PURPOSE. To evaluate differences in fluorescein angiography (FA) and indocyanine green angiography (ICGA), findings between subjects affected by Stargardt disease (STGD) and atrophic AMD.METHODS. This was a consecutive, cross-sectional case series. A total of 24 eyes of 12 patients with STGD and 23 eyes of 14 patients with atrophic AMD were enrolled in the study. Patients underwent dynamic simultaneous FA and ICGA using a dual beam confocal scanning system. Images were recorded from the initial filling of choroidal and retinal vessels throughout all the phases of the angiogram. Spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence were also executed. FA and ICGA findings in the two groups were evaluated.RESULTS. In 92% (22/24) of eyes affected by STGD, ICGA showed hypocyanescence from the areas of atrophy, more evident in the late phases. This finding, defined as ICGA-imaged ''dark atrophy,'' was present in only 13% (3/23) of the eyes affected by atrophic AMD. The remaining eyes in both groups showed iso-or mild hypercyanescence from the areas of atrophy. Eyes with ICGA-imaged dark atrophy, both in STGD and in atrophic AMD groups, did not show early obscuration of the choroidal vessels by FA. SD-OCT revealed morphologically intact choroid in STGD patients with ICGA-imaged dark atrophy. In atrophic AMD eyes with ICGA-imaged dark atrophy, SD-OCT revealed a severely thinned choroid.
CONCLUSIONS.Hypocyanescence by ICGA from the areas of atrophy was more frequent in STGD compared with atrophic AMD. This finding, along with SD-OCT evidence of intact choroid, suggests a possible selective damage of the choriocapillaris in STGD. (Invest Ophthalmol Vis Sci. 2012;53:3999-4004) DOI:10.1167/iovs.11-9258 R ecessive Stargardt disease (STGD) and age-related macular degeneration (AMD) lead to progressive and severe visual acuity loss. STGD is one of the most common inherited retinal dystrophies, while AMD is the most important cause of central visual acuity loss in western countries. STGD typically appears before age 20. It exhibits simple Mendelian transmission and is caused by mutations in the ABCA4 gene. A reduction in ABCA4 activity in the photoreceptors results in the increased production and accumulation of A2E and related bisretinoids within RPE cells.1,2 These compounds cannot be readily metabolized and have negative effects on RPE cell function and viability. 2 The result of these pathogenic elements is a progressive loss of RPE and photoreceptors. In contrast, AMD, which typically appears in the sixth decade, has an acquired etiology with a progressive and multifactorial pathology. RPE damage constitutes the initial event.3,4 RPE cell loss might originate from several mechanisms, including photooxidative stress, 5 vascular alterations, 6,7 and deposition of toxic lipofuscin material under RPE. 1 In the atrophic form of AMD, these alterations lead to progressive loss of RPE and photoreceptor cells.Fluorescein angiography (FA) and indocyanine green angiography (ICGA) are important tools for...