 80% in Grave’s, 90% in Hashimoto’s Anti-thyroglobulin 25% in Grave’s, 55% in Hashimoto’s CT preferred for planning decompression as better bony resolution MRI (T2 and STIR); STIR best modality to look at recti muscles; classical of TED to have swollen muscle bells with no tendon involvement Orthoptics Treatment General MDT Supportive e.g. selenium supplementation, counselling, lubricants Smoking cessation Medical Consider if CAS 3 or more Early aggressive treatment in active phase can prevent morbidity Corticosteroid or other immunosuppression Radiotherapy: not for sight threatening disease, hypertension or diabetes mellitus Surgical For acute disease with optic neuropathy or keratopathy For burnt-out disease to improve function/cosmesis Poor prognostic factors Older age Male Smoker Diabetes Reduced VA Rapid progression at onset Longer duration of active disease

Answer 20

This scenario describes Duane retraction syndrome (DRS) which is a congenital disorder where there is hypoplasia of CN VI with subsequent aberrant co-innervation of lateral rectus and medial rectus by CN III. Possible features of DRS: Limitation of horizontal eye movements Compensatory head posture Retraction of globe on adduction with narrowing of palpebral aperture Manifest strabismus: ET more common (worse in the distance), XT when adduction is more marked than abduction Upshoot and/or downshoot on adduction Poor convergence Associated ocular abnormalities e.g. coloboma, heterochromic iridis, opacities of lens, persistent pupillary membrane, microphthalmos Skeletal and facial abnormalities: Goldenhar syndrome, Klippel-Feil syndrome, ear abnormalities, deafness, syndactyly, cleft palate and spinal meningocoele There are two classification systems: Huber classification (based on EMG findings) and Brown classification (based on clinical features). Huber classification of Duane syndrome: Type I: marked limitation of abduction (remember 1x "b" in ABduction) Type II: limitation of adduction (remember 2x "d" in ADDuction) Type III: limitation of both abduction and adduction Brown classification: Type A: limited abduction, less marked limitation of adduction Type B: limited abduction, normal adduction Type C: limitation of adduction is more than limitation of abduction with exotropia It is important to recognise that restoring normal ocular motility is an unrealistic goal. Observation is often the best management, particularly if the patient has a comfortable binocular single vision. A slight face tum with sensory fusion is acceptable. Surgical intervention should be reserved for those with manifest deviation in primary position, a large face turn, severe globe retraction or significant up- and down-shoots. In this case, surgery is not indicated. Surgical options are varied and complex, depending on many factors and we will not be going into a great detail here. If this patient had a large head turn and/or other indications for surgery, then an acceptable option would be a right medial rectus recession. Muscle resection is often prohibited in classic teaching (best to avoid in exam situations), but have been used in very selected situations. An MRI head is unlikely to yield any useful results. An MRI head would be useful if we were suspecting a 6th cranial nerve palsy but the palpebral aperture narrowing on adduction and the small angle of esotropia (<30△) in primary position with a large abduction limitation strongly suggests DRS. Observation is likely to be best in this case, avoiding the need for neuroimaging (and possibly a general anaesthetic for young children).

Answer 21

When talking about syphilis, a distinction should be made between congenital and acquired syphilis. Here we are focusing on the acquired form. It can be divided into 3 stages Primary (approx 2-6 weeks post infection) - Systemic: painless ulcer (chancre), regional lymphdenopathy Secondary (approx 8 weeks post-infection) - Systemic: Diffuse maculopapular rash appears and this includes palms and/or soles, generalised lymphadenopathy, malaise, fevers. Ocular: Anterior/posterior uveitis Tertiary (from 5 yrs post infection)- Systemic: heart (e.g. aortitis), CNS (e.g. vasculitis, meningitis). Ocular: anterior/posterior uveitis, interstitial keratitis Although there can be a myriad of ocular manifestations from syphilis, the most common ocular manifestation for both secondary and tertiary syphilis is anterior uveitis. What is interstitial keratitis (IK)? This knowledge will come in handy in FRCOphth Part 2 too. It is an inflammatory condition of the corneal stroma but in the absence of primary involvement of either the corneal epithelium or endothelium. Syphilis is a cause of IK. When this occurs, deep stromal vessels appear in the periphery and make their way centrally. The cornea has been described as "salmon patch" in appearance, if the vascularisation is dense. It tends to burn out itself even if untreated and can leave formerly perfused (now empty) stromal blood vessels called ghost vessels, amongst corneal scarring. Although we have been talking about syphilis causing interstitial keratitis, the most common cause of interstitial keratitis is herpetic disease. Other causes: Mycobacterium tuberculosis (tuberculosis) Mycobacterium leprae (Leprosy) Borrelia burgdorferi (Lyme disease) Cogan disease (non-infectious)

Answer 22

Duane’s syndrome Aberrant co-innervation of LR and MR by 3rd CN which may be associated with 6th CN nucleus hypoplasia Most common type 1 > 2 > 3 F>M Bilateral in 20% Clinical features Attempted adduction will lead to Retraction of globe Reduction of palpebral aperture +/- up or downshift Systemic associations present in 30% Deafness Goldenhar syndrome Klippel-Feil Wilderwank Type 1 85% Primary position is eso or ortho Reduced abduction Mild globe retraction Type 2 14% Primary position is exo or ortho Reduced adduction Severe globe retraction Type 3 1% Eso or ortho Reduced abduction and adduction Moderate globe retraction Memory aids: Type involves 1 D - abDuction; type 2 involves 2 Ds - aDDuction; type 3 involves 3Ds - aBduction and aDDuction. Treatment Treat refractive error: amblyopia usually due to refractive error rather than diplopia Prisms for comfort and to improve head position Surgery to improve binocular single vision and head position Usually uni/bilateral MR recession for esotropia Uni/bilateral LR recession for exotropia Avoid LR resection, as this increases retraction Hering’s law of equal innervation Yoke muscles receive equal innervational input when they are activated. Dissociated vertical deviation (DVD) violates this law as there is slow upward drifting of one eye when the other eye fixates. Sherrington’s law of reciprocal innervation Contraction of a muscle is accompanied by a decrease in contraction of its antagonist. Duane’s violates this law as there is co-contraction of MR and LR. Alexander’s law Nystagmus is more pronounced when gaze is directed toward the side of the fast-beating component. If there is right jerk nystagmus, it worsens on right gaze and improves on left gaze. Therefore, patients then to turn their head to the same size as the fast beating nystagmus, so that they’re looking at the side which improves their nystagmus.

Answer 23

Thinnest (0.3mm) just behind the insertions of the recti muscles Thickest (1.0mm) at the posterior pole around the optic nerve head It is 0.4–0.5 mm thick at the equator and 0.6 mm thick anterior to the muscle insertions Because of the above, the most common sites of scleral rupture following blunt trauma are: in the superonasal quadrant, close to the limbus in a circumferential arc parallel to the corneal limbus opposite the site of impact behind the insertion of the rectus muscles The Bruch's membrane can buckle as a result of traumatic mechanical event at site of contusion or away from the impact. When a rupture occurs through the choroid/Bruch's membrane/RPE but the sclera stays intact, this is termed a choroidal rupture. The rupture is often concentric to the disc. There is no treatment for this but a CNV is a late complication and may be treated the conventional way.

Answer 24

relapsing polychondritis The features mentioned in the stem of the question is most consistent with relapsing polychondritis. Relapsing polychondritis (RP) A progressive systemic inflammatory disease characterised by auricular chondritis, polyarthritis, nasal and respiratory tract chondritis Auricular chondritis is the most common systemic manifestation, causing redness, swelling, and tenderness of the pinna or ear canal, classically sparing the ear lobes, often bilateral. It can lead to drooping or cauliflower ears due to softening of the cartilage. Nasal chondritis affects some patients and may lead to saddle nose deformity A wide variety of ocular manifestations can occur but episcleritis and scleritis is most common RP can also affect cardiac valves and large vessels, with the aorta being most commonly involved. Aortic vessel and aortic valve involvement is possible. Rheumatoid arthritis, Cogan syndrome and sarcoidosis can present with ocular inflammation but chondritis is a much more well known feature of RP.

Answer 25

specialist referral and oral steroids This patient most likely has peripheral ulcerative keratitis with rheumatoid arthritis. The patient should be commenced on oral steroids for systemic immunosuppression and be referred to a rheumatologist. Topical steroids may not be suitable in this case due to stromal thinning and possibility of an infected ulcer. PUK associated with systemic disease Common systemic causes Rheumatoid arthritis Wegener's Relapsing polychondritis SLE Idiopathic Sarcoidosis Churg-Strauss Type 1 diabetes Infectious causes Bacteria, virus, fungi, acanthamoeba Non-infectious Terrien's Marginal keratitis/blepharitis -Pellucid| Rosacea Neurotrophic Clinical features Presents with pain, redness and reduced vision May be bilateral There is peripheral corneal ulceration with stromal thinning and associated limbal inflammation There may be sectoral or diffuse scleritis Management Topical lubricants (and consider punctual plugs/cautery) Microbiology including corneal scrapings to exclude infection Systemic immunosuppression Doxycycline (anti-collagenase activity along with Vitamin C which helps promote collagen rebuilding. ) Oral vitamin C Topical steroids (may accelerate keratolysis) Cycloplegia Globe protection eg. tarsorrhaphy or botox ptosis Therapeutic CL Gluing Surgery: conjunctival recession, amniotic graft, lamellar keratoplasty Mooren's ulcer A rare form of PUK Autoimmune Associated with hepatitis C Two forms: Limited: affects middle-aged to elderly Caucasian patients, unilateral and responsive to treatment Aggressive: affects young African patients (?antigen-antibody reaction to helminthic toxins), bilateral, resistant to treatment and higher risk of perforation Clinical features Pain, photophobia, reduced visual acuity Progressive peripheral ulceration Leading edge to ulcer undermining the epithelium- Grey infiltrate at the leading edge Progresses centrally and circumferentially Stromal melt No limbal clear zone (cp. Marginal keratitis and Terrien's) No scleritis (cp. Typical PUK) Immunoglobulin, complement and plasma cells in the conjunctiva Tests Exclude hepatitis C Systemic review of BP, FBC, ESR, CRP, U&Es, LFTs, glucose, HbAlc, vasculitis screen, ANA, ANCA, dsDNA, ACE, urinalysis, CXR Management Topical steroids Systemic immunosuppression: steroids, cyclophosphamide, ciclosporin A Topical antibiotics Cycloplegia BCL +/- glue Surgery: lamellar keratoplasty Prognosis: typically burns out over 6-18 months but can cause blindness Terrien marginal degeneration Asymmetrically bilateral Superior thinning then spreads circumferentially Pannus traverses the area of thinning A lipid line is seen at the end of the pannus, posterior to the area of thinning Clear interval between limbus and ulcer (cp. With Mooren’s) Onset 2-3rd decade M>F| No loss of epithelium (therefore not painful) Against the rule astigmatism: steepening occurs 90 degrees away A paediatric form exists: Fuch's superficial marginal keratitis Management: Glasses/CLs for astigmatism Crescentic lamellar transplantation if perforation occurs (rare)

