Glaucoma Flashcards
what is the pathophysiology behind glaucoma
abnormally raised pressure in the eye
what is pressure in the eye related to
the amount of vitreous fluid and anterior chamber aqueous humour
how does fluid normally drain out of the eye
through the trabecular meshwork into the Canal of Schlemm in the anterior eye
when does glaucoma occur
when there is a blockage in the drainage through the Canal of Schlemm or the trabecular meshwork
what parts of the eye are at most risk of damage in glaucoma
optic disc and optic nerve
what is the most common type of glaucoma and what is the mechanism behind it
primary open angle glaucoma, due to poor drainage through the trabecular meshwork
(most common cause of blindness in world)
describe the mechanism behind angle closure glaucoma
trabecular meshwork is patent and working fine, but increased pressure causes iris bows forward obstructing trabecular meshwork, increasing pressure further
describe the onset of primary open angle glaucoma
slow gradual onset, often asymptomatic
describe how raised intraocular pressure can be observed on the optic disc
can observe “cupping” of the disc, the edges of the disc become rolled up and centre become depressed
what is papilloedema
swelling of the optic disc/nerve, relating the intracranial pressure
what are the symptoms associated with closed angle glaucoma
painful, red eye, sudden visual loss, headache, nausea, vomiting
what signs are associated with closed angle glaucoma
red eye, cloudy cornea, dilated pupil
what signs are associated with open angle glaucoma
cupped disc(ie loss of retinal ganglions), visual field defect, possibly raised IOP
what does glaucoma ultimately result in
optic nerve damage, and therefore visual loss
what type of glaucoma causes gradual and what type causes sudden visual loss
gradual = open angle sudden = closed angle
