Post-cataract surgery endophthalmitis presenting 6 weeks after surgery with gradual painless visual decline is most likely caused by:

• A Staphylococcus aureus causing acute fulminant endophthalmitis
• B Aspergillus species causing exogenous fungal endophthalmitis
• C Propionibacterium acnes (Cutibacterium acnes) causing chronic low-grade endophthalmitis ✓
• D Pseudomonas aeruginosa causing delayed-onset bacterial endophthalmitis

Explanation

Delayed-onset (chronic or late) post-cataract endophthalmitis presenting weeks to months after surgery with gradually declining vision, often with a white plaque on the IOL surface or within the capsular bag, is classically caused by Cutibacterium acnes (formerly Propionibacterium acnes). This slow-growing, sequestered anaerobe is trapped within the capsular bag during surgery and causes a delayed low-grade inflammation. Acute post-cataract endophthalmitis (within 1 week) is typically caused by coagulase-negative staphylococci.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.