Answer 26

This patient has severe non-proliferative diabetic retinopathy, as he has venous beading in ≥ 2 quadrants. This does not warrant pan-retinal photocoagulation, particularly as he is a regular clinic attender and only has moderate non-proliferative diabetic retinopathy. He can be observed and reviewed in less than 3 months. To quality for severe pre-proliferative diabetic retinopathy, remember the 4-2-1 rule, one of the following features are present: More than 20 intraretinal haemorrhages in each of 4 quadrants Definite venous beading in ≥ 2 Intraretinal microvascular abnormalities (IRMA) in 1 or more quadrants The Royal College of Ophthalmologists Diabetic Retinopathy Guidelines published in 2012 suggest pan-retinal photocoagulation (PRP) for those with neovascularisation of disc/elsewhere/iris/angle. However PRP can be considered for severe/very severe non-proliferative (NPDR) in: Older patients with Type 2 diabetes mellitus (DM) Cases of difficult retinal view Prior to cataract surgery (inflammation possibly associated with progression) Only eye where first eye has been lost to PDR Regular clinic attendance is likely to be poor Patients who are difficult to examine for other reasons

Answer 27

A Fleischer ring is a feature that be found in patients with keratoconus. The ring is made from iron deposit often present within the epithelium around the base of the cone, giving it a brown colour. It may be best seen using a cobalt blue filter. Do not confuse Fleischer ring with Kayser-Fleischer ring, a feature of Wilson's disease, where there is build up of copper. In Kayser-Fleischer ring copper is deposited in the descemet's membrane of the cornea.

Answer 28

The stem of the question is quite vague, and you will likely get more information in a real clinical scenario but it is likely pointing to a diagnosis of retinoschisis. Retinoschisis is splitting the retina and can be divided into degenerative retinoschisis (much more common) and X-linked juvenile retinoschisis. Degenerative retinoschisis is often asymptomatic, more common in hypermetropes and there is ballooning of the inner leaf into the vitreous. Inferotemporal is a common location where this occurs. It is unclear if the patient is symptomatic in the question stem, but the dome shaped elevation points towards a diagnosis of either retinoschisis or retinal detachment, and the absolute scotoma points towards a diagnosis of retinoschisis. In a retinal detachment the neurosensory retina is intact, typically producing a relative field defect. Retinoschisis can look similar to a chronic rhegmatogenous retinal detachment and it is important to know how to differentiate the two conditions: Giant retinal tear and retinal dialysis would not look like a dome shaped retinal elevation.

Answer 29

The lesion shown in this case is a large, hyperpigmented lesion with hypopigmented halo and lacunae. This is typical of a congenital hypertrophy of the retinal pigment epithelium (CHRPE). It can present as a solitary lesion like in this case or multifocal lesions. Multifocal ones are usually arranged clusters and usually limited to one quadrant, and tend to lack haloes. They have been called "bear tracks". Solitary and multifocal lesions are termed typical CHRPE. It is characterised with RPE hypertrophy and on autofluorescence, typically demonstrating hypoautofluorescence. The non-pigmented haloes and lacunae can appear autofluorescent. Typical CHRPE, solitary (like this case) or multifocal is typically benign and has no association with systemic issues. Atypical CHRPE are usually multiple, smaller in diameter (50-100µm), shaped oval/comma/fishtail and their distribution is haphazard across the fundus. Atypical CHRPE can be associated with familial adenomatous polyposis (FAP).

Answer 30

Remember, first order neurons arise in the posterolateral hypothalamus and descend ipsilaterally through midbrain and pons, subsequently terminating in the spinal cord at levels of C8-T2. Second order neurons then exit the cord at T1 and ascend via the cervical sympathetic chain, then synapse at the superior cervical ganglion (at the level of bifurcation of common carotid into internal and external carotid arteries). The brachial plexus is a somatic nerve plexus formed by intercommunications among the roots of the lower four cervical nerves (C5-8) and first thoracic nerve (T1). At each vertebral level, the paired spinal nerves arise and leave the spinal cord via the intervertebral foramina of the vertebral column. Therefore, damage to the brachial plexus is more likely to cause a second order (pre-ganglionic) injury of the sympathetic chain as the brachial plexus is formed from roots of spinal nerves at level of T1 and above. Pharmacological tests can then be used to aid the diagnosis: As this is likely a pre-ganglionic injury, the pupil will fail to dilate with cocaine but dilate with hydroxyamphetamine.

Answer 31

the signs suggest secondary angle closure post scleral buckle. You may also see choroidals on peripheral fundal examination. Secondary angle closure with scleral buckle Due to ciliary body swelling and choroidal effusion/detachment (possibly due to pressure on the vortex veins) May appear as flattening of peripheral iris with a relatively deep central anterior chamber; can mimic plateau iris syndrome May be blood in Schlemm’s canal indicating raised episcleral venous pressure caused by scleral buckle compressing on vortex vein inhibiting drainage Usually resolved spontaneously over days to weeks Treat medically with cycloplegic, steroids and glaucoma medication

Answer 32

6, 11, 16, 18 are associated with benign papilloma (warts). Kaposi’s sarcoma Vascular purple-red nodule in any part of the body Also bright red mass which may mimic a persistent subconjunctival haemorrhage Usually in inferior fornix May be caused by Herpes virus 8, usually in the presence of HIV Treat with radiotherapy if large/aggressive

Answer 33

Conjunctival melanoma Solitary grey/black/non-pigmented, vascularised nodule fixed to episclera Most commonly at limbus Mets to lymph nodes, lung, liver and brain Prognosis 13% 5y mortality Poor prognosis multifocal lesion caruncle, fornix, palpebral thickness > 1mm recurrence pagetoid/lymphatic/orbital spread de novo origin (compared to PAM or naevus) tumours not involving limbus

Answer 34

The question stem and the fundal appearance is most typical of multiple evanescent white dot syndrome (MEWDS). Features of MEWDS: Unilateral Typical group that gets affected: Young women, myopic Can be preceded by viral prodrome Symptoms: Acute reduced visual acuity, scotomas +/- photopsias Signs: May have anterior uveitis, vitritis and classically tiny-orange dots are found perifoveally. Scotomas often correspond to an enlarged blind spot on visual field testing. FFA: Early punctate hyperfluorescence with late staining of the lesions arranged in a "wreath-like" configuration around the fovea Usually recovers spontaneously within 2-3 months, so treatment not usually indicated. There is often permanent abnormal reflectivity of the IS/OS/ellipsoid zone.

Answer 35

Features of SAH Communicating hydrocephalus Thunderclap headache Meningism Altered consciousness Relevant information: Terson’s syndrome Bilateral haemorrhage (intraretinal +/- preretinal +/-vitreous) with papilloedema in patients with subarachnoid haemorrhage Note that similar picture may occur with acute increases in ICP from other causes (retinal haemorrhage occurs due to increases in cavernous sinus pressure with retinal venous stasis)

Answer 36

ipsilateral MR recession This patient has type I Duane retraction syndrome (DRS). Recall the Huber classification of DRS: Type I: marked limitation of abduction (remember 1x "d" in AbDuction) Type II: limitation of adduction (remember 2x "d" in ADDuction) Type III: limitation of both abduction and adduction It is important to recognise that restoring normal ocular motility is an unrealistic goal. Observation is often the best management. Surgical intervention should be reserved for those with manifest deviation in primary position, a large face turn, severe globe retraction or significant up- and down-shoots. For type I DRS, there is usually a hypoplastic CN VI nucleus or nerve, and relative LR dysfunction. The affected eye is usually esotropic. These patients can have associated limited abduction and/or co-contraction in adduction. Surgical options are varied and complex, depending on many factors and we will not be going into a great detail here. However of the options presented in this question, ipsilateral medial rectus recession (therefore weakening it) is the most common surgery used. Muscle resection is often prohibited in classic teaching (best to avoid in exam situations) as it could worsen the "leash phenomenon" causing aggravation of up- and down-shoots but have been used in very selected situations. The other options presented would work against the possible LR weakness and/or esotropia with associated head turn in type I DRS.

