Intraocular Pressure Spike Following Stand-Alone Phacoemulsification in the IRIS® Registry (Intelligent Research in Sight)

To evaluate risk factors for intraocular pressure (IOP) spike following cataract surgery using the IRIS® Registry (Intelligent Research in Sight).Retrospective clinical cohort study.Adults with IRIS® Registry data who underwent stand-alone phacoemulsification from January 1, 2013 to September 30, 2019.IOP spike was defined as a postoperative IOP >30 mmHg and >10 mmHg from baseline within the first postoperative week. Odds ratios (OR) for demographic and clinical characteristics were calculated with univariate and multivariate logistic regression analyses.Incidence and OR of IOP spike.We analyzed data from 1,191,034 eyes (mean age 71.3 years, 61.2% female sex and 24.8% with glaucoma). An IOP spike occurred in 3.7% of all eyes, 5.2% of eyes with glaucoma and 3.2% of eyes without glaucoma (P<0.0001). Multivariable analyses of all eyes indicated a greater risk of IOP spike with higher baseline IOP (OR 1.57 per 3 mmHg), male sex (OR 1.79), glaucoma (OR 1.19), Black race (OR 1.39 compared to Asian and OR 1.21 compared to Hispanic), older age (OR 1.07 per 10 years), and complex surgery coding (OR 1.22, all P<0.0001). Diabetes (OR 0.90) and aphakia after surgery (OR 0.60) appeared to be protective against IOP spike (both P<0.0001). Compared to glaucoma suspects, there was a greater risk of IOP spike with ocular hypertension (OR 1.55), pigmentary glaucoma (OR 1.56), and pseudoexfoliative glaucoma (OR 1.52), and less risk for normal tension glaucoma (OR 0.55), primary angle closure (PAC) suspect (OR 0.67), and PAC glaucoma (OR 0.81, all P<0.0001). More baseline glaucoma medications was associated with IOP spike (OR 1.18 per medicine) while topical beta-blocker use (OR 0.68) was protective (both P<0.0001).Higher baseline IOP, male sex, glaucoma, Black race, older age, and complex cataract coding were associated with an early postoperative IOP spike whereas diabetes and postoperative aphakia were protective against a spike following stand-alone phacoemulsification. Glaucomatous eyes demonstrated different risk profiles dependent on subtype of glaucoma. The findings may help surgeons stratify and mitigate the risk of IOP spike after cataract surgery.