Certain rapid eye movements of a subgroup of people on the Autism Spectrum Disorder may aid in diagnosis. The brain controls the eyes. Therefore, certain eye movement tests provide insight into the brain’s functioning.
Researchers at the University of Rochester Medical Center1 studied “saccades.” These are the rapid eye movements people make when shifting their attention from one object to another. A neurotypical person has saccades that are precise, rapid and accurate. However, certain people on the autism spectrum have noticeably different saccades.
The study required subjects to track a target on a screen visually. The targets were designed to cause the subject’s focus to overshoot the target often. Neurotypical subjects corrected their eye movements after trying the task a few times. Autistic subjects kept missing the target. This indicated impairment in the cerebellum’s sensory-motor controls that handle eye movement.
Fetal Eye Development and Autism
During fetal development, the neural plate develops two tiny dimples. These dimples develop into the retinas. Therefore, the retina is actually neural tissue. The eyes and vision are part of the central nervous system. The fetus floats in amniotic fluid. When the mother shifts position, the fetus learns a sense of balance (the vestibular system). One theory of autism is that disruptions occurred that hampered fetal vestibular development. Vision is closely linked to the sense of balance.
Abnormal Eye Movements
The abnormal eye movements in the study indicate cerebellum dysfunction. The researchers believe that they may also offer explanations for social and communication deficits in autistic individuals.
Autism is a broad spectrum of symptoms that vary widely between individuals. Therefore, treatment is not a one-size-fits-all solution. Doctors are aiming to provide very detailed diagnoses (phenotypes). Specific diagnoses could lead to more effective treatments.
The hope is that further research will lead to more treatments. Helping autistic patients improve their saccade adaptation could help heal the brain and alleviate autistic symptoms.
- Edward G. Freedman, John J. Foxe. Eye movements, sensorimotor adaptation and cerebellar-dependent learning in autism: toward potential biomarkers and subphenotypes. European Journal of Neuroscience, 2017; DOI: 10.1111/ejn.13625 ↩