Comparison of Cataract Surgery Endophthalmitis Rates in Operating Rooms With and Without Laminar Air Flow and High-Efficiency Particulate Air Filters

Purpose: To determine if use of laminar air flow (LAF) and high-efficiency particulate air (HEPA) filtration during cataract surgery reduces the rate of postoperative endophthalmitis (POE). Design: Retrospective, clinical cohort study. Subjects: A total of 452 770 cataract surgeries performed at 14 hospitals within the Aravind Eye Care System in India during the 2023 calendar year. Methods: A retrospective analysis of the study population was conducted. Identical surgical and infection prophylaxis protocols were used at every surgical facility, including periocular povidone-iodine and intracameral moxifloxacin. POE rates were determined for each type of air handling unit (AHU) used during cataract surgery: LAF with HEPA filter (group 1), central air conditioning (AC) with HEPA filter (group 2), central AC without HEPA filter (group 3), or split-type AC without HEPA filter (group 4). Additional subanalyses were performed based on the cataract surgical method (phacoemulsification vs manual small-incision cataract surgery) and patients’ socioeconomic status (paying vs nonpaying). Main Outcome Measures: Rates of postoperative endophthalmitis. Results: Of 452 770 cataract surgeries performed at the Aravind Eye Care System in 2023, 74 cases of POE (0.016%) were diagnosed. The POE rates for each AHU type were determined to be 0.013% for group 1 (15 cases in 116 981 eyes), 0.016% for group 2 (21 cases in 128 089 eyes), 0.017% for group 3 (16 cases in 93 074 eyes), and 0.019% for group 4 (22 cases in 114 626 eyes). There was no statistically significant difference in POE rates across all 4 groups (P > .05). Furthermore, there was no statistically significant difference in POE rates among the 4 AHU groups (P > .05) within each of 4 patient categories: phacoemulsification, manual small-incision cataract surgery, paying, and nonpaying. Conclusions: This large, multicenter, retrospective study found no infection-reducing benefit for LAF or HEPA filtration for cataract surgery. This contradicts mandating these more expensive AHU systems for ophthalmic surgery. Recommending or requiring LAF or HEPA unnecessarily imposes additional infrastructural barriers for ophthalmic operating rooms in resource-limited settings and for office-based surgery in high-income countries.