PURPOSE: To investigate the distribution of cone density and spacing as well as the preferred packing arrangement of the cone mosaic as a function of retinal eccentricity. METHODS: An adaptive optics retinal camera (rtx1, www.imagine-eyes.com) was used to obtain images of the parafoveal cone mosaic in nineteen healthy volunteers. Cone density and spacing were estimated for each subject (both eyes) using a sampling window of 80 × 80 pixels, at 250-, 450-, 650- and 1100-μm eccentricities from the fovea along the nasal and temporal retina of both eyes. The inter-subject and intra-subject variation of cone density and spacing were calculated via Coefficient of Variation (CoV). Cone packing arrangement was assessed using Voronoi analysis; calculations were done over 1024 × 128 pixels image sections of the cone mosaic across the horizontal meridian from 200- to 1050-μm eccentricities. RESULTS: The inter-subject variation of parafoveal cone density ranged between 10% and 15% (p < 0.001) and the intra-subject variation of cone density was lower than 8% in all subjects, except for two. The cone spacing values showed a moderate inter-subject (CoV<7%; p < 0.001) and a low intra-subject variation (CoV<4% in all subjects, except for two cases). In the parafoveal region, 40-50% of cones were hexagonally arranged; the percentage of non-hexagonal Voronoi tiles increased at greater eccentricities. CONCLUSION: The use of multiple and complementary metric descriptors allows for a more detailed description of packing distribution and preferred arrangement of cone photoreceptors across the parafoveal retina.
PURPOSE: To investigate the distribution of cone density and spacing as well as the preferred packing arrangement of the cone mosaic as a function of retinal eccentricity. METHODS: An adaptive optics retinal camera (rtx1, www.imagine-eyes.com) was used to obtain images of the parafoveal cone mosaic in nineteen healthy volunteers. Cone density and spacing were estimated for each subject (both eyes) using a sampling window of 80 × 80 pixels, at 250-, 450-, 650- and 1100-μm eccentricities from the fovea along the nasal and temporal retina of both eyes. The inter-subject and intra-subject variation of cone density and spacing were calculated via Coefficient of Variation (CoV). Cone packing arrangement was assessed using Voronoi analysis; calculations were done over 1024 × 128 pixels image sections of the cone mosaic across the horizontal meridian from 200- to 1050-μm eccentricities. RESULTS: The inter-subject variation of parafoveal cone density ranged between 10% and 15% (p < 0.001) and the intra-subject variation of cone density was lower than 8% in all subjects, except for two. The cone spacing values showed a moderate inter-subject (CoV<7%; p < 0.001) and a low intra-subject variation (CoV<4% in all subjects, except for two cases). In the parafoveal region, 40-50% of cones were hexagonally arranged; the percentage of non-hexagonal Voronoi tiles increased at greater eccentricities. CONCLUSION: The use of multiple and complementary metric descriptors allows for a more detailed description of packing distribution and preferred arrangement of cone photoreceptors across the parafoveal retina.
Authors: Shu Feng; Michael J Gale; Jonathan D Fay; Ambar Faridi; Hope E Titus; Anupam K Garg; Keith V Michaels; Laura R Erker; Dawn Peters; Travis B Smith; Mark E Pennesi Journal: Invest Ophthalmol Vis Sci Date: 2015-09 Impact factor: 4.799
Authors: R Battu; M C Akkali; D Bhanushali; P Srinivasan; R Shetty; T T J M Berendschot; J S A G Schouten; C A Webers Journal: Eye (Lond) Date: 2016-02-26 Impact factor: 3.775
Authors: Marco U Morales; Saker Saker; Craig Wilde; Martin Rubinstein; Paolo Limoli; Winfried M Amoaku Journal: Int Ophthalmol Date: 2019-10-03 Impact factor: 2.031
Authors: Stephen A Burns; Ann E Elsner; Kaitlyn A Sapoznik; Raymond L Warner; Thomas J Gast Journal: Prog Retin Eye Res Date: 2018-08-27 Impact factor: 21.198