Purpose:
To demonstrate the high concordance between eyes in visual acuity and in lesion size in patients with Stargardt disease
Methods:
Eighty–one patients with Stargardt disease were seen between 1997 and 2004. Baseline visual acuity, and baseline imaging fundus photographs, fluorescein angiograms, and scanning laser ophthalmoscope imaging and perimetry were compared between eyes. ImageJ software was used to calculate lesion size
Results:
The visual acuity and photographic features of these patients show striking concordance between the two eyes, but significant differences between patients. Figure 1 plots the visual acuity in the worse eye versus the better eye when the patient was first seen. Sixty four percent of patients had less than 1 line of acuity difference between the eyes, and 17% had 1 to 2 lines of acuity difference between eyes. For the 22 eyes with 2 or more years of follow–up, 16 (73%) had less than two lines of acuity difference between the two eyes at baseline. Eleven of these sixteen patients (69%) had the same number of lines of acuity lost in each eye by the last follow–up visit, four had a difference between eyes of one line of acuity loss, and only one patient had a difference of more than one line of acuity. Analysis of the baseline area of central hyperfluorescence on fluorescein angiography to date showed a mean area of 2.63 sq mm. Ten of the 16 patients analyzed (63%) had a difference in area between eyes of less than 20%.
Conclusions:
There is a high degree of concordance between eyes in visual acuity and in area of involvement in patients with Stargardt disease. Preliminary data suggest that in patients with similar visual acuity in the two eyes at baseline, there is likewise high concordance in the subsequent rate of visual loss. These data suggest that a trial of a uniocular therapy for Stargardt disease will require a small sample size to detect a difference between eyes.
Keywords: degenerations/dystrophies • macula/fovea