Effect of sustained-release long-acting intravitreal dexamethasone implant in patients of non-proliferative diabetic retinopathy undergoing phacoemulsification: A randomized controlled trial.

Purpose: Cataract and diabetes, both being a major health care problem, an intervention evaluated for the combination of the two attains paramount importance. The purpose of the study was to determine the role of intraoperative intravitreal dexamethasone implant in patients with diabetic retinopathy with/without macula edema undergoing phacoemulsification.

Methods: The study was a two-arm, single-center, randomized, assessor-blinded trial of 151 patients with type-2 diabetes mellitus and cataract. It had two groups: dexamethasone group (DEX) versus standard of care (SOC) group, i.e. phacoemulsification and intraocular lens (IOL) implantation without injection of dexamethasone drug delivery system (DDS). The number of rescue interventions required, central macular thickness by optical coherence tomography (OCT), Early Treatment Diabetic Retinopathy Study (ETDRS) score, laser flare meter (LFM) values, intraocular pressure (IOP), and grade of diabetic retinopathy (DR) were recorded until three months follow up. Macular thickness and number of rescue medications between the treatment groups were the co-primary outcomes.

Results: A statistically significant interaction was present between treatment and time on OCT score (P < 0.001). The requirement of rescue interventions in the dexamethasone DDS group [40.2% (33/82)] was lesser as compared to the SOC group [49.3% (34/69)] at the end of 12 weeks [odds ratio (OR), 0.70 (0.36-1.33)] follow up although not statistically significant (P = 0.343). A statistically significant interaction was present between treatment and time on LFM score (P = 0.003). No statistically significant interaction was present between the treatment and time on visual acuity score (P = 0.08) and IOP score (P = 0.375).

Conclusion: Dexamethasone implant may have potential as a valuable therapy for patients undergoing cataract surgery with DR with/without macular edema with effects lasting for at least three months.