Abstract
Purpose :
To evaluate the impact of insulin use on visual and anatomic response to aflibercept, bevacizumab, and ranibizumab in patients with diabetic macular edema (DME) during the DRCR.net protocol I, S, and T trials.
Methods :
A post-hoc analysis of randomized clinical trial data from DRCR.net protocols I, S, and T was performed using a multivariate linear regression. Patients treated with intravitreal bevacizumab 1.25 mg, aflibercept 2 mg, or ranibizumab 0.3 mg and 0.5 mg at monthly intervals were included. Changes in visual acuity (VA) assessed with Early Treatment Diabetic Retinopathy Study (ETDRS) letters and central macular thickness (CMT) measured by optical coherence tomography at 1, 3, and 12 months of treatment were compared among those using insulin and those who were not. Controlling factors were gender, race, ethnicity, age, diabetes duration, hypertension and smoking status, hemoglobin A1C, albumin/creatinine ratio, baseline VA, history of anti-VEGF in the year prior to study onset, history of laser treatment, injection number over 12 months of the study period, and lens status.
Results :
204 patients (144 using insulin, 60 not using insulin) and 193 patients (116 using insulin, 77 not using insulin) were treated with 0.3 mg and 0.5 mg ranibizumab respectively. 283 (182 using insulin, 101 not using insulin) and 224 (145 using insulin, 79 not using insulin) were treated with bevacizumab and aflibercept respectively. Patients using insulin had significantly less improvement in VA after 12 months of monthly 0.3 mg ranibizumab injections (10.4 vs 13.2 gain in ETDRS letters; p = 0.0293). Patients using insulin had significantly less improvement in CMT after 12 months of monthly 0.5 mg ranibizumab injections (108 vs 160 μm improvement; p = 0.0169). There were no significant differences in VA or CMT improvement between insulin and non-insulin users at 1, 3, or 12 months for those treated with bevacizumab or aflibercept.
Conclusions :
Insulin use is associated with less improvement in VA and CMT after 12 months of monthly ranibizumab treatment in patients treated under DRCR.net protocols I, S, and T. Insulin use had no impact on visual or anatomic outcomes in those treated with aflibercept or bevacizumab. This may be useful for counseling and treatment planning in patients with DME.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.