Intraocular Pressure Changes Following Stand-Alone Phacoemulsification: An IRISR Registry Analysis

center dot PURPOSE: To describe real-world intraocular pressure (IOP) changes following stand-alone cataract surgery by comparing postoperative IOP to phakic fellow eyes.center dot DESIGN: Retrospective clinical cohort study.center dot METHODS: A total of 1,334,868 patients (336,060 with glaucoma and 998,808 without glaucoma) in the IRIS (R) Registry (Intelligent Research in Sight) under-went stand-alone phacoemulsification from 1 January 2013 to 30 September 2019 with a fellow eye that had subsequent cataract surgery. Postoperative daily mean IOP was compared between surgical and control eyes from postoperative day 1 to 90. A generalized linear model determined when the postoperative daily mean IOP stabilized to calculate a final mean IOP, which was then compared to baseline IOP.center dot RESULTS: Postoperative daily mean IOP was initially greater for surgical than for control eyes because of an early postoperative IOP spike. By postoperative day 13, postoperative daily mean IOP was significantly lower for surgical than for control eyes every day through postop-erative day 90 ( P < .001). There was a mean (SD) de-crease from baseline to final mean IOP of 1.55 (3.52) mm Hg or 7.79% for all surgical eyes, 1.91 (3.93) mm Hg or 8.89% for surgical eyes with glaucoma, and 1.37 (3.28) mm Hg or 7.24% for surgical eyes without glau-coma, respectively. There was a statistically significant decrease from baseline to the final mean IOP for all sur-gical eyes, surgical eyes without glaucoma, and all cate-gories of pre-glaucoma and glaucoma ( P < .0001 for all, excluding uveitic glaucoma [ P = .0016]).center dot CONCLUSIONS: Eyes both with and without glaucoma that underwent stand-alone phacoemulsification had a significant decrease in IOP through the 90-day postoper-ative period compared to baseline and phakic fellow eyes.(Am J Ophthalmol 2023;245: 25-36.(c) 2022 Elsevier Inc. All rights reserved.)