Amblyopia is the most common cause of monocular vision impairment among children, affecting 2 or 3 of every 100 children. Amblyopia commonly results when there is binocularly discordant input associated with strabismus or anisometropia during visual development. Sensory and oculomotor deficits are well-established in the amblyopia literature; yet, the functional consequences of amblyopia on the developing visuocognitive and visuomotor systems are less known. Initial studies show slow reading and poor fine motor ability in amblyopic children and adults, even when they have one eye with normal visual acuity under binocular viewing conditions. Yet, causes of these impairments remain poorly understood. Strabismic and anisometropic children, with or without amblyopia, between the ages of 4-12 years will be enrolled and compared to a group of normal control children. Three projects will be conducted in these groups of children. Eye movements during reading will be evaluated using the EyeLink 1000 binocular eye tracking system, and temporal eye-hand coordination during visually-guided reach-to-point and during visually-guided precision grasp will be evaluated using the EyeLink 1000 and the LEAP Motion capture device. These studies will determine how sensory deficits (visual acuity, stereoacuity, suppression), oculomotor dysfunction (gaze instability, abnormal saccades), and deficits in visual planning and guidance of hand movements affect reading, reaching and grasping in amblyopic children under binocular conditions. Data from the proposed experiments will determine the consequences of abnormal visual experience during development on the visuocognitive and visuomotor systems, provide information on sensory and motor integration during maturation, and aid in determining more effective amblyopia treatments and academic accommodations that allow amblyopic children to thrive.
Amblyopic children and adults read slowly and experience difficulty performing tasks that require fine motor skills. This project will evaluate potential sensory, oculomotor, and kinematic factors associated with these deficits in amblyopic children to determine the effects of abnormal visual experience on the developing visuocognitive and visuomotor systems, and to provide essential information on the interaction between these developing systems. These data will guide the design of school accommodations and interventions to promote academic success and potentially open a new avenue for amblyopia treatment to surmount obstacles to proficient reading and adept visuomotor skills.
