Post-cataract surgery endophthalmitis occurring within 6 weeks of surgery most commonly involves which organism?

• A Streptococcus viridans
• B Coagulase-negative Staphylococci (Staphylococcus epidermidis) ✓
• C Pseudomonas aeruginosa
• D Bacillus cereus

Explanation

Acute post-cataract endophthalmitis (within 6 weeks) is most commonly caused by coagulase-negative staphylococci (especially Staphylococcus epidermidis), which account for approximately 70% of cases in the Endophthalmitis Vitrectomy Study (EVS). These are commensal organisms introduced during the perioperative period. Streptococcus species cause more virulent acute disease. Bacillus cereus is associated with post-traumatic endophthalmitis. Delayed endophthalmitis (months–years, bleb-associated) is more commonly caused by Streptococcus and H. influenzae.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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