Abstract
Purpose :
To evaluate the change in the area of reticular pseudodrusen (RPD) over a two year period in eyes with age-related macular degeneration (AMD).
Methods :
AMD eyes with RPD enrolled in the Amish Eye Study (AES) with baseline and two year follow-up infrared reflectance (IR) images were eligible for this analysis. Eyes were excluded for poor quality images, extension of RPD beyond the margins of the image, or if they developed geographic atrophy at the month 24 visit. Thirty-degree IR images and volume OCTs (6x6mm, 512x97, ART=9, fovea-centered) were obtained using the Spectralis HRA+OCT. Using the instrument software, a certified grader delineated the RPD area (mm2) on the IR image using the free hand tool, and measured the choroidal thickness on the OCT at the foveal center as well as at 3500 µm superior and inferior to the foveal center. Measurements were performed on both baseline and Month 24 images. 30% of eyes were randomly selected for reproducibility analysis by a second masked grader. The change over two years was assessed using paired t tests.
Results :
Of 1332 eyes (666 subjects) enrolled in the AMISH eye study, a total of 108 eyes (from 54 subjects) were noted to have RPD and from these 35 eyes of 22 subjects were included in the final analysis (32 eyes were excluded due to extension of RPD to the image border, 19 due to poor image quality, and 22 due to development of GA). The mean age of included subjects was 72.7 ± 9.1 (range: 3.5 – 84) years and 13 were female (37%). Mean subfoveal choroidal thickness at baseline was 194.58 ± 79.2 µm. RPD area was increased significantly (p <0.001) at month 24 (17.67 ± 9.59 mm2) compared to baseline (11.44 ± 7.96 mm2) with a mean increase of 6.23 ± 4.64 mm2. There was no significant change at 2 years, however, in choroidal thickness in any of the regions: superior (p = 0.09), subfoveal (p = 0.26) and inferior (p = 0.52). Intraclass correlation (ICC) for RPD area between the two graders was 0.997 with a mean difference of 0.49 mm2.
Conclusions :
In this longitudinal natural history analysis, we observed an increase in RPD area of >6mm2 over two years despite no significant change in choroidal thickness. These findings may provide new insight into the evolution and lifecycle of RPD.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.