Anterior Subtenon Triamcinolone Injection for Refractory Macular Edema: A Retrospective Case Series

Purpose: To evaluate the effectiveness of anterior subtenon triamcinolone (AST) injections in the management of refractory macular edema. Methods: This is a retrospective case series of consecutive eyes with refractory macular edema treated with AST at a single vitreoretinal surgeon’s practice at Toronto Western Hospital, University of Toronto, Canada in 2018-2023. Refractory was defined as persistent macular edema with a central subfield thickness of 250μm or greater over a 24-week period, receiving at least four intravitreal anti-VEGF injections. Vision outcomes and optical coherence tomography features for all eyes were compared for three visits pre-AST treatment and two visits post-AST treatment. Results: Ninety-three patients (119 eyes; diabetic macular edema (26%), and pseudophakic CME (74%), with a mean follow-up duration of 161 days were included. The presence of subretinal fluid (p=0.0013), central subfield macular thickness (p<0.0001), cube average thickness (p=0.0024) and macular cube volume (p= 0.0017) significantly improved from pre-AST to post-AST treatment. Visual acuity also significantly improved from pre-AST treatment to post-AST treatment (p<0.0001). There was no significant change in the intraocular pressures from pre-AST to post-AST (p=0.7920) and no complications were noted throughout the follow-up period. Conclusion: The findings from this study suggest that AST injections show modest improvement in anatomical and functional outcomes, and are safe for the treatment and management of refractory macular edema.