Effect of a single intravitreal bevacizumab injection on different optical coherence tomographic patterns of diabetic macular oedema.

Purpose: The aim of this study is to compare the therapeutic effect of a single intravitreal bevacizumab (IVB) injection in eyes with diabetic macular oedema (DMO) of different patterns determined by optical coherence tomography (OCT).

Methods: Medical records of patients who had a single IVB injection for DMO were analysed retrospectively. Eyes with a clinically significant DMO and a central foveal thickness (CFT) of 250 μm or more determined by OCT were included in the analysis. Best-corrected visual acuity (BCVA), CFT and total macular volume values before and after the injection were recorded. Eyes were divided into sponge-like diffuse retinal thickening (DRT), cystoid macular oedema (CMO) and serous retinal detachment (SRD) groups according to the morphology on OCT.

Results: A total of 92 eyes (42 with DRT, 31 with CMO and 19 with SRD) were included in the study. There was no statistically significant variation between three groups regarding the change in BCVA (P=0.695). CMO and SRD groups had greater reductions in their mean CFT, and the amount of reduction showed statistically significant variation between three groups (P=0.048). However, no statistically significant difference was found between groups in terms of percentage of change in CFT (P=0.278).

Conclusion: CMO and SRD subtypes are associated with a greater reduction in the CFT than the DRT subtype. Although the change in BCVA was not significantly different between groups, the DRT group showed markedly better visual improvement in proportion to the decrease in CFT.