Angiographic and OCT features of retinal angiomatous proliferation

Background To propose a classification system for retinal angiomatous proliferation (RAP) on the basis of the indocyanine green angiography (ICG). Methods Retrospective chart review of 55 eyes of 55 patients presenting with RAP. Fluorescein angiography (FA), ICG and optical coherence tomography (OCT) were used to evaluate the patients. Results All RAP lesions appeared as occult or minimally classic CNV on FA without clear evidence of pigment epithelium detachment (PED). We were able to identify five different patterns of RAP on the basis of ICG. These were focal (27.2%), irregular (21.8%), circular (21.8%), multifocal (18.2%), and combined (10.9%) hyperfluorescence. The sudden termination of retinal vessel course sign was observed in 14 of 55 eyes (25.4%), which had a circular or irregular pattern on the ICG. Only the circular RAP exhibited a late hypofluorescence ('wash out') with staining of the surrounding tissue on the ICG. Forty eight of 55 eyes (86%) had PED according to the OCT. Out of these 48 eyes, 19 had intraretinal fluid (IRF) alone, and the rest had IRF and subretinal fluid. The eight eyes (14%) without PED belonged to the focal hyperfluorescence group and the fluid was located intraretinally in cystic spaces. In addition, in four eyes (7%) with coexisting CNV a band of tissue beneath the RAP protruding in the PED was observed. Conclusion We propose a classification system for RAP on the basis of ICG and present the angiographic and OCT findings of these lesions. These data may further aid in the early diagnosis of RAP and can be also used for prognosis and clinical course documentation. Eye (2010) 24, 1633-1643; doi: 10.1038/eye.2010.134; published online 29 October 2010