Opthalmology

Question 1

Treatment for allergic conjunctivits

Answer 1

Lubricating drops
Oral antihistamines (for hayfever, not very helpful for conjunctivitis)
topical mast cell stabilisers (allerfix, cromal)

Question 2

What is this and how does it present

Answer 2

Retinitis pigmentosa
tunnel vision, loss of night vision, peripheral black spots on fundoscopy

Question 3

The commonest cause for of progressive vision loss and how does it present

Answer 3

AMD - Age related Macular Degeneration
Dry (90% of cases, drusen) or wet (abnormal neovascularisation)

blurred central vision, staight lines become wavy, central scotoma
Age biggest RF, FHx, smoking
Tx: nil, vitamin supplementation may slow progression

Question 4

Corneal ulcer vs abrasion

(Risk factors?)

Answer 4

Corneal Abrasion: a superficial scratch or scrape on the cornea

Corneal Ulcer: a deeper open sore or erosion on the cornea, often due to an infection or severe injury

RFs:
contact lens use
vitamin A deficiency: a particular problem in the developing world

Question 5

presentation of corneal ulcer

Answer 5

eye pain
photophobia
watering of the eye
focal fluorescein staining of the cornea

Question 6

Potential causes for painless sudden loss of vision

Answer 6

• ‘amaurosis fugax’
• central retinal vein occlusion
• central retinal artery occlusion
• vitreous haemorrhage
• retinal detachment
• retinal migraine

Field defects: think stroke/TIA, migraine, brain lesion

Question 7

What is PVD and how does it cause flashers/floaters

Answer 7

**Posterior vitrious detatchment*

Due to ageing and thickening of the vitreous, which eventually pulls away/detatches (flashes). Also has condensations of collagen, which float in front of the retina, casting a shadow (floaters).

In some cases PVD will be complicated by a retinal tear, and about 50% of retinal tears will then progress to retinal detachment.

diabetic retinopathy can also cause floater from viterous haemmorhages

Question 8

How does retinal tear vs a retinal detachment present

Answer 8

Retinal Tear: May have minimal symptoms. Symptoms include sudden appearance of floaters, flashes, and reduced vision.

Retinal detatchment: significant flasher/floaters, then dark curtain that starts peripherally progresses towards the central vision, Straight lines appear curved, Central visual loss

Question 9

Stye vs chalazion

Answer 9

Stye (hordeolum): bacterial infection of an oil gland in the eyelid. Painful

Chalazion: cyst formed from a blocked oil gland in the eyelid. Not painful

Question 10

Difference between conjunctivits, episcleritis, Scleritis, keratitis, anterior uveitis and acute-angle glaucoma

Answer 10

Conjunctivitis: diffuse redness, mild pain, +/- purulent discharge (if bacterial), no vision changes

Episcleritis: Localised/segmental redness, mild pain, no visual changes, associated with systemic diseases.

Scleritis (sclera proper): Diffuse redness, severe boring pain, no pupil change, often associated with systemic diseases.

Keratitis (cornea): redness, gritty sensation, painful, photophobia, reduced vision, ciliary flush, corneal haze, often associated with contact lenses, hypopyon may be present, fluoroscein uptake if an ulcer

Anterior uveitis: Red eye, pain, photophobia, ciliary flush, irregular or small pupil

Acute angle glaucoma: red eye, severe pain/headache, halos in vision, marked vision loss, cloudy cornea, fixed dilated pupil, raised IOP

Question 11

treatment of keratitis (corneal infection/ulcer)

Answer 11

Remove contact lens
Refer to opthalmology
do not start antibiotics ( antivirals if HZO) as needs a culture/ulcer scraping first
cycloplegic for pain relief e.g. cyclopentolate

Question 12

What is HZO and how do we treat it

Answer 12

VZV reactivation in the opthalmic nerve (CN5 V1) with Rash and skin eruption in the V1 dermatome, usually spreads up into the hair line.
Vesicles on the tip of the nose (hutchisons sign) indicates involvement of the nasociliary branch and a higher risk of severe ocular disease.

