A 22-year-old contact lens wearer presents with an acute, rapidly progressive corneal ulcer over 24 hours. Slit-lamp shows a dense, central, suppurative infiltrate with mucopurulent discharge, hypopyon, and a large overlying epithelial defect. Which organism is most likely responsible?

• A Staphylococcus aureus
• B Streptococcus pneumoniae
• C Moraxella species
• D Pseudomonas aeruginosa ✓

Explanation

Pseudomonas aeruginosa is the most common cause of bacterial keratitis in contact lens wearers, presenting with rapid progression, suppurative infiltrate, and hypopyon. The mucoid variant associated with contact lens cases is especially virulent. Staph and Strep cause more indolent ulcers. Moraxella causes angular, peripheral ulcers in malnourished patients.

Reference: AAO BCSC Section 8: External Disease and Cornea, 2022-2023 ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.