Purchase this article with an account.
Erica N. Woertz, Bisola Omoba, Stephanie J. Chiu, Sina Farsiu, Joseph Carroll; Assessing ganglion cell layer topography in human albinism using optical coherence tomography. Invest. Ophthalmol. Vis. Sci. 2018;59(9):1106.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To characterize ganglion cell layer (GCL) topography in subjects with albinism and normal individuals.
Optical coherence tomography (OCT) scans were acquired in 10 subjects with albinism (4 M, 6 F, ages 9-44) and 10 normal subjects (3 M, 7 F, ages 23-33). Horizontal and vertical 6- or 7-mm B-scans were acquired at the fovea (or incipient fovea), followed by registration and averaging of 15-32 frames from each scan using ImageJ. The Duke OCT Retinal Analysis Program was used to automatically segment the combined GCL-inner plexiform layer (IPL) and total retinal thickness, followed by program-assisted manual segmentation of the boundary between the GCL and IPL. Image segmentation coordinates were then used to calculate layer thickness and area under the curve (AUC) within 2.7 mm of the (incipient) fovea. Nasal-temporal (N-T) and superior-inferior (S-I) asymmetry was calculated as a ratio of AUC in each quadrant, then compared using a two-tailed t-test.
In control subjects the GCL comprised 0-85.5% of the combined GCL-IPL thickness, while in subjects with albinism the GCL comprised 21.4-73.9% (0.2-2.7 mm from fovea). When AUC in all four quadrants was summed, GCL AUC in controls (mean±SD: 0.375±0.039 mm2) was not significantly different from that in albinism (0.382±0.026 mm2), but IPL AUC was significantly greater (p=0.03) in albinism (0.435±0.049 mm2) than in controls (0.394±0.030 mm2). Both groups showed N-T asymmetry in the GCL (AUC ratios: controls=1.25±0.13, albinism=1.46±0.21), consistent with histologic studies showing greater ganglion cell density nasally than temporally. Notably, asymmetry was greater in albinism than controls (p=0.019) and showed 1.65-fold variation across subjects. Neither group showed significant S-I asymmetry in the GCL or IPL.
Subjects with albinism have increased N-T asymmetry in the GCL compared to control subjects, suggesting alterations in GCL topography. Additionally, total IPL AUC was greater in albinism than in controls, though the origins of the IPL differences in albinism remain unknown. Further, the variation in GCL contribution to the combined GCL-IPL layer seen in all subjects illustrates the need to delineate the GCL from the IPL when evaluating inner retinal layers in any population, as measuring the combined GCL-IPL obscures each layer’s independent contribution. PMID: 20940837 PMID: 2229487
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
This PDF is available to Subscribers Only