Optical Coherence Tomography Angiography of Macula and Optic Nerve in Autism Spectrum Disorder: A Pilot Study

The aim of this study was to compare retinal thicknesses and vascular parameters between autism spectrum disorder (ASD) and neurotypical (NT) individuals. Recruited ASD subjects and age- and sex-matched NT controls underwent 2 optical coherence tomography scans (OCT) (macular cube and optic nerve cube) and 2 OCT angiography (OCTA) scans (macular and optic nerve head (ONH) OCTA) with the device Cirrus 5000 (Zeiss). Concerning OCT, we considered full retina thickness in 9 macular sectors of the Early Treatment Diabetic Retinopathy Study (ETDRS) pattern and peripapillary retinal nerve fiber layer (pRNFL) thickness in 4 quadrants and 12 clock-hour sectors. Vessel density and capillary perfusion density in 9 sectors were measured using 6 x 6 mm macular OCTA. Foveal avascular zone (FAZ) parameters were also considered. ONH 4.5 x 4.5 mm OCTA estimated perfusion density and flux index in 4 peripapillary quadrants. Comparisons between groups of all these parameters were performed. ASD subjects showed higher ONH perfusion density and lower ONH flux index at the peripapillary inferior quadrant when compared with NT individuals (p < 0.05). Plus, a trend towards higher macular thicknesses, higher pRNFL thickness at inferior clock-hour sectors and higher macular vessel density and perfusion was observed in ASD. No differences were found in FAZ parameters. In conclusion, retinas of ASD subjects may present some structural and vascular differences when compared with retinas of NT individuals.