About Sickkids
About SickKids

Carol Westall, PhD, BSc (Optom)

The Hospital for Sick Children
Vision Scientist
Ophthalmology and Vision Sciences

Research Institute
Senior Associate Scientist
Neurosciences & Mental Health

University of Toronto
Professor
Ophthamology and Vision Sciences

Graduate Coordinator and Member
Institute of Medical Sciences

Other Positions

York University
York Centre for Vision Research
Adjunct Member


Phone: 416-813-6516
Fax: 416-813-7661
e-mail: carol.westall@sickkids.ca

For more information, visit:

Visual Electrophysiology Unit

Brief Biography

Dr. Carol Westall obtained her PhD from the University of California (Berkeley) in 1984. She is a registered clinical optometrist at SickKids. She was Director of the Visual Electrophysiology Unit from 1999 to 2014 and led the unit to become a world leader in clinical paediatric visual electrophysiology. Westall is member of the Board of the International Society for Clinical Visual Electrophysiology of Vision and is the Associate Editor of the Society’s journal (Documenta Ophthalmologica).

 Westall's research investigates neuro-visual markers of visual dysfunction when the developing visual system has been compromised. In 2009 Westall took on the role of Graduate Coordinator at the University of Toronto, Institute of Medical Science.

 

Clinical Care Activities

Provides leadership to the Visual Electrophysiology Unit (VEU) through technical expertise and academic advancement in paediatric visual electrophysiology and vision function assessment. Supports research and translates new knowledge to clinical procedures.

Research Interests

  • Neuro-Visual Development
  • Electroretinography
  • Visual Toxicity
  • Markers of visual dysfunction in diabetes

Research Activities

Translational research from cellular elements to neuro-visual functioning in children -
The focus of my research is the interface between disease or toxically induced cellular changes and neuro-retinal function in childhood. Three arms of this research are outlined below:

Retinal toxicity attributed to vigabatrin -
For 10 years my lab conducted a prospective cohort study assessing neuro-visual functions in children with a paediatric seizure disorder (infantile spasms) who were treated with the anti-epileptic drug vigabatrin. Approximately 30 per cent of adult patients treated with this drug develop vigabatrin attributed visual field defect. Using the electroretinogram as a surrogate marker for visual field defect we found that approximately 35 per cent of children with infantile spasms develop vigabatrin attributed retinal toxicity. Findings from this investigation resulted in a change in vigabatrin prescribing practice; the length of vigabatrin treatment was reduced to minimize the occurrence of toxicity. The data on vigabatrin toxicity in a pediatric cohort were presented in the Ovation Pharmaceuticals new drug application (NDA) submission to the Food and Drug Administration (FDA), presented at the FDA advisory Committee Meeting for vigabatrin, Washington DC January 2009 and are published (Invest Ophthalmol Vis Sci. 2009, and J Child Neurol 2012.)

Neuro-visual structure and function in children and adolescents with early Type 1 diabetes -
For six years my lab conducted studies of visual dysfunction in type 1 diabetes to define the earliest neuro-marker of disease. Funding was procured from the Juvenile Diabetes Research Foundation in 2005 and CIHR 2010. Data show that chromatic mechanisms are disrupted at puberty (Invest Ophthalmol Vis Sci. 2005) and short-wavelength retinal processing disrupted in adolescence (Invest Ophthalmol Vis Sci. 2011). Multifocal electroretinography in adolescents show deficits in localized retinal processing (Invest Ophthalmol Vis Sci. 2010.). Multi-model adaptive optics imaging protocols have been integrated into our testing regimen and allow us to identify the earliest signs of diabetic eye disease in children with type 2 diabetes (ARVO presentation, 2012).

Phenotypic Characteristics in cone dystrophies -
For the past two years, in collaboration with Dr Elise Héon, we characterized retinal phenotype in diseases with known mutations. Data are published in Retina (2012), Ophthalmic Genetics (2011) and Molecular Vision (2011). Recently we published data from In vivo imaging of the Cone Photoreceptor Mosaic in children with cone dystrophy and the KCNV2 mutation (Investigative Ophthalmology (2013). This is the first study to of Ultra-high frequency retinal imaging in this population and the first report of retinal imaging of the cone mosaic in children.

