Anterior Chamber Angle Anatomy in Non-Glaucomatous Eyes Receiving Repeated Anti-VEGF Injections: A Paired-Eye Cross-Sectional Study

Background This study aimed to evaluate anterior chamber angle anatomy after multiple intravitreal anti-vascular endothelial growth factor (VEGF) injections for age-related macular degeneration (AMD), diabetic macular edema (DME), or retinal vein occlusion (RVO), and to identify associated factors. Methods This cross-sectional paired-eye study included 96 non-glaucomatous patients with unilateral AMD, RVO, or DME receiving repeated intravitreal anti-VEGF injections. Anterior segment optical coherence tomography was used to measure angle parameters in the nasal and temporal quadrants of treated and contralateral untreated eyes. Intraocular pressure (IOP) was measured in both eyes. Quadrant angle parameters and IOP were compared between eyes. Inter-eye difference (treated minus untreated eye) was calculated for quadrant angle parameters and IOP. Associations of inter-eye differences in quadrant angle parameters with inter-eye IOP difference, number of injections, and diagnosis were evaluated using univariate and multivariable analyses. The number of injections in treated eyes was compared between occludable and non-occludable angles. Results Temporal quadrant angle parameters did not differ significantly between treated and untreated eyes (all p > 0.05). Nasal quadrant angle parameters were statistically smaller in treated eyes (all p < 0.05), but the differences were minimal (1.0–2.9%). Mean IOP was significantly higher in treated eyes (p = 0.031). Inter-eye differences in nasal and temporal quadrant angle parameters were not associated with inter-eye IOP difference, number of injections, or diagnosis (all p > 0.05). In treated eyes, the number of injections did not differ significantly between occludable and non-occludable angles (p = 0.237). Conclusions In non-glaucomatous eyes, anterior chamber angle anatomy after multiple intravitreal anti-VEGF injections is not related to the number of injections or the primary retinal diseases managed with this therapy (AMD, RVO, DME).This finding suggests that angle anatomy is unlikely to explain the sustained IOP elevation reported after multiple anti-VEGF injections in previous studies, and that routine gonioscopic monitoring may not be necessary in patients receiving repeated intravitreal anti-VEGF injections.