Diabetics more likely to lose their vision

Experts in the United States have found that vision loss is more common in people with diabetes than those without the disease.

The scientists at the Centers for Disease Control and Prevention (CDC) in Atlanta say approximately 14.6 million Americans were diagnosed with diabetes mellitus (type 2 diabetes) in 2005 and another 6.2 million had undiagnosed diabetes and it is estimated that number will increase to 48.3 million by 2050.

The researchers say diabetic retinopathy - damage to the retina caused by diabetes - is one of the most common microvascular complications of diabetes, and is considered to be one of the major causes of blindness and low vision.

Though research suggests that controlling glucose and blood pressure have reduced the rate of retinal diseases, other ocular conditions suffered by diabetic patients, such as cataract and glaucoma, may increase the risk of visual impairment - decreased vision caused by an abnormal shape of the cornea is also common among people with diabetes.

Dr. Xinzhi Zhang and colleagues at the CDC used data from the National Health and Nutrition Examination Surveys from 1999 to 2004, which included 1,237 adults with diabetes and an average age of 59 and 11,767 adults without the disease with an average age of 45.

The team also measured the participants' vision which was tested while they were wearing any glasses or contacts they typically used, and their demographic information was also noted.

It was found that around 11% of American adults with diabetes had some form of visual impairment as against 5.9% of those without diabetes.

The researchers say people with diabetes were more likely to have uncorrectable vision impairment than those without diabetes and a strong association was suggested between visual impairment and older age - racial/ethnic minorities, lower income and lack of health insurance, were all independent of diabetes status.

They say the high prevalence of visual impairment among people with diabetes indicates a need for diverse public health strategies to reduce the burden of both correctable and uncorrectable visual impairment and they say it is important to identify and pursue ways to increase access to eye care for everyone and to correct visual impairment, where possible, to diminish morbidity and mortality due to impaired vision.

The research is published in the October issue of Archives of Ophthalmology, one of the JAMA/Archives journals.