Future Research Interests

To investigate the impact of blood vessel tortuosity with inner retinal function in adolescents with type one diabetes.

External Funding

2010-2015. CIHR project grant 
Structural and functional markers of neuro-retinal complications in adolescents with early type 1 diabetes. PI: Westall, Co-inv: Campbell.

2010-2015. CIHR project grant
Donor Human Milk Versus Preterm Formula as a Substitute for Mothers' Own Milk for Feeding Very Low Birth Weight Infants. PI: O'Connor, Co-inv: Asztalos, Kiss, Rovet, Westall.

2010-2012. CHRP
Localizing Light in the Eye for Diagnostic and Therapeutic Applications. PI: Campbell M. Co Inv: Boyd S, Bizheva K, Sanderson, Strickland D, Westall C.

2007-2011. Canada Foundation for Innovation
Centre for the Investigation of Neuroplasticity and Developmental Disorders. PI: Snead III OC. Co Inv: Taylor M, Campbell M, Cheyne D, Dennis M, Josselyn S, Salter M, Sled J, Tannock R, Westall CA.

2009-2012. Lunbeck Pharmaceuticals inc.
Markers of neuro-retinal change over time in children with infantile spasms. PI: Westall CA.

Achievements

  • May 2010 - Fellow ARVO (FARVO), The Association for Research in Vision and Ophthalmology. (Distinction) In honor of outstanding service to the eye and vision community.
  • September 2007. Member at Large, International Society for Clinical Electrophysiology of Vision.
  • 2007. Vice Chair, Optical Society of America Fall Vision Meeting, clinical section.
  • December 2006. American Academy of Optometry. Chair of the Vision Sciences Section, Diplomat committee.
  • April 2004. Mel Silverman Mentorship Award, The Institute of Medical Science, University of Toronto.
  • December 2004. American Academy of Optometry, Elected Vice Chair of the Vision Sciences Section, Diplomat committee.
  • December 2003. Diplomate in Vision Sciences (visual electrophysiology), The American Academy of Optometry.
  • November 2002. EDITORIAL BOARD: Documenta Ophthalmologica.

Publications

Westall CA, Wright T, Cortese F, Kumarappah A, Snead C, Buncic R. (2014). Prevalence of vigabatrin retinal toxicity in children with infantile spasms: an observational cohort study. Neurology. 83(24): 2262-8.

Tan W, Wright T, Dupuis A, Lakhani E, Westall C. (2014). Localizing functional damage in the neural retina of adolescents and young adults with type 1 diabetes. Invest. Ophthalmol. Vis. Sci. 55(4): 2432-41.

Vincent A, Wright T, Garcia-Sanchez Y, Kisilak M, Campbell M, Westall C, Héon E. Phenotypic characteristics including in vivo cone photoreceptor mosaic in KCNV2-related "cone dystrophy with supernormal rod electroretinogram." Invest Ophthalmol Vis Sci 2013 54(1):898–908

McFarlane M, Wright T, Stephens D, Westall C. S-cone ERG PhNR changes associated with poor long-term glycemic control in adolescents with type 1 diabetes. Investigative Ophthalmology and Visual Science (Published online before print January 4, 2012, doi: 10.1167/iovs.11-8263).

Sergott RC, Westall CA. Primer on visual field testing, electroretinography, and other visual assessments for patients treated with vigabatrin. (2011). Acta Neurologica Scandinavic, 124, (SUPPL. 192), 48-56.

Vincent A, Wright T, Day MA, Westall CA, Heon, E. (2011). A novel p.Gly603Arg mutation in CACNA1F causes Al and island eye disease and incomplete congenital stationary night blindness phenotypes in a family.  Mol Vis 17: 3262-3270.

Lakhani E. (2010) Insufficient long-term glycaemia control is associated with multifocal ERG defects in adolescents with type 1 diabetes.  Invest Ophthalmol Vis Sci. 2010 Oct;51(10):5297-303.

Wygnanski-Jaffe T, Panton CM, Buncic JR, Westall CA. (2009) Robust visual evoked potentials in young patients with cortical blindness. Documenta Ophthalmologica 1119(2): 01-7.

