Retinal angiomatous proliferation in age-relatedd mscular degeneration

NG Ghazi - Retina, 2002 - journals.lww.com
NG Ghazi
Retina, 2002journals.lww.com
I read the article by Yannuzzi et al 1 with a great deal of interest. The authors retrospectively
reviewed the clinical and angiographic characteristics of 143 eyes (108 patients) with
neovascular age-related macular degeneration (ARMD) with retinal angiomatous
proliferation (RAP), most of which were previously classified as having neovascular ARMD
with retinal–choroidal anastomosis (RCA). They also proposed a theoretical sequence of
events, or staging system of the neovascular process, based on their observations. Occult …
I read the article by Yannuzzi et al 1 with a great deal of interest. The authors retrospectively reviewed the clinical and angiographic characteristics of 143 eyes (108 patients) with neovascular age-related macular degeneration (ARMD) with retinal angiomatous proliferation (RAP), most of which were previously classified as having neovascular ARMD with retinal–choroidal anastomosis (RCA). They also proposed a theoretical sequence of events, or staging system of the neovascular process, based on their observations. Occult choroidal neovascularization (CNV) or minimally classic CNV secondary to ARMD was the most common initial misdiagnosis in all these cases, regardless of the stage of RAP eventually assigned to each of these cases after review of clinical and angiographic findings. RAP, a new phenotype of neovascular ARMD, shares very similar characteristics with idiopathic parafoveal telangiectasia. 2 In fact, the characteristics of the vascular anomaly are almost identical in both entities that are differentiated by drusen and retinal pigment epithelium (RPE) changes that accompany ARMD-related RAP. In the absence of definite histologic evidence of its existence, 3 RAP remains a speculative clinical entity.
The authors proposed three stages of RAP: stage 1, or intraretinal neovascularization (IRN); stage 2, or subretinal neovascularization (SRN); and stage 3, or CNV. IRN, which was present in 41% of the cases, is characterized by the development of a mound of intraretinal capillary proliferation in the extramacular area and is usually symptomatic. Multiple small intraretinal hemorrhages, intraretinal leakage, and surrounding retinal telangiectatic vessels are typical associated findings. Fluorescein angiography (FA) in these cases discloses the sea urchin–like intraretinal angiomatous complex. Indocyanine green angiography (ICG) is not needed in these early cases, but when performed discloses a focal area of intense hyperfluorescence—a hot spot—within the retina, and corresponds to the area of IRN. A retinal–retinal anastomosis (RRA) characterized by prominent dilated perfusing arteriole (s) and/or draining venule (s) is present in 30% of the cases. This stage of the neovascular process is easy to diagnose according to the authors, but 61% of their cases were initially misdiagnosed with occult CNV. Careful stereoscopic biomicroscopic and angiographic assessment of the lesion and associated findings is essential in reaching the exact diagnosis of the retinal angiomatous process.
Lippincott Williams & Wilkins