Test 2: lecture 32 glaucoma Flashcards
— is the major cause of blindness
glaucoma
what is glaucoma
OPTIC NEUROPATHY: Neurodegenerative disease causing irreversible damage to optic nerve (axons of retinal ganglion cells)
increased intraocular pressure
what happens to optic nerve with glaucoma
will degrade
optic disc cupping
aqueous humor is made by what enzyme
ciliary processes of the ciliary body
carbonic anhydrase catalyzes aqueous humor production
conventional outflow of AH
made in ciliary body
drains through iridocorneal angle into trabecular meshwork
unconventional outflow of AH
uveoscleral outflow
flows into vessels and leaves
acute vs chronic glaucoma
acute- vision can still be saved
chronic- irreversible vision loss
how to measure IOP
tonometry
clinical signs of acute glaucoma
optic disc still normal: no cupping
pain: blinking, squinting
vision: menace/PLR/dazzle (±), mydriasis (±) normal to mildly abnormal optic disc
apperance: red(conjunctival/episcleral injections diffuse), diffuse corneal edema, normal globe size
clinical signs of chronic glaucoma
+/- pain
vision:
* menace/PLR/dazzle (-)
* mydriasis
* retinal atrophy
apperance:
* conjunctival/episcleral injection
* diffuse corneal edema (mild-severe)
* buphthalmia (large cow eye)→ Haab’s striae( descets membrane breaks), lens luxation
episcleral injection- big thick vessels
conjunctival hyperemia- diffusely red
large cow eye is caused by chronic glaucoma
buphthalmia
increase IOP for long time
how to see iridocorneal angle
gonioscopy
primary glaucoma is a — problem.
structural problem
risk is always bilateral
- Primary closed/narrow-angle glaucoma (PCAG)
- Pectinate ligament dysplasia - not enought holes to let AH out
two causes of primary glaucoma
- Primary closed/narrow-angle glaucoma (PCAG)
- Pectinate ligament dysplasia - not enought holes to let AH out
risk is always bilateral
what does it mean that risk is bilateral in primary glaucoma
both eyes will eventually go blind
could take years or weeks but both eyes have the same structural problem and leads to galucoma enentually
what gene mutation causes primary open-angle glaucoma
ADAMTS10 in beagles and elkhound
ADAMTS17 in bassets
how can anterior uveitis cause secondary glaucoma
cells that leak into the anterior chamber can block angle and lead to increased IOP →glaucoma
aqueous flare= proteins flooding into the eye
— lens luxation can lead to secondary glaucoma
anterior
eye emergency
how to medically treat glaucoma by decreasing AH production
carbonic anhydrase inhibitors- stop AH production- dorzolamide
β blockers- block receptors on ciliart epithelium- Timolol
how to medically increase AH outflow
Prostaglandin Analogues -
* Latanoprost increases uveoscleral outflow - causes uveitis to allow fluid to leave through vessels
miotics-
* Cholinergic: Pilocarpine
* Anticholinesterase: Demecarium brom
how to increase AH outflow surgically
anterior chamber shunt
how to reduce AH production surgerically
damage/laser/ablate ciliary body
