Comment on: Efficacy of intracameral moxifloxacin in prevention of post-cataract surgery endophthalmitis: a randomized controlled trial

We congratulate Sharma et al. for completing and publishing their large randomized controlled trial (RCT) of intracameral moxifloxacin prophylaxis (ICMP) for phacoemulsification.1 This audacious study fulfills a critical unmet need—that of an adequately powered RCT to complement large retrospective studies in evaluating and validating the efficacy of intracameral antibiotics such as moxifloxacin in reducing the risk of postoperative endophthalmitis (POE).2 To accurately determine the rate of a rare complication, such as POE, very large surgical volumes are needed. This has historically been the main obstacle to conducting RCTs to assess any form of antibiotic prophylaxis for cataract surgery. We previously published a study comparing 1 million consecutive cataract surgeries without ICMP with 1 million consecutive surgeries with ICMP at the Aravind Eye Care System (AECS) during an 8-year period from 2011 to 2018.3 This included both phacoemulsification and manual small incision cataract surgery (MSICS) cases, and the overall rate of POE decreased from 0.07% (692/993 009) to 0.02% (185/1 069 634) (P < .001) with adoption of routine ICMP. A subgroup analysis found a POE rate of 0.01% (38 cases) in 335 037 consecutive phacoemulsification procedures receiving ICMP. Although the multiple regional AECS hospitals in our study shared identical, standardized perioperative drug regimens, instrument processing protocols, and surgical equipment, supplies, and instrumentation, the lack of randomization left open the theoretical possibility that other factors might have contributed to this reduction in POE rate.4 All AECS hospitals completed the transition to adopting routine ICMP for all cataract surgeries by January 2016. We therefore chose to further analyze the phacoemulsification POE rates from that starting point through December 2024, an 9-year period which overlapped the current RCT's 6-year study period (2018 to 2024). We can now report that the POE rate was 0.01% in 1 133 959 consecutive phacoemulsification cases during that period. When MSICS is also included, the overall POE rate during this period was 0.013% in 3 026 042 consecutive cataract surgeries. Figure 1 shows that once ICMP was routinely adopted by January 2016, annual POE rates for phacoemulsification at AECS were consistent from year to year and were comparable with the 0.02% POE rate reported for the 30 000 eyes receiving ICMP in the current RCT. Because we used an identical dosing regimen of injecting 0.1 mL of 0.5% solution containing 500 mcg of moxifloxacin into each eye, we believe that our large retrospective dataset nicely complements this RCT and further strengthens its conclusion that ICMP is safe and effective. Combining the results of this seminal RCT with our newly updated retrospective data makes a compelling argument for adopting ICMP for routine cataract surgery.Figure 1.: A: Annual POE rates for phacoemulsification cases from 2011 to 2024. 2015 was the transition year when routine ICMP was initiated at every facility; ICMP had been adopted by all facilities by January 2016. B: Annual POE rates for all cataract surgery (both phacoemulsification and MSICS). ICMP = intracameral moxifloxacin prophylaxis; MSICS = manual small incision cataract surgery; POE = postoperative endophthalmitis