Vision
The Brain Research Centre is involved in research relating to the following vision disorders:
- macular degeneration
- glaucoma
- amblyopia
- dyslexia
How does the eye work?
What is macular degeneration?
Would you like to learn more about macular degeneration?
What is glaucoma?
Would you like to learn more about glaucoma?
What is amblyopia?
What is dyslexia?
How is the Brain Research Centre helping those who live with dyslexia and other vision disorders?
Would you like to learn more about dyslexia?
Who researches vision?
Would you like to support vision research?
How does the eye work?
The eye is a very complex organ. Nerve cells in the retina at the back of the eye respond to light and send signals to the visual processing parts of the brain. Rods and cones convert the light energy into electrochemical signals. The optic nerve is formed by the fibres emanating from the retina, and connects the eye to the brain. The brain then receives these signals and reassembles them into images that we can see.
Because of this complicated process, much can go awry. Disorders of vision are extremely common, and range from mild refractive errors to serious degenerative disorders. In particular, photoreceptors are vulnerable in diseases such as retinitis pigmentosa and macular degeneration. In addition, the cells that give rise to the fibres in the optic nerve are destroyed selectively in chronic degenerative diseases such as glaucoma. As well, since a substantial part of the brain is devoted to processing visual information, several developmental disorders of vision are also being investigated by Brain Research Centre scientists. These include amblyopia ("lazy eye"), which can lead to reduced vision in one eye as a result of inappropriate visual exposure early in life, and developmental dyslexia.
What is macular degeneration?
Macular degeneration is the leading cause of vision loss in adults over the age of 65. It occurs when photoreceptors and the supporting epithelial cells in the central part of the retina, called the macula, die. Affected individuals typically experience blurred or distorted central vision with the inability to resolve fine details required for normal day-to-day activities. There are different types of macular degeneration and in some cases, complete loss of vision can occur.
Age-related macular degeneration (AMD) can be divided into two main classes. The wet form of AMD accounts for 10-15% of the cases and is the most severe form of the disease. Wet AMD is caused when abnormal bloodvessels grow in the macular region of the retina. These blood vessels can leak causing macular scarring and a permanent loss of central vision. The dry form, accounting for most cases of AMD, is characterized by the gradual loss of retina epithelial cells. In some cases, dry AMD can progress into the wet form of AMD. Regardless, AMD is a complex disease involving both environmental and genetic factors. In addition to age, smoking, a high fat diet, deficiencies in antioxidants, high blood pressure, and excessive sunlight appear to increase one’s risk for AMD, as well as certain genetic factors.
Early onset or juvenile macular degeneration is also a relatively common form of visual loss. In this set of retinal degenerative diseases, individuals inherit a defective gene encoding a protein critical for the function and survival of photoreceptor cells in the macula. There are many genetic and clinical variants of early onset macular degeneration. These include Stargardt macular degeneration, X-linked Juvenile Retinoschisis, Best’s Disease, Pattern dystrophy, Sorby’s macular dystrophy, and others.
Would you like to learn more about macular degeneration?
Download a two-page summary to learn more about macular degeneration.
What is glaucoma?
In glaucoma, elevated intraocular pressure is thought to lead to damage to the optic nerve and retinal ganglion cells, and to result in a slow and progressive decline in visual capabilities. The incidence of glaucoma is increasing as the population ages, and affects one person in 10 over 70 years of age. The disease incidence is forecast to increase markedly in the next century. Centre scientists including Drs. Fred Mikelberg, Stephen Drance, and Max Cynader are investigating the mechanisms of glaucoma, in order to understand how and why retinal ganglion cells die in this disease. Paradoxically, some people with normal eye pressure develop glaucoma, and an understanding of the mechanisms of vulnerability in this population is of great interest.
Would you like to learn more about glaucoma?
More information on glaucoma can be obtained from the Glaucoma Research Foundation.
What is amblyopia?
Amblyopia (commonly known as "lazy eye", or literally "blunt sight") is a condition in which vision in one eye is poor even though any refractive error is corrected and there is no other obvious damage to the eye. It is now widely accepted that the critical pathology in amblyopia involves a functional weakening of connections between visual cortex of the brain and one or both of the eyes. It is generally caused by conditions originating in childhood, such as strabismus, unilateral cataract, or anisometropia, which result in a reduction in the normal degree of similarity between the two retinal images, and which in turn affect the development of functional connections of retinal input to the visual cortex. The condition affects about 3% of the general population and arises during childhood while the visual centers of the brain are still developing. Although early treatment (typically forced use of the affected eye) is helpful, the condition is not treatable beyond seven or eight years of age, and it will persist into old age with severe consequences if vision in the good eye should be lost. Even in the most developed countries, many children still miss early examination and are only diagnosed at an age which is already too late for clinical correction.
What is dyslexia?
Dyslexia is a neurological disorder that affects the brain’s ability to receive and process written information. It is named from Greek and means “word blindness.” In spite of normal or above normal intelligence and vision, people suffering from dyslexia face severe obstacles in reading and writing — basic tasks that in our culture are essential to a person’s ability to function socially and professionally. Estimates of the incidence of the disease range from 2%-10% of the population, with 5% being a commonly quoted figure.
