PPO2 Flashcards
(103 cards)
what is arcus?
form of degeneration around the limbus composed of CHOLESTEROL esters and LDL @ stroma. Usually @ inf. cornea and stroma. There are varying degrees.
what does a unilateral arcus possibly indicate? which side is “bad?”
vascular occlusion on the side WITHOUT the arcus.
what is limbal girdle of vogt? what does it mean?
Age-related sub-EPIthelium collagen degeneration @ cornea. There are white crystal appearances @ 3 & 9 o’clock.
**Type1– clear translucid zone due to Ca deposits at the Bowman’s layer, which is at a difference location on the sclera
hudson-Stahli line
iron deposit along Bowman’s layer that looks brown/yellow @ margins of inf. pupil. More common in dry eye people and frequency is the same with age (20y/o= 20% etc)
Descemet’s striae
striation in Descemet’s membrane @ cornea. If very very large–> maybe corneal edema.
What is Hassal-Henle bodies?when is it a guttata?
- peripheral= hassal-Henle bodies=iron deposit @ bowman’s membrane
- central cornea= guttata nodular thickening of Descemet’s membrane composed of collagen and byproduct of ENDO-thelial cells
what is grayson’s disease of cornea?
deterioration of layer–due to age mostly
- peripheral cornea
- vascularization may be present
what is the % of population that has arcus between 40-60 years old? past 70-90 years old?
- 60% have arcus
2. 90% have arcus
what eye disease is common in Hudson-stahli line?
- dry eye or tear flow problems @ pupil margin
- change increases with age
- A NORMAL FINDING
what is Descemet’s striae?
- Descemet’s membrane striation
- normal finding that’s VERTICAL
- bad if paried with stromal edma**
what is the aka of “crocodile shagreen”? what is characterized by this disease?
- Mosaic Shagreen
- gray/white opacity that has clear spaces–looks like crocodile!
- mostly peripheral
- due to Bowman’s Layer relaxation
what is a risk factor for pt. with guttata (which is normally age related)
Fuch’s endothelial dystrophy
- look for corneal stromal edma
- check pachymetry
what is corneal farinata?
- tiny, dust like flecks @ STROMA–looks like sprinkled flour
- retro illumination
- bilateral w/ no VA change
what is band keratopathy?
- Ca salts @ inter-palp zone (begins @ basement membrane)
- corneal degeneration where corneal nerves penetrate Bowman’s
- mostly central, but mild cases can be at 3&9 o’clock
- if in KIDS= rheomoetoid arthritis is risk factor and get irididis
- decreased VA
where does the Ca salts come from in band keratopathy?
- tears that have Ca and Phosphate
- dry eye/evaporative tears increase solute concentration esp. @ INTRA-palp and the balance is affected
how do we get Band Keratopathy?
- inflammation= uveitis, glauc, corneal edma
- systemic= hyper-parathyroid (immuno), juvenile rheumatoid arthritis, thiazides, vit. D toxicity, renal failure
what is treatment of band keratopathy?
ONLY IF VA AFFECTED—scraping with a knife + Ca binding agent EDTA
- surgical excimer laser keratectomy to polish cornea
what is Salzamann’s Nodular Degernation?
- elongated basal epi cell lesions
- plaques @ epi and Bowman’s= opaque color
- has keratocytes, esp. at anterior
what is the dimensions of the normal cornea?
- 6mm x 10.6mm vertically
- central thickness 0.53 and 0.70
list layers of the cornea
- epi ( surface with microplicae+microvillie for absorption of mucin= rewetting, 5-7 layers of basal columnar cells attached via hemidesomosomes to BM + wing cells)
- BM
- bowman’s
- stroma (any break after here will scar)
- Descemet’s membrane
- endo
does the epithelium scar as a result of inflammation?
no, epi has regenerative properties 7-14 days
does the BM lesion cause scar?
yes/no…takes 6-8weeks to regenerate and disruption can cause corneal erosions
does Bowman’s lesions cause scar?
YES, doe NOT regenerate—very STRONG though, so if finally break through, then will scar!
-aceulluar structure that will undergo hypertrrophy
what makes up your stroma?
- collagen, fibroblasts with keratocytes etc.
* * DUA’S LAYER: acellular and pre-Descemet’s that separates the LAST row of keratocytes