Twelve‑month Response and Safety of Intravitreal Dexamethasone Implant in Treatment‑Naïve and Recalcitrant Cystoid Macular Edema Secondary to Branch Retinal Vein Occlusion (TREAT-BRVO Study)

Somnath Chakraborty,1 Jay U Sheth,2 Santanu Ganguly,1 Preesha Reddy11Department of Retina Services, Retina Institute of Bengal, Siliguri, India; 2Department of Retina Services, Shantilal Shanghvi Eye Institute, Mumbai, IndiaCorrespondence: Somnath Chakraborty, Department of Retina Services, Retina Institute of Bengal, C/O Reddy Health Care 3rd Floor Uttarapan Market Complex, Hill Cart Road, Pradhan Nagar, Siliguri, West Bengal, 734003, India, Tel +91-9002508334, Email [email protected]: To compare anatomical and visual outcomes following dexamethasone intravitreal implant (Ozurdex) in treatment-naive versus recalcitrant cystoid macular edema (CME) secondary to branch retinal vein occlusion (BRVO).Patients and Methods: This retrospective study included 45 eyes with BRVO-related CME treated with Ozurdex and followed for 12 months. Eyes were classified as treatment-naive (n=13) if they received no prior treatment, including intravitreal therapy or laser photocoagulation. Eyes were classified as recalcitrant (n=32) if previously treated with at least three anti-vascular endothelial growth factor (anti-VEGF) agents. Primary outcomes were best-corrected visual acuity (BCVA) in logMAR and central macular thickness (CMT). Secondary outcomes included changes intraretinal fluid (IRF), subretinal fluid (SRF), hyperreflective intraretinal foci (HRIF), disorganization of retinal inner layers (DRIL), lens status, and retreatment rates.Results: Baseline BCVA and CMT were comparable between groups. A mean of 1.74± 0.81 dexamethasone implants was administered, with no difference between groups. BCVA improved significantly from 0.625± 0.262 to 0.299± 0.14 logMAR at 12 months (P< 0.001), with similar gains and no between-group differences (month 12 P=0.492). CMT decreased from 522.6± 141.3 μm to 266.9± 66.6 μm (P< 0.001); despite mild recurrence, reductions remained significant versus baseline throughout. The intraocular pressure (IOP) remained stable, with one medically managed elevation. The optical coherence tomography (OCT) imaging showed marked resolution of IRF (84.4%), SRF (95.2%), and HRIF (100%). Retreatment, including repeat implants and/or laser, was frequent (88.9%). Cataract progression occurred in 12.1% of phakic eyes.Conclusion: Intravitreal dexamethasone implant was associated with significant anatomical and functional improvements in both treatment-naïve and anti-VEGF refractory BRVO-related CME. While no statistically significant differences were identified between the groups, adequately powered prospective studies are required to determine whether treatment outcomes differ according to prior anti-VEGF exposure.Keywords: dexamethasone implant, branch retinal vein occlusion, cystoid macular edema, ozurdex, real-world