Retinal Vascular Changes in Radiation Maculopathy after Intravitreal Ranibizumab by Optical Coherence Tomography Angiography

In this prospective study, we investigated the structural and vascular retinal changes at baseline and after Ranibizumab injections at the last follow up to one year in patients affected by Radiation Maculopathy (RM) after plaque brachytheraphy in choroidal melanoma, using Spectral Domain Optical Coherence Tomography (SD-OCT) and OCT Angiography (OCTA). A total of 40 eyes with RM of 40 patients (18 females, 22 males, mean age 51.9 +/- 11 years) that underwent ruthenium-106 plaque brachytherapy were included. All patients received one monthly intravitreal injection of Ranibizumab (Pro Re Nata regimen). We analyzed the Foveal Avascular Zone (FAZ) area, the retinal vessel density (VD) of the superficial capillary plexus (SCP) and of the deep capillary plexus (DCP), using OCTA, and we detected the Central Foveal Thickness (CFT) by SD-OCT at baseline and after treatment. At the last follow up, we found a significant improvement of the CFT (p< 0.001) while OCTA parameters revealed no change in VD of the SCP (p= 0.402), DCP (p= 0.282), and FAZ area (p= 0.255), resulting in a stabilization of the visual acuity (p= 0.210) respect to baseline. The absence of functional improvement, despite the anatomical recovery of the macula, could be due to the absence of improvement in FAZ area and in retinal VD after treatment. OCTA parameters could represent predictive biomarkers to anti-vascular endothelial growth factor (anti-VEGF) intravitreal response and to help to better understand the physiopathological mechanisms of the RM.