A patient fitted with a silicone hydrogel extended-wear contact lens develops a peripheral corneal infiltrate with overlying epithelial defect, mild anterior chamber reaction, and no frank hypopyon. The most likely diagnosis and recommended first-line treatment are:
- A Contact lens-related peripheral ulcer (CLPU) / sterile infiltrative keratitis; discontinue lens use and topical fluoroquinolone or lubricants ✓
- B Acanthamoeba keratitis; PHMB and propamidine
- C Fungal keratitis; topical natamycin 5%
- D Herpes simplex keratitis; topical acyclovir ointment
Explanation
Contact lens-related peripheral ulcers (CLPUs) are sterile inflammatory infiltrates caused by bacterial exotoxin-mediated hypersensitivity (often Staphylococcus exotoxin). They are characterised by peripheral stromal infiltrate, overlying epithelial defect, mild AC reaction, but are distinguished from infectious ulcers by their peripheral location, small size, and relatively mild discharge. Management includes lens discontinuation, short-course topical corticosteroid (after excluding infection), and/or fluoroquinolone antibiotics prophylactically. Acanthamoeba classically causes severe ring infiltrate; fungal ulcers appear satellite, feathery; HSK is usually central.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.