View Full Version : Canadian Researchers Break Ground Unlocking Mysteries Of Glaucoma In One Of World's Largest Studies

Medical Videos
07-02-2007, 04:11 PM

The world community of glaucoma researchers and 67 million people with this devastating eye disease worldwide can expect to benefit from a groundbreaking CNIB-funded study released. More than 15 years in the making, the Canadian Glaucoma Study positively identified, for the first time, several risk factors predicting the progression of this little understood disease.

"The results provide a gold mine of data that is unparalleled in the field," said Dr. Balwantray Chauhan, the study's principal investigator, and chair of vision research at Dalhousie University's Faculty of Medicine. "It's very exciting, and it's going to open the door for much more targeted research that will help us understand this disease." Dr. Chauhan presented the study's results at the Canadian Ophthalmological Society (COS) conference in Montreal.

Open-angle glaucoma involves damage to the eye's optic nerve, often characterized by high intraocular pressure (IOP). The disease often progresses over many years, and many people do not realize they have it until vision loss is permanent and untreatable. Until now, scientists knew little about why some patients develop the disease faster than others after IOP is taken into account. The Canadian Glaucoma Study looked at multiple, controlled factors, and found four of highest significance:

-- Anticardiolipin antibodies: Patients who had an antibody, associated with thrombosis (clotting in the circulatory system) or autoimmune disease, were four times more likely to progress in the disease. This had never before been considered as a possible risk factor, and will require further study.

-- Gender: Women were twice as likely as men to progress in the disease.

-- Age: For every year someone ages, their chance of progressing increases by 4%, confirming that open-angle glaucoma is primarily age-related.

-- IOP: Even though the study controlled for IOP, it still emerged as a major factor in the progression of glaucoma - making it even more significant than previously imagined. The study showed that for every mmHg of increased IOP, the risk of progression increases by an astonishing 20%.

Significantly, the study also ruled out several factors previously thought to be important, concluding that people with diabetes, hypertension and a history of cardiovascular disease were not more likely to than others to progress if they had glaucoma.

The investigation is the largest and most rigorous study on glaucoma ever undertaken in Canada (and among only half a dozen studies of such size and scope worldwide in the last 10 years). It was designed in 1992 with the unprecedented participation of leading glaucoma specialists across Canada and followed 258 patients in university hospitals at McGill, Université de Montreal, Dalhousie, University of British Columbia, and University of Toronto.

The length of the study (following patients between 1994 and 2005) contributed greatly to its significance. "It is important to look at any slowly progressing disease over a long period," said Dr. Chauhan, "But longitudinal studies of this duration are rarely funded. We're grateful to CNIB and all our partners who made this possible." CNIB contributed $1.8 million to the study, with the balance of the $2.2 million cost coming from the Glaucoma Research Society of Canada, Merck Frosst, Pfizer, and Allergan.

"As someone who was born with a severe form of open-angle glaucoma, I know how devastating this disease can be," said CNIB president and CEO Jim Sanders after the study's release. "CNIB is enormously proud to have supported Dr. Chauhan and the entire team who contributed to this landmark research across Canada."

About CNIB

CNIB is a nationwide, community-based, registered charity committed to public education, research and the vision health of all Canadians. CNIB provides the services and support necessary to enjoy a good quality of life while living with vision loss. Founded in 1918, CNIB reaches out to communities across the country, offering access to rehabilitation training, innovative consumer products and peer support programs, as well as alternative format newspapers and magazines, and braille and talking books from its library.

http://www.cnib.ca (http://www.cnib.ca/)

To read more about glaucoma, please link here (http://www.cnib.ca/en/your-eyes/eye-conditions/glaucoma/Default.aspx).