Glaucoma Flashcards
define
progressive optic neuropathy (damage to optic nerve)
causes
unknown
associated with high intraocular pressure (IOP)
two types
- closed angle
2. open angle
define closed angle
angle between the iris and cornea is blocked as the iris has been pushed forward due to build-up of fluid
why is closed angle an emergency?
pressure must be reduced to avoid blindness
presentation of closed angle
red eye
sudden visual loss (haloes around lights)
headache
nausea and vomiting due to extreme pain
signs of closed angle
cloudy cornea (high pressure drives fluid into cornea) dilation of pupil (ischaemia of sphincter pupillae preventing constriction)
what increases risk of closed angle glaucoma?
certain medications age female FH chinese/ east asian shallow anterior chamber
management of closed angle
lower IOP with drops e.g. pilocarpine, etc
laser iridotomy
define open angle glaucoma
trabecular meshwork becomes clogged so fluid cannot escape and pressure builds in the eye
presentation of open angle
asymptomatic
signs of open angle?
cupped disc (loss of retinal ganglion cells) visual field defect/ tunnel vision may or may not have raised IOP
what does the neuro-retinal rim consist of?
ganglion axon cells (if this is lost then vision worsens)
diagnosis of open
visual fields (tunnel vision) goldmann applanation tonometry fundoscopy
risk factors for open angle glaucoma
age
FH
black
myopia
