Abstract
Purpose :
Autism spectrum disorder (ASD) is associated with atypical visual processing (e.g. Simmons et al. 2010). Previous electrophysiology studies have indicated reduced electroretinogram b-wave amplitude in ASD (Ritvo et al. 1986, Creel et al. 1989). Huynh et al. (2006) report thicker retinae in males using optical coherence tomography (OCT). This is relevant given the known male bias in ASD, and also the ‘extreme male brain’ theory of ASD (Baron-Cohen et al. 2005). However, the only study to investigate retinal structure in ASD reported reduced retinal thickness at the optic nerve head in their autism subgroup (n=11) (Emberti et al. 2013).
Methods :
Right eye retinal thickness was analysed using the Heidelberg Spectralis SD-OCT in 29 children with ASD (mean (±sd) age 13.2±3 years; range 8-17 years; 24 male; 17 Autism and 12 Asperger’s diagnosis). SD-OCT measures consisted of line and central 3mm volume scans. Age-matched typically developing children acted as controls (n=64, mean age 12.4±2.6 years; range 8-17 years; 30 male). Supplementary measures included axial length (AL) (Zeiss IOLMaster) and visual acuity (VA) (Keeler crowded LogMAR).
Results :
Volume OCT measures were successful in 25 ASD participants (86%) and 58 controls (91%). The ETDRS grid was used to segment areas of retinal thickness for analysis. For the ASD group, mean overall retinal thickness measures at the different test locations were: central foveal subfield (CFS) 285.8±22.2µm, superior 354.2±18.3µm, inferior 352.2±17.3µm, nasal 356.5±17.8µm, temporal 341.4±17.0µm. For the control group, mean CFS 281.8±18.4µm, superior 351.0±13.7µm, nasal 352.3±13.8µm, inferior 347.4±12.9µm, temporal 336.3±13.9µm. There was no significant difference in retinal thickness between groups in any test location (p>0.15), or when male data were analysed (p>0.66). There was no significant association between VA or AL and retinal thickness in either group (VA; ASD F(5,19)=1.6, p=0.21; controls F(5,52)=1.4, p=0.25: AL; ASD F(5,19)=1.6, p=0.21; controls F(5,50)=1.9, p=0.11). There was no significant difference in thickness between ASD diagnostic categories (F(1,23)=1.3, p=0.27).
Conclusions :
Retinal thickness is comparable in ASD and control children and is not influenced by gender or ASD diagnostic category. These data do not support the hypothesis for either a reduction in retinal thickness indicating a neural deficit in ASD, nor increased thickness as a biomarker for ASD.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.