Chlorhexidine Versus Povidone-Iodine for Intravitreal Injection Antisepsis: A Systematic Review and Meta-Analysis.

Summary

Across seven comparative studies, chlorhexidine and povidone-iodine yielded similar rates of presumed and culture-confirmed endophthalmitis after intravitreal injections. Visual outcomes were comparable, but chlorhexidine provided better tolerability and lower pain, and was associated with fewer S. epidermidis-positive cultures in endophthalmitis cases.

Key Findings

• No significant difference between chlorhexidine and povidone-iodine in presumed, culture-positive, or culture-negative postinjection endophthalmitis rates.
• Best-corrected visual acuity outcomes in endophthalmitis cases were comparable between antiseptics.
• Chlorhexidine showed better tolerability and lower pain than povidone-iodine.
• Chlorhexidine was associated with lower odds of S. epidermidis-positive cultures in endophthalmitis cases.

Clinical Implications

Chlorhexidine is a reasonable alternative to povidone-iodine for pre-injection antisepsis, especially in patients with iodine sensitivity or poor tolerance to PI. Implementation should consider local protocols, CHX concentration, and rare-event surveillance.

Limitations

• Only seven studies; potential heterogeneity in protocols, antiseptic concentrations, and outcome definitions.
• Rare event rates limit power to detect small differences in endophthalmitis incidence.

Future Directions

Large, pragmatic randomized trials directly comparing PI vs CHX at standardized concentrations, with patient-reported pain, cost, and microbiologic endpoints; implementation studies across high-volume clinics.