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Eye (2010) 24, 491496& 2010 Macmillan Publishers Limited All rights reserved 0950-222X/10 $32.00
http://www.nature.com/eye
Web End =www.nature.com/eye
AW Scott and SB Bressler
Retinal angiomatous proliferation or retinal anastomosis to the lesion
CAMBRIDGEOPHTHALMOLOGICALSYMPOSIUM
Abstract
Much debate exists within the literature with respect to the variant of neovascular age-related macular degeneration (AMD) known as retinal angiomatous proliferation (RAP). We prefer the term retinal anastomosis to the lesion (RAL), as we believe that the choroidal neovascularization (CNV) lesion precedesthe development of an anastomosing retinal vessel to this lesion. Natural history data surrounding RAP lesions are available through analysis of the eyes with subfoveal occult CNV within the placebo arm of the Verteporn in Photodynamic Therapy (VIP) trial. Although many reports ascribe a poor prognosis to RAP lesions, the data suggest that the true natural history of RAP lesion may be highly variable and similar to that of other CNV lesions. Information from clinical trials suggests that the response of RAP lesions to CNV treatments may also be similar to that of other variants of neovascular AMD.
Eye (2010) 24, 491496; doi:http://dx.doi.org/10.1038/eye.2009.311
Web End =10.1038/eye.2009.311 ; published online 18 December 2009
Keywords: RAP; RAL; retinal angiomatous proliferation; retinal anastomosis to the lesion; type 3 neovascularization; occult choroidal neovascularization
Introduction
The variant of neovascular age-related macular degeneration (AMD), known as retinal angiomatous proliferation (RAP), representsan estimated 1012% of newly diagnosed neovascular AMD lesions.1,2 Multiple terms have been used to describe these lesions including deep retinal vascular anomalous complex and retinalchoroidal anastomosis.1,3
Don Gass proposed a classication scheme that straties neovascularization with respect to its
physical relationship to the retinal pigment epithelium (RPE).4 Type 1 neovascularization describes brovascular tissue that is posterior to the RPE, whereas Type 2 neovascularization refers to a brovascular complex that lies anterior to the RPE. Freund has proposed modifying the original Gass classication to add Type 3 neovascularization to refer to intraretinal neovascularization, as is suspected to occurin these RAP lesions.5,6
Yannuzzi et al. introduced the term retinal angiomatous proliferation to describe a vascular process that these authors believe originates within the neurosensory retina, beginning with capillary proliferation, formation of intraretinal neovascularization, and retinalretinal anastamoses. This retinal neovascularization then extends beneath the neurosensory retina to become subretinal neovascularization (SRN). With time, theSRN may merge with the...