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Purpose To describe the enlargement of the dense scotoma over time in Stargardt disease and to highlight methodologic issues in tracking enlargement. Methods Retrospective study of patients with full mapping of the border of the dense scotoma using the MP-1 for at least two visits. Results 14 eyes of 7 patients met this criterion. Patients had median of 3 visits (range 2-5), with median total follow-up of 4.5 years (range 1.5-8). Mean baseline visual acuity was 20/56 (range 20/25-20/200), mean baseline dense scotoma area was 2.23 mm (range 0.41-5.48), and mean dense scotoma enlargement rate was 1.36 mm/year (range 0.22-2.91). The younger patients tended to have more rapid loss of visual acuity, which tended to plateau when the visual acuity was 20/100 or worse. The patients who developed Stargardt before age 20 years, and the single patient who developed Stargardt disease after age 40 years, had more rapid enlargement rates, with preservation of central vision in the oldest patient. The ability to precisely define the dense scotoma area was dependent on the density location of the points tested; this led to significant variability in the assessment of the scotoma enlargement rate in three of the seven patients. The dense scotoma was not described adequately by the extent of the homogeneous dark area on fundus autofluorescence imaging. Conclusion Microperimetry is necessary for mapping the scotoma in patients with Stargardt disease, because current imaging is not adequate. Standardized grid testing, plus a standardized procedure for refining the border of the dense scotoma, should allow more precise testing and longitudinal assessment of enlargement rates.

To develop a computer-based image segmentation method for standardizing the quantification of geographic atrophy (GA).The authors present an automated image segmentation method based on the fuzzy c-means clustering algorithm for the detection of GA lesions. The method is evaluated by comparing computerized segmentation against outlines of GA drawn by an expert grader for a longitudinal series of fundus autofluorescence images with paired 30° color fundus photographs for 10 patients.The automated segmentation method showed excellent agreement with an expert grader for fundus autofluorescence images, achieving a performance level of 94 ± 5% sensitivity and 98 ± 2% specificity on a per-pixel basis for the detection of GA area, but performed less well on color fundus photographs with a sensitivity of 47 ± 26% and specificity of 98 ± 2%. The segmentation algorithm identified 75 ± 16% of the GA border correctly in fundus autofluorescence images compared with just 42 ± 25% for color fundus photographs.The results of this study demonstrate a promising computerized segmentation method that may enhance the reproducibility of GA measurement and provide an objective strategy to assist an expert in the grading of images.

Purpose: To demonstrate the potential and limits of autofluorescence imaging in identifying and delineating areas of atrophy. Methods: Fundus photographs and infrared scanning laser ophthalmoscope (SLO) imaging, SLO macular perimetry, and SLO autofluorescence imaging results were compared for two patients with geographic atrophy (GA) from age-related macular degeneration, one patient with pigmentary alteration of the retina, and two patients with Stargardt disease. The main outcome measure in this case series was the presence of reduced autofluorescence. Results: Drusen may become undetectable during autofluorescence imaging for some patients, allowing simple identification of areas of GA with areas of reduced autofluorescence. In other patients, drusen themselves have decreased autofluorescence, despite having intact retinal function in the retina overlying them. Some patients may have areas of reduced autofluorescence that persist for many years, without evidence of the development of atrophy. In Stargardt disease, decreased autofluorescence can easily detect and delineate areas of scotoma. Areas with mottled autofluorescence may have overlying function, but the function may not be adequate to support a fixation locus in that area. Conclusions: Using decreased autofluorescence to delineate areas of atrophy may be helpful in atrophic macular disorders. For GA, correlation with fundus photographs or macular perimetry findings may be necessary to differentiate between drusen and atrophy. For Stargardt disease, the nature of areas of decreased autofluorescence may help explain visual function of those areas.