A 22-year-old myopic contact lens wearer presents with acute onset severe pain, purulent discharge, and a rapidly progressive ring-shaped stromal infiltrate with suppurative necrosis in the right eye. He admits to frequently sleeping in his lenses. Which of the following factors most strongly predisposed him to Pseudomonas aeruginosa keratitis?

• A Swimming while wearing contact lenses
• B Occasional use of topical lubricating drops
• C Using expired contact lens solution
• D Overnight (extended) contact lens wear ✓

Explanation

Overnight contact lens wear is the strongest independent modifiable risk factor for Pseudomonas aeruginosa keratitis. It causes corneal hypoxia and enhances bacterial adhesion to the epithelium. Swimming while wearing lenses is a major risk factor for Acanthamoeba keratitis, not Pseudomonas. Expired solution increases contamination risk but overnight wear directly compromises epithelial barrier function and local immunity, permitting Pseudomonas invasion.

Reference: AAO Basic Course of Ophthalmology (BCSC Section 8: External Disease and Cornea), 2023-2024 ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.