Answer 37

The OCT shows sub-retinal fluid accumulation. This lady has developed central serous retinopathy (CSR). Pregnancy is a risk factor but usually resolves 1-2 months after pregnancy. Furthermore, it is important to check if the patient is on nasal corticosteroid spray for her hayfever as it is also a risk factor for CSR. Conservative management is recommended as first presentation of CSR has a high rate of spontaneous remission. Central serous chorioretinopathy Sub- RPE and sub-retinal fluid accumulation 80% spontaneously recover to near normal within 1-6 months 5% are chronic or recurrent <2% have CNV Pregnancy related CSR normally resolves 1-2 months post delivery Risk factors 20-50y male Type A personality, psychosocial stress, pregnancy (usually 3rd trimester), Cushing’s disease Corticosteroid use Clinical features Usually sudden VA reduction with positive central scotoma, metamorphosis and increased hypermetropia Shallow detachment of sensory retina at posterior pole SRF and/or RPE detachment (PED) Multifocal or diffuse pigmentary changes suggest chronicity Occasionally, fluid tracks inferiorly from posterior pole to cause bulls non-rhegmatogenous detachment of inferior peripheral retina Investigations Rule out systemic causes in chronic or recurrent disease e.g. urine and blood cortisol levels in Cushing’s disease FFA may show one or more points of progressive leakage and pooling, classical in a smoke-stack or ink-blot pattern ICG shows choroidal hyper permeability in late phase, with area of hyper fluorescence more widespread than the leakage point on FFA and commonly bilateral changes OCT shows neurosensory retinal detachment and accompanying small PEDs. Chronic cases can have overlying cystoid degeneration Treatment Conservative for new cases Lifestyle counselling and avoid glucocorticoid medication if possible Other treatments needed if persistent >6m, recurrence, occupational need, contralateral visual impairment Argon laser treatment PDT: half-dose PDT may be beneficial for severe disease

Answer 38

anterior inferior cerebellar artery (AICA). Hemifacial spasms can either be primary or secondary. Primary hemifacial spasm is when there is compression of the facial nerve when it exits from the brainstem. The most common mechanism is said to be compression from dolichoectasia of an artery, and the artery that is most commonly implicated is the anterior inferior cerebellar artery (AICA). Secondary causes of hemifacial spasms include atherosclerosis, aneurysms, arteriovenous malformations, peripheral facial nerve trauma, parotid gland tumours and cerebellopontine angle tumours, brainstem strokes, demyelinating lesions and Bell's palsy.

Answer 39

topical fumagilin Oral ivermectin is used to treat some worm parasites e.g. blackflies (river blindness), onchocerciasis Natamycin and amphotericin are polyene antifungals often used in topical form for fungal keratitis Polyhexamethylene biguanide is used as one of the topical treatments for acanthamoeba Microsporida Fungi Very rarely may cause conjunctivitis or epithelial/stromal keratitis in immunocompromised Treat with topical fumagillin

Answer 40

orbital decompression > strabismus surgery > eyelid surgery

Answer 41

The Collaborative Normal Tension Glaucoma study (CNTGS) IOP reduction by >30% slows the rate of field loss from 35% to 12% Without treatment, 50% of NTG patients show no progression of field defects at 5 years Risk factors for progression were female, migraine and disc haemorrhage at diagnosis 12% of aggressively treated normal tension glaucoma patients showed progression (showing other factors at play) Clinical tips: you would treat NTG as for POAG but some emphasises the role of optic nerve head perfusion and the possible role of nocturnal dips in BP. Consider using prostaglandin analogues as they have better IOP control at night, rather than non-selective B-blockers which may reduce blood flow at night. For treatment of systemic hypertension, CCB may be used instead of B-blockers. Optimise 24 hours BP control. Treat chronic obstructive sleep apnoea, anaemia and folate/B12 deficiency.

Answer 42

CMV retinitis usually occurs in the immunocompromised with CDF <50. CD4 count and it’s associated disease 250-500: HZO, TB 150-250: Lymphoma, Kaposi’s sarcoma 50-150: Pneumocytosis, toxoplasmosis, miyrosporidosis, VZV retinitis <50: CMV, lymphoma CMV retinitis Leading cause of visual loss in AIDS Usually only when CD4 <50 Usually starts of unilateral but could progress to bilateral Raised IOP Anterior segment Floaters, reduced VA AC inflammation +/- stellate KPs with no obvious iris atrophy (unlike HSV/VZV) Corneal endotheliitis (more common in far east) with possible diffuse iris atrophy Posterior segment Vitritis with retinitis Haemorrhagic retinitis: haemorrhage and necrosis with loss of fundal details i.e. “pizza pie” appearance Granular retinitis: relatively indolent with minimal haemorrhage and no vascular sheathing Perivascular retinitis: “frosted branch angiitis” which spreads along the course of the retinal vessels Retinal detachment in up to 30%, optic nerve disease in 5% Treatment Ensure CD4 above 50 with HAART Systemic antivirals e.g. valganciclovir, ganviclovir, foscarnet

Answer 43

Believe or not, a similar question was asked in a FRCOphth Part 2 exam. Dermal filler made of hyaluronic acid can cause complications such as nodule formation, misplacement, migration, infection, and vascular occlusion. Hyaluronidase can be used to dissolve these derma fillers in filler complication management.

Answer 44

sectoral iris atrophy more painful complete dermatomal involvement NOT terminal bulbs Herpes simplex classically presents with dendrites with terminal bulbs. Herpes zoster ophthalmicus Reactivation of dormant VZV virus in the sensory ganglion with involvement of ophthalmic branch of CN V 15% of shingles Risk factors Immunosuppression: chronic illness, drugs, HIV Age > 60 Caucasian Clinical features Pre-herpetic neuralgia: intermittent tingling to severe constant electric pain Rash (papules to vesicles to pustules to scabs) Hutchinson’s sign (cutaneous involvement of tip of nose indicating nasociliary nerve involvement, indicating high likelihood of ocular complications) Beware of dissemination in immunocompromised May cause neurotrophic cornea Epithelial Acute and common (2-3d after rash, resolves in a few weeks) Superficial punctate keratitis Pseudodendrites Anterior stromal infiltrate Stromal Early and uncommon (10d after rash) Nummular keratitis with anterior stromal granular deposits Necrotising interstitial keratitis with stromal infiltrates, thinning, perforation (rare and occurs late 3m-years) Disciform Late and uncommon (3m-years) Endotheliitis with disc of corneal oedema DM folds Mild AC activity KPs Neurotrophic May cause corneal nerve damage causing persisted ED, thinning, perforation Treatment Treat with systemic anti-viral acyclovir 800mg 5x/day for 5 days or valaciclovir 1g 3x/day for 7 days or famciclovir 750mg once a day for 7 days If immunosuppressed, acyclovir IV 10mg/kg 3x/day Then to consider: Epithelial Topical lubricants Stromal and disciform Topica steroid Consider BCL, glue and tectonic grafting in risk of perforation Neurotrophic Topical lubrication Tarsorrhaphy Amniotic membrane or conjunctival flap Monitor IOP Corneal scarring Penetrating keratoplasty Complications Conjunctivitis, microbial keratitis, glaucoma, anterior uveitis, necrotising retinitis (ARN, PORN), episcleritis, scleritis, optic neuritis, cranial nerve palsies Strokes, neuralgia Herpetic Eye Disease study main points Effectiveness of topical steroids in stromal keratitis (on topical antivirals): safe and effective Effectiveness of oral acyclovir in stromal keratitis: no benefit Effective of oral acyclovir in herpetic uveitis: effective Effectiveness of oral acyclovir in recurrent HSV: decreased recurrence rate by 50% Oral acyclovir does not prevent progression from epithelial to stromal disease Differences between HSV and VZV Zoster Consider demographic: normally elderly or immunocompromised Dermatome: complete More painful and more likely to develop post-herpetic neuralgia Nummular stormal infiltrates Raised plaque like lesions stain with Rose-Bengal Mucous epithelial plaques Sectoral iris atrophy No terminal bulbs (dendrites) HSV Incomplete dermatome Patchy iris atrophy Terminal bulbs

Answer 45

lacrimal gland acinar cells Lactoferrin Produced by acinar cells of lacrimal gland; indirect measure of lacrimal gland function Binds iron and prevents bacterial growth By measuring lactoferrin levels, you can help differentiate aqueous tear deficiency from evaporative dry eye Matrix metalloproteinase 9 (MMP-9) Inflammatory cytokine released by epithelial cells in response to stres Elevated levels suggests evaporative dry eye IgE levels can be used to differentiate patients who have allergic conjunctivitis Tear osmolarity of 306-308 mOsm/L suggests aqueous tear deficiency

Answer 46

Ceftazidime Fluoroquinolone Cafezolin Tobramycin ANS Cefazolin Cephalosporins B-lactams First generation Covers gram-positive mostly with little gram-negative cover such as E.coli, Proteus mirabilis and Klebsiella pneumonia Cefazolin, cephalothin, cephapirin, cephradine, cefadroxil, and cephalexin Second generation Reduced gram positive, and increased gram-negative compared to first generation Covers Haemophilus influenzae, Moraxella catarrhalis, and Bacteroides Cefuroxime, cefprozil, cefmetazole, cefotetan, and cefoxitin Third generation Covers less gram-positive and have increase gram negative such as Enterobacteriaceae, Neisseria, Haemophilus Cefotaxime, ceftazidime, cefdinir, ceftriaxone, cefpodoxime, cefoperazone, and cefixime Fourth generation Covers similar to third generation but covers bacteria with B-lactamase Cefepime Fifth generation Covers MRSA and penicillin resistant pneumococci Ceftaroline

Answer 47

30% Broadly speaking, RVO can be classified into ischaemic and non-ischaemic types. Ischaemic CRVO is associated with 1 or more of the following characteristics: Poor vision (44% of eyes with VA <6/60 develop rubeosis) Presence of multiple dark deep intra-retinal haemorrhages Presence of multiple cotton wool spots RAPD Degree of retinal vein dilatation and tortuosity Electrodiagnostic testing showing reduced b-wave FFA showing >10 disc diameters of retinal capillary non-- perfusion on 7-field fluorescein angiography However it must be noted that 30% of eyes with non-ischaemic CRVO may convert to an ischaemic CRVO over 3 years. References/further reading: Royal College of Ophthalmologists (January 2022). Clinical Guidelines: Retinal Vein Occlusion (RVO). Retrieved 13 June 2024, from https://www.rcophth.ac.uk/wp-content/uploads/2015/07/Retinal-Vein-Occlusion-Guidelines-2022.pdf

Answer 48

Erythrocyte sedimentation rate (ESR), can be influenced by various factors. Factors that may cause an elevated ESR: Females Pregnancy Ageing Inflammatory disorders Infections Anaemia Kidney disease Low serum albumin Lymphoma, multiple myeloma Technical factors e.g. tilted ESR, raised specimen temperature Factors that may decrease ESR: Polycythaemia - increased RBCs causing increase in blood viscosity Haemoglobinopathies e.g. sickle cell (due to abnormal shape of RBC impairing stacking) Regular use of alcohol Medications such as valproic acid, NSAIDs, statins

Answer 49

Aflibercept is a fusion protein, NOT a monoclonal antibody fragment (tip: observe its name that does not end in -mab). Aflibercept consists of an IgG backbone fused to extracellular VEGF receptor sequences of the human VEGF receptor 1 and 2 and acts as a soluble decoy. It binds to VEGF-A isoforms and other members of the VEGF family, including PIGF 1 and 2. Ranibizumab is a recombinant humanised monoclonal antibody fragment and binds to VEGF-A isoforms. Bevacizumab is a full length recombinant humanised antibody and binds to VEGF-A isoforms. Faricimab, a newer anti-VEGF on the market, is a IgG1-derived bispecific antibody which binds to both VEGF-A and angiopoietin-2 (Ang-2).

