Why high blood pressure and diabetes combined harm the eyes
University of Georgia researchers have pinpointed why hypertension or high blood pressure and diabetes create a perfect scenario for eye damage. In their study, the researchers discovered high blood pressure quickly leads to cell death in diabetic animals.
High blood pressure and diabetes a double whammy for eye health
Within 10 weeks, blood vessels that nourish the optic nerve begin to decay. The finding is important and shows why people with type 2 diabetes need to control blood sugar levels, be regularly screened for eye disease take prescribed medications and follow lifestyle recommendations for keeping blood pressure in check.
Islam Mohamed, a third-year clinical and experimental therapeutics graduate student who co-authored the paper said in a news release, "Our study highlights the synergistic and immediate interaction between systemic hypertension and diabetes as two independent risk factors for persistent retina damage known as retinopathy. This emphasizes the importance of addressing different cardiovascular risk factors in a holistic approach for improving management and prevention of retinopathy."
Diabetic retinopathy is a leading cause of blindness among working age people in America, according to the National Institutes of Health (NIH). The disease has no symptoms until blood vessels are severely damaged, which makes it important to have an annual eye exam if you’ve been diagnosed with type 1 or type 2 diabetes.
Symptoms of retinopathy include blurred vision, ‘floaters’, or seeing spots and difficulty seeing at night. Shadows can also appear as well as missing areas of vision.
Treatment is aimed at keeping the disease from progressing by managing risk factors of high cholesterol, high blood sugar levels and with smoking cessation. Laser surgery is performed if the blood vessels in the eye begin to leak, which leads to swelling and to eliminate fragile blood vessels.
For the study, the researchers, led by Azza El-Remessy, assistant professor in the UGA College of Pharmacy and director of the UGA clinical and experimental therapeutics program, looked at diabetic animals that had just developed diabetes as well as those with established stages of the disease. The animals also had hypertension.
The study authors wrote, “Early stage hypertension and diabetes exacerbate oxidative stress and inflammation” that is responsible for the eye damage that can also occur from high blood pressure alone. In animals with diabetes, cells in the eye died at an accelerated rate.
According to the CDC, approximately 13% of people with diabetes also have hypertension.
The authors say patient education about keeping cholesterol, blood pressure and blood sugar levels under control, each of which is an independent risk factor for diabetic retinopathy can lead to better patient outcomes. The finding is the first to show why diabetes combined with high blood pressure harms the blood vessels in the eyes and is a dangerous duo. The finding is published in the journal Molecular Vision
Mol Vis. 2012; 18: 1457–1466.
Published online 2012 June 2.
Islam N. Mohamed, et al.
“Diabetes exacerbates retinal oxidative stress, inflammation, and microvascular degeneration in spontaneously hypertensive rats”
Diabetes and Eye Disease
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