Opthalmology Flashcards
define glaucoma?
refers to a number of disorders where there is a progressive optic neuropathy and raised intraocular pressure is typically a key factor
which condition is characterised by a normal angle between the iris and cornea. It is divided into primary and secondary forms?
open angle glaucoma
commonest form of glaucoma?
primary open angle glaucoma
which condition is characterised by a closing or narrowing of the angle between the iris and cornea. Again may be split into primary and secondary forms?
angle-closure glaucoma
pathology closed angle glaucoma??
The closure of the anterior chamber angle (cornea-iris. due to lens being pushed against the iris) results in reduced drainage of the aqueous humour and rising IOP rapidly - cupping
pressure builds up particularly in posterior chamber
threshold above which IOPs are said to be raised?
21mmHg
what are the boundaries of the anterior chamber of the eye?
cornea - iris
what are the boundaries of the posterior chamber of the eye?
iris - lens `
boundaries of the vitreous chamber?
lens-back of the eye
anterior chamber filled with??
aqueous humor
posterior chamber filled with ??
vitreous humor
what does the cilliary epithelium do in the eye?
produces the aqueous humor
provides structural support
what is the normal pathway of the aqueous humor in the eye?
produced by the cilliary epithelium into post chamber flows to anterior chamber through trabecular meshwork canal of schemm aqueous veins (part of the episcleral venous system)
pathology open angle glaucoma?
angle between cornea and iris ‘open’ - slow clogging of trabecular meshwork over time
-> gradual increase in pressure on Optic nerve - cupping
-> outer rim atrophy - decrease in peripheral vision
THEN central vision loss as pressure increases
symptoms of closed angle glaucoma?
eye pain, redness, blurred vision, headaches, nausea, visual halos
what does tonometry assess?
introccular pressure
what will optic nerve imaging and direct observation show in closed angle glaucoma?
‘cupping’
medications for glaucoma?
to lower pressure by decreasing aqueous humor production - 1. BBs,
carbonic anhydrase inhibitors (dorzolamide)
to increase outflow of humor - prostaglandin analogues also 1.
to do both: alpha adrenergic agonists
treatments (non-pharm) for glaucoma:
trabeculoplasty - OA
laser iridotomy - CA
causes of ectropion:
muscle weakness
bell’s palsy - facial paralysis
trauma/previous surgery
eyelid growths
watery eyes, excessive dryness of eyes - gritty and sandy
easy irritated eyes - burning sensation and redness
photophobia:
ectropion
ectropion mx:
surgical definitive
what causes stye?
saureus
can be described in questions as an eyelid abscess
differentiate between stye and chalazion?
styes are typically tender to palpate