Answer 50

smoking cessation and slelenium supplemntation Although thyroid dysfunction in thyroid eye disease (TED) should be treated, preferably with anti-thyroid medications particularly if risk factors for deterioration or progression for thyroid eye disease are present, the treatment of this is best commenced by a practitioner who is more well versed with the medication and the monitoring of thyroid function, e.g. endocrinologist. All patients with Graves disease irrespective of presence of graves orbitopathy, should be advised to stop smoking. Smoking increases the risk of thyroid eye disease in patients with Graves disease, and smokers have been found to have more severe TED, to be more likely to develop/have progression of TED after radioactive iodine and have delayed or worse outcomes from immunosuppressive treatment. Patients with mild TED taking oral selenium have been reported to have better overall ophthalmic outcome and lower rates of progression to more severe TED compared to the placebo group in a trial. However, in patients with moderate-to-severe and active thyroid eye disease, there is no evidence of a beneficial adjuvant effect of selenium. Therefore, the EUGOGO guidelines generally recommend that patients should refrain from smoking and selenium supplementation may be advised as systemic adjunct therapy for mild TED. Other management for mild TED also include: Artificial tears, particularly when dry eyes are present Ophthalmic gels for protecting the cornea during the night Patients with mild TED may also be referred to thyroid-eye clinics if risk factors are present e.g. active TED, smoker, high thyrotropin receptor antibody levels, unstable or severe hyperthyroidism. Steroids and orbital radiotherapy (second-line treatment) should be reserved for moderate-severe TED cases. Reference(s)/Further reading: Bartalena, L., Kahaly, G. J., Baldeschi, L., Dayan, C. M., Eckstein, A., Marcocci, C., Marinò, M., Vaidya, B., & Wiersinga, W. M. (2021). The 2021 European Group on Graves' orbitopathy (EUGOGO) clinical practice guidelines for the medical management of Graves' orbitopathy. Eur J Endocrinol, 185(4), G43-g67. https://doi.org/10.1530/eje-21-0479

Answer 51

AL has more impact on IOL power calculation than central corneal ppower Using SRK formula is SRK formula = A- (2.5xL) - (0.9xK) (L = axial length, K = power of central cornea), L has a bigger impact than K. Some studies quote approximately 1 diopter of error in IOL calculation for every 0.33mm error in AL. Wrong answers: Previous hyperopic refractive surgery may cause an underestimation in IOL power A patient with active herpes keratitis may cause an underestimation in IOL power Retained viscoelastic causes a myopic shift Staphyloma Posterior staphylomas are usually (70%) located in the macular region. This causes measurements to be made from the cornea to the depths of the staphyloma, rather than the fovea. A erroneously long eye is therefore measured. Using SRK formula above, an underestimation of IOL power is created; this increases the risk of a hyperopic error. High axial myopia High axial myopes with AL greater than 28mm increases likelihood of hyperopic error due to difficulties in measuring AL accurately. Silicone oil Silicone oil has a higher refractive index than vitreous. This “slows down” the light travelling inside the eye when being measured, creating an artificially “long” eye (increased AL). Using SRK formula above, an underestimation of IOL power is created; this increases the risk of a hyperopic error. Corneal oedema Especially in stromal oedema, the posterior corneal curvature is flattened, thus “thickening” the refracting medium causing it to be more powerful. Using SRK formula above, an overly high K creates an underestimation of IOL power; this increases the risk of a hyperopic error. In patient’s with corneal oedema secondary to Fuch’s, it is recommended that DMEK or DSAEK is performed prior to cataract surgery. Following resolution of corneal oedema, a better estimation of biometry can be obtained. In combined DMEK/DSAEK + cataract cases, it is crucial to account for the increase in posterior curvature of cornea following endothelial grafting. This “thins” the refracting medium (cornea), causing it to be weaker, causing a hyperopic shift. A stronger intraocular lens should be picked to compensate for this phenomenon. Dislocated lens Can result in either hyperopia or myopia depending on position after dislocation Retained viscoelastic Myopic shift CMO A raised macula post-op may cause a hyperopic shift as light is refracted “behind” the macula. LASIK/PRK Most myopia correcting surgeries are performed by flattening the anterior curvature of the cornea. Biometry estimates K by first measuring the anterior curvature, and the posterior curvature is usually calculated by extrapolating the anterior/posterior curvature ratio. The anterior/posterior ratio is no longer valid post LASIK/PRK. The result of this set of calculations is an abnormally large K, and an underestimation of IOL power is created; this increases the risk of a hyperopic error. The opposite is also true for patients who have undergone hyperopia correcting surgery. This results in an abnormally small K, and over estimation of IOL and yields a myopic error.

Answer 52

Altered Corneal Curvature and Keratometry Hyperopic refractive surgery steepens the central cornea by removing peripheral stromal tissue, resulting in a more prolate shape. Post-surgery, standard keratometers or topographers may incorrectly measure the corneal curvature because they assume the pre-surgery relationship between the anterior and posterior corneal surfaces remains constant. This leads to an overestimation of the corneal power, causing IOL power calculations to underestimate the true power needed.

Answer 53

Anterior Displacement of the IOL Viscoelastic material trapped behind or around the intraocular lens (IOL) can push the IOL slightly forward (anterior displacement). Since the effective lens position (ELP) is a critical factor in determining refractive outcomes, even a small anterior shift of the IOL increases the eye's overall refractive power, leading to a myopic shift.

Answer 54

haematogenous Choroidal melanoma most commonly spreads haematogenously and the liver is the most common site of metastasis. Other possible sites would include the lung and bone. Reference(s)/further reading: Koutsandrea, C., Moschos, M. M., Dimissianos, M., Georgopoulos, G., Ladas, I., & Apostolopoulos, M. (2008). Metastasis rates and sites after treatment for choroidal melanoma by proton beam irradiation or by enucleation. Clin Ophthalmol, 2(4), 989-995. https://doi.org/10.2147/opth.s4006

Answer 55

The photo shows a full thickness lower lid defect of >50%. Reconstruction rules Direct closure: <33% defect Lateral canthotomy + Tenzel flap (semicircular flap): 33-50% defect Cutler-beard procedure (upper lid) or modified Hughes procedure (lower lid): >50% defect Direct closure: Ensure tarsus is repaired first, ensuring alignment of lid margin. Orbicularis and skin are then repaired. Tenzel flap: eyelid is freed with a lateral canthotomy and then a semicircular flap is rotated into defect Cutler-Beard: Full thickness lower lid eyelid flap is created inferior to the lower tarsus. The flap is advanced past the intact lower lid margin and into the upper eyelid defect. The flap is sutured into place and then allowed to vascularise for several weeks, then the upper and lower lids are separated Modified Hughes procedure: An upper eyelid flap of conjunctiva and tarsus are advanced downward into the lower lid defect to reconstruct the posterior lamella (tarsus and conjunctiva). The anterior lamella (skin and orbicular) is reconstructed with a full-thickness skin graft. The flap is allowed to vascularise for several weeks and then upper and lower lids are separated.

Answer 56

surgical failure to improve anatomical closure Endophthalmitis after vitrectomy is relatively low ranging from 0.04%-0.133%. Late reopening of hole is 5% Retinal tear/detachemnt is 1% Surgical failure in anatomical closure and visual acuity improvement are 10% and 20% respectively.

