A 28-year-old contact lens wearer presents with a painful red eye, photophobia, and a 3 mm central corneal ulcer with a hypopyon. Corneal scraping reveals Gram-negative rods. Which organism is most likely responsible?

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

Explanation

Pseudomonas aeruginosa is the leading cause of bacterial keratitis in contact lens wearers and produces a rapidly progressive ulcer with a bluish-green, necrotic appearance and hypopyon. It is a Gram-negative rod that adheres to soft contact lenses via pili. Prompt treatment with fluoroquinolone eye drops is essential to prevent corneal perforation.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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