Refer to opthalmology
Oral antivirals

Question 13

Treatment of acute angle glaucoma

Answer 13

Analgesia
acetazolamide or mannitol
eye drops such as timolol or pilocarpine nitrate

definitive tx: laser peripheral iridotomy

Question 14

Open angle glaucoma symptoms

Answer 14

OAG has no symptoms until it is very advanced, causing irreversible loss of vision.

• peripheral visual field loss
• decreased visual acuity
• optic disc cupping

Question 15

What is this and how would it present

Answer 15

Central retinal artery occlusion
Due to thromboembolism (from atherosclerosis) or arteritis (e.g. temporal arteritis)

• Sudden painless loss of vision
• RAPD
• cherry red spot on pale retinal

Question 16

How would a retinal vein occlusion present

Answer 16

Subacute painless vision loss
Linked with age and HTN
fundoscopy: severe retinal haemorrhages - ‘stormy sunset’

Question 17

What can cause flashers/floaters

Answer 17

Posterior Vitreous Detachment (PVD): This occurs when the vitreous pulls away from the retina, often causing floaters and flashes. It’s more common in people over 50.

Retinal Detachment or Tears:

Uveitis: Inflammation inside the eye can lead to floaters.

Hemorrhage: Bleeding in the eye, often due to injury or conditions like diabetic retinopathy, can cause floaters.

Eye Surgery or Trauma: Previous eye surgeries or injuries can sometimes lead to floaters or flashes.

Migraines:

Question 18

what is optic neuritis and what diseases is it associated with

Answer 18

inflammation of the optic nerve causing pain, vision loss and colour vision loss, RAPD and central scotoma

Associated with
Multiple sclerosis
Diabetes
Syphillus

Question 19

Investigation and management of optic neuritis

Answer 19

Ix: MRI
Tx: high dose steroids

Question 20

What is amaurosis fugax

Answer 20

Amaurosis fugax is a temporary loss of vision in one or both eyes due to a lack of blood flow to the retina, often described as a “curtain” coming down over the eye.
It typically lasts for a few seconds to several minutes and is usually a warning sign of a more serious underlying condition, such as a transient ischemic attack (TIA), carotid artery disease, or other vascular disorders.

It should be treated as a TIA /stroke with aspirin loading and referral

Question 21

causes for a bitemporal hemianopia

Answer 21

damage or compression to the optic chiasm, most common cause being a pituitary adenoma

Question 22

most common bug associated with contact lens related keratitis

Answer 22

Pseudomonas aeruginosa >60%

Staph aureus accounts for oppurtunisitc infections

Question 23

6th nerve palsy - presentation

Answer 23

Inward eye (esotropia)
horizontal diplopia

LR6SO4 everything else 3

Question 24

4th nerve palsy - presentation

Answer 24

Slightly up & out

vertical diplopia and vertical tilts

LR6SO4 everything else 3

Question 25

3rd nerve plasy - presentation

Answer 25

ptosis, mydriosis, down and out

LR6SO4 everything else 3

Question 26

Horners syndrome - presentation and cause

Answer 26

ptosis, miosis (small pupil) and anhydrosis

Due to compression of sympathetic nerves
Often from pancoast tumour (can also compress recurrent laryngeal and brachial plexus)

Question 27

why do we worry about a 3rd nerve palsy

Answer 27

often a sign of posterior communicating artery aneurysm (emergency)
can also be from brain herniation, tumours, inflammation

Question 28

normal IOP

Answer 28

10 to 21 mmHg

~15

Question 29

features of open angle glaucoma on slit lamp

Answer 29

An increased cup-to-disk ratio (vertical ratio 0.6 or more)
Thinning and/or notching of the neuroretinal rim
Flame-shaped disk haemorrhage

Question 30

treatment of open angle glaucoma

Answer 30

aimed at decreasing IOP (even though 1/3 of glaucoma pts have a IOP <21mmHg)

first line: topical prostaglandins latanoprost
second line: topical beta-blockers, timolol

*topical BB should not be used in HF, w other BB or in asthma