Answer 57

50% ETDRS study PRP safe to defer until severe non-proliferative DR or proliferative CONSIDERING PRP for severe non-proliferative or proliferative DR SHOULD perform PRP for *high risk PDR Focal laser reduced risk of moderate visual loss by 50% Small but significant reduction in severe visual loss 4-10% Defined clinically significant macular oedema Aspirin had no effect for diabetic retinopathy and vitreous haemorrhage *High risk PDR NVD: NVD that is greater than one-fourth to one-third of the disc area in size, or located on or within one disc diameter of the optic disc NVE: NVE that is associated with vitreous or preretinal hemorrhage Vitreous or preretinal hemorrhage: NVD or NVE associated with vitreous or preretinal hemorrhage

Answer 58

high risk of aspiration from GA Myotonic dystrophy: Autosomal dominant disease Causes muscle weakness, atrophy and myotonia Most common ocular findings: christmas tree cataracts, ptosis, lower IOP, Fuchs endothelial dystrophy and reticular maculopathies Cataract extraction in myotonic dystrophy patients: May be warranted if visually significant High risk of capsular contraction and PCO formation, hydrophobic acrylic IOLs may be preferred to reduce risk of these If general anaesthetic is being considered, patients with myotonic dystrophy are at higher risk of systemic complications affecting the cardiac and endocrine system, and are sensitive to muscle relaxants and opioids Higher risk of aspiration due to reduced gastric emptying and pharyngeal muscle dysfunction Recent literature showed that myotonic dystrophy patients are no more susceptible to malignant hyperthermia than the general population. However factors such as hypothermia, shivering, or mechanical or electric stimulation during surgery can precipitate myotonia, therefore it is important to maintain normothermia during surgery. The literature do not appear to report a higher risk of fragile zonules or posterior capsule tear for patients with myotonic dystrophy. Reference(s)/further reading: Moshirfar, M., Webster, C. R., Seitz, T. S., Ronquillo, Y. C., & Hoopes, P. C. (2022). Ocular Features and Clinical Approach to Cataract and Corneal Refractive Surgery in Patients with Myotonic Dystrophy. Clin Ophthalmol, 16, 2837-2842. https://doi.org/10.2147/opth.S372633 Mangla, C., Bais, K., & Yarmush, J. (2019). Myotonic Dystrophy and Anesthetic Challenges: A Case Report and Review. Case Rep Anesthesiol, 2019, 4282305. https://doi.org/10.1155/2019/4282305 Parness, J., Bandschapp, O., & Girard, T. (2009). The myotonias and susceptibility to malignant hyperthermia. Anesth Analg, 109(4), 1054-1064. https://doi.org/10.1213/ane.0b013e3181a7c8e5 Gandhi, R., Jain, A. K., & Sood, J. (2011). Desflurane anaesthesia in myotonic dystrophy. Indian J Anaesth, 55(1), 61-63. https://doi.org/10.4103/0019-5049.76599

Answer 59

Tube Versus Trabeculectomy (TVT) 2009 study Trabeculectomy + MMC vs Baerveldt Tube (All had previous ocular surgery – glaucoma or cataract) Showed that tube less likely to fail than trab Probability failure at five years 46.9% trab vs 29.8% tube Re-operation rate at five years 29% trab vs 9% tube Risk of serious complications 20% trab vs 22% tube Trab = better early pressure control Trab failure rate 10%/yr vs tube 5%/yr Failure was defined as intraocular pressure (IOP) > 21 mmHg less than 20% reduction of IOP IOP < 5 mmHg additional glaucoma surgery loss of light perception.*

Answer 60

Volk Super 66 Magnification correction factors (assuming emmetropia) Volk 60D: 0.87 Volk Super 66: 1.00 Volk 78D: 1.08 Volk 90D: 1.32 Nikon 60D: 1.03 Nikon 78D: 1.3 Nikon 90D: 1.63

Answer 61

it is known to cause facial palsy The causative organism of Lyme disease is Borrelia burgdoferi, a spirochete. Humans become infected via a bite from a tick of the Ixodes genus, and animals that serve as reservoir are deer (most common), but also horses, cows, rodents etc. After a few days to weeks later post a deer tick bite, Lyme disease can be divided into 3 stages: Local disease Systemic: Target rash at bite site, constitutional symptoms Ocular: Follicular conjunctivitis Disseminated disease Systemic: Skin, heart, CNS, joints. CNS involvement is common (up to 40%); typical manifestations are meningitis, encephalitis, cranial nerve palsies. Any or all CN palsies affecting the eye (II-VII) can be involved, but most likely affected is CN VII. Ocular: uveitis Persistent disease Systemic: Joints Ocular: Not common but if occurs usually keratitis Uveitis caused by Lyme disease can be anterior, intermediate, posterior or pan-uveitis. But the most common form is intermediate uveitis. If it causes anterior uveitis, it is most likely to occur in the granulomatous form.

Answer 62

Marfan's syndrome is most commonly due to a mutation in the FBN1 gene on chromosome 15. In the majority of cases, it is genetically inherited and follows follows an autosomal dominant inheritance pattern however there is about 25% patients that are effected by a sporadic mutation. If genetically inherited, it is subject to pleiotropy and variability expressivity, resulting to a broad phenotypic continuum and there is a high degree of clinical variability.

Answer 63

Berlin nodules are seen in sarcoidosis. Koeppe and Berlin nodules are seen in FHI and also sarcoidosis and TB. Koeppe, Berlin and Busacca nodules are seen in the pupillary margin, central iris and iridocorneal angle respectively. Fuch’s heterochromic uveitis Mild chronic anterior uveitis Iris heterchromia Cataract Glaucoma in 10-30% Unilateral in >90% cases Strong association with viruses e.g. rubella, CMV, herpes Clinical features Reduced VA due to cataract Floaters Asymptomatic White eye Stellate KPs diffuse in endothelium Iris atrophy (washed out moth eaten) Transillumination Abnormal iris vessels Iris heterochromia (affected eye is blue-er) Iris nodules Cataract (PSC/subcapsular) Raised IOP Possible twi-like neovascularisation of angle Treatment Steroids usually not necessary Treat high IOP as per POAG

Answer 64

vitamin A deficiency After bariatric surgery, reduced food intake, suboptimal dietary quality, altered digestion and absorption, and nonadherence with supplementation regimens contribute to risk of deficiency. Vitamin A can cause night blindness. Common deficiencies include Vitamin B12, A, D, E, folate, iron, copper, zinc and calcium.

Answer 65

superonasal Rhabdomyosarcoma Commonest primary orbital malignancy in children M>F 87% presents before 15y, median age 7-8y 50% are introconal, 25% are within superior orbit Clinical features Most commonly superonasal Most common presenting features: proptosis > globe displace > conj and lid swelling > ptosis Pain is possible but rare Orbital inflammation Subtypes Embryonal: most common Alveolar: worst prognosis Pleomorphic: best prognosis

Answer 66

CMV retinitis CD4 count and it’s associated disease 250-500: HZO, TB 150-250: Lymphoma, Kaposi’s sarcoma 50-150: Pneumocytosis, toxoplasmosis, miyrosporidosis, VZV retinitis <50: CMV, lymphoma CMV retinitis Leading cause of visual loss in AIDS Usually only when CD4 <50 Usually starts of unilateral but could progress to bilateral +/- Raised IOP Anterior segment Floaters, reduced VA AC inflammation +/- stellate KPs with no obvious iris atrophy (unlike HSV/VZV) Corneal endotheliitis (more common in far east) with possible diffuse iris atrophy Posterior segment Vitritis with retinitis Haemorrhagic retinitis: haemorrhage and necrosis with loss of fundal details i.e. “pizza pie” appearance Granular retinitis: relatively indolent with minimal haemorrhage and no vascular sheathing Perivascular retinitis: “frosted branch angiitis” which spreads along the course of the retinal vessels Retinal detachment in up to 30%, optic nerve disease in 5% Treatment Ensure CD4 above 50 with HAART Systemic antivirals e.g. valganciclovir, ganviclovir, foscarnet

Answer 67

sup oblique muscle overaction present Brown syndrome and inferior oblique will both have limited elevation in adduction of the affected eye. However the table below helps to differentiate the two conditions: In Brown syndrome, the issue is a restriction from the trochlea-superior oblique complex leading to a limitation of elevation of the eye, maximal in the adducted position. When the affected eye cannot move up, it moves OUT. So in upgaze, a Brown syndrome patient gets a divergence pattern causing a V-pattern. There are no problems with the superior oblique muscle, so there is no over or under-action of the muscle. In inferior oblique palsy, there is frequently a secondary superir oblique muscle over-action. This overaction of the superior oblique causes an A-pattern, intorsion of the eye and a positive tilt test.

Answer 68

Based on the tables above, she has 2+ cells. And as there is only a faint haze with clear details of the iris, it's a 1+ flare.

Answer 69

Silicone oil is buoyant in water, which explains why sometimes peripheral iridotomy is performed at 6’o clock instead of 12’o clock to prevent development of pupillary block if silicone oil bubbles occlude the pupil and prevent the flow of aqueous. Wrong answers: Patients who have undergone vitrectomy + perfluoro-propane (C3F8) are not permitted to travel by plane for at least 8-10 weeks. Resolution of gas bubble is required. Perfluoro-propane (C3F8) remains in the eye for 8-10 weeks 12% is a non expansile concentration for perfluoro-propane (C3F8) when mixed with air Properties of gas tamponades

Answer 70

Properties of fluid tamponades

Answer 71

discuss with prescribing physician Hydroxychloroquine is a medication used by our rheumatology and rheumatology colleagues for the treatment of some autoimmune diseases. Unfortunately it can cause damage to photoreceptors and RPE, leading to irreversible structural and functional retinal deficits. According to the RCOphth clinical guidelines on Hydroxychloroquine and Chloroquine Retinopathy: Recommendations on Monitoring published in 2020, if there are signs of retinopathy, one should discuss with prescribing physician about hydroxychloroquine cessation. It would be inappropriate for ophthalmologists to stop hydroxychloroquine treatment. Reference: Royal College of Ophthalmologists (2020). Clinical Guidelines - Hydroxychloroquine and Chloroquine Retinopathy: Recommendations on Monitoring. Retrieved 2 June 2024, from https://www.rcophth.ac.uk/wp-content/uploads/2020/12/Hydroxychloroquine-and-Chloroquine-Retinopathy-Monitoring-Guideline.pdf

Answer 72

2 weeks Limbal stem cell transplantation can be performed about 2 weeks after chemical injury once inflammation has improved. An inflamed eye increases the chance of graft rejection.

