Cornea

Question 1

Prominent type of collagen in Descemet’s?

Answer 1

Type IV

Question 2

Cause (and 2 subtypes of) bilateral, early onset corneal edema with thickened Descemet’s without guttae, with endothelial cell loss and diffuse corneal edema.

Answer 2

CHED (congenital hereditary endothelial corneal dystrophy).

• AR form: present at birth, accompanied by nystagmus, nonprogressive.
• AD form: first few years of life, no nystagmus, progressive

Question 3

Diagnosis, inheritance, histopath and stain for poorly-defined stromal lesions with hazy intervening stroma, affecting entire cornea from limbus to limbus?

Answer 3

Macular. AR. Mucopolysaccharide in interlamellar spaces and keratocytes. Stains with alcian blue and colloidal iron.)

Question 4

Diagnosis, inheritance, histopath and stain of sharply defined stromal lesions with clear intervening spaces, involving central cornea?

Answer 4

Granular dystrophy. AD (TGF beta-1). Irregular-shaped, well-circumscribed deposits of hyaline material. Masson trichome.

Question 5

Diagnosis, inheritance, histopath and stain of refractile lines with hazy intervening stroma of central cornea?

Answer 5

Lattice dystrophy. AD (BIGH3). Poorly-localized amyloid depostis concentrated in anterior stroma. Congo Red (and apple green birefringence under polarized light).

Question 6

Features of both granular and lattice dystrophy? Inheritance? Gene?

Answer 6

Avellino. AD. BIGH3

Question 7

Multilayered endothelium that stains with cytokeratin?

Answer 7

PPMD

Question 8

Dx and pathophys of bilateral central corneal edema with iris stands contacting central cornea, present at birth?

Answer 8

Peters anomaly. Failure of neural crest migration in AC (which forms corneal stroma and endothelium, TM, and iris stroma)

Question 9

Most common infection-related indication for PK?

Answer 9

visually-significant scarring from HSV keratitis

Question 10

Radial keratoneuritis and ring infiltrate? How to culture causitive agent?

Answer 10

acanthamoeba. non-nutrient blood agar with E. coli overlay

Question 11

features of infectious crystalline keratopathy

Answer 11

infection (often with S. viridans) in chronically immunosupressed patient, appears as crystalloid opacity, often occurs along a suture track, frequently without epidefect.

Question 12

most common cause of interstitial keratitis?

Answer 12

herpes

Question 13

gray-white or blue flat or raised peripheral corneal lesion in middle aged woman with chronic blepharitis?

Answer 13

Salzmann nodule

Question 14

Dx and histology of band-shaped calcific plaque in interpalpebral zone

Answer 14

calcific band keratopathy, calcium deposition in Bowman’s and anterior stroma

Question 15

elastotic degeneration of corneal collagen of interpalpebral zone, related to UV exposure?

Answer 15

spheroidal degeneration aka Labrador keratopathy aka actinic keratopathy

Question 16

What is a corneal pannus?

Answer 16

fibrous or fibrovascular tissue between epithelium and Bowman’s

Question 17

Post-surgical loss of endothelial cells, Descemet thickening and folds, stromal edema, microcysts, and bullae?

Answer 17

bullous keratopathy

Question 18

final common pathway of corneal graft failure?

Answer 18

endothelial cell loss

Question 19

fibrous retrocorneal membrane contiguous with corneal stroma?

Answer 19

fibrous ingrowth

Question 20

surface epithelium growing through a poorly opposed wound and onto the retrocorneal surface?

Answer 20

epithelial ingrowth

Question 21

histology of keratoconus

Answer 21

central corneal stromal thinning and focal discontinuities of Bowman’s. may see Descemet breaks if h/o acute hydrops

Question 22

iron deposition at basal epithelial layer at base of cone in KC?

Answer 22

Fleischer ring

Question 23

what do map/fingerprint lines and dots represent hitstologically in EBMD?

Answer 23

maps/fingerprints: thickened, redundant basement membrane projecting into epithelium

dots: basement membrane encircling epithelial cells resulting in epithelial debris within cystoid spaces

Question 24

mnemonic for deposited material and stain of stromal dystrophies?

Answer 24

Marilyn Monroe Always: Macular, mucopolysaccharide, alcian blue
Gets Her Man: Granular, hyaline, Masson trichrome
in L A County: Lattice, amyloid, Congo Red