In vivo measurement of lipofuscin in Stargardt's disease--Fundus flavimaculatus

Several histopathologic studies have concluded that Stargardt's disease (Fundus flavimaculatus) is associated with abnormally high levels of lipofuscin-like material in the retinal pigment epithelium. The purpose of this study was to determine whether this material has the same fluorescence characteristics as lipofuscin in vivo and whether noninvasive measurements identify a significant elevation in this material. Five patients with autosomal recessive Stargardt's disease were included in this study, as were 45 healthy controls. All patients had the angiographic dark choroid sign. The intensity and emission spectra of lipofuscin fluorescence were measured by noninvasive fundus spectrophotometry at 7 degrees temporal to the fovea. The fluorescence intensities in the five patients with Stargardt's disease were significantly higher (P < 0.0001) than those observed in normal subjects of the same age. The emission spectra in the patients are similar in shape to those measured in normals, but flecks appear to shift the spectra toward shorter wavelengths. The spectral characteristics of the fluorophore observed in patients with Stargardt's disease are consistent with those of retinal pigment epithelial lipofuscin. These patients have abnormally high levels of lipofuscin, confirming previous histopathologic observations. Noninvasive retinal pigment epithelial lipofuscin measurements may be a useful adjunct in the diagnosis of Stargardt's disease.-F. flavimaculatus.