Surgical Interventions for Childhood Eye Movement Disorders

Eye movement disorders which occur in early childhood can result in lasting impairments in vision.  Surgery can help correct these impairments, but much still remains to be learned about how best to use these surgeries, particularly in terms of the best timing for the surgical intervention.

Strabismus surgery is typically used to re-align the eyes in children with congenitally crossed eyes (called infantile esotropia; where the gaze of both eyes turns inward from time of birth). Traditionally in North America this surgery has been performed from 11-18 months of age, but Donald K Johnson Eye Institute Scientist Dr.  Agnes Wong, and her team are exploring whether an earlier surgery might have better outcomes.

Evidence suggests that a child’s binocular vision (the ability to see with and coordinate vision from both eyes) is established between 4-6 months of age. If infantile estropia persists beyond that period, the brain may not learn to coordinate input from the eyes correctly, resulting in impaired processing of images and poor visual tracking of objects in these young patients. An emerging body of scientific literature suggests that earlier surgery (before 11 months of age) may produce better long-term outcomes for these children.

Dr. Wong is working with surgical colleagues at the Hospital for Sick Children on a clinical trial comparing outcomes for children who have the surgery prior to 11 months of age, versus those who have the surgery at the traditional time. Dr. Wong’s group will conduct detailed ongoing testing of the children’s vision from two to five years of age, to better understand how the surgery affects their 3D vision (which relies on input from both eyes) and their ability to visually track moving objects.

Dr. Wong’s research is support by grants from the Canadian Institutes of Health Research.