Adjuvant topical dorzolamide or timolol with intravitreal bevacizumab for diabetic macular edema: A double-blind randomized controlled trial

Diabetic macular edema (DME) is a leading cause of visual impairment among diabetic patients, primarily managed with intravitreal anti-VEGF agents such as bevacizumab. However, the exploration of adjunctive therapies to enhance treatment outcomes remains an area of ongoing research. This study investigated the effects of adjuvant topical dorzolamide or timolol in combination with intravitreal Bevacizumab (IVB) injections for treating DME. In this study, 34 patients (68 eyes) with bilateral DME were randomized to receive either topical dorzolamide 2% or timolol 0.5% in one eye, along with IVB injections in both eyes. The contralateral eye served as a control, receiving only IVB injections. Central macular thickness (CMT) and visual acuity (VA) were assessed at baseline and one month after the third injection. Results showed statistically significant decreases in CMT for all three groups (dorzolamide, timolol, and control) post-treatment compared to baseline (p < 0.001). Similarly, VA decreased significantly in all groups (p < 0.001). However, there were no statistically significant differences in CMT or VA between the dorzolamide or timolol groups and the control group. Our findings suggest that the addition of topical dorzolamide or timolol to IVB injections does not provide significant additional benefits in reducing CMT or improving VA in DME patients. Further research with larger cohorts and extended follow-up periods is needed to fully elucidate the potential role of adjunctive topical therapy in DME management and to identify patient subgroups that may benefit from this approach.