Ophthal

Question 1

Types of conjunctivitis

Answer 1

Bacterial
Viral
Allergic

Question 2

Conjunctivitis presentation

Answer 2

Unilateral or bilateral
Red eyes
Bloodshot
Itchy or gritty sensation
Discharge from the eye

Does not cause pain

Question 3

How does bacterial conjunctivitis usually present

Answer 3

A purulent discharge and an inflamed conjunctiva. It is typically worse in the morning when the eyes may be stuck together. It usually starts in one eye and then can spread to the other. It is highly contagious.

Question 4

How does viral conjunctivitis usually present

Answer 4

Is common and usually presents with a clear discharge. It is often associated with other symptoms of a viral infection such as dry cough, sore throat and blocked nose. You may find tender preauricular lymph nodes (in front of the ears). It is also contagious.

Question 5

Management of conjunctivitis

Answer 5

usually resolves without treatment after 1-2 weeks.

Advise on good hygiene to avoid spreading (e.g. avoid sharing towels or rubbing eyes and regularly washing hands) and avoiding the use of contact lenses. Cleaning the eyes with cooled boiled water and cotton wool can help clear the discharge.

If bacterial conjunctivitis is suspected then antibiotic eye drops can be considered, however bear in mind it will often get better without treatment. Chloramphenicol and fuscidic acid eye drops are both options.

Question 6

Why is it important to refer patients under 1 month with conjunctivitis

Answer 6

Neonatal conjunctivitis can be associated gonococcal infection and can cause loss of sight and more severe complications such as pneumonia

Question 7

Management of allergic conjunctivitis

Answer 7

Antihistamines (oral or topical) can be used to reduce symptoms.

Topical mast-cell stabilisers can be used in patients with chronic seasonal symptoms. They work by preventing mast cells releasing histamine. These require use for several weeks before showing any benefit.

Question 8

Lesion location in left homonymous hemianopia

Answer 8

Visual field defect to the left –> lesion of the right optic tract

Question 9

Congruous vs incongruous visual defects

Answer 9

A congruous visual field defect is identical between the two eyes, whereas an incongruous defect differs in appearance between the eyes.

Congruous defects are complete whereas incongruous defects are incomplete

Question 10

Which lesions cause incongruous visual defects

Answer 10

Optic tract lesions

Question 11

Which lesions cause congruous defects

Answer 11

Optic radiation lesion or occipital cortex

Question 12

Which lesions cause homonymous hemianopia

Answer 12

incongruous defects: lesion of optic tract

congruous defects: lesion of optic radiation or occipital cortex

macula sparing: lesion of occipital cortex

Question 13

Which lesions cause superior homonymous quadrantanopias

Answer 13

superior: lesion of the inferior optic radiations in the temporal lobe (Meyer’s loop)

mnemonic = PITS (Parietal-Inferior, Temporal-Superior)

Question 14

Which lesions cause inferior homonymous quadrantanopias

Answer 14

inferior: lesion of the superior optic radiations in the parietal lobe

mnemonic = PITS (Parietal-Inferior, Temporal-Superior)

Question 15

Which lesions cause bitemporal hemianopia

Answer 15

lesion of optic chiasm
upper quadrant defect >

lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour

lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma

Question 16

What is glaucoma

Answer 16

Refers to the optic nerve damage that is caused by a significant rise in intraocular pressure.

The raised intraocular pressure is caused by a blockage in aqueous humour trying to escape the eye.

Question 17

What is aqueous humour produced by

Answer 17

Ciliary body

Question 18

Normal intraocular pressure

Answer 18

10-21 mmHg

The pressure is created by the resistance to flow through the trabecular meshwork into the canal of scheme

Question 19

Pathophys of open-angle glaucoma

Answer 19

There is a gradual increase in resistance through the trabecular meshwork.

This makes it more difficult for aqueous humour to flow through the meshwork and exit the eye.

Therefore the pressure slowly builds within the eye and this gives a slow and chronic onset of glaucoma.

