Chlorhexidine for ocular antisepsis before intravitreal injection: A systematic review and meta-analysis

Povidone-iodine (PI) is the gold standard for pre-intravitreal injection ocular antisepsis. Chlorhexidine (CHX) is an emerging alternative with less ocular irritation. This meta-analysis aims to evaluate post-injection endophthalmitis rates with the use of CHX compared to PI. A systematic search of PubMed, Embase, and Scopus was performed for studies published between January 1, 2000 and February 21, 2024. Data on the number of injections and endophthalmitis cases were analyzed. A sample-size weighted mean difference (MD) meta-analysis was performed using RevMan 5.4.1, p < 0.05 was considered statistically significant. Five studies including 230,656 injections were pooled to determine an endophthalmitis rate of 0.0003 [95 % CI, 0.0001–0.0005] with preinjection CHX antisepsis. Three studies included an additional PI branch and thus were used for secondary meta-analysis comparing CHX against PI. The analysis consisted of 185,799 injections in the CHX group and 269,441 injections in the PI group. No significant difference in the weighted relative risk of endophthalmitis with CHX was found (RR = 1.27 [95 %CI 0.50–3.22], p = 0.62). A total of 24 and 31 cases of culture-positivity were recorded in the CHX and PI groups respectively but no significant difference in weighted means was found (RR = 1.42[95 %CI 0.96–2.12], p = 0.08). This meta-analysis disclosed that the rate of post-IVI endophthalmitis while using CHX antisepsis is approximately 1 in 3937 injections, compared to 1 in 3906 with PI. CHX was not associated with a significant difference in the rate of endophthalmitis or culture-positivity compared to PI.