Research activities
Visual Development and Visual Functions in the Compromised Visual System.
We investigate visual development when the visual system has been compromised pre- or post-natally. We record signals from the brain using visual evoked potentials (VEPs) and from the retina using full field and multifocal electroretinograms (ERGs).
Some children develop strabismus (eye turn) soon after birth. Strabismus affects visual system development. Using VEPs we found functional units in the visual cortex, which respond to simultaneous input from each eye. We are now investigating the ability of children with strabismus to use eye movement responses (vergence) to correct for apparent changes in depth.
Drugs or other toxic insult affect visual system development. Visual and retinal function are investigated in subjects with exposure to environmental insult or prescribed drugs, which cause visual toxicity. These include vigabatrin (used for seizure control), chemotherapy or anti-malarials. Visual functions are assessed using visual evoked potentials (sweep VEP) to study contrast sensitivity and visual acuity and pattern onset VEPs (equiluminant colour) to assess L-M and S- colour mechanisms in the human visual system. Retinal function is investigated with electroretinography (single flash and multifocal).
Our team is comprised of Carol Westall (director of Visual Electrophysiology, associate professor of Ophthalmology), three graduate students, 1 post doctoral fellow, one research technologist and 3 persons involved primarily in clinical electrophysiology.