Ophthalmology Flashcards
What are risk factors for age-related macular degeneration?
- Advancing age
- Smoking
- Family history
- CVD - hypertension, dyslipidaemia, diabetes mellitus
What are the two forms of age-related macular degeneration
Dry:
* 90% of cases
* also known as atrophic
* characterised by drusen - yellow round spots in Bruch’s membrane
* Treat with zinc + vitamin A,C,E
Wet:
* 10% of cases + worst prognosis
* also known as exudative or neovascular macular degeneration
* characterised by choroidal neovascularisation
* leakage of serous fluid and blood can subsequently result in a rapid loss of vision (red patches on fundoscopy)
* carries the worst prognosis
* Stabilise with anti-VEGF
What is the mangement of primary open angle glaucoma?
- Offer 360° selective laser trabeculoplasty (SLT) first-line to people with an IOP of ≥ 24 mmHg
- Prostaglandin analogue (PGA) eyedrops should be used next-line
What are the features of central retinal artery occlusion?
- Sudden, painless unilateral visual loss
- Relative afferent pupillary defect
- ‘cherry red’ spot on a pale retina - rest of retina is pale due to restricted blood flow
It is caused by thromboembolism (from atherosclerosis) or arteritis (e.g. temporal arteritis)
What are the differences seen on fundosocpy of central retinal artery vs vein occlusion?
CRAO: cherry red’ spot on a pale retina
CRVO: widespread hyperaemia + severe retinal haemorrhages - ‘stormy sunset’
What are the features of scleritis?
- red eye
- classically painful (in comparison to episcleritis), but sometimes only mild pain/discomfort is present
- watering and photophobia are common
- gradual decrease in vision
What are risk factors for scleritis?
- rheumatoid arthritis: the most commonly associated condition
- systemic lupus erythematosus
- sarcoidosis
- granulomatosis with polyangiitis
What is the management of scleritis?
- Same-day opthalmologist assessment
- oral NSAIDs are typically used first-line
- oral glucocorticoids may be used for more severe presentations
- immunosuppressive drugs for resistant cases (and also to treat any underlying associated diseases)
How does episcleritis differ from scleritis?
- Classically not painful, but can be irritating
- In episcleritis, the injected vessels are mobile when gentle pressure is applied on the sclera. In scleritis, vessels are deeper, hence do not move
- Phenylephrine drops may be used to differentiate between episcleritis and scleritis. Phenylephrine blanches the conjunctival and episcleral vessels but not the scleral vessels
- Management: convervative + artificial tears
What are features of acute angle-closure glaucoma?
- 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
What is the management of acute angle-closure glaucoma?
- Emergency ophthalmologist review
- Eye drops to include: a direct parasympathomimetic, beta-blocker and alpha-2 agonist
- Intravenous acetazolamide (reduce aqueous secretions)
- Definitive: laser peripheral iridotomy
What is the presentation of herpes simplex keratitis?
- red, painful eye
- photophobia
- epiphora
- visual acuity may be decreased
- fluorescein staining may show an epithelial ulcer
Treat with topical aciclovir
What is the mechanism of action of pilocarpine?
Pilocarpine is a direct parasympathomimetic
Contraction of the ciliary muscle → opening the trabecular meshwork → increased outflow of the aqueous humour
What is the mechanism of action of timolol?
Timolol is a beta blocker
It decreases aqueous humour production
What is the mechanism of action of apraclonidine?
Apraclonidine is an alpha-2 agonist
It has a dual mechanism: decreasing aqueous humour production and increasing uveoscleral outflow