Diabetes trial participants needed

Article by Stuart Galbraith, Centre for Eye Research Australia

Last November, CERA released the ‘Out of Sight' report which identified that diabetes affects approximately one million Australian adults. The number is expected to double by the year 2025, posing major public health and economic concerns.

However, little is known whether blood vessel dysfunction in the eye, which causes vision loss in people with diabetes, is due to the effects of high blood glucose (sugar) or an indirect result of chronic cell damage.

With the support of the Juvenile Diabetes Research Foundation's Type 1 Diabetes Clinical Research Network, CERA has initiated a study which seeks to confirm whether high blood glucose directly causes blood vessel dysfunction in the eyes of people with type 1 diabetes and whether the normalisation of blood glucose will improve the function of these vessels. Almost all people with type 1 diabetes will develop diabetic eye disease within 20 years of diagnosis.

CERA is also testing if vitamin C can protect against blood vessel dysfunction caused by high blood glucose in type 1 diabetes. This finding will provide important information on the potential clinical use of vitamin C to prevent complications of type 1 diabetes such as diabetic retinopathy.

Vitamin C is a potent, naturally occurring antioxidant in normal human diets. Given the widespread and affordable nature of vitamin C, the addition of vitamin C to insulin regimes may be a simple and economical means to reduce the risk of diabetes complications after stable glucose control has been achieved.

The study also builds on previous research which has found that vitamin supplementation can delay the progression of certain types of age-related macular degeneration.

If you have, or know someone with, type 1 diabetes who may be interested in participating in this study please contact Dr Jonathan Noonan on +61 3 9929 8363 or email

The study involves two morning visits to St Vincent's Hospital in Fitzroy, a detailed medical assessment, intravenous infusions of insulin and glucose to control blood glucose levels and three non-invasive measurements of flicker light-induced blood vessel dilation in the eye at each visit. Participants will also receive $50 and a meal at each visit.

Associate Professor Ecosse Lamoureux, Health Sciences Principal Investigator at CERA said this study is being undertaken at a critical time with increasing rates of diabetes across the world.

"If you know anyone who may be interested in the trial, please contact us, the benefits to future generations of people with type 1 diabetes could be substantial," he said.

The research is a joint project between the St Vincent's Hospital Department of Endocrinology and Diabetes and the Centre for Eye Research Australia.