Abstract
Purpose:
Stargardt disease is characterized by distinct patterns of increased and decreased signals on near-infrared (NIR) and short wavelength (SW; blue) fundus autofluorescence (AF) imaging. The aim of this study was to evaluate the structure-function correlation between patterns on fundus AF images and maps of retinal sensitivity derived from microperimetry testing.
Methods:
Fifty eyes of 25 patients with Stargardt disease underwent functional testing using fundus controlled perimetry (MAIA, CenterVue, Italy). A confocal scanning laser ophthalmoscope (HRA2, Heidelberg Engineering, Germany) was used for recording NIR-and SW fundus AF. Disease-related patterns on AF images were categorized as follows: 1) no pattern, 2) granular pattern, 3) bright > dark flecked pattern, 4) dark > bright flecked pattern, 5) dark pattern and 6) atrophic lesions. Retinal sensitivity along a horizontal line of 15° eccentricity through the fovea was compared between these regions.
Results:
Pattern-related retinal sensitivity was not different between both eyes of each patient (ANOVA; p=0.16 and p=0.54 for SW- and NIR-fundus AF, respectively). Borders between consecutive patterns on NIR-fundus AF images were more eccentric compared to equivalent borders on SW- fundus AF images. For both SW- and NIR fundus AF retinal sensitivity was different between patterns (ANOVA, p<0.0001; post hoc test, p<0.0001 to p=0.047) except for the comparison between patterns 1 and 2 (p=0.06 and p=0.98 for SW- and NIR fundus AF, respectively), as well as between patterns 2 and 3 (p=0.42 and p=0.05 for SW- and NIR fundus AF, respectively). The largest drop in retinal sensitivity was observed at the border to regions with predominantly dark pattern in both SW- and NIR- fundus AF (mean retinal sensitivity [dB±SEM], SW fundus AF: 1 = 23.33±0.81, 2 = 19.94±1.45, 3 = 16.60±1.53, 4 = 9.27±1.43, 5 = 4.13±1.18, 6 = 0.58±0.35; NIR fundus AF: 1 = 24.08±0.58, 2 = 23.66±0.67, 3 = 19.38±1.33, 4 = 12.62±1.48, 5 = 2.97±0.67, 6 = 0.71±0.41).
Conclusions:
Structure-function correlations reveal consistent functional deficits of fundus AF patterns in Stargardt disease. In both, SW- and NIR fundus AF the transition to a predominantly dark pattern is associated with a marked impairment of retinal sensitivity. Areas of equivalent patterns on NIR fundus AF images exceed those on SW fundus AF, suggesting superiority of NIR- fundus AF imaging to indicate early functional alterations.
Keywords: 696 retinal degenerations: hereditary •
550 imaging/image analysis: clinical •
642 perimetry