Abstract
Purpose :
To study thickness of intraretinal segmentations at the fovea and parafovea in dyslexic individuals and controls.
Methods :
22 dyslexic participants and 22 non-dyslexic controls had OCT scans of the macula using the 8x8 posterior pole algorithm. The sixteen most centrally-located superpixels of the grid, corresponding to the fovea and parafovea (4x4 grid), were considered in the these segmentations: complete retina, outer retina, inner retina, outer nuclear layer + outer plexiform layer + inner nuclear layer (ONL+OPL+INL, in other words, middle retinal layers) and ganglion cell complex (GCC). The results of the right and left eyes were compared between groups with unpaired t test.
Results :
Significant increases of thickness in the superpixels of the studied 4x4 grid were found in the dyslexic group in right an left eyes, mainly in ONL+OPL+INL (13 thicker cells in the right eye and 16 in the left one in the dyslexic group, with mean superpixel thickening ranging from 4.95 to 11.15 microns) but also in complete retina (4 thicker superpixels in the right eye and 8 in the left one in the dyslexic group, with mean superpixel thickening ranging from 7.80 to 11.30 microns) and inner retina (6 thicker superpixels in the right eye and 10 in the left one in the dyslexic group, with mean superpixel thickening ranging from 6.50 to 12.4 microns). In contrast, GCC only showed one thicker superpixel in the dyslexic group (in the left eye, with mean superpixel thickening of 4.33 microns, but none in the right eye) and outer retina did not show any significant difference in the superpixels of right or left eyes between groups.
Conclusions :
Middle retinal layers are thicker at the fovea and parafovea in dyslexia. This fact allows to consider that the fovea and parafovea could play a role in dyslexia.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.