Cornea

Question 1

• DDx for corneal crystals

Answer 1

Macular dystrophy, granular dystrophy, lattice, bietti’s dystrophy, schneider’s dystrophy, ciloxan deposits, infectious crystalline keratopathy, cystinosis, multiple myeloma, monoclonal gammopathy

Question 2

• Epithelial/subepithelial dystrophies

Answer 2

EBMD, meesmann, gelatinous, subepithelial mucinous corneal dydstrophy, epithelial recurrent erosion dystrophy, lisch epithelial corneal dystrophy

Question 3

• Gelatinous dystrophy

Answer 3

mutation in TAC STD 2—autosomal recessive. Diffuse subepithelial and stromal amyloid deposits. Recurrent erosions are common. Recurrence in nearly 100% of patients.

Question 4

• Chlamydia trachoma

Answer 4

leads to limbal follicles and Herbert pits, tarsal conjunctival scrarring, vascular pannus most marked superiorly. Conjunctival follicles most numerous on the superior tarsus.

Question 5

• Meesmann corneal dystrophy

Answer 5

autosomal dominant, PAS positive microcysts; “peculiar substance”; mild foreign body sensation, mild reduction in VA. Causative mutation is keratinK3 (KRTK3) or keratin K12 (KRTK12) (“stocker-holt variant”) genes. Treatment is artificial tears, +/- contact lens. Another name is JUVENILE HEREDITARY CORNEAL DYSTROPHY.

Question 6

• DDx for limbal stem cell deficiency:

Answer 6

chemical burns, ocular surgery, longterm contact lens wear, SJS or mucous membrane pemphigoid, infections (like HSV), aniridia

Question 7

• Corneal donor criteria

Answer 7

age >2 yo and <70 yo; cell count 2,000+; death to presentation time less than 12-18 hours; tissue storage time <4 days.

Question 8

• Terrien’s marginal degeneration

Answer 8

Think T’s. Thinning of cornea, Top (superior), thirties, transversing pannus over area of thinning, treatment is transplant if perforation.

Question 9

Thiel Behnke and Reis Bucklers:

Answer 9

autosomal dominant, with mutations in TGF Beta-1 (codes for keratoepithelin). Bowman’s layer; on EM Thiel behnke has curly fibers while Reis Buckler’s does not. Bowman’s layer replaced with sawtooth pattern. Patients have honeycomb opacities which spare the peripheral cornea. Recurrent erosions are worse in reis buckler than in thiel Behnke

Question 10

• Antifungals

Answer 10

natamycin is good for filamentous. Vori is inferior to Nat (MUTT Trial) for fusarium but has coverage for both yeast and filamentous. Amphoteracin is better than natamycin for yeast.

Question 11

• Causes of band-K:

Answer 11

uveitis, ELEVATED phosphorus level (eg renal failure), ELEVATED calcium level, DECREASED potassium level, silicone oil, exposure to mercurial vapors

Question 12

• Scleromalacia perforans

Answer 12

usually painless with minimal inflammation and RARELY spontaneously perforates. Associated with globe rupture after minimal trauma.

Question 13

Terriens marginal degeneration

Answer 13

Males more than females (3:1); thinning of cornea with traversing paninis, more on top (superior first), age commonly 30s at presentation, treatment is transplant if perforated