Question 20

Pathophys of acute angle-closure glaucoma

Answer 20

The iris bulges forward and seals off the trabecular meshwork from the anterior chamber preventing aqueous humour from being able to drain away.

This leads to a continual build-up of pressure. This is an ophthalmology emergency.

Question 21

Effect of increased intraocular pressure on the optic disc

Answer 21

Increased pressure in the eye causes cupping of the optic disc. In the centre of a normal optic disc is the optic cup.

This is a small indent in the optic disc. It is usually less than half the size of the optic disc.

When there is raised intraocular pressure, this indent becomes larger as the pressure in the eye puts pressure on that indent making it wider and deeper.

Question 22

Abnormal optic cup size

Answer 22

An optic cup greater than 0.5 the size of the optic disc is abnormal.

Question 23

Risk factors for open-angle glaucoma

Answer 23

Increasing age
Family history
Black ethnic origin
Nearsightedness (myopia)

Question 24

Presentation of open-angle glaucoma

Answer 24

Asymptomatic

Peripheral vision affected first until it closes in to result in tunnel vision

Gradual onset of fluctuating pain, headaches, blurred vision and halos appearing around lights, particularly at night time

Question 25

Diagnosis of open-angle glaucoma

Answer 25

Goldmann applanation tonometry can be used to check the intraocular pressure. Fundoscopy assessment to check for optic disc cupping and optic nerve health. Visual field assessment to check for peripheral vision loss.

Question 26

When is treatment for open-angle glaucoma usually started

Answer 26

Treatment is usually started at an intraocular pressure of 24 mmHg or above. Patients are followed up closely to assess the response to treatment.

Question 27

1st line mx for open-angle glaucoma

Answer 27

Prostaglandin analogue eye drops (e.g. latanoprost) are first line. These increase uveoscleral outflow.

Question 28

Notable side effects of prostaglandin analogue eye drops

Answer 28

Notable side effects are eyelash growth, eyelid pigmentation and iris pigmentation (browning).

Question 29

Other options of management of open-angle glaucoma

Answer 29

Beta-blockers (e.g. timolol) reduce the production of aqueous humour Carbonic anhydrase inhibitors (e.g. dorzolamide) reduce the production of aqueous humour Sympathomimetics (e.g. brimonidine) reduce the production of aqueous fluid and increase uveoscleral outflow

Question 30

Surgical intervention for glaucoma

Answer 30

Trabeculectomy surgery may be required where eye drops are ineffective. This involves creating a new channel from the anterior chamber, through the sclera to a location under the conjunctiva. It causes a “bleb” under the conjunctiva where the aqueous humour drains. It is then reabsorbed from this bleb into the general circulation.

Question 31

Risk factors for acute angle-closure glaucoma

Answer 31

Increasing age Females are affected around 4 times more often than males Family history Chinese and East Asian ethnic origin. Unlike open-angle glaucoma, it is rare in people of black ethnic origin. Shallow anterior chamber

Question 32

Medications which can precipitate acute angle-closure glaucoma

Answer 32

Adrenergic medications such as noradrenalin Anticholinergic medications such as oxybutynin and solifenacin Tricyclic antidepressants such as amitriptyline, which have anticholinergic effects

Question 33

Presentation of acute angle-closure glaucoma

Answer 33

Severely painful red eye Blurred vision Halos around lights Associated headache, nausea and vomiting

Question 34

Examination findings in acute angle closure glaucoma

Answer 34

``` Red-eye Teary Hazy cornea Decreased visual acuity Dilatation of the affected pupil Fixed pupil size Firm eyeball on palpation ```

Question 35

Initial management of acute angle closure glaucoma

Answer 35

same-day assessment by an ophthalmologist Lie patient on their back without a pillow Give pilocarpine eye drops (2% for blue, 4% for brown eyes) Give acetazolamide 500 mg orally Given analgesia and an antiemetic if required

Question 36

How does pilocarpine work

Answer 36

Pilocarpine acts on the muscarinic receptors in the sphincter muscles in the iris and causes constriction of the pupil. Therefore it is a miotic agent. It also causes ciliary muscle contraction. These two effects cause the pathway for the flow of aqueous humour from the ciliary body, around the iris and into the trabecular meshwork to open up.

Question 37

How does acetazolamide work

Answer 37

Acetazolamide is a carbonic anhydrase inhibitor. This reduces the production of aqueous humour.

Question 38

Secondary care management of acute angle-closure glaucoma

Answer 38

