Glaucoma Flashcards
what is the function of the aqueous humour?
- Nutrition
- Transport of waste products
- thermoregulation
- buffering
Explain the drainage of the aqeous humour
It collects from the posterior chamber into the anterior chamber. Then travels from the trabecular meshwork, into the sinus venosus sclerae and into the episcleral veins
What are the 3 types of glaucoma?
- Acute angle closure glaucoma
- Developmental glaucoma
- Chronic open angle glaucoma
The norma pressure in the eye is?
10-20 mmHG
What are the different ways to measure intraocular pressure?
- Digital examination with index fingers
- Schiotz tonometry which is good for GP
- Goldmann applanation tonometer
- Tono-pen
- Non-contact tonometers which is a puff tonometer
To what pressure does primary acute angle closure get up to in hours?
60-100mmHG
What causes the intense pain in acute angle closure glaucoma?
The ocular ischaemia and thecorneal odeoma
What are 4 symptoms of acute angle closure closure?
- Red eye
- Deep seated, intense pain that radiates ipsilaterally, nausea and vomiting
- Halos around lights
- Decreased visual acuity-corneal oedema and ocular ischaemia
What are the signs of primary acute angle closure glaucoma?
- Positive eclipse test
- Ciliary injection
- Rock hard globe on palpation
- Mid-dilated pupil, fixed pupil
What is emergency treatment of primary acute angle closure glaucoma?
- Acetazolamide 500mg stat IV or IM
- Glycerol 1ml/kg stat orally-draws water out of the eye
- Topical B-blocker 1 drop half-hourly for not more than 2 hours
- Pilocarpine 1 drop every 15 minutes for 2 hours\
- Systemic analgesia and emetic
What is the definitive surgical treatment of glaucoma?
prophylactic surgical iridectomy
What are the ocular abnormalities associated with secondary acute angle closure glaucoma?
- anterior uveitis
- advanced cataract
- lens subluxation and dislocation
- drugs: miotics
What is the most common type of glaucoma?
chronica open angle glaucoma
What are the high risk groups for open angle glaucoma?
Older than 50 and African decsent
What are the signs of open angle glaucoma?
- Decreased VA
- Loss of visual field
- Optic disc changes
- The colour becomes pale
- the cup is large C/D>0.6, vertically oval amd has an undermined edge, laminar dots are present
- The blodd vessels are nasally displaced
- Border: nerve fibre layer haemmorhage
What is the treatment of primary open angle glaucoma?
- Topical B-Blockers-reduces aqeuous secretion
- Topical prostagladin analogues-increases aqeous outflow
- Topical adrenaline preparations-increases aqeous outflow
- Topical pilocarpine-increases aquous outflow
Developmental glaucoma definition?
Development of the drainage angle known as trabeculodysgenesis-sporadic mutation associated with congenital rubella
The age that glaucoma develops depends on when the symptoms:
- congenital
- infantile
- juvenile
What are the 3 signs of developmental glaucoma in children?
- Tearing
- Photophobia
- Blephorospasm
What is megacornea and buphthalmos?
It is an enlarged globe and only happens in babies as a result of increased intra-ocular pressure
What is secondary acute angle closure glaucoma?
It is the abnormalities that reduce aqeous outflow despite an open angle
What are the causes of secondary open angle glaucoma?
- Trabeculitis
- drugs-steroids
- clogging of the trabeculum(white cells in uveitis/red cells in hyphaema)
