Study of human pupillary light reflex and its potential application in autism

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Pupillary light reflex (PLR) can be used as an objective and non-invasive method to evaluate certain brain functions. In this research, we developed a binocular pupillogram recording system and investigated the properties and potential applications of PLR in a series of studies. We investigated the sex effects on transient PLR in healthy young adults and found that females had significantly larger relative constriction amplitudes than males in a dark-adapted condition. The sex difference in contraction anisocoria was investigated in young children. We found a right-side lateralization of contraction anisocoria in boys but not in girls. We compared PLR parameters in children with autism spectrum disorders (ASDs) and children with typical development. We found that participants with an ASD showed significantly longer PLR latency, smaller constriction amplitude and lower constriction velocity than children with typical development. Finally, we reviewed, implemented and compared existing pupil light reflex models. We proposed a model based on the visco-elastic property of the iris muscle. Simulation results indicated that the new model can reproduce experimental observations under various stimulation conditions.