Durban S, Mirabella G, Buncic JR, Westall CA. (2009)  Reduced grating acuity associated with retinal toxicity in children with infantile spasms on vigabatrin therapy. Invest Ophthalmol Vis Sci.  50(8): 4011-6

Nilsson J, Wright T, Westall C. (2008) Rod photoreceptor function in a clinical population referred for ERG: bright flash rod response adds information on rod system function. Vision Research 48(18): 1920-5.

Wright T, Nilsson J, Gerth C, Westall C. (2008). A comparison of signal detection techniques in the multifocal electroretinogram. Doc Ophthalmol. 117(2): 163-70.

Gerth CG, Mirabella G, Li X, Wright T, Westall CA, Colpa L, Wong A. (2008). Timing of surgery for infantile esotropia in humans: effects on cortical motion visual evoked responses. Invest Ophthalmol Vis Sci. (49) (08): 3432-7

Mirabella G, Morong S, Buncic JR, Snead OC, Logan WJ, Weiss SK, Westall CA. (2007) Contrast sensitivity is reduced in children with childhood epilepsy. Investigative Ophthalmology & Vis Sci. 48 (08): 3610-5.

Chang BCM, Mirabella G, Yagev R, Banh M, Mezer E, Parkin PC, Westall CA, Buncic JR. (2007) Screening and diagnosis of optic pathway gliomas in children with neurofibromatosis type 1 using sweep visual evoked potentials. Investigative Ophthalmology & Vis Sci. 48 (06): 2895-902.

Gerth C, Wright T, Heon E, Westall CA. (2007) Assessment of central retinal function in patients with advanced retinitis pigmentosa. Invest Ophthalmol Vis Sci 48(03): 1312-8

Mirabella G, Morong S, Buncic JR, Snead OC, Logan WJ, Weiss SK, Westall CA. (2007) Contrast sensitivity is reduced in children with childhood epilepsy. Investigative Ophthalmology & Vis Sci. 48 (08): 3610-5.

Gerth C, Wright T, Heon E, Westall CA. (2007) Assessment of central retinal function in patients with advanced retinitis pigmentosa. Invest Ophthalmol Vis Sci 48(03): 1312-8

Chang BC, Mirabella G, Yagev R, Banh M, Mezer E, Parkin PC, Westall CA, Buncic JR. (2007). Screening and diagnosis of optic pathway gliomas in children with neurofibromatosis type 1 by using sweep visual evoked potentials. Invest Ophthalmol Vis Sci, 48 (6), 2895-2902.

Elia YT, Daneman D, Rovet J, Abdolell M, Lam WC, Till C, Erraguntla V, Rubab S, Lodha N, Westall CA. (2005). Color visual evoked potentials in children with type 1 diabetes: relationship to metabolic control. Invest Ophthalmol Vis Sci, 46 (11), 4107-4113.

Till C, Westall CA, Koren G, Nulman I, Rovet JF. (2005). Vision abnormalities in young children exposed prenatally to organic solvents. Neurotoxicology, Aug;26(4):599-613.

Fulton AB, Brecelj J, Lorenz B, Moskowitz A, Thompson D, Westall CA. (2006). Pediatric clinical visual electrophysiology: a survey of actual practice. Doc Ophthalmol 113(3): 193-204.

Elia YT, Daneman D, Rovet J, Abdolell M, Lam WC, Till C, Erraguntla V, Rubab S, Lodha N, Westall CA. (2005). Color visual evoked potentials in children with type 1 diabetes: relationship to metabolic control. Invest Ophthalmol Vis Sci 46(11): 4107-13.

Westall CA. (2005). Detecting ocular-visual function changes in diabetes. Br J Ophthalmol 89(11): 1392-3.

Buncic JR, Westall CA, Panton CM, Munn JR, MacKeen LD, Logan WJ. (2004). Characteristic retinal atrophy with secondary "inverse" optic atrophy identifies vigabatrin toxicity in children. Ophthalmology, 111 (10), 1935-1942.

Westall CA, Eizenman M, Kraft SP, Panton CM, Chatterjee S, Sigesmund, D. (1998). Cortical binocularity and monocular optokinetic asymmetry in early-onset esotropia. Invest Ophthalmol Vis Sci, 39 (8), 1352-1360.

Intellectual Property

CRACK ERG: Software package to derive normal ranges of ERG results based on age. Licensed to SickKids