Intergrader agreement of foveal cone topography measured using adaptive optics scanning light ophthalmoscopy

Abstract

The foveal cone mosaic can be directly visualized using adaptive optics scanning light ophthalmoscopy (AOSLO). Previous studies in individuals with normal vision report wide variability in the topography of the foveal cone mosaic, especially the value of peak cone density (PCD). While these studies often involve a human grader, there have been no studies examining intergrader reproducibility of foveal cone mosaic metrics. Here we re-analyzed published AOSLO foveal cone images from 44 individuals to assess the relationship between the cone density centroid (CDC) location and the location of PCD. Across 5 graders with variable experience, we found a measurement error of 11.7% in PCD estimates and higher intergrader reproducibility of CDC location compared to PCD location (p < 0.0001). These estimates of measurement error can be used in future studies of the foveal cone mosaic, and our results support use of the CDC location as a more reproducible anchor for cross-modality analyses.

Foveal Phenotypes in Choroideremia on Adaptive Optics Scanning Light Ophthalmoscopy

“…In 86/102 eyes (51 individuals), a PCD estimate was generated. Compared with healthy control retinas, 17 PCD was lower in CHM ( P < 0.0001, healthy control mean 169,828 cones/mm 2 , range: 121,139–224,836 cones/mm 2 , CHM mean: 78,268 cones/mm 2 range: 29,382–157,717 cones/mm 2 ) (Figure 4). The mean difference was 90,528 (95% CI = [80,896, 100,161]).…”

“…Peak cone density is lower in CHM than in healthy control retinas. Control measurements were taken from Wynne et al, 17 which measured PCD in the right eyes of 44 participants aged 12 to 61 years. Control measurements are shown as empty circles, whereas purple points represent salt and pepper phenotypes, blue points represent spiderweb phenotypes, and orange points represent relatively normal phenotypes from CHM eyes.…”

“…Cone density at each pixel within the image was calculated using a custom script that used a sliding window of 150 cells and the maximum calculated density was taken as the peak cone density (PCD). 17…”

Macular and Plasma Xanthophylls Are Higher in Age-related Macular Degeneration than in Normal Aging

“…23 , 25 Authors of a supplementation study noted that detecting a treatment effect depended on how the foveal center was defined. 63 Commercially available and prototype imaging technology currently defines the foveal center in several ways, 64 , 65 , 66 each having distributions that may be offset from each other. 67 Macular pigment optical volume 2° in our studies captures the central 1.15 mm diameter of macula and does not assess smaller anatomical features within that region.…”

Foveal Cone Structure in Patients With Blue Cone Monochromacy

“…These coordinates were used to calculate cone metrics ( Table 2 ), 29 as well as for subsequent analysis. PCD ( Table 2 ) was calculated from unbound coordinates (i.e., including cells on the boundary of the analysis window, because of the sparsity of waveguiding cones) across a fixed window size of 37 µm using a custom Matlab script 30 to enable comparison with previous literature. 25 , 31 It is worth noting that, in the case of waveguiding cones, the location of PCD is not expected to coincide with the fovea, given the presence of the S-cone free zone, which has been shown to be present in patients with BCM 10 and was also observed in many (but not necessarily all: see JC_10066 in Fig.…”