Longitudinal Changes in Ganglion Cell Complex Thickness Before and After Intravitreal Bevacizumab Injections in...

Background/Objectives: Diabetic macular edema (DME) is a major cause of vision impairment in patients with diabetes mellitus, and intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy is widely used for its management. However, the longitudinal effects of anti-VEGF treatment on the ganglion cell complex (GCC) remain unclear. This study evaluated changes in GCC thickness in eyes with DME following intravitreal bevacizumab injections over a one-year period. Methods: In this retrospective observational study, 55 eyes from 55 patients with DME who received intravitreal bevacizumab injections were analyzed. Central foveal thickness (CFT), total macular volume (TMV), and retinal layer thicknesses including the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and GCC were measured using spectral-domain optical coherence tomography and compared with those of fellow eyes without DME. Results: At baseline, eyes with DME showed significantly greater CFT, TMV, RNFL, IPL, and GCC thickness compared with fellow eyes. After one year of treatment, CFT and TMV decreased significantly, and significant reductions were also observed in RNFL, GCL, IPL, and GCC thickness. At the one-year follow-up, GCC and inner retinal layer thicknesses were no longer significantly different between DME and fellow eyes. Multiple regression analysis showed that final visual acuity was associated with baseline visual acuity and CFT at one year, but not with GCC thickness. Conclusions: These findings suggest that the reduction in GCC thickness after bevacizumab treatment may reflect anatomical normalization following edema resolution rather than true ganglion cell loss. Further studies with larger cohorts and longer follow-up are required to clarify the long-term effects of anti-VEGF therapy on retinal neurostructure.