Answer 73

Proptosis should not occur in ocular myasthenia and should make you question the diagnosis. The most common ocular sign is ptosis which may initially be unilateral, frequently shifting from one eye to the other but eventually involve bilateral upper eyelids. Cogan’s twitch is a feature. To elicit this, ask the patient to look down for 20s then at an object at primary position. If the lid overshoots, then then the test is positive. Rarely, ocular myasthenia can present with unilateral eyelid retraction (and therefore scleral show) and obicularis weakness. Possible reasons for lid retraction: Seen with contralateral ptosis due to Hering's law (due to increased innervation to the ptotic eyelid), or Sign of co-existing thyroid eye disease, or Post-tetanic facilitation of the levator palpebral superioris after prolonged upgaze Reference(s)/further reading: Nair, A. G., Patil-Chhablani, P., Venkatramani, D. V., & Gandhi, R. A. (2014). Ocular myasthenia gravis: a review. Indian J Ophthalmol, 62(10), 985-991. https://doi.org/10.4103/0301-4738.145987

Answer 74

Arnold chiari malformation The description of this patient's nystagmus points towards a downbeat nystagmus, where there is a downward fast phase. The cervico-medullary junction is where the pathology normally lies for downbeat nystagmus., e.g. tumours at the foramen magnum, Arnold-Chiari malformation, stroke, demyelination. Pathologies like drug toxicity, paraneoplastic syndrome and antibody to glutamic acid decarboxylase can also cause downbeat nystagmus. Although there are different types, an Arnold-Chiari malformation is basically an anatomical defect of the upper spinal area and base of skull. In Type 1 Arnold-Chiari, there is downward displacement of the cerebellar tonsils through the opening at the base of the skull (foramen magnum), accompanied by syringomyelia. Type I Arnold-Chiari is most common, and although most cases are congenital, if symptoms do manifest, it would manifest during teenage or young adult years. Some of the other different types of nystagmus/nystagmoid patterns and summary of main causes/problematic locations: Upbeat nystagmus - classically Wernicke, but also posterior fossa, i.e. cerebellar or lower brainstem pathology typically medulla See-saw - parasellar area, e.g. craniopharyngioma Opsoclonus - paraneoplastic, e.g. neuroblastoma, small cell lung cancer, ovarian, breast Periodic alternating nystagmus - cervico-medullary junction Peripheral vestibular nystagmus (conjugate horizontal jerk nystagmus) - semicircular canal, otolith structures or vestibular nerve, e.g. labyrinthitis, vestibular neuritis

Answer 75

Direct CCF carotid-cavernous fistula Given the sudden onset and history of trauma, this patient is likely to have a direct carotid-cavernous fistula (CCF). Direct CCF often have more acute onset, and more severe signs and symptoms compared to indirect CCF which are more likely to have gradual onset and chronic course. Symptoms of CCF can include: Diplopia Orbital/retro-orbital pain Swelling Swishing/buzzing sounds Headache Vision loss Signs of CCF can include: Proptosis Eyelid oedema Ptosis Conjunctival hyperaemia, arterialisation of conjunctival/episcleral veins --> tortuous corkscrew vessels Elevated IOP Pulsatile exophthalmos Papilooedema Ophthalmoplegia The classic triad of direct CCF: Pulsatile exophthalmos Orbital bruit Chemosis The other false options: Subdural haemorrhage: It is possible the patient may have this as well if he had a head strike after he fell, but the symptoms and signs are pointing towards a CCF. Orbital floor fracture: Although a patient with orbital floor fracture may present with some limited eye movements (typically limited upgaze), it is unlikely an orbital floor fracture alone will cause proptosis. Remember to always exclude a retrobulbar haemorrhage in any trauma patient with proptosis and ophthalmoplegia though.

Answer 76

Mostly affects young women unilaterally Would result in anisocoria worse in bright conditions compared to dim conditions Affects the parasympathetic supply to the iris and ciliary ganglion; loss of post-ganglionic nerve fibres results in denervation hypersensitivity, such that the iris sphincter becomes supersensitive to dilute pilocarpine e.g. 0.125%; pilocarpine is a muscarinic agonist which in normal eyes requires approximately 1% or more to cause miosis Classically mydriatic pupil poorly responsive to light, “vermiform”(worm-like) movements, slow and sustained response to near response With time the pupil tends to become miotic

Answer 77

superior and lateral recti Heavy eye syndrome Progressively worsening hypotropia and esotropia in high myopes The elongated globe can herniate between the superior and lateral recti; there is stretching and dehiscence of the intermuscular septum between these two muscles High myopia can also cause inferior slippage of the lateral rectus pulley Also in high myopes, the medial rectus is frequently tight which can worsen the esotropia. Management: prisms surgical intervention will need to address the lateral rectus muscle slippage by joining the superior and lateral rectus muscle with a loop myopexy to reposition the globe. Recession of the medial rectus muscle may also be needed if that muscle is tight.

Answer 78

BEhcet disease A very similar question was asked in a FRCOphth Part 2. The question was very vague and had no mention of oral ulceration. In the presence of bilateral AAU, BRVO and skin lesions, the most likely cause amongst the given options is Behcet’s. Ankylosis spondylitis usually affects one eye at a time, and may affect the other sequentially. VKH can cause a bilateral granulomatous anterior uveitis with retinal changes. However, vessel occlusion is not a feature of VKH. Posterior features like multifocal neurosensory detachments, exudative RD, choroidal depigmentation (sunset glow), Dalen-Fuchs are more likely. Behcet’s Highest prevalence in Turkey and other Silk Route regions Young adults Clinical features Ophthalmic Anterior uveitis: non-granulomatous, hypopyon possible Posterior uveitis: vitritis, macular oedema, retinal haemorrhages, BRVO/CRVO Cataract, glaucoma, optic/retinal atrophy Systemic Oral (aphthous or scarring) GU ulceration Skin lesions (erythema nodosum, pseudofolliculitis, papulopustules) Joint arthritis Vascular (venous>arterial) GI CNS Investigations Positive pathergy test - sterile pustule appearing 24-48h after oblique insertion of 20G needle MRI/MRV if neurological sign present Treatment Systemic corticosteroids Other immunosuppression

Answer 79

bare sclera Post pterygium excision, several techniques can be adopted to prevent recurrence: Conjunctival autograft has a low recurrence rate. Amniotic membrane allows the preservation of conjunctiva but recurrence rates may be slightly higher than conjunctival autograft Simple closure if there is lack of resources and if conjunctival tissue is unavailable Bare sclera i.e. leaving the area open is an extremely high recurrence rate and is usually not done

Answer 80

MRI orbits Although this patient has a a family history of glaucoma, her presentation is atypical of glaucoma. She has significant asymmetry in visual acuity and coinciding optic atrophy and peripapilllary choroidal atrophy. Investigations should be performed for compressive optic neuropathy. General features suggestive of compressive neuropathy over glaucoma: Positive visual symptoms Unexplained VA reduction Reduced colour vision RAPD Optic disc pallor VF defect observing the vertical midline Mismatch between optic disc and VF defect

Answer 81

anti acetylcholine receptor antibody This patient has features most consistent with myasthenia gravis (MG). MG should be considered a possibility when there is intermittent diplopia. Methods for investigating for MG include: ice-pack test serum antibodies - anti-acetylcholine (anti-ACh) receptor antibody present in >95% of patients with generalised myasthenia but only 50% of ocular myasthenia; anti-skeletal muscle is present in 85% of patients with thymoma single fibre electromyography (EMG) As MG is associated with other autoimmune diseases, e.g. Graves’s disease in 4–10%, thyroid function test may help to detect associated thyroid disease but will not diagnose MG. Skeletal muscle biopsy assessing for mitochondrial myopathic changes is used to diagnose chronic progressive external ophthalmoplegia (CPEO). Whilst double vision can possibly occur, most CPEO patients do not have double vision due to the symmetric and diffuse nature of the weakness of extraocular muscles.

Answer 82

Epstein-Barr virus Most common cause of acute dacryoadenitis May cause stroma keratitis, characterised by multiple corneal infiltrates

Answer 83

frontoethmoidal mucocoele A frontoethmoidal mucocoele will cause a inferolateral proptosis/globe displacement. The other options will cause an axial proptosis. Axial proptosis can be caused by any tumour that is intraconal. Axial proptosis causes: Axial proptosis - cavernous haemangioma, optic nerve glioma, optic nerve haemangioma, schwanomma, neurofibroma Non-axial proptosis can be caused by any tumour that is extraconal. The direction of proptosis is opposite to the origin of the tumour. Non-axial proptosis: dermoid cyst, rhabdomyosarcoma, lacrimal gland tumour, sinus tumours e.g. maxillary sinus causing a superior displacement, frontalethmoidal causing a inferolateral displacement.

Answer 84

This is most likely a case of aberrant 3rd nerve regeneration following 3rd nerve injury during brain tumour resection. Aberrant regeneration of 3rd nerve AKA oculomotor synkinesis is an abnormal response to firing of oculomotor nerve causing co-contraction of muscles. Synkinesis basically means involuntary muscle contraction which accompanies voluntary muscle contraction. Ocular synkinesis is caused by partial oculomotor dysfunction caused by failure of complete recovery. Incidence of aberrant regeneration of 3rd nerve is up to 15% after trauma injury. This classically presents as unresolving diplopia and/or ptosis with possible signs noted below. Signs of aberrant 3rd nerve regeneration: “Pseudo-Argyll Robertson pupil”: greater constriction of pupil to convergence than to light and gaze-evoked pupillary constriction Adduction of the eye on attempted upward or downward gaze “Pseudo Von-Graefe Sign:” elevation of upper eyelid on downward gaze or adduction Limitation of elevation and depression of the eye with retraction of the globe on attempted vertical movement Wrong answers: The typical features of reproducible synkinetic movements seen in aberrant 3rd nerve regeneration won’t be seen in some differentials such as neurosyphilis or myasthenia. Adie’s pupil is initially mydriatic with light near dissociation. Chronic Adie’s pupil may be miotic. Argyll Robertson pupil presents in 3rd stage neurosyphilis. It may cause a unilateral/bilateral irregular miotic pupil with light near dissociation. A combined 3rd and 6th nerve injury will probably also cause features of 3rd nerve and also lateral movement restriction (6th nerve).

