Regenerate Damaged Cells and Tissues to Restore Sight

Transplanted vision cells (in green) may one day be used to restore vision.
 

Without intervention, diseases of the eye can destroy nerve cells. Once this occurs, the process of vision is interrupted, and vision is permanently lost. However, scientific research over the past 20 years has begun to reveal how the cells of the eye develop in the human embryo.

Unlocking the secrets of cell development is leading to important advances in eye disease, cancer and many other fields. Research at our centre has been part of these advances. For example, former centre scientists Brenda Gallie and Rod Bremner, played a pivotal role in understanding how cell development goes awry in children with retinoblastoma, a childhood cancer of the eye. Dr. Gallie’s work has vastly improved treatment outcomes for children with these cancers, while Dr. Bremner’s work focuses on preventing abnormal cell development in at-risk families. Similarly, our current Director, Valerie Wallace, has shown how signals in the hedgehog pathway control the development of stem cells into more mature cells in the brain and retina. Work by Philippe Monnier is guiding transplanted cells to establish new connections between the eye and brain.

Today there is promise that the natural process of cell development could be harnessed to grow new cells for a damaged eye. At the Donald K Johnson Eye Institute, stem cells and other immature cell types are being used to create new eye cells in the laboratory, and the genetic and chemical control of this growth process is being studied in minute detail. Transplants of these cells may finally offer treatments for currently irreversible blindness associated with age-related macular degeneration and glaucoma.

Stem cell transplants are already being used at the Donald K. Johnson Eye Institute to restore sight to people blinded by severe cornea disease and injuries. This surgical team, led by Dr. Allan Slomovic, is the only Canadian team with the expertise to perform this procedure.

As well, a current clinical trial led by Dr. Robert Devenyi is testing the use of an implanted chip that responses to light and can send electrical signals to the brain. This technology provides very low resolution vision to people who are completely blind. The research may provide insights about how the eyes and brain of a completely blind person will respond to a new source of visual information, such as transplanted cells.