Comparison of a Single Intravitreal Injection of Bevacizumab versus Triamcinolone Acetonide as Primary Treatment for Diffuse Diabetic Macular Edema: The Pan-American Collaborative Retina Study Group (PACORES)

Abstract

Purpose: : To compare the functional and anatomic outcomes of a single intravitreal injection of triamcinolone acetonide (IVT) versus a single intravitreal injection of bevacizumab (IVB) as primary treatment for diffuse diabetic macular edema (DDME).

Methods: : Retrospective multicenter interventional comparative case series. We reviewed the clinical records of 158 consecutive eyes with previously untreated DDME that were managed with a single intravitreal injection of 1.25 mg or 2.5 mg of IVB (77 eyes) or 4 mg of IVT (81 eyes). Patients were evaluated at 1, 3 and 6 months after the injection. The main outcome measures were central macular thickness (CMT) and Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA).

Results: : Both groups had a statistically significant improvement on BCVA and CMT from baseline at each follow-up time period (p < 0.001). However, when the mean BVCA improvement from baseline was compared between groups, this difference was not statistically significant. There was a mean of 3 lines improvement in BCVA in the IVB group versus a mean of 4 lines improvement in the IVT group (p = 0.39). CMT analysis demonstrated that the IVT group had a more significant decrease at each follow up time point (1, 3 and 6 months): 179.83 µm, 168.84 µm and 99.26 µm versus 113.48 µm, 66.32 µm and 39.12 µm in the IVB group, (p < 0.001).

Conclusions: : This short-term study suggests that both IVT (4 mg) and IVB (1.25 or 2.5 mg) may improve BCVA and CMT as primary treatment for DDME. However, a single injection of IVT seems to be more effective than IVB to reduce CMT for up to six months.

Keywords: diabetic retinopathy • retina