In the past, people with dyslexia faced the stigma of being thought of as lazy, stupid, or unmotivated individuals. With the advent of advanced brain imaging technology, our knowledge of dyslexia has expanded dramatically in the past ten years. We now understand that it is a challenging disorder which is very common, and which is amenable to scientific investigation and treatment. Still, dyslexia is usually left undiagnosed until a reading disability becomes apparent, usually at around ages seven to nine. This late diagnosis makes early, more effective intervention difficult. The concept of early identification is an important one. Many studies have shown that during the first few years of life the brain is at its most malleable and flexible state, and has the best ability to assimilate new training. If we can identify children who are at risk for dyslexia early in life—before they ever manifest a reading disability—and provide them with a training program to strengthen the pathways that are weakened in dyslexia, then we have an opportunity to provide a powerful new approach to this disease.
How is the Brain Research Centre helping those who live with dyslexia and other vision disorders?
At the Brain Research Centre, Dr. Deborah Giaschi and colleagues have made an amazing discovery. Using fMRI, they tested the perception of a specific class of moving images in children with dyslexia against a control group. They found that the children with dyslexia registered the motion on the right side of the brain only, while children in the control group showed activity on both sides of the brain. This is a critical breakthrough for dyslexia because the ability to see moving images and the ability to read are very closely linked in the brain. Investigators are now working to discover how small malfunctions in a particular area of the brain can have such an amplified effect on the ability to make sense of written material.
It is now well established that there is an important genetic component in dyslexia. There appear to be several distinct genes that are involved in predisposing a person to this disorder, but as of yet none have been identified. The prominent experts at the Brain Research Centre have pioneered a powerful and novel approach to identifying genes that may be malfunctioning in dyslexia. Their strategy involves looking at the large numbers of genes that are at work in the parts of the brain which do not appear to function properly in dyslexia, including the magnetocellular pathway, which connects the eye to the brain and which is responsible for visual-spatial and attention functions.
While we are making great progress in dyslexia and other vision research, there is still much work to be done. We house the talent capable of accomplishing impressive results through sophisticated, complex research, and will continue to do so.
Would you like to learn more about dyslexia?
Download a two-page summary to learn more about dyslexia.
Who researches vision?
M. Stella Atkins, MPhil, PhD School of Computing Science, Simon Fraser University
Jason Barton, PhD Department of Ophthalmology
Gordon Binsted, PhD Department of Human Kinetics, UBC Okanagan
C. Laird Birmingham, MD Department of Psychiatry
Robert Chow, PhD Department of Biology, University of Victoria
Margo S. Clarke, MD Department of Ophthalmology
Max S. Cynader, PhD Department of Ophthalmology; Director, Brain Research Centre
Shoukat Dedhar, PhD Department of Biochemistry & Molecular Biology
Adele Diamond, PhD Department of Psychiatry
Vincent Di Lollo, PhD Department of Psychology, Simon Fraser University
Robert M. Douglas, MA, PhD Department of Ophthalmology
Stephen M. Drance, OC, MB, ChB, MD Department of Ophthalmology
James T. Enns, MA, PhD Department of Psychology
Brian Fisher, PhD Department of Computer Science
Deborah Giaschi, MA, PhD Department of Ophthalmology / Department of Psychology
Cheryl Gregory-Evans, PhD TD Department of Ophthalmology
Kevin Gregory-Evans, MD, PhD Department of Ophthalmology
Kurt Haas, PhD Department of Cellular & Physiological Sciences
Todd Handy, PhD Department of Psychology
Farsheed Hedayati Vala, MD Faculty of Medicine
Manraj Heran, MD Department of Radiology
Martin J. Hollenberg, MD, MSc, PhD Department of Cellular & Physiological Sciences
Alan Kingstone, PhD Department of Psychology
Luba Kojic, PhD Department of Ophthalmology
Jocelyne S. Lapointe, MD Department of Radiology
Mario Liotti, PhD Department of Psychology, Simon Fraser University
James Little, PhD Department of Computer Science
David Lowe, PhD Department of Computer Science
Alan Mackworth, AM, PhD Department of Computer Science
Philippe Margaron, PhD Department of Ophthalmology
Joanne A. Matsubara, PhD Department of Ophthalmology
John McDonald, PhD Department of Psychology, Simon Fraser University
Frederick Mikelberg, MD Department of Ophthalmology
Robert S. Molday, MS, PhD Department of Biochemistry & Molecular Biology
Hakima Moukhles, PhD Department of Cellular & Physiological Sciences
Robert A. Nugent, MD Department of Radiology
Joel Oger, MD Division of Neurology, Department of Medicine
Ipek Oruc, PhD Department of Ophthalmology & Visual Sciences
Dinesh Pai, PhD Department of Computer Science
Glenda Prkachin, PhD Department of Psychology, University of Northern British Columbia
Andrew Rawicz, PhD School of Engineering Science, Simon Fraser University
Ronald Rensink, PhD Department of Computer Science / Department of Psychology
Urs Ribary, PhD Department of Psychology, Simon Fraser University
Jack Rootman, MD Department of Ophthalmology
Miriam Spering, PhD Department of Opthalmology & Visual Sciences
Nicholas Swindale, PhD Department of Ophthalmology
Filip Van Petegem, PhD Department of Biochemistry & Molecular Biology
Naznin Virji-Babul, PhD Department of Physical Therapy
Lawrence Ward, PhD Department of Psychology
Robert J. Woodham, PhD Department of Computer Science
Pierre Zakarauskas, PhD Department of Ophthalmology
Would you like to support vision research?
The Brain Research Centre is committed to advancing our knowledge of the brain and to exploring new discoveries and technologies which have the potential to reduce the suffering and cost associated with disease and injuries of the brain. We invite you to help us deliver on this commitment.
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