The Responses of Different Types of Diabetic Macular Edema after Three Loading Doses of Anti-vascular Growth Factor: Outcomes in Two Medical Centers

Abstract

Background: Diabetic macular edema (DME) is currently treated by anti-vascular endothelial growth factor (anti-VEGF). Aim: The aim of this study was to evaluate the effect of intravitreal anti-VEGF in different types of DME classified by optical coherence tomography (OCT). Methods: This retrospective study included 161 treatment-naive eyes (116 patients) diagnosed with DME in two tertiary medical centers, which were classified into three groups according to initial OCT finding: diffuse retinal thickening (DRT), cystoid macular edema (CME), and serous retinal detachment (SRD). All eyes received three monthly loading doses of anti-VEGF. Primary and secondary outcomes were the improvement of best-corrected visual acuity (BCVA) and the decrease of central foveal thickness (CFT) on OCT, respectively. Results: Among the three groups, there was no significant difference in baseline BCVA (P = 0.137); however, the SRD group had the thickest baseline CFT (P < 0.001). After three loading doses of anti-VEGF, the BCVA of all three groups improved from baseline (DRT vs. CME vs. SRD, P = 0.0002, P < 0.0001, and P < 0.0001, respectively), while the SRD group seemed to have relatively better improvement among three groups although not significant (P = 0.051). The CFTs of all three groups significantly decreased from baseline (P < 0.0001 in all three groups). The CFT decreased the most in the SRD group, followed by the CME group, and the least in the DRT group (P < 0.001). Conclusion: Anti-VEGF therapy improved the anatomical structure and function in all types of DME; SRD responded the best.