Diabetes induced vision loss occurs in three ways: diabetic retinopathy, cataracts and glaucoma. Diabetic retinopathy is the consequence of damage to the blood vessels in the retina. Cataracts occur when the eye's lens clouds, producing blurred vision. And glaucoma is the consequence of elevated fluid pressure in the eye that damages the optic nerve.
Identification
Early warning signs of vision loss often do not occur. Most symptoms, like blurred or spotted vision, only arise once the disease is severe. Dilated eye exams are superior to conventional eye exams, which are usually insufficient to determine whether retinal blood vessels are damaged. In order to specifically visualize the blood vessels in the eye, doctors can perform a fluorescein angiography. In this procedure, dye is injected into a vein--usually in the arm--and pictures are taken as the dye moves through the eye's blood vessels. This procedure can identify whether retinopathy is occurring.
Risk Factors
Anyone diagnosed with diabetes before age 30 is likely to develop retinopathy within 15 years, while 75 percent of those diagnosed after age 30 develop retinopathy. Smoking and alcohol increase the risk of vision loss. Hypertension is also a common problem associated with diabetes. High blood pressure needs to be treated with medication, diet and exercise. If a patient is diagnosed with hypertension and diabetes, annual eye examinations become even more important because the increased blood pressure can cause accelerated decay of retinal neurons.
Prevalence
"Diabetes is the leading cause of new cases of blindness among adults ages 20 to 74," states the American Optometric Association. Diabetic retinopathy accounts for 25,000 additional cases of blindness every year. Approximately 8 million people with diabetes in the United States have early signs of diabetic retinopathy. General retinopathy, cataracts or glaucoma affect the general population at a low rate, but diabetics are approximately 30 times more likely to lose their sight, according to the National Eye Institute.
Stages of Diabetic Retinopathy
The four stages of diabetic retinopathy include mild nonproliferative retinopathy, moderate nonproliferative retinopathy, severe nonproliferative retinopathy and proliferative retinopathy. The first three stages characterize minor to severe blood vessel leakages and swellings that impede blood flow to the eye. Proliferative retinopathy occurs when the previous blood vessel changes signal to the body to create new blood vessels to replenish the retina. These new abnormal, fragile blood vessels grow along the retina and on the surface of the clear, vitreous gel, causing vision loss, explains the National Eye Institute.
Prevention and Treatment
The American Optometric Association recommends that anyone diagnosed with diabetes should receive a dilated eye exam every year. Early detection of vision loss is critical to prevent further vision loss and subsequent blindness. Yearly glucose tolerance checks will ensure that pre-diabetes or diabetes is diagnosed before serious vision loss occurs. Maintaining glucose levels at or near normal levels of 70 to 140 milligrams per deciliter will slow or stop the progression of retinopathy.
