Response to anti-VEGF injections for diabetic macular edema among patients on chronic exogenous insulin therapy

Abstract Purpose Diabetic macular edema (DME) is a leading cause of vision loss in diabetic patients worldwide. This study assessed whether there was a difference in functional and anatomic responsiveness to anti-VEGF therapy for DME among patients on chronic exogenous insulin therapy. Methods This was a single-center retrospective cohort study of patients diagnosed with DME between 2014 and 2022. Patients were divided into two groups: those who were treated with exogenous insulin and those who were not. Treatment characteristics such as the type and total number of anti-VEGF injections, the use of intravitreal or periocular steroids, and length of follow-up were recorded from patient charts. Functional and anatomic ocular characteristics were measured at baseline and six-month intervals up to 24 months from the time of DME diagnosis. The main outcome measures were change in best corrected visual acuity (BCVA), central foveal thickness (CFT), and macular volume (MV). Results 101 patients (148 eyes) met the criteria for inclusion in this study. 82 patients (81.2%) used insulin while 19 patients (18.8%) did not. There were no significant differences in the stage of diabetic retinopathy, BCVA, CFT, or MV at baseline between the two groups. Patients in the no insulin group received more steroid injections in the first 12 months of treatment (0.8 vs. 0.2, p = 0.003); however, there were no significant differences in final BCVA, CFT, or MV between groups after 24 months ( p > 0.05). Conclusion The results of this study suggest that the chronic use of exogenous insulin may not influence the functional or anatomic response to anti-VEGF injections.