Intraretinal hyperreflective spots in eyes with radiation induced maculopathy

Abstract

AbstractPurpose To evaluate in vivo the presence of intraretinal hyperreflective spots in eyes with radiation induced maculopathy.Methods 25 subjects affected by maculopathy secondary to eye irradiation for a primary uveal melanoma were enrolled. All eyes previously underwent I‐125 brachytherapy with a standard apex dose (85 Gy). Full ophthalmic examination, including spectral domain‐OCT (SD‐OCT) and fluorescein angiography, was performed in all eyes. After segmentation of retinal layers, retinal images were analyzed for reflectivity changes (hyperreflectivity spots) at the level of: internal limiting membrane plus retinal nerve fiber layer (ILM+RNFL), inner nuclear layer plus outer plexiform layer (INL+OPL) and outer nuclear layer (ONL). Hyperreflective spots were analyzed in a full retinal section both in the foveal area, and between 500 and 1500 µm from the foveal center. All examinations were performed twice, by two independent masked graders. Results The inter‐grader agreement was at least substantial for all measurements. In all studied eyes hyperreflective spots were detected by SD‐OCT. Hyperreflective spots were mainly located in the inner retina (ILM+RNFL and INL+OPL) compared to the outer retina (ONL) (p<0.005), and their expression significantly progressed with the progression of macular (radiation induced) edema (p= 0.002). Conclusion The presence of hyperreflective spots may represent an in vivo biomarker of retinal microglia activation in radiation maculopathy, as previously shown in other macular disorders. This aspect may be related to the so‐called senescence process induced by irradiation of solid tumors. This phaenomenon may offer more tailored approaches for the treatment of radiation‐induced maculopathy.