Accommodative responses were significantly poorer in individuals with autism spectrum disorder (ASD) compared with age-matched typically developing control subjects, and hypoaccommodation was associated with reduced near visual acuity (NVA) and convergence.
Autism spectrum disorder is a neurodevelopmental disorder with a reported prevalence of 1.1 to 1.5%. Accommodative dysfunction has been noted in other developmental conditions including cerebral palsy and Down syndrome. The aim of this study was to investigate how accommodative accuracy and near visual function in ASD compared with typically developing control subjects.
This study investigated accommodative function in children with ASD, in conjunction with other vision measures with habitual refractive corrections. Accommodative accuracy was assessed using modified Nott dynamic retinoscopy. Individual accommodative demand and response were calculated incorporating residual refractive error (difference between cycloplegic and habitual refractive state). Near visual measures included NVA, near point of convergence, fusional reserves, and stereoacuity. Cycloplegic autorefraction confirmed refractive error.
Accommodative responses were measured from 124 participants with ASD (6 to 17 years old) and 204 age-matched control subjects. There was no significant difference in the magnitude of residual refractive error between groups (P = .10). The prevalence of a clinically significant lag of accommodation was greater in the ASD group compared with control subjects (ASD = 17.4%, control subjects = 4.9%, χ2 = 13.04, P < .0001). Near visual acuity was significantly reduced in the ASD group with a clinically significant lag of accommodation (P < .01). A few participants (n = 24 control subjects, n = 14 ASD) had uncorrected or undercorrected refractive errors (spherical equivalent refractive error ≥+2.00 D, >1.00 DC), and when these were removed from analysis, there was still an increased prevalence of hypoaccommodation in ASD (14.7%).
Children with ASD were significantly more likely to have accommodative deficits (and associated near visual deficits) in their presenting refractive state than typically developing children. Appraisal of refractive error, accommodation, and NVA should be considered in visual assessment of children with ASD.
1Orthoptic Department, Belfast Health & Social Care Trust, Royal Victoria Hospital Belfast, United Kingdom
2Optometry & Vision Science Research Group, Biomedical Sciences Research Institute, Ulster University, Coleraine United Kingdom
3School of Psychology, Ulster University Coleraine, United Kingdom
4Department of Paediatrics, Northern Health & Social Care Trust, Antrim Northern Ireland, United Kingdom *Ja.firstname.lastname@example.org
Submitted: August 24, 2016
Accepted: December 3, 2017
Funding/Support: Doctoral Fellowship Award, Health & Social Care (HSC) Research & Development Office, Belfast, UK.
Conflict of Interest Disclosure: None of the authors have reported a financial conflict of interest.
Author Contributions and Acknowledgments: Data Curation: PMA; Formal Analysis: PMA, JAL; Investigation: PMA, KJS, JAL; Methodology: PMA, KJS, SMG, CB, JAL; Project Administration: PMA, JAL; Writing – Original Draft: PMA, KJS, CB, JAL; Writing – Review & Editing: PMA, KJS, SMG, JAL; Conceptualization: KJS, SMG, JAL; Funding Acquisition: KJS, JAL; Supervision: KJS, SMG, JAL; Resources: CB, JAL; Software: JAL.
The authors thank Dr. Khan for assistance with recruitment, Dr. Sara McCullough and Dr. Lesley Doyle for assistance with data collection, and Mrs. Clare Stevenson and Mrs. Joy Peters for providing test facilities. The authors are grateful to all participants and schools who consented to involvement in the study including Bangor Central Primary School, Belmont House, Castle Gardens Primary School, Foyleview School, Knockavoe School, Londonderry Primary School, Loreto College, Strangford College, and Victoria Primary School in Northern Ireland, United Kingdom. This work formed part of a doctoral thesis by the lead author and was previously presented in part at the Association for Research in Vision and Ophthalmology Meeting (Tampa, FL, 2014) and the International Orthoptic Association Conference (Rotterdam, the Netherlands, 2016).