Massive advancing non-exudative type 1 choroidal neovascularization in CTRP5 Late Onset Retinal Degeneration: longitudinal findings on multimodal imaging and implications for age-related macular degeneration.

Abstract

PURPOSE\nTo describe longitudinal multimodal imaging findings of non-exudative choroidal neovascularization (CNV) in CTRP5 late-onset retinal degeneration (CTRP5-LORD).\n\n\nMETHODS\nFour patients with CTRP5-positive LORD underwent repeated ophthalmoscopic examination and multimodal imaging. All four patients (two siblings and their cousins, from a pedigree described previously) had the heterozygous S163R mutation.\n\n\nRESULTS\nAll four patients demonstrated large subretinal lesions in the mid-peripheral retina of both eyes. The lesions were characterized by confluent hypercyanescence with hypocyanescent borders on indocyanine green angiography, faintly visible branching vascular networks with absent/minimal leakage on fluorescein angiography, type 1 neovascularization on OCT angiography, and absent retinal fluid, consistent with non-exudative CNV. The neovascular membranes enlarged substantially over time and the birth of new membranes was observed, but all lesions remained non-/minimally exudative. Without treatment, all involved retinal areas remained free of atrophy and subretinal fibrosis.\n\n\nCONCLUSION\nWe report the existence of massive advancing non-exudative type 1 CNV in CTRP5-LORD. These findings have implications for age-related macular degeneration (AMD). They provide a monogenic model system for studying the mechanisms underlying the distinct events of CNV development, enlargement, progression to exudation, and atrophy in AMD. They suggest that choroidal hypoperfusion precedes neovascularization and that non-exudative neovascularization may protect against atrophy.