Natural history of phenotypic changes in Stargardt macular dystrophy.
ABSTRACT Stargardt macular dystrophy is the most common form of juvenile onset macular degeneration. This article reviews the four stages through which this dystrophy may progress. Also, reviewed here are the variations that may be observed in the visual acuity of patients with Stargardt disease.
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ABSTRACT: Purpose: To quantify fundus autofluorescence (qAF) in patients with recessive Stargardt disease (STGD1). Methods: 42 STGD1 patients (ages: 7-52 years) with at least one confirmed disease-associated ABCA4 mutation were studied. Fundus AF images (488 nm excitation) were acquired with a confocal scanning laser ophthalmoscope equipped with an internal fluorescent reference to account for variable laser power and detector sensitivity. The gray levels (GLs) of each image were calibrated to the reference, zero GL, magnification, and normative optical media density to yield qAF. Texture factor (TF) was calculated to characterize inhomogeneities in the AF image and patients were assigned to the phenotypes of Fishman I-III. Results: qAF in 35/42 patients and TF in 27/42 patients were above normal limits for age. Young patients exhibited the relatively highest qAF, with levels up to 8-fold higher than healthy eyes. qAF and TF were higher in Fishman II and III than Fishman I, who had higher qAF and TF than healthy eyes. Patients carrying the G1916E mutation had lower qAF and TF than most other patients, even in the presence of a second allele associated with severe disease. Conclusions: qAF is an indirect approach to measuring RPE lipofuscin in vivo. We report that ABCA4 mutations cause significantly elevated qAF, consistent with previous reports indicating that increased RPE lipofuscin is a hallmark of STGD1. Even when qualitative differences in fundus AF images are not evident, qAF can elucidate phenotypic variation. qAF will serve to establish genotype-phenotype correlations and as an outcome measure in clinical trials.Investigative ophthalmology & visual science 03/2014; · 3.43 Impact Factor
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ABSTRACT: Retinal degeneration represents a huge burden of blinding disease, and currently there are no effective treatments that reverse the most common causes of neural retinal degeneration. Stem cell biology has the potential to significantly ease this burden, not only through the development of disease models of retinal degeneration but also in the manufacture of a replacement for the neural retinal tissue. This review summarizes the major advancements in the last decade in the field of neural retinal regeneration with an emphasis on the differentiation of embryonic and induced pluripotent stem cells into cells with retinal and specifically photoreceptor characteristics. © 2014 S. Karger AG, Basel.Developments in ophthalmology 01/2014; 53:97-110.
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ABSTRACT: To investigate psychophysical thresholds in Stargardt disease with the full-field stimulus test (FST). Visual acuity, spectral domain optical coherence tomography, full-field electroretinogram, and FST measurements were made in 1 eye of 24 patients with Stargardt disease. Dark-adapted rod FST thresholds were measured with short-wavelength stimuli, and cone FST thresholds were obtained from the cone plateau phase of dark adaptation using long-wavelength stimuli. Correlation coefficients were calculated for FST thresholds versus macular thickness, visual acuity, and electroretinogram amplitudes. The Stargardt disease patients' FST cone thresholds correlated significantly with visual acuity, macular thickness, and electroretinogram cone response amplitudes (all P < 0.01). The patients' FST rod thresholds correlated with electroretinogram rod response amplitudes (P < 0.01) but not macular thickness (P = 0.05). All patients with Stargardt disease with flecks confined to the macula, and most of the patients with flecks extending outside of the macula had normal FST thresholds. All patients with extramacular atrophic changes had elevated FST cone thresholds and most had elevated FST rod thresholds. Full-field stimulus test rod and cone threshold elevation in patients with Stargardt disease correlated well with measures of structure and function, as well as ophthalmoscopic retinal appearance. The Full-field stimulus test appears to be a useful tool for assessing rod and cone function in Stargardt disease.Retina (Philadelphia, Pa.) 04/2014; · 2.93 Impact Factor