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PURPOSE To characterize the intrinsic fluorescence (autofluorescence) of the human ocular fundus with regard to its excitation and emission spectra, age relationship, retinal location, and topography, and to identify the dominant fluorophore among the fundus layers. METHODS Using a novel fundus spectrophotometer, fluorescence measurements were made at 7(More)
PURPOSE To test the hypothesis that hypoxia induces retinal neovascularization. METHODS To produce relative hypoxia in the avascular retina, newborn rats were exposed for 11 days to 80% oxygen interrupted daily by short episodes in room air. Episodes in room air lasted 1/2 hour or 1 hour followed by abrupt reintroduction, or 1/2 hour followed by(More)
PURPOSE Inferential evidence indicates that macular pigments (lutein and zeaxanthin) protect photoreceptors and/or retard age-related macular degeneration. These experiments tested the hypothesis that retinal zeaxanthin prevents light-induced photoreceptor cell death. METHODS Retinal damage was assessed in quail fed a carotenoid-deficient (C-) diet for 6(More)
PURPOSE 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(More)
Cultured porcine retinal pigment epithelial cells release superoxide, measured as superoxide dismutase (SOD)-suppressible reduction of cytochrome C, and SOD-suppressible luminol-dependent chemiluminescence. Latex beads stimulated a significant release of superoxide that reached 82 nmol/mg protein in the first 15 min and declined thereafter. Formation of an(More)
PURPOSE To characterize the age-related accumulation of lipofuscin in a population of normal subjects, resolve differences in estimated accumulation rates obtained in previous studies, and characterize the spatial distribution of lipofuscin in the normal fundus. METHODS Spectrophotometric measurements were made at the fovea and 7 degrees temporal to the(More)
We examined the impact of aging on the numbers of photoreceptors and retinal pigment epithelium (RPE) cells, and the number of photoreceptors per RPE cell profile, in selected regions of 30 human eyes. The mean ratio of photoreceptors to RPE cell was higher in the macula than in the paramacula (P less than 0.01) or the equatorial area (P less than 0.001).(More)
PURPOSE To determine whether drusen in patients with age-related maculopathy and macular degeneration (ARM/AMD) are associated with focal changes in retinal pigment epithelium (RPE) lipofuscin fluorescence. METHOD A new autofluorescence imaging device was used to study lipofuscin distribution associated with individual drusen in 20 patients with ARM/AMD.(More)
To test the hypothesis that oxidative damage associated with tissue hypoxia plays a role in neovascularization, a lipid hydroperoxide (LHP) was injected into the vitreous of rabbits. Single injections of LHP (50-600 microg) caused a sustained retinal neovascularization visualized clinically by ophthalmoscopy and confirmed by microscopy. Vasodilators, i.e.(More)
PURPOSE The xanthophyll carotenoids (lutein and zeaxanthin) are hypothesized to delay progression of age-related macular degeneration. The quail has a cone-dominant retina that accumulates carotenoids. The purpose of these experiments was to characterize the carotenoid composition of retina, serum, liver, and fat in quail and to determine whether dietary(More)