Abstract
Purpose :
To assess cone photoreceptor survival in the human eye with age-related macular degeneration (AMD), using adaptive optics scanning laser ophthalmoscopy (AOSLO) and spectral-domain optical coherence tomography (SDOCT).
Methods :
AOSLO was performed to image cones in central 20°of the retinae. A 2-dimensional normative macular cone density map was obtained in 29 eyes of 18 subjects aged 67.1 ± 10.8 years without evidence of any macular disease. In 10 eyes of 7 patients with intermediate stage AMD including 5 eyes with predominantly subretinal drusenoid deposits (SDD) and 5 eyes with classical drusen but without SDD, AOSLO and SDOCT were acquired 4 times over 39.6 ± 3.3 months. Retinal regions absent of AMD lesions were ascertained by reflectivity and packing structure of the cones imaged by AOSLO, and by the integrity of the cross-sectional structure in SDOCT. Cone density change was evaluated using linear regression at 1174 loci in these regions. The change of the proportion of retinal loci with cone density lower than normal values was estimated among the locations where cone density could be measured at both the baseline and the 4th visit, including 197 loci in eyes with SDD and 268 in eyes with drusen but without SDD.
Results :
Cone density decreased over time at 98.3% (1154/1174) of the examined locations. In eyes with SDD, cone density declined with a slope of -160 ± 75 cones/degree2/year in the central 5° of the retina and with a slope of -59 ± 24 cones/degree2/year in the 5°-10° surrounding annular zone. In eyes with drusen but without SDD, cone density reduction slopes were -98 ± 48 cones/degree2/year in the central 5° and -27 ± 18 cones/degree2/year in the 5°-10° annular zone, respectively. Over the follow-up period, the percentage of retinal locations with cone density lower than normal (Z-score < -2) in eyes with SDD increased from 16% (32/197) to 59% (117/197). In contrast, in eyes with drusen but without SDD, this number changed from 1.5% (4/268) to 16.4% (44/268).
Conclusions :
AOSLO revealed cone density reduction over time in retinal regions that were not clinically impacted by AMD lesions. Eyes with SDD showed an accelerated rate of cone density decrease compared with eyes with only classical drusen, suggesting a different natural history of photoreceptor degeneration in AMD of different phenotypes, and implying more severely impaired visual function.
This is a 2021 ARVO Annual Meeting abstract.