Evaluation of retinal ganglion cell layer in patients with macular edema treated with intravitreal anti-VEFG and corticosteroid

Purpose: The aim of the study is to detect the effect of the different intravitreal therapies (anti-VEFG drugs and corticosteroids) on the single layer of retinal ganglion cells (GCL) in patients affected by macular edema. Methods: Forty (17 males/23 females) Caucasian patients (40 eyes) affected by macular edema treated with intravitreal injections (anti-VEGF and steroids) are included. Spectralis HRA-OCT device with a specific protocol for the acquisition and evaluation of the GCL layer has been used. Macular GCL thickness is assessed with automated retinal segmentation based on ETDRS grid rings. Retinal layer automated segmentation is carefully assessed and manually corrected for any misalignment. GCL measurements are correlated with best-corrected visual acuity (BCVA) measured with Early Treatment Diabetic Retinopathy Study (ETDRS), central macular thickness (CMT) and intraocular pressure (IOP). All patients have been evaluated at baseline and at the subsequent follow-up: 4 weeks, 8 weeks and 12 weeks. Results: Neither anti-VEFG drugs (Bevacizumab, Ranibizumab and Aflibercept) nor corticosteroids (Dexametasone) has a significant effect on GCL layers during three months of follow up compared to long-term treatments. A significant correlation between GCL and ETDRS has found (p=0.0453, R2=0.023). Conclusions: This study shows that anti-VEFG drugs and corticosteroids do not significantly affect GCL layer over three months of treatment. This study also demonstrates that the ganglion cell layer is correlated to visual acuity, an important factor for future investigations on the effects of new treatments.