Pathology Flashcards
what are cataracts
the opacification of the lens, usually age related
what is the main cause of cataracts
sun damage- UVB
what causes the lens to become opaque
epithelium covering it matures and contents replaced as nucleus disappears, cell becomes fibre within which can rupture and scar
what else can cause cataracts
hypertension smoking post op trauma metabolic disorders genetics diabetes (change in osmotic pressures alter fluid content)
what is glaucoma
an abnormal increase in pressure in the eye- blockage in drainage of aqueous humor
what is the path the aqueous humor
produced by cilliary body, comes out between iris and lens, drains through trabecular meshwork into schlemm canal
what does increased intraocular pressure have worst consequence for
optic disc and nerve
describe the two types of glaucoma
primary open angled glaucoma - most common, caused by poor drainage through the trabecular meshwork/ canal of schlemm
angle closure glaucoma -drainage through the meshwork is patent but iris is kinked and blocks the flow of fluid = pupillary block
what are the presentations of the different types of glaucoma
primary open- slow, asymptomatic, drugs can slow progression
closed- 1/3 emergency, acute red eye, vision loss and head ache, N&V. treated by lasering hole in iris
what is cupping
when a raised intracoluar pressure damages the optic nerve and disc - edges roll up and centre becomes depressed
what is papilloedema
swelling of the optic nerve/ disc due to rasied ICP
what is the most common cause of conjunctivitis
viral
what are the features of scleritis
worse than episcleritis, associated with pain on movement, affects the body of the sclera, may have underlying autoimmune condition
what are the features of episcleritis
superficial, self limiting
what are the types of macular degeneration
age related
dry- no significant vascular proliferation
wet- vascular proliferation (leaky blood vessels, haemorrhage)
