Glaucoma Flashcards
1
Q
Glaucoma
A
- ocular disease causing irreversible damage to the optic nerve
- several different types
- if not caught early enough or treated appropriately can cause PERMANENT BLINDNESS
- 2nd leading cause of blindness worldwide
- most types have no symptoms
2
Q
Primary open angle glaucoma (POAG)
A
- most common form
- imbalance of production and drainage of aqueous fluid inside the eye
- most often causing elevated eye pressure
- increased IOP causes damage to optic nerve leading to optic atrophy (cupping) which increases cup to disc ratio
- has “open angle” (can see trabecular meshwork)
- slow progression
- peripheral field loss first
3
Q
Primary open angle glaucoma risk factors
A
- more common over 50
- more common in African Americans and Hispanic
- tendency to run in families
- associated with DM, HTN, and heart conditions
- systemic medications: corticosteroid use
4
Q
Angle closure glaucoma
A
- acute, considered an ocular emergency
- IOP rises quickly and can cause permanent vision loss in a matter of hours
- symptoms: cloudy vision, HA, nausea, rainbows around lights
- require surgical intervention
- associated more with high farsightedness (due to compactness of eye)
5
Q
Normal tension glaucoma
A
- optic nerve damage despite IOP in the normal range
- more common in those with a family hx, Japanese decent, certain heart conditions
- tx: same as POAG
- tend to be missed so they have a higher risk of vision loss
6
Q
Ocular HTN
A
- elevated IOP without optic nerve damage
- increases the risk for optic nerve damage - true glaucoma
- risk of tx vs. monitoring
- if you leave a person with high IOP they will eventually get nerve damage
7
Q
Congenital glaucoma
A
- rare condition usually found within the first year of life
- common associated with abnormally large eyes, larger corneas, excessive tearing, cloudy eyes, and photo sensitivity
- requires surgical intervention
- usually results in reduced vision
8
Q
Secondary causes of Glaucoma
A
- trauma
- chronic uveitis
- chronic steroid use
- diabetic retinopathy
- ocular vascular occulsions
9
Q
Glaucoma testing
A
- IOP: appplanation consider gold standard
- normal IOP 10-20 mmHG
- dilated fundus exam: observation of optic nerve characteristics like color rim tissue, and cupping (standard of care)
- secondary testing: pachymetry (corneal thickness), gonioscopy (angle assesment), visual field (functional measurement of vision loss), OCT (retinal scan of optice nerve and tissue loss)
10
Q
Pachymetry
A
- central corneal thickness
- average thickness is 555 um
- IOP adjustment due to corneal thickness: thin cornea have to “add” pressure points and thick cornea “subtracts” pressure points
- thinner corneas INCREASE risk of glaucoma
11
Q
Gonioscopy
A
- contact lense placed on corneal surface to view the structures of the “angle”
- narrow or closed angle require surgical innervation
- peripheral iridotomy used to create permeant opening for aqueous fluid
12
Q
OCT or HRT
A
- retinal scanning allows for RNFL loss measurment and a means to monitor for progression over time
- objective vs. subjective
- new technology allowing for earilier detection of RNFL loss (ganglion cell changes)
13
Q
Visual field testing
A
- a subjective measurement of central and peripheral visual field
- a functional measurement of early vision loss and signs of progression
- have pt click button when they see a flash of light or an image
14
Q
Glaucoma treatment
A
- dependent on severity on initial diagnosis (more severe the more aggressive)
- first line therapies include drops with the primary goal to reduce IOP in order to stabilize RNFL of the optic nerve
- in severe/progressive cases surgical intervention is required
15
Q
Drop
A
- Prostaglandings: increase aqueous outflow GOLD STANDARD
- Beta-block: decrease aqueous production
- alpha-angonist: decrease aqueous production and increase outflow
- CAI inhibitors: decrease aqueous production
- combination: 2 medicines to maximize effect and pt compliance
