Ophthalmology

Question 1

Causes of painless loss of vision

Answer 1

ischaemic/vascular (e.g. thrombosis, embolism, temporal arteritis etc). This includes recognised syndromes e.g. occlusion of central retinal vein and occlusion of central retinal artery
vitreous haemorrhage
retinal detachment
retinal migraine

Question 2

ischaemic/vascular causes of painless loss of vision

Answer 2

often referred to as ‘amaurosis fugax’
wide differential including large artery disease (atherothrombosis, embolus, dissection), small artery occlusive disease (anterior ischemic optic neuropathy, vasculitis e.g. temporal arteritis), venous disease and hypoperfusion
may represent a form of transient ischaemic attack (TIA). It should therefore be treated in a similar fashion, with aspirin 300mg being given
altitudinal field defects are often seen: ‘curtain coming down’
ischaemic optic neuropathy is due to occlusion of the short posterior ciliary arteries, causing damage to the optic nerve

Question 3

Central retinal vein occlusion

Answer 3

incidence increases with age, more common than arterial occlusion
causes: glaucoma, polycythaemia, hypertension
severe retinal haemorrhages are usually seen on fundoscopy

Question 4

Central retinal artery occlusion

Answer 4

due to thromboembolism (from atherosclerosis) or arteritis (e.g. temporal arteritis)
features include afferent pupillary defect, ‘cherry red’ spot on a pale retina

Question 5

vitreous haemorrhage

Answer 5

causes: diabetes, bleeding disorders, anticoagulants

features may include sudden visual loss, dark spot

Question 6

retinal detachment

Answer 6

features of vitreous detachment, which may precede retinal detachment, include flashes of light or floaters

Question 7

Posterior vitreous detachment

Answer 7

Flashes of light (photopsia) - in the peripheral field of vision
Floaters, often on the temporal side of the central vision

Question 8

Retinal Detachment

Answer 8

Dense shadow that starts peripherally progresses towards the central vision
A veil or curtain over the field of vision
Straight lines appear curved
Central visual loss

Question 9

Vitreous Haemorrhage

Answer 9

Large bleeds cause sudden visual loss
Moderate bleeds may be described as numerous dark spots
Small bleeds may cause floaters

Question 10

Rheumatoid arthritis: ocular presentations

ocular manifestations

Answer 10

keratoconjunctivitis sicca (most common)
episcleritis (erythema)
scleritis (erythema and pain)
corneal ulceration
keratitis

Question 11

Rheumatoid arthritis: ocular presentations

Iatrogenic

Answer 11

steroid-induced cataracts

chloroquine retinopathy

Question 12

What is Retinitis pigmentosa?

Answer 12

Retinitis pigmentosa primarily affects the peripheral retina resulting in tunnel vision

Question 13

Features of retinitis pigmentosa

Answer 13

night blindness is often the initial sign
tunnel vision due to loss of the peripheral retina (occasionally referred to as funnel vision)
fundoscopy: black bone spicule-shaped pigmentation in the peripheral retina, mottling of the retinal pigment epithelium

Question 14

Conditions associated with retinitis pigmentosa

Answer 14

Refsum disease: cerebellar ataxia, peripheral neuropathy, deafness, ichthyosis
Usher syndrome
abetalipoproteinemia
Lawrence-Moon-Biedl syndrome
Kearns-Sayre syndrome
Alport's syndrome

Question 15

Pilocarpine - what is it

Answer 15

muscarinic receptor agonist - increases uveoscleral outflow

adverse effects - constricted pupil, headache and blurred vision.

Question 16

What is glaucoma

Answer 16

optic neuropathies associated with raised intraocular pressure (IOP). They can be classified based on whether the peripheral iris is covering the trabecular meshwork, which is important in the drainage of aqueous humour from the anterior chamber of the eye. In open-angle glaucoma, the iris is clear of the meshwork. The trabecular network functionally offers an increased resistance to aqueous outflow, causing increased IOP.

Question 17

Open angle glaucoma

Symptoms

Answer 17

characterised by a slow rise in intraocular pressure: symptomless for a long period
typically present following an ocular pressure measurement during a routine examination by an optometrist

Question 18

Open angle glaucoma

Signs

Answer 18

increased intraocular pressure
visual field defect
pathological cupping of the optic disc1

Question 19

Open angle glaucoma

Case finding

Answer 19

optic nerve head damage visible under the slit lamp
visual field defect
IOP > 24 mmHg as measured by Goldmann-type applanation tonometry
if suspected full investigations are performed

Question 20

investigations for open angle glaucoma

Answer 20

automated perimetry to assess visual field
slit lamp examination with pupil dilatation to assess optic neve and fundus for a baseline
applanation tonometry to measure IOP
central corneal thickness measurement
gonioscopy to assess peripheral anterior chamber configuration and depth
Assess risk of future visual impairment, using risk factors such as IOP, central corneal thickness (CCT), family history, life expectancy

