The macula in dyslexia: a comparative OCT study.

Abstract

Purpose : To compare thickness of different retinal segmentations between dyslexic individuals and controls at the macula, including the fovea, the parafovea and the perifovea.

Methods : Twenty dyslexic volunteers and twenty age- and sex-matched non-dyslexic controls underwent macular optical coherence tomography (OCT) scans in both eyes using the Early Treatment Diabetic Retinopathy Study protocol. The thickness of the fovea, 4 sectors of the parafovea and 4 sectors of the perifovea (temporal, nasal, superior and inferior sectors) were considered in the following segmentations: complete retina, outer retina, inner retina, outer nuclear layer + outer plexiform layer + inner nuclear layer (ONL+OPL+INL) and ganglion cell complex (GCC). The results of the right and left eyes were independently compared between groups.

Results : Significantly higher thickness in all the sectors of the parafovea and some sectors of the perifovea, but not the fovea, was found in right and left eyes in complete retina and inner retina in the dyslexic group. Plus, all sectors of the macula of ONL+OPL+INL in both eyes (including the fovea) were significantly thicker in the dyslexic group. In contrast, no thickness differences between both groups were found in any of the sectors of GCC or outer retina in any eye.

Conclusions : Middle retinal segmentation (ONL+OPL+INL) at the macula is thickened in dyslexia in both eyes as measured by OCT. This fact seems to induce thickening in inner retina and complete retina results at the macula in the context of this disorder. Considering that a certain degree of integration of visual stimuli takes place at middle retinal layers our results suggest that the retina could play a role in the development of the dyslexia.

This is a 2021 ARVO Annual Meeting abstract.