Abstract
Purpose :
We wanted to assess the quality of images of photoreceptors and cone density in parafoveal region using the High Magnification Module of Heidelberg Spectralis in patients with age-related macular degeneration.
Methods :
We captured 8x8-degree area on primary gaze using the high magnification lens of the Heidelberg Spectralis in high-resolution mode. 10 eyes of 6 subjects with age-related macular degeneration were imaged. A 2mm pupil diameter was achieved by illuminating the fellow eye with a flashlight to eliminate the diffraction from astigmatic errors. We analyzed 200 x 200 µm within 5 degrees from the fixation. Using the image J, we estimated for the cone density and computed for the proportion to the number of cones/mm2.
Results :
Astigmatic errors can be reduced by taking the scans through a pupil of less than 3mm. The mean cone density in our study was 10992 cones/mm2 (±1460.07) in 6 patients (mean age of 80 years) compared to 14,988 cones/mm2 (±1403.15) in non-AMD eyes (Mendonça et al.) in 8 patients (mean age of 33 years). Our patient population is significantly older, and as expected, analysis of regions in each macula shows more photoreceptor loss in areas of drusen in younger and non-AMD eyes (Mendonça).
Conclusions :
We found that elderly patients have reduced number of cone count compared to younger patients. Areas adjoining drusen have particularly lower cone counts. Drusen and age are associated with reduced global and focal macular density. The high magnification SLO using narrow aperture does permit study of regional and focal cone density without adaptive optics.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.