Question 21

management of open angle glaucoma

Answer 21

first line: prostaglandin analogue (PGA) eyedrop
second line: beta-blocker, carbonic anhydrase inhibitor, or sympathomimetic eyedrop
if more advanced: surgery or laser treatment can be tried2

Question 22

Prostaglandin analogues (e.g. latanoprost)

Answer 22

Increases uveoscleral outflow Once daily administration

Adverse effects include brown pigmentation of the iris, increased eyelash length

Question 23

Beta-blockers (e.g. timolol, betaxolol)

Answer 23

Reduces aqueous production Should be avoided in asthmatics and patients with heart block

Question 24

Sympathomimetics (e.g. brimonidine, an alpha2-adrenoceptor agonist)

Answer 24

Reduces aqueous production and increases outflow Avoid if taking MAOI or tricyclic antidepressants

Adverse effects include hyperaemia

Question 25

Carbonic anhydrase inhibitors (e.g. Dorzolamide)

Answer 25

Reduces aqueous production Systemic absorption may cause sulphonamide-like reactions

Question 26

Herpes simplex keratitis Features

Answer 26

``` red, painful eye photophobia epiphora visual acuity may be decreased fluorescein staining may show an epithelial ulcer- dendritic corneal ulcer ```

Question 27

herpes simplex keratitis management

Answer 27

immediate referral to an ophthalmologist | topical aciclovir

Question 28

What is Argyll-Robertson Pupil

Answer 28

Argyll-Robertson pupil is one of the classic pupillary syndrome. It is sometimes seen in neurosyphilis. A mnemonic used for the Argyll-Robertson Pupil (ARP) is Accommodation Reflex Present (ARP) but Pupillary Reflex Absent (PRA)

Question 29

Features of Argyll-Roberston Pupil

Answer 29

small, irregular pupils | no response to light but there is a response to accommodate

Question 30

Causes of Argyll-Robertson pupil

Answer 30

diabetes mellitus | syphilis

Question 31

Herpes zoster ophthalmicus

Answer 31

Herpes zoster ophthalmicus (HZO) describes the reactivation of the varicella-zoster virus in the area supplied by the ophthalmic division of the trigeminal nerve. It accounts for around 10% of case of shingles.

Question 32

Features of herpes zoster ophthalmicus

Answer 32

vesicular rash around the eye, which may or may not involve the actual eye itself Hutchinson's sign: rash on the tip or side of the nose. Indicates nasociliary involvement and is a strong risk factor for ocular involvement

Question 33

Management of herpes zoster ophthalmicus

Answer 33

oral antiviral treatment for 7-10 days ideally started within 72 hours intravenous antivirals may be given for very severe infection or if the patient is immunocompromised topical antiviral treatment is not given in HZO topical corticosteroids may be used to treat any secondary inflammation of the eye ocular involvement requires urgent ophthalmology review

Question 34

Complications of herpes zoster opthalmicus

Answer 34

ocular: conjunctivitis, keratitis, episcleritis, anterior uveitis ptosis post-herpetic neuralgia

Question 35

Holmes Adie pupil - what is it

Answer 35

pupil is a benign condition most commonly seen in women. It is one of the differentials of a dilated pupil.

Question 36

Holmes-Adie pupil overview

Answer 36

unilateral in 80% of cases dilated pupil once the pupil has constricted it remains small for an abnormally long time slowly reactive to accommodation but very poorly (if at all) to light

Question 37

Homes-Adie syndrome

Answer 37

association of Holmes-Adie pupil with absent ankle/knee reflexes

Question 38

typical history of scleritis

Answer 38

a woman with a history of rheumatoid arthritis presents with severe, constant pain in her right eye. On examination the right eye is red and there is a degree of photophobia. Visual acuity is normal

Question 39

Fundoscopy findings in retinitis pigmentosa

Answer 39

Black bone spicule- shaped pigmentation in the peripheral retina

Question 40

Retinal detachment

Answer 40

Painless loss of vision | Dense shadow moving from periphery to central

Question 41

Bevacizumab

Answer 41

Monoclonal antibody against vascular endothelial growth factor Used in treatment of age related macular degeneration

Question 42

Fluocinolone

Answer 42

orticosteroid used via intraocular injection in some eye conditions as an anti-inflammatory. Corticosteroids are used in conditions such as diabetic macular oedema, vasculo-occlusive macular oedema, posterior uveitis

Question 43

Laser photocoagulation

Answer 43

used in the management of several eye conditions, normally to finely cauterise ocular blood vessels Mainly used in diabetic retinopathy

Question 44

Verteporfin

Answer 44

photosensitiser prior to photodynamic therapy. Verteporfin can be used in eye conditions with ocular vessel proliferation where it accumulates in the abnormal vessels. When exposed to a specific red light wavelength in phototherapy there is a resulting local damage to these vessels endothelium, blocking and destroying them.

Question 45

Zinc supplementation

Answer 45

slow the progression of AMD however it has not been associated with an anti-VEGF effect and is instead thought to work by increasing autophagy, the orderly degradation and recycling of cellular components, something that is decreased in AMD.

Question 46

Marcus Gunn pupil (relative afferent pupillary defect)

Answer 46

diagnosed during the swinging light test. If there is damage to the afferent pathway (retina or optic nerve) of one eye, the pupil of that affected eye will abnormally dilate when a light is shone into it. This is because the consensual pupillary relaxation response from the healthy eye will dominate. Marcus Gunn pupil can be found in patients with multiple sclerosis

Question 47

Causes of tunnel vision

Answer 47

