Characteristics of Retinal Angiomatous Proliferation Confined to the Neurosensory Retina as Imaged by Fundus Photography, Fluorescein Angiography, and ICG Angiography

Abstract

Abstract: : Purpose: To describe the clinical and angiographic features of retinal angiomatous proliferation (RAP) confined to the neurosensory retina in eyes with no choroidal neovascularization (CNV). Methods: Consecutive patients over the age of 55 with the clinical diagnosis of neovascular age–related macular degeneration with macular edema were studied with fluorescein angiography (FA), indocyanine green video angiography (ICG–A) and fundus photography. Cases with RAP confined to the neurosensory retina were included; eyes with any CNV were excluded. Results: Ninety one eyes (80 patients) had RAP confined exclusively to the neurosensory retina. Sixty–three (79%) were women; 17 (21%) were men. Ten women and one man had bilateral RAP. VA ranged from 20/20 to less than 20/400 (mean = 20/120.) Clearly defined inner retinal vascular abnormalities (124 lesions in 91 eyes) were identified on ICG–A in all and were classified into four categories: focal: 56/124 (45.2%), circular: 35/124 (28.2%), non–circular geometric: 14/124 (11.3%), and more complex lesions: 19/124 (15.3%). Color photographs revealed no drusen: 42 (46%), intraretinal hemorrhages: 61 (67%), lipid: 41 (45%), and geographic atrophy: 24 (26%). In 58/61 eyes (95%) with hemorhage, the blood was within 200 microns of the RAP. On FA 59/91 eyes (65%) had some occult CNV component; in 23/91 (25%) PED was the only lesion, but 18/91 (20%) had PED with some other lesion component. 4% had classic CNV. Of the 91 eyes, 89 (98 %) had some lesion component of either PED or occult CNV. Conclusions: Early RAP is a form of intraretinal NV. RAP lesions are indistinguishable from various forms of true CNV when FA is the only test used. ICG–A can clearly identify those eyes in which all leakage is from discrete intraretinal neovascular lesions (RAP) and distinguish them from classic and occult CNV. RAP lesions leak profusely and cause edema out of proportion to their size. They are frequently found in eyes with a FA pattern of occult CNV or with a PED and are usually located near the intraretinal hemorrhage they cause. ICG–A is essential to identify the differing forms of RAP and to distinguish RAP from the more prevalent CNV.

Keywords: retinal neovascularization • age-related macular degeneration • imaging/image analysis: clinical