Ophthalmology

Question 1

What is the mode of action of pilocarpine?

Answer 1

Muscarinic receptor agonist.

It increases uveoscleral outflow by constricting the pupil.
- Causes contraction of the ciliary muscle → opening the trabecular meshwork → increased outflow of the aqueous humour

Question 2

Most common ocular manifestations of RA?

Answer 2

• Keratoconjunctivitis sicca (most common)
• Episcleritis (erythema, no pain)
• Scleritis (erythema and pain)
• Corneal ulceration
• Keratitis

Question 3

Treatment for herpes zoster ophthalmicus?

Answer 3

Oral aciclovir 7 - 10 days.

Question 4

What is Hutchinson’s sign in herpes zoster ophthalmicus?

Answer 4

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 5

Features of optic neuritis?

Answer 5

1. Unilateral decrease in visual acuity over hours or days.
2. Poor discrimination of colours, ‘red desaturation’.
3. Pain worse on eye movement.
4. Relative afferent pupillary defect.
5. Central scotoma.

Question 6

Mode of action of Timolol?

Answer 6

Beta blockers such as timolol work in primary open-angle glaucoma by reducing aqueous production.

Question 7

Feature of central retinal vein occlusion?

Answer 7

Presents as sudden, painless reduction or loss of visual acuity, usually unilaterally.

Fundoscopy:
- Widespread hyperaemia
- Retinal Haemorrhages - ‘stormy sunset’

Question 8

Feature of central retinal artery occlusion?

Answer 8

This is usually due to a thromboembolic occlusion.

It would present as a sudden painless loss of vision.

Fundoscopy would show a pale retina with a cherry-red spot at the macula.

Question 9

First line pharmacological treatment for primary open angle glaucoma?

Answer 9

Prostaglandin analogues such as Latanoprost are first-line treatments for open-angle glaucoma.

Latanoprost is a prostaglandin analogue and it works by increasing the outflow of aqueous humour from the eye, thereby reducing intraocular pressure.