L5 - GLAUCOMA + CATARACT Flashcards
(33 cards)
Cornea does __ of focusing of the eye
Lens does __ of focusing of the eye as well as ___
(emphasized)
Cornea does 2/3 of focusing of the eye
Lens does 1/3 of focusing of the eye as well as fine tuning
What is the 2nd leading cause of bilateral blindness in the world?
(emphasized)
Glaucoma
Glaucoma definition
A progressive optic neuropathy - p/w acquired optic nerve atrophy accompanied by loss of retinal ganglion cells + their axons
(ganglion cell damage = death of ganglion cell axons = optic nerve damage)
What happens to the optic cup as glaucoma progresses?
emphasized
As more nerves (axons) die the optic cup gets larger
Cup to disc ratio used to describe severity of glaucoma
*cup:disc = 1 = all nerves dead
1 risk factor for glaucoma
emphasized
Elevated IOP
What is the most important factor for preserving vision in glaucoma?
Early DX*/TX
Aqueous humor is made in the ___ and drains from ___ + ___
What happens when this drain is clogged?
Aqueous humor is made in the ciliary body and drains from trabecular meshwork + episcleral veins
What happens when this drain is clogged? = IOP increases
What is the MC form of glaucoma?
Is it chronic or acute?
Is damage reversible? (emphasized ^)
Primary Open Angle Glaucoma (POAG)
Chronic
Damage is irreversible (emphasized ^)
What is a hallmark feature of Normal Tension Glaucoma?
Normal IOP
A patient p/w sudden rise in IOP which causes pain, redness, N/V, and decreased vision
What form of glaucoma would you suspect?
Primary Angle Closure Glaucoma (PACG)
What is one of the definite TX’s for an acute attack of PACG?
Laser Peripheral Iridotomy (LPI)
laser creates microscopic hole in the iris so fluid can enter through hole instead of traveling through pupil
Many acute attacks of PACG happen in __?
What does this cause?
Many acute attacks of PACG happen in DARK rooms
Dark rooms cause:
Pupil dilation = increase contact b/w iris + lens = narrowing of angle = attack triggered
What are the 3 types of primary glaucoma?
- Open Angle
- Angle Closure (acute + chronic)
- Normal Tension
What are the 6 types of secondary glaucoma?
- Neovascular
- Pigmentary
- Phacolytic
- Phacomorphic
- Uveitic
- Trauma-related
What are some of the features of primary open-angle glaucoma?
- Age?
- Sxs?
- IOP?
- Vision loss?
- Trabecular mesh network?
PAOG
Affects mainly > 50 yo
No sxs / painless
IOP slowly rises (slow vision loss - 1st noticed @ late stages)
No visible damage to trabecular meshwork cells but TMCs lose ability to carry out nml fxn
What are some of the features of normal-tension glaucoma?
Progressive optic nerve damage + visual field loss (peripheral)
Normal IOP
In part d/t poor blood flow to optic nerve
What are some of the features of primary angle-closure glaucoma?
- etiology?
- types?
Fluid pressure builds up behind the iris + forces it against trabecular meshwork (blocking it)
When trabecular meshwork blocks completely it l/t PACG
Can be acute or chronic (acute is an emergency + can l/t permanent vision loss)
In Chronic Angle Closure Glaucoma the __ gradually closes over trabecular meshwork causing scarring + elevated IOP
In Chronic Angle Closure Glaucoma the IRIS gradually closes over trabecular meshwork causing scarring + elevated IOP
What are some of the features of pigmentary glaucoma?
- what kind?
- age?
- etiology?
Open angle (inherited)
2nd - 3rd decade of life
Irido-zonular contact l/t trabecular meshwork blockage by pigment
What are some of the features of pseudo-exfoliative glaucoma?
- MC amongst?
- age?
- etiology?
- increases risk of?
MC among european (scandinavian)
6th - 8th decade of life
Whitish dandruff-like material (protein) builds up + clogs trabecular meshwork
Pseudo-exfoliation syndrome increases chance of POAG + CACG by 6x
Most important aspect of diagnosing glaucoma?
emphasized
Measure IOP!!! (tonometry)
What kind of vision is lost first in glaucoma?
Peripheral vision
Measuring visual fields in glaucoma patients is an important factor to measure/determine:
Measure peripheral vision
Determine extent of optic n. damage
Thickness of ___ is a risk factor for developing glaucoma
How can this be measured?
Thickness of cornea (thinner cornea = increased risk)
Pachymetry measures central corneal thickness
