A patient wearing soft hydrophilic contact lenses develops a painful red eye with a ring infiltrate at the peripheral cornea, minimal epithelial defect, and sterile culture. The MOST likely diagnosis is:

• A Contact lens-induced peripheral ulcer (CLPU) ✓
• B Acanthamoeba keratitis
• C Sterile marginal infiltrate (hypersensitivity to staphylococcal exotoxins)
• D Pseudomonas aeruginosa suppurative keratitis

Explanation

Contact lens-induced peripheral ulcer (CLPU) presents as a sterile, usually single, peripheral/paracentral rounded ulcer with a crater-like epithelial defect and dense stromal infiltrate in contact lens wearers; it resolves on lens discontinuation. Marginal (catarrhal) infiltrates are multiple, subepithelial, peripheral infiltrates due to staphylococcal hypersensitivity and are usually bilateral with minimal symptoms. Acanthamoeba causes severe pain, ring infiltrate, and positive culture/PCR. Pseudomonas causes a rapidly expanding, purulent, central infiltrate with epithelial defect.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.