Answer 85

Topical trifluoridone was used in every arm of HEDS 1, not ganciclovir. Herpetic Eye Disease Study (HEDS) HEDS 1 Trifluoridone (anti-viral) used in all arms HEDS 1 Stromal Keratitis Not on steroids trial Steroid drops effective in HSV stromal keratitis HEDS 1 Stromal Keratitis on steroids No benefit in adding aciclovir to topical steroid + topical antiviral in stromal keratitis HEDS 1 Iridicyclitis receiving topical steroids Possible benefit in adding oral aciclovir in HSV iritis but non significant due to slow recruitment and small study HEDS 2 HEDS 2 Epithelial Keratitis Trial No benefit in adding oral aciclovir to topical antiviral for epithelial keratitis HEDS 2 Acyclovir Prevention Trial Prophylactic aciclovir effective and well tolerated in patients with previous history of herpectic eye disease Risk of overall recurrence 19% vs 32% (40% reduction) Risk of epithelial keratitis recurrence 9% vs 14% Risk of stromal keratitis recurrence 14% vs 28%

Answer 86

Fornix-based Initial conjunctival incision made at the limbus Technically easier and can be done without assistant Higher incidence of wound leaks since the edge of the wound is at the limbus Lower, more diffuse blebs since the subconjunctival scar (created by suture line) is anterior to the scleral flap This promotes fluid flow posterior to the flap resulting in a lower and more diffuse filtering bleb Limbal-based Initial conjunctival incision made 8-10mm posterior to the limbus (in the fornix) Technically more difficult due to poorer exposure More focal and elevated blebs since the scar is posterior to the scleral flap Wound closure less prone to leaks since suture line is far from limbus

Answer 87

anterior segment ischemia This patient has poor cardiovascular health and in the listed options, anterior segment ischaemia is most likely. Wrong options: Lost muscle is when an extraocular muscle slips out of place or detaches from eye. Consecutive strabismus is a term used for overcorrection of a squint. Anterior segment ischaemia Dull ache AC flare, cells, sluggish pupil Possible signs of ocular ischaemic syndrome in retina e.g. dilated retinal veins, attenuated retinal arterioles, retinal haemorrhages, rubeosis etc. Investigate for carotid artery stenosis

Answer 88

syndactyly is not seen in blepharophimosis syndrome. Syndactyly is a condition where two or more fingers or toes are fused together, or "webbed" Blepharophimosis syndrome Most commonly an autosomal dominant syndrome (some cases can arise de novo) Presents with four major facial features: blepharophimosis (horizontal shortening of the palpebral fissures) epicanthus inversus (extra skin fold arising from lower eyelid up to upper eyelid which covers medial canthus) telecanthus (wide intercanthal distance but normal interpupillary distance) ptosis (with poor levator function) Two types Type I involves premature ovarian insufficiency in females (which can lead to infertility) and thus the need for hormone replacement therapy Type II has no systemic associations, and is characterized by the facial features alone. Surgical correction involves repair of the eyelid malformations, including eyelid ptosis with frontalis suspension techniques

Answer 89

The symptoms described are typical of giant cell arteritis. In this condition, there is inflammatory cell infiltration (lymphocytes, plasma cells, eosinophils and macrophages) in the media. But the inflammation may be patchy with skip lesions. This is why biopsy length of ⩾ 2cm to avoid likelihood of skip lesions. Multinucleated giant cells are typically located close to fragmented internal elastic lamina, but giant cells are only present in about 50% positive biopsies. The lumen may become obliterated by fibrin thrombus, which becomes organised and recanalised. The adventitia and small periarterial vessels are frequently affected in the chronic inflammatory process.

Answer 90

Although this patient has macular oedema secondary to CRVO, his visual acuity (VA) is better than 6/12, and therefore it is acceptable to observe for spontaneous resolution. This is based on the Royal College of Ophthalmologist Retinal Vein Occlusion guidelines published in 2022. If VA is 6/96 or better with presence of macular oedema, patient should be offered intravitreal anti-VEGF. If VA is worse than 6/96 with significant macular oedema, patients should still be offered intravitreal anti-VEGF. However, the potential for significant improvement in VA is guarded, and these eyes need to be watched closely for ocular neovascularisation. The CVOS study failed to demonstrate benefit from grid treatment. Pan-retinal photocoagulation (PRP) should not be an option here as there is no evidence of neovascularisation. Even in cases of ischaemic CRVO, the CVOS study failed to show benefit from prophylactic PRP. References/further reading: Royal College of Ophthalmologists (January 2022). Clinical Guidelines: Retinal Vein Occlusion (RVO). Retrieved 13 June 2024, from https://www.rcophth.ac.uk/wp-content/uploads/2015/07/Retinal-Vein-Occlusion-Guidelines-2022.pdf

Answer 91

Choroidal neovascularisation (CNV) can develop as a complication in certain types of white dot syndromes and these are: Birdshot chorioretinopathy (6%) Serpiginous choroiditis (25%) Multifocal choroiditis with panuveitis (33%) Punctate inner choroidopathy (17-40%) Of the options, punctate inner choroidopathy (PIC) is most likely to develop CNV.

Answer 92

asteroid hylaosis This is quite a difficult question, you are required to pick the BEST option. The discrepancy of AL should prompt further investigation. Studies quote that for every 0.33 - 0.40mm in axial length, there is a 1.00 D change in cases of axial ametropia. Using this estimation, the refractive error difference between the right and left eye should be approximately 11.5-13.9D, but the above results only show a difference of 0.50D, so something else is contributing to the difference. PSC and nuclear cataract are known to induce a myopic shift. However, the degree of myopic shift quoted in studies are usually < 2D, so both axial and index hypermetropia are unlikely options for the discrepancy seen above. Spherophakia can cause high myopia and lens instability. It is a bilateral disease but it is not associated with asymmetrical axial lengths, especially to this degree. Asteroid hyalosis has been showed to cause underestimations in axial length during biometry. References: https://pubmed.ncbi.nlm.nih.gov/2040975/ https://pmc.ncbi.nlm.nih.gov/articles/PMC1771794/

Answer 93

Teprotumumab is a monoclonal antibody which blocks IGF1 receptor, reducing hyaluronan production and inflammatory signalling. It has been shown to reduce proptosis and inflammation in patients with active TED.

Answer 94

Fuch’s typically cause vision deterioration past the age of 50 The other dystrophies shown here occur at a younger age in the following order starting from the oldest: granular, lattice and finally macular dystrophy. Helpful mnemonic: My Lovely Granny is the Oldest Young to old: Macular < Lattice < Granular

Answer 95

coaxial beam When coaxial illumination is reflected from the patient retina to the observer, it results in red reflex. The intense of red reflex helps the surgeon to maintain the adequate visualization during surgery as well as identify corneal and anterior segment abnormalities. Coaxial illumination is also useful for visualisation of posterior capsule and for vitreous surgery.

Answer 96

argon laser peripheral iridoplasty ALPI is performed by using a ring of argon laser burn to cause cicatricial contraction of the peripheral iris stroma to tighten the iris and widen the angular approach. This is particularly useful for plateau iris syndrome (PIS). PIS is a post-operative (usually peripheral iridotomy) condition whereby there is a persistent narrow angle capable of closure despite PI. This is caused by the abnormal anterior displacement of the ciliary body causing unusual position of the peripheral iris in relation to the trabecular meshwork. An acute glaucoma crisis after peripheral iridotomy is diagnostic for PIS. Plateau iris configuration (PIC) usually describes the pre-operative condition where the iris root is short and the ciliary body processes may be larger and more anteriorly positioned than normal. This causes a mechanical repositioning of the peripheral iris, and crowding of the angle thereby obstructing flow through the trabecular meshwork. Peripheral laser iridotomy is usually the first surgical intervention performed. If unsuccessful in lowering IOP, it helps confirm the diagnosis of plateau iris syndrome.

Answer 97

LE MR recession , LR resection This child has simulated divergence excess exotropia (XT). This is because although the deviation was ≥ 10△ larger when measured at distance fixation than at near, following 1 hour of monocular occlusion, the measurement at near fixation increased to <10△ of the angle at distance. The best surgical option would be a unilateral medial rectus resection and lateral rectus recession. If there was no change following an hour of monocular occlusion, then the child has true divergence excess XT, and the best option would be bilateral lateral rectus recession. The other options would exacerbate the exotropia. b/l MR recesion

Answer 98

ipsilateral MR recession Type I Duane is characterised by marked limitation of abduction. Recall the Huber classification of Duane syndrome: Type I: marked limitation of abduction (remember 1x "d" in AbDuction) Type II: limitation of adduction (remember 2x "d" in ADDuction) Type III: limitation of both abduction and adduction It is important to recognise that restoring normal ocular motility is an unrealistic goal. Observation is often the best management. Surgical intervention should be reserved for those with manifest deviation in primary position, a large face turn, severe globe retraction or significant up- and down-shoots. For Type 1 Duane syndrome, there is usually a hypoplastic CN VI nucleus or nerve, and relative LR dysfunction. The affected eye is usually esotropic. These patients can have associated limited abduction and/or co-contraction in adduction. Surgical options are varied and complex, depending on many factors and we will not be going into a great detail here. However of the options presented in this question, an ipsilateral medial rectus recession (therefore weakening it) is an acceptable surgical option. Muscle resection is often prohibited in classic teaching (best to avoid in exam situations) as it could worsen the "leash phenomenon" causing aggravation of up- and down-shoots but have been used in very selected situations. The other options presented would work against the possible LR weakness and/or esotropia with associated head turn in Type 1 Duane syndrome. b/l LR recession i/p LR recession i/p LR resection

Answer 99

OCP does not cause a ptosis. It could cause a cicatricial ectropion. ocular cicatricial pemphigoid Wrong answers: Lambert-Eaton Disorder of the presynaptic calcium channels, causing impaired release of ACh It is usually associated with malignancy (e.g. small cell lung cancer) but may be an isolated autoimmune disorder Decreased lacrimation Ocular motility abnormalities and tonic pupils may occur +/- Ptosis and diplopia In contrast to MG, repeated or sustained testing may cause improvement in any abnormalities Bell’s palsy could cause a ptosis. Cluster headache is one of the causes of central or 1st order Horner’s.