``` Pilocarpine Acetazolamide (oral or IV) Hyperosmotic agents such as glycerol or mannitol Timolol Dorzolamide Brimonidine ```

Question 39

Purpose of hyper osmotic agents in acute angle closure glaucoma

Answer 39

Hyperosmotic agents such as glycerol or mannitol increase the osmotic gradient between the blood and the fluid in the eye

Question 40

Use of beta-blockers in acute angle closure glaucoma

Answer 40

Beta-blockers reduce production of aqueous humour

Question 41

Use of brimodine in acute angle closure glaucoma

Answer 41

Brimonidine is a sympathomimetic that reduces the production of aqueous fluid and increase uveoscleral outflow

Question 42

Definitive treatment for acute angle-closure glaucoma

Answer 42

Laser iridotomy - involves using a laser to make a hole in the iris to allow the aqueous humour to flow from the posterior chamber into the anterior chamber. The relieves pressure that was pushing the iris against the cornea and allows the humour the drain.

Question 43

What is posterior vitreous detachment

Answer 43

Posterior vitreous detachment is the separation of the vitreous membrane from the retina. This occurs due to natural changes to the vitreous fluid of the eye with ageing.

Question 44

Risk factors for posterior vitreous detachment

Answer 44

As people age, the vitreous fluid in the eye becomes less viscous, and thus, does not hold its shape as well. Therefore, it pulls the vitreous membrane away from the retina towards the centre of the eye. Highly myopic (near-sighted) patients are also at increased risk of developing posterior vitreous detachment earlier in life. This is because the myopic eye has a longer axial length than an emmetropic eye.

Question 45

Symptoms of posterior vitreous detachment

Answer 45

The sudden appearance of floaters (occasionally a ring of floaters temporal to central vision) Flashes of light in vision Blurred vision Cobweb across vision The appearance of a dark curtain descending down vision (means that there is also retinal detachment)

Question 46

Signs of posterior vitreous detachment

Answer 46

Weiss ring on ophthalmoscopy (the detachment of the vitreous membrane around the optic nerve to form a ring-shaped floater).

Question 47

IX for suspected vitreous detachment

Answer 47

All patients with suspected vitreous detachment should be examined by an ophthalmologist within 24hours to rule out retinal tears or detachment.

Question 48

Mx of posterior vitreous detachment

Answer 48

Posterior vitreous detachment alone does not cause any permanent loss of vision. Symptoms gradually improve over a period of around 6 months and therefore no treatment is necessary. If there is an associated retinal tear or detachment the patient will require surgery to fix this.

Question 49

What is retinal detachment

Answer 49

Retinal detachment occurs when the neurosensory tissue that lines the back of the eye comes away from its underlying pigment epithelium. It is a reversible cause of visual loss, provided it is recognised and treated before the macula is affected.

Question 50

Risk factors for retinal detachment

Answer 50

Age Previous surgery for cataracts (accelerates posterior vitreous detachment) Myopia Eye trauma (consider boxing) Family history Previous history of retinal break/detachment in either eye

Question 51

Symptoms of retinal detachment

Answer 51

New onset floaters or flashes, as these indicate pigment cells entering the vitreous space or traction on the retina respectively. Sudden onset, painless and progressive visual field loss, described as a curtain or shadow progressing to the centre of the visual field from the periphery should also raise suspicion of detachment. If the macula is involved, central visual acuity and visual outcomes become much worse.

Question 52

Examination findings in retinal detachment

Answer 52

Peripheral visual fields may be reduced, and central acuity may be reduced to hand movements if the macula is detached. Relative afferent pupillary defect if the optic nerve is involved. On fundoscopy, the red reflex is lost and retinal folds may appear as pale, opaque or wrinkled forms. If the break is small, however, it may appear normal.

