ABSTRACT: Post-operative endophthalmitis is a rare and dreaded complication in ophthalmic operations because it often induces irreparable vision loss. Although many ophthalmological studies aimed at reducing the rate of endophthalmitis have been performed around the world, controversy continues to surround some issues, including the choice of antimicrobials and their route of administration, duration and timing. The aim of this study is to investigate some of these unresolved issues.A systematic review and meta-analysis of randomized controlled trials and observational studies was performed. The PubMed, EMBASE, Cochrane Library and Clinical Trials databases were searched to identify studies published until Feb. 2016. The relative risk (RR) for each clinical outcome data is presented with 95% confidence intervals (CIs). Pooled estimates of effects were calculated using random-effect models.Thirty-four studies from twenty-four reports involving 1264797 eyes were included in this analysis. Endophthalmitis occurred, on average, in one out of 6177 eyes when intracameral vancomycin/moxifloxacin were used and in one out of 1517 eyes when intracameral vancomycin/moxifloxacin were not used. The relative risk (95% CI) of endophthalmitis was reduced to 0.20 (0.10, 0.42) when intracameral antibiotics were used (p<0.0001). The subconjunctival injection of antibiotics was not superior to other administration routes included in this study (RR = 1.67, 95% CI (0.55, 5.05), p = 0.36). A statistically significant difference was found in the rate of endophthalmitis between the use and lack of use of topical antibiotics (RR = 0.65, 95% CI (0.43, 0.99), p = 0.04). However, no statistically significant difference was found in microbial isolation rates between these groups (RR = 0.77, 95% CI (0.34, 1.75), p = 0.53). When long-term and short-term use of topical antibiotics before surgery were compared, a statistically significant difference was found in microbial isolation rates (RR = 0.57, 95% CI (0.44, 0.74), p<0.0001).This meta-analysis concluded intracameral antibiotics are effective at preventing endophthalmitis in ocular surgery. A randomized controlled trial confirms the efficacy of cefuroxime but recent large cohort studies support the efficacy of vancomycin/moxifloxacin intracamerally. Intracameral antibitoics are superior to subconjunctival injections but that irrigation antibitoic data are not of enough quality to make a comparison. Different results were found in two clinical outcomes between the use or lack of use of topical antibiotic therapy, we did not find sufficient evidence to conclude that its use prevents endophthalmitis.