Answer 100

reduced levator function Features of congenital ptosis include: Reduced levator function Low or absent skin crease Normal orbicularis function Normal Bell's phenomenon unless associated elevator palsy Lid lag in down gaze A weak orbicularis function and poor Bell's phenomenon should make you suspect a myogenic cause, especially if they also have ocular motility limitation. High (or lost) skin crease is typical of ptosis from aponeurotic dehiscence. A summary of the features of various types of ptosis: Reference(s)/further reading: Leatherbarrow, B. (2011). Oculoplastic surgery (2nd edition). Chapter 7: Blepharoptosis. Informa Healthcare, London, UK.

Answer 101

A larger spot size is used for selective laser trabeculoplasty (SLT) compared to argon laser trabeculopasty (ALT). For ALT, the laser beam is focused via a goniolens at the junction of the anterior non-pigmented and the posterior pigmented edge of trabecular meshwork. More inflammation, pigment dispersion, prolonged IOP elevation and PAS can result form very posterior application of the laser beam. As the aiming beam in SLT is larger, it straddles the entire trabecular meshwork and precise placement of the laser beam is not as necessary as in ALT. It is believed that PAS Is more likely to occur with ALT compared to SLT, although the literature has not shown this. Less histopathological destruction have been observed with SLT compared to ALT, and therefore there is more promoted repeatability of SLT over ALT. shorted exposure time is used in SLT than ALT It is more typical for topical steroids to be prescribed post ALT whilst it is more common not to prescribe any anti-inflammatory medications post SLT. It is a common conception that steroids or anti-inflammatories may blunt the inflammatory process induced by the laser for it to work. However the Steroids after Laser Trabeculoplasty (SALT) study, which treated subgroups with steroids vs NSAID vs saline, in fact showed a greater reduction in IOP in the NSAID group (refer to study for more details). In an RCT, SLT has been shown to be equivalent to ALT in terms of IOP lowering at 1 year. Reference(s)/further reading: Damji KF, Bovell AM, Hodge WG, Rock W, Shah K, Buhrmann R et al. Selective laser trabeculoplasty versus argon laser trabeculoplasty: results from a 1-year randomised clinical trial. Br J Ophthalmol 2006; 90(12): 1490-1494. Groth SL, Albeiruti E, Nunez M, Fajardo R, Sharpsten L, Loewen N et al. SALT Trial: Steroids after Laser Trabeculoplasty: Impact of Short-Term Anti-inflammatory Treatment on Selective Laser Trabeculoplasty Efficacy. Ophthalmology 2019; 126(11): 1511-1516. Kramer TR, Noecker RJ. Comparison of the morphologic changes after selective laser trabeculoplasty and argon laser trabeculoplasty in human eye bank eyes. Ophthalmology 2001; 108(4): 773-779.

Answer 102

park bieschowsky 3 step test

Answer 103

breast ca followed by lung ca

Answer 104

only Ahmed is valved the rest valveless ; Molteno, Baervedlt, Paul better iop lowering effect whilst on few AGM but at expense of hypotony

Answer 105

Heart rate decrease due to direct pressure on extraocular muscle, globe or conjunctiva Defined by a drop in heart rate of >20% Mediated by connection between the ophthalmic branch of the trigeminal nerve and the vagus nerve The reflex most commonly induces bradycardia but it has also been reported to induce arrhythmias and cardiac arrest Most often encountered in strabismus surgery but have been reported in cases of regional anaesthetic nerve blocks and facial trauma Incidence appear to decrease with age, with paediatric population being at risk There are mixed reports with retrobulbar anaesthesia in preventing oculocardiac reflex. But they have been reported to also trigger the reflex during administration Interestingly, oculocardiac reflex have been reported in previously enucleated or enviscerated empty orbit WJ, Vance JP. Oculocardiac reflex from the empty orbit. Anaesthesia 1983; 38(9): 883-885. Batterbury M, Wong D, Williams R, Kelly J, Mostafa SM. Peribulbar anaesthesia: Failure to abolish the oculocardiac reflex. Eye 1992; 6(3): 293-295. Juan I, Lin M, Greenberg M, Robbins SL. Surgical and anesthetic influences of the oculocardiac reflex in adults and children during strabismus surgery. Survey of Ophthalmology 2023; 68(5): 977-984

Answer 106

Autosomal dominant Chromosome 22 Ocular features Early onset posterior subcapsular/cortical cataract Combined hamartoma of the RPE and retina Extra ocular features Acoustic neuroma Meningioma Glioma Schwannoma First degree relative

Answer 107

severe pain on presentation dispropotion to mild clinical findings ddx abx resistant pseudomonas circumferential ring 48 hrs later They are ubiquitous free-living protozoaIsolated from soil, dust, sea, fresh and chlorinated water risk fx Related to extended CL wear, poor CL hygiene, and swimming with CL Corneal trauma in rural or agricultural setting clinical features Variable from asymptomatic to severe pain disproportionate to clinical findings Epithelial ridges, pseudo or true dendrites, stromal infiltrates which may progress to form a ring, perineurial infiltrates, reduced corneal sensation Commonly misdiagnosed with herpes simplex keratitis Complications: limbal and scleral extension, corneal perforation ix In vivo confocal microscopy allows for direct visualisation of cysts which is diagnostic Early corneal scrapes recommended if high clinical suspicion If available, send CL, solutions and cases for culture Gram stain, Giemsa stain, Calcofluor white and histology Culture in non-nutrient agar with E.coli overlay at 25-37C (this may take up to 14 days) Corneal biopsy if above investigations negative and high clinical suspicion remains Treatment: Admit Stop CL wear Hourly treatment - Aminoglycosides (neomycin)or imidazole (itraconazole or fluconazole) -Biguanide (polyhexamethylene 0.02% or chlorhexidine 0.02%) -Aromatic diamidine (propamidine isethionate 0.1% or hexamidine 0.1%). Analgesia and cycloplegia Taper according to clinical improvement Relapse is common and will require prolonged treatment Topical steroids to reduce scarring Scleritis treated with immunosuppression with systemic steroids and steroid-sparing agent severe corneal scarring treated with PK Necrosis treated with PK Severe pain treated with enucleation

Answer 108

Bilateral accelerated endothelial cell loss leading to Na/K ATPase pump failure Loss of hexagonal shape due to neighbouring hexagonal cells filling gaps created by death of previously healthy endothelial cells F>M, develops in the 7th and 8th decades Associated with open angle glaucoma Typically sporadic, rarely AD with COL8A2 gene (also ZEB1, SLC4A11 or LOXHD1) Clinical features Worsening blurring especially in the morning due to oedema Corneal guttata: irregular excrescences on DM secreted by abnormal endothelial cells appear centrally Histopathology shows multi-laminar Descemet's membrane studded with excrescences  Specular microscopy shows: pleomorphism, polymethaism, reduced endothelial density Tiny dark spots develop into beaten metal appearance Central stromal oedema as cornea decompensates Bowman's membrane scarring Epithelial oedema in advanced cases and bullous keratopathy which can cause acute pain if bullae rupture Increased CCT on pachymetry: a thickness greater than 650 microns increases the risk of symptomatic and chronic corneal oedema after cataract surgery (same with cell counts <1000)

Answer 109

coliform bacteria gram -, rod shaped common in immunosuppressed, neonates, trauma : Infective organisms: Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes and Haemophilus influenzae (commoner in children but has reduced since Hib vaccination)In a study by Harris et al (1994), typically infections in children <9 yrs: from one aerobic organisms; in children > 9 yrs + adults: may be polymicrobial with both aerobic + anaerobic bacteria Sinus disease: Ethmoid sinus is the only developed sinus at birth. Under age of 7, typically involved sinus is ethmoid sinus which spread through thin lamina papyracea or medial orbital wall. Ethmoid sinusitis underlying cause in majority of paediatric cases. Frontal, maxillary and sphenoid sinuses develop later in childhood. Frontal sinusitis more common cause in adults compared to children.Infection of other adjacent structures: pre-septal or facial infection, dacryocystitis, dental abscess Trauma: Septal perforation, retained foreign body Surgical: Orbital, lacrimal and vitreoretinal surgery Endogenous spread: In immunocompromised patients

Answer 110

4x other rx Male gender 2x Younger age: <60y has 5x Longer axial length: 4x PCR: 16x

Answer 111

A recurrent unilateral episode of painless high IOP occurring in a white eye Hypothesised to be caused by acute trabeculitis possibly secondary to HSV It is characterised by increased IOP of 40-80 mmHg in a white eye with minimal flare, with occasional cells/KPs, no synechiae and open angle Topical steroids if inflammatory For high IOP: consider topical or systemic OP lowering

Answer 112

demarcation line retinoschisis SHD NOT HV demarcation line

Answer 113

Only eye”, or one "good eye "Vulnerable adults who may not report ocular/vision symptoms Family history of significant angle closure disease High hypermetropia (more than +6.00 dioptres) Condition necessitating regular pupil dilation e.g. diabetes Use of antidepressants or medication with an anticholinergic action People living/working in remote locations

Answer 114

anti- MuSK if still negative antiLRP4 anti agrin

Answer 115

Thiel Behnke

Answer 116

high stress selenium deficiency smoking X high BP

Answer 117

It typically is caused by retained visco- elastic material posterior to the lens and involves shallowing of the anteri- or chamber associated with anterior vaulting of the IOL, distension of the posterior capsule, and a postoperative myopic shift.

Answer 118

female > male risk for TED

CLINICAL OPHTHALMOLOGY Flashcards

CATARACT AND LENS (232 cards)