Frequency-dependent risk of steroid-induced ocular hypertension

Abstract

Purpose To evaluate the incidence and risk factors of steroid-induced ocular hypertension (SIOH) following repeated intravitreal dexamethasone (DEX) implant injections, with particular focus on delayed SIOH, defined as its absence at the first injection and occurrence following subsequent injections. Methods This retrospective study included 1,105 eyes treated with DEX implants between 2005 and 2024. Intraocular pressure (IOP) was measured at baseline, 1 week, and 1, 2, 3, 6, and 12 months after each injection. Multivariable logistic regression assessed potential predictors including injection number, and cumulative incidence of SIOH was analyzed using Cox proportional hazards models. Subgroup analyses of multiple-injection SIOH risk factors and IOP trajectories were compared between single-injection and multiple-injection SIOH. Results Compared to eyes that received only one DEX implant injection, the odds ratios (ORs) for SIOH were: 2.190 (p = 0.004), 2.558 (p = 0.012), 2.560 (p = 0.049), and 4.306 (p = 0.005) for two, three, four, and five injections, respectively. In eyes that experienced SIOH after multiple injections, longer axial length was a significant anatomical predictor (OR = 1.630, p = 0.013). IOP trends differed: multiple-injection SIOH cases showed slower but more sustained elevations. Conclusion Repeated intravitreal DEX implant injections significantly increased the risk of SIOH. Delayed SIOH may occur after subsequent injections even in eyes without SIOH at first injection. Long axial length may contribute to SIOH after multiple injections, with delayed and sustained IOP elevation, underscoring the importance of continued monitoring.