Background: The purpose of the study was to ascertain the prevalence of retinal angiomatous proliferation (RAP) by means of dynamic indocyanine green angiography (d-ICGA) in patients with newly diagnosed fibrovascular pigment epithelium detachment (type 1) or late leakage of undetermined source (type 2) occult choroidal neovascularization (CNV) on fluorescein angiography.
Methods: We carried out a review of digital fluorescein and ICG angiograms obtained by confocal scanning laser ophthalmoscope (HRA; Heidelberg Engineering GmbH, Dossenheim, Germany) in 253 consecutive patients (270 eyes) with a clinical diagnosis of type 1 or type 2 occult CNV on fluorescein angiography (1998 through 2003).
Results: Sixty eyes had type 1 and 210 eyes type 2 occult CNV on fluorescein angiography. Overall, 57 cases of RAP were identified in 54 eyes (20%) with d-ICGA. RAP was present in 6 out of 60 eyes with type 1 (10%) and in 51 out of 210 eyes with type 2 occult CNV (24%). Mean distance of the lesion from the fovea was 682 +/- 304 microm (mean +/- SD).
Conclusions: d-ICGA is invaluable for early diagnosis of RAP in exudative age-related macular degeneration (ARMD). In our series, up to one fourth of type 2 occult CNV were in fact RAP.