acute angle closure glaucoma Flashcards
what is glaucoma
a group of disorders characterised by optic neuropathy duet to raised intraocular pressure (in most patients)
what causes a rise in intra ocular pressure in acute angle closure glaucoma
rise in intra ocular pressure secondary to impairement of aqueous outflow
what are the 3 factors predisposing to AACG
- hypermetropia (long-sightedness)
- pupillary dilatation
- lens growth associated with age
what are the features of AACG
severe pain - ocular or headache
decreased visual acuity
hard, red eye
haloes around lights
semi-dilated non- reacting pupil
corneal oedema results in dull or hazy cornea
systemic upset may be seen - nausea and vomiting even abdominal pain
mydriasis (dilated pupils that do not respond to change in light)
what are systemic features of AACG that can be seen
nausea vomiting
abdominal pain
how is AACG managed?
- emergency. requires prompt urgent referral to opthalmologist
- emergency treatment required to reduce intra ocular pressure acutely before definitive surgery
- definitive management = laser peripheral iridotomy - creating a tiny hole in peripheral iris
give an example regime for managing AACG
- combination of eye drops = direct parasympathomimetic, beta blocker, a2 agonist
- iv acetazolamide
- definitive surgery = laser peripheral iridotomy
give example of a direct parasympathomimetic and its mode of action
pilocarpine = causes contraction of the ciliary muscle = opening of trabecular meshwork and increases outflow of the aqueous humour
give example of a beta blocker used in AACG and its mode of action
timolol
decreases aqueous humour production
give example of a alpha -2 agonist and its mode of action in AACG
APRACLONIDINE
dual action
acts to decrease aqueous humour production and increases uvesceral outflow
describe the action of intravenous acetazolamide in treating AACG
reduced aqueous secretions