``` papilloedema glaucoma retinitis pigmentosa choroidoretinitis optic atrophy secondary to tabes dorsalis hysteria ```

Question 48

Acute closed angle glaucoma

Answer 48

ise in IOP secondary to an impairment of aqueous outflow. Factors predisposing to AACG include: hypermetropia (long-sightedness) pupillary dilatation lens growth associated with age

Question 49

Features of Acute closed angle glaucoma

Answer 49

severe pain: may be ocular or headache decreased visual acuity symptoms worse with mydriasis (e.g. watching TV in a dark room) hard, red-eye haloes around lights semi-dilated non-reacting pupil corneal oedema results in dull or hazy cornea systemic upset may be seen, such as nausea and vomiting and even abdominal pain

Question 50

Acute management of acute closed angle glaucoma

Answer 50

combination of eye drops, for example: a direct parasympathomimetic (e.g. pilocarpine, causes contraction of the ciliary muscle → opening the trabecular meshwork → increased outflow of the aqueous humour) a beta-blocker (e.g. timolol, decreases aqueous humour production) an alpha-2 agonist (e.g. apraclonidine, dual mechanism, decreasing aqueous humour production and increasing uveoscleral outflow) intravenous acetazolamide reduces aqueous secretio

Question 51

Definitive management of acute closed angle glaucoma

Answer 51

laser peripheral iridotomy | creates a tiny hole in the peripheral iris → aqueous humour flowing to the angle

Question 52

Cause of primary open angle glaucoma

Answer 52

gradual rise in intraocular pressure in the eyes due to reduced drainage within the trabecular meshwork of the eye. This presents as a gradual vision loss. Examination findings include increased cupping and raised intraocular pressure on examination.

Question 53

1st line treatment of primary open-angle glaucoma

Answer 53

β-blockers (timolol), prostaglandin analogues (latanoprost), carbonic anhydrase inhibitors (brinzolamide) and alpha-2-agonist (brimonidine)

Question 54

Mechanism of action: B- Blockers (timolol)

Answer 54

reducing the aqueous humour production of the eye.

Question 55

Mechanism of action Carbonic anhydrase inhibitors (acetazolamide/dorzolamide/brinzolamide)

Answer 55

Reduce aqueous humour production

Question 56

Mechanism of action: Prostaglandin analogues (latanoprost)

Answer 56

acts by increasing the uveoscleral outflow

Question 57

Mechanism of action: Alpha-2-agonists ( brimonidine)

Answer 57

improves symptoms by having a dual action (reducing humour production and increased outflow).

Question 58

Conditions associated with retinitis pigmentosa

Answer 58

``` Refsum disease: cerebellar ataxia, peripheral neuropathy, deafness, ichthyosis Usher syndrome abetalipoproteinemia Lawrence-Moon-Biedl syndrome Kearns-Sayre syndrome Alport's syndrome ```

Question 59

Causes of mydriatic (dilated) pupil

Answer 59

``` third nerve palsy Holmes-Adie pupil traumatic iridoplegia phaeochromocytoma congenital ```

Question 60

Argyll-Roberts Pupil

Answer 60

Typically the pupil accommodates but doesn't react. A mnemonic used for the Argyll-Robertson Pupil (ARP) is Accommodation Reflex Present (ARP) but Pupillary Reflex Absent (PRA) Features small, irregular pupils no response to light but there is a response to accommodate Causes diabetes mellitus syphilis

Question 61

Enophthalmus

Answer 61

the posterior displacement of the globe in an anteroposterior plane within the orbit.

Question 62

anisocoria

Answer 62

unequal pupil size.

Question 63

Horner's syndrome - anhydrosis (determines site of lesion)

Answer 63

head, arm, chest - central: stoke or syringomelia Just face- pre-ganglionic lesion- Pancoast, cervical rib Absent anhydrosis - carotid artery dissection