Vitreoretinal interface abnormalities in diabetic macular edema and effectiveness of anti-VEGF therapy: an optical coherence tomography study

Purpose To study vitreoretinal interface (VRI) abnormalities in diabetic macular edema (DME) and the influence of these on the effectiveness of intravitreal anti-vascular endothelial growth factor (VEGF) therapy. Methods VRI status and central retinal thickness (CRT) were evaluated using line and 3D-reference scans obtained using spectral domain-optical coherence tomography RTVue-100 before and 1 month after intravitreal anti-VEGF injection (IVI). VRI status was categorized into five subgroups: normal VRI, retinal surface wrinkling associated with the eccentric epiretinal membrane (ERM), ERM involving the macular center, vitreomacular adhesion (VMA), and vitreomacular traction (VMT). Results A total of 105 eyes of 89 patients were included in the study. One month after IVI, the mean change of CRT in normal VRI eyes and eyes with VRI abnormalities was -128.0±144.7 µm and -53.0±96.4 µm (p<0.05), respectively. The mean change of CRT 1 month after IVI in each subgroup with VRI abnormalities, apart from the subgroup with retinal wrinkling associated with eccentric ERM, was statistically significantly lower compared to the eyes with normal VRI (p<0.05). Conclusion VRI abnormalities significantly reduce the effectiveness of intravitreal anti-VEGF therapy in eyes with DME. Eyes with noticeable changes of VRI, including ERM involving the macular center, VMA, and VMT have a poorer response to anti-VEGF therapy compared to eyes with normal VRI or eccentric ERM.