Question 53

Management of retinal tears

Answer 53

Management of retinal tears aims to create adhesions between the retina and the choroid to prevent detachment. This can be done using: Laser therapy Cryotherapy

Question 54

Surgical options for retinal detachment

Answer 54

Vitrectomy involves removing the relevant parts of the vitreous body and replacing it with oil or gas. Scleral buckling involves using a silicone “buckle” to put pressure on the outside of the eye (the sclera) so that the outer eye indents to bring the choroid inwards and into contact with the detached retina. Pneumatic retinopexy involves injecting a gas bubble into the vitreous body and positioning the patient so the gas bubble creates pressure that flattens the retina against the choroid and close the detachment.

Question 55

What is anterior uveitis

Answer 55

inflammation in the anterior part of the uvea. The uvea involves the iris, ciliary body and choroid

Question 56

Conditions associated with acute anterior uveitis

Answer 56

HLA B27 related conditions: Ankylosing spondylitis Inflammatory bowel disease Reactive arthritis

Question 57

Conditions associated with chronic anterior uveitis

Answer 57

``` Sarcoidosis Syphilis Lyme disease Tuberculosis Herpes virus ```

Question 58

Acute anterior uveitis presentation

Answer 58

``` Unilateral Dull,aching,painful red eye Ciliary flush Miosis Photophobia Floaters and flashes ```

Question 59

Tear production acute anterior uveitis

Answer 59

Increased

Question 60

What is a hypoyon

Answer 60

Collection of white blood cells in the anterior chamber, seen as a yellowish fluid collection settled in front of the lower iris, with a fluid level. seen in acute anterior uveitis

Question 61

Mx of acute anterior uveitis

Answer 61

Steroids Cylopegic-mydriatic meds(atropine) Immunsuppressants(DMARDS) Laser therapy

Question 62

Conditions associated with episcleritis

Answer 62

Rheumatoid arthritis | IBD

Question 63

Presentation of episcleritis

Answer 63

``` Mild pain(no pain typically) Segmental redness(patch) Foreign body sensation Dilated episcleral vessels Watering of eye ```

Question 64

Mx of episcleritis

Answer 64

Self-limiting - recovery in 1-4 weeks Lubricating eye drops Analgesia Cold compress

Question 65

Complications of scleritis

Answer 65

Necrotising scleritis | Perforation of sclera

Question 66

Systemic conditions associated with scleritis

Answer 66

RA SLE IBD Sarcoidosis

Question 67

Presentation of scleritis

Answer 67

``` Severe pain Pain with eye movement Photophobia Eye watering Reduced visual acuity Abnormal pupil reaction to light ```

Question 68

Mx of scleritis

Answer 68

Same day assessment by ophthalmologist Consider underlying systemic condition NSAIDS Steroids Immunosuppression

Question 69

What is keratitis

Answer 69

Inflammation of the cornea

Question 70

Most common cause of keratitis

Answer 70

Herpes simplex infection

Question 71

Other causes of keratitis

Answer 71

Bacterial infection - pseudomonas or staph Fungal - Candida Contact lens acute red eye(CLARE)

Question 72

Complications of herpes keratitis

Answer 72

Can lead to stromal keratitis(inflammation of layer between epithelium and endothelium) --> stromal necrosis, vascularisation and scarring and can lead to corneal blindness

Question 73

Presentation of herpes keratitis

Answer 73

``` Painful red eye Photophobia Vesicles around the eye Foreign body sensation Watering eye Reduced visual acuity ```

Question 74

Diagnosis of herpes keratitis

Answer 74

Staining with fluorescein will show a dendritic corneal ulcer Slit-lamp examination Corneal swabs/scrapings

Question 75

Mx of herpes keratitis

Answer 75

Aciclovir (topical or oral) Ganciclovir eye gel Topical steroids may be used alongside antivirals to treat stromal keratitis Corneal transplant if scarring caused by stromal keratitis