Cornea and External Disease Flashcards

A soft contact lens wearer who rinses lenses with tap water has severe pain out of proportion to exam findings and radial perineuritis. What is the most likely organism?

Answer: Acanthamoeba species

Radial perineuritis with pain out of proportion in a contact lens wearer exposed to water is classic for early Acanthamoeba keratitis.

Which genetic abnormality is most commonly associated with late-onset Fuchs endothelial corneal dystrophy?

Answer: CTG trinucleotide repeat expansion in TCF4

A CTG repeat expansion in an intron of TCF4 is found in most patients with late-onset Fuchs dystrophy.

Corneal stromal deposits in granular corneal dystrophy type 1 stain most characteristically with which stain?

Answer: Masson trichrome

Granular dystrophy deposits are hyaline and stain bright red with Masson trichrome.

Which corneal stromal dystrophy is inherited in an autosomal recessive pattern and is caused by CHST6 mutations?

Answer: Macular corneal dystrophy

Macular corneal dystrophy is autosomal recessive and results from abnormal keratan sulfate production caused by CHST6 mutations.

An elderly patient has a painful peripheral corneal ulcer with an overhanging central edge and no scleritis or systemic disease after a full workup. What is the most likely diagnosis?

Answer: Mooren ulcer

Mooren ulcer is an idiopathic, painful peripheral ulcer with an undermined leading edge and no associated scleritis or systemic disease.

Which topical agent is FDA-approved for moderate-to-severe (stage 2 and 3) neurotrophic keratitis?

Answer: Cenegermin (recombinant human nerve growth factor)

Cenegermin, a recombinant human nerve growth factor, is FDA-approved for neurotrophic keratitis.

What is the preferred chelating agent for removing visually significant calcific band keratopathy?

Answer: Disodium EDTA

After epithelial debridement, topical disodium EDTA chelates the calcium deposited in Bowman layer.