Purpose: The purpose of this research was to compare the thickness of different retinal layers between dyslexic subjects and controls at the macula by means of optical coherence tomography (OCT). Methods: Each patient underwent a complete ophthalmic examination including macular OCT in both eyes. The thickness of the fovea, four sectors of the parafovea and four sectors of the perifovea were obtained according to the Early Treatment Diabetic Retinopathy Study protocol in the following 13 segmentations: complete retina, outer retina, inner retina, retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), INL + OPL + ONL, IPL + INL, OPL + ONL and ganglion cell complex (RNFL + GCL + IPL). The results of the right and left eyes were independently compared between groups. Results: The thickness in all the four sectors of the parafovea was found significantly higher in the right and in the left eyes in the dyslexic group in the following segmentations: complete retina, inner retina, middle retinal layers and OPL + ONL. Several macular sectors were also thicker in IPL + INL, INL, IPL and ONL in dyslexia. In contrast, no thickness differences between both groups were found in any of the sectors of RNFL, GCL, GCC, or outer retina in any eye. Conclusions: Anatomy of the macula is different in dyslexic and normoreader subjects in middle retinal layers, especially in the parafovea. This fact suggests that the macula may play an important role in the development of dyslexia.

The macula, as the central part of the retina, plays an important role in the reading process. However, its morphology has not been previously studied in the context of dyslexia. In this research, we compared the thickness of the fovea, parafovea and perifovea between dyslexic subjects and normal controls, in 11 retinal segmentations obtained by optical coherence tomography (OCT). With this aim, we considered the nine sectors of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid and also summarized data from sectors into inner ring subfield (parafovea) and outer ring subfield (perifovea). The thickness in all the four parafoveal sectors was significantly thicker in the complete retina, inner retina and middle retina of both eyes in the dyslexic group, as well as other macular sectors (fovea and perifovea) in the inner nuclear layer (INL), inner plexiform layer (IPL), IPL + INL and outer plexiform layer + outer nuclear layer (OPL + ONL). Additionally, the inner ring subfield (parafovea), but not the outer ring subfield (perifovea), was thicker in the complete retina, inner retina, middle retina (INL + OPL + ONL), OPL + ONL, IPL + INL and INL in the dyslexic group for both eyes. In contrast, no differences were found between the groups in any of the sectors or subfields of the outer retina, retinal nerve fiber layer, ganglion cell layer or ganglion cell complex in any eye. Thus, we conclude from this exploratory research that the macular morphology differs between dyslexic and normal control subjects, as measured by OCT, especially in the parafovea at middle retinal segmentations.