Longitudinal Detection of Radiation-Induced Peripapillary and Macular Retinal Capillary Ischemia Using Optical Coherence Tomography Angiography

Abstract Purpose To study longitudinal changes in retinal capillary circulation in eyes treated with iodine 125 (I-125) plaque brachytherapy for uveal melanoma using optical coherence tomography angiography (OCTA). Design Longitudinal prospective study of 21 subjects undergoing treatment for uveal melanoma with I-125 plaque brachytherapy. Eyes with melanoma were imaged with OCTA prior to treatment and at 12 month intervals until 2 years post-brachytherapy. Participants After IRB-approval, participants were enrolled prospectively from an academic ocular oncology clinic. Patients with low vision of Methods Peripapillary (4.5 x 4.5-mm) and macular (3 x 3-mm) OCTA scans were acquired with AngioVue (Optovue, Inc.). Main Outcome Measures The peripapillary nerve fiber layer plexus capillary density (NFLP_CD), macular superficial vascular complex vessel density (mSVC_VD) and foveal avascular zone (FAZ) area were calculated. Results Prior to treatment, there was no significant difference in the NFLP_CD, mSVC_VD, or FAZ area between eyes with melanoma and normal fellow eyes. By 24 months, 11 eyes had developed clinical signs of radiation retinopathy and/or radiation optic neuropathy. In treated eyes, the NFLP_CD (48.4 ± 4.1%) was reduced at 12 months (46.7 ± 5.0%; P=0.04, Wilcoxon signed-rank test) and 24 months (44.5 ±6.1%; P Conclusion OCTA demonstrates early emergence of peripapillary and macular capillary vasculature changes after I-125 plaque brachytherapy. OCTA provides a quantitative measurement of retinal capillary changes associated with ischemia that correlates with visual acuity and radiation dose and may predict future development of radiation-induced retinal toxicity.