Our UHN programs and services are among the most advanced in the world. We have grouped our physicians, staff, services and resources into 10 medical programs to meet the needs of our patients and help us make the most of our resources.
University Health Network is a health care and medical research organization in Toronto, Ontario, Canada. The scope of research and complexity of cases at UHN has made us a national and international source for discovery, education and patient care.
Our 10 medical programs are spread across eight hospital sites – Princess Margaret, Toronto General, Toronto Rehab’s five sites, Toronto Western – as well as our education programs through the Michener Institute of Education at UHN. Learn more about the services, programs and amenities offered at each location.
Maps & Directions
Find out how to get to and around our nine locations — floor plans, parking, public transit, accessibility services, and shuttle information.
Ways You Can Help
Being touched by illness affects us in different ways. Many people want to give back to the community and help others. At UHN, we welcome your contribution and offer different ways you can help so you can find one that suits you.
The Newsroom is the source for media looking for information about UHN or trying to connect with one of our experts for an interview. It’s also the place to find UHN media policies and catch up on our news stories, videos, media releases, podcasts and more.
Glaucoma is one of the most common eye diseases, but most patients won't know they have it until it's too late.
That's because the eye disease silently stalks it's victims over several years. It may cause no pain, but gradually wears down a person's vision by damaging the optic nerve, a vital link responsible for sending what you see to your brain.
Of the estimated 400,000 Canadians who live with glaucoma, most will first notice a loss of peripheral vision followed eventually by a disintegration of their central vision. The effects are irreversible and often lead to blindness.
"It's an incredibly common and serious problem because it has no direct treatment that addresses what is pathologically taking place," says Dr. Jeremy Sivak, a scientist at the Krembil Research Institute's Donald K. Johnson Eye Institute at UHN.
Dr. Sivak, who investigates, among other things, the mechanisms that underpin glaucoma as well as methods for drug delivery in the eye, sat down with
UHN News recently to discuss the search for answers about the disease ahead of World Glaucoma Week, which wraps up on March 18.
QUICK FACTS ABOUT GLAUCOMA
Question: What is glaucoma?
Dr. Sivak: All of our visual perception of the world is acquired through our eyes. All of that information that the eye collects is sent through the optic nerve at the back of the eye. The nerve is really just a fine thread that is very vulnerable. It's actually quite long and is part of the central nervous system and our brain. Glaucoma really is the degeneration of the nerve at that pinch point where it exits the eye, and the neuron cells that form it.
Q: What have we learned from recent research in this area?
A: We've learned that glaucoma is essentially a neurodegenerative disease and there is a lot of research looking into parallels between glaucoma and other neurodegenerative diseases, such as Alzheimer's disease. Glaucoma is similarly a slow, chronic, irreversible process which is associated with aging.
Q: What are the risk factors for it?
A: There are a wide variety of risk factors associated with glaucoma. Increased intraocular pressure (pressure inside the eye) is the most prominent, but many of the risk factors for other neurodegenerative diseases are the same. The biggest one is age. Smoking, vascular disorders, low or high blood pressure – anything that upsets the normal metabolic balance in this very delicate tissue – also contribute to the cause.
Q: Where do you see your research going in the future?
A: Methods to reduce eye pressure are partially effective, and have become very refined. The direction we need to go is toward neuroprotection; towards directly treating the degenerative cascade and protecting those neurons that are dying, prior to the degeneration - interrupting that process and then toward developing regenerative therapies.
Q: What is your approach in the lab?
A: As far as understanding glaucoma, we are behind some of the other neurodegenerative diseases in that we don't have a smoking gun. There are all these risk factors, but we are still looking for the central cause of the optic nerve degeneration. No matter which combination of risk factors, the disease proceeds in a similar way. Something is happening at that site in the retina, in that thin string coming out the back of the eye. My lab is trying to better understand what that injury is, and find ways to prevent and repair it.