Diabetes is the leading cause of new cases of blindness among adults 20 to 74 years of age. Diabetic retinopathy causes from 12,000 to 24,000 new cases of blindness each year.People with diabetes can maintain optimal vision and healthy eyes by having an annual comprehensive vision examination, including a dilated eye examination.
Diabetes-Related Eye Conditions
People with diabetes are at 25 times greater risk for blindness from cataracts, glaucoma, and macular degeneration. People with diabetes who smoke, have poor nutrition, and do not control their diabetes have an even greater risk of developing eye complications. Because many people with diabetes have a slower healing time, eye injuries-even minor corneal scratches-should not be taken lightly.
Retinopathy is a common eye complication among people with diabetes. Poor blood glucose (or glycemic) control and longer duration of diabetes lead to increased rates of retinopathy in people with type 1 and type 2 diabetes. Poor glycemic control and longer duration of diabetes lead to increased rates of retinopathy in people with type 1 and type 2 diabetes. Retinopathy is a leakage of damaged blood vessels in the back of the eye and collapse and deterioration of blood vessels. The condition affects the retina’s macula (the area responsible for fine visual acuity), causing vision reduction and potentially leading to blindness. However, diabetic retinopathy is one of the most preventable forms of vision loss.
Early detection and treatment can prevent or delay blindness due to diabetic retinopathy in 90 percent of people with diabetes. Good glycemic control has been shown to reduce or delay by 76 percent the development of retinopathy in people with diabetes.Intensive therapy reduces the first appearance of any retinopathy by 27 percent. Retinal laser photocoagulation surgery can reduce the risk of severe vision loss from proliferative diabetic retinopathy (PDR) to 4 percent or less.
Doctors of optometry and ophthalmologists can provide low-vision aids-from simple hand magnifiers to innovative optical devices-to help persons who have experienced uncorrectable severe vision loss due to diabetic retinopathy. These eye care providers also can provide the care and services that allow people with diabetes to maintain good vision, which they need to maintain their quality of life and to help control their diabetes (e.g., to read instructions, take medication, drive to medical appointments).
Other Eye Complications
Other eye complications include diplopia (double vision) and frequent visual fluctuations. These complications tend to be more prevalent in people with type 2 diabetes.
Double vision. People with diabetes may complain about sudden onset of double images oriented in either a vertical or horizontal fashion. This may be due to mononeuropathy-damage to a single nerve-usually cranial nerves III, IV, and VI. The sixth and third nerves are most frequently affected. Third-nerve palsies occur with pupillary sparing in 80 percent of the cases. Most diabetic third-nerve palsies usually resolve spontaneously within 2 to 3 months.
Vision fluctuation. Poor control of blood glucose levels may lead to a fluctuation in vision and reduced ability to see both far and near. Visual fluctuations occur because of fluid imbalance in the crystalline lens. When the glucose level is elevated, the lens thickens, causing a more myopic refractive error. Conversely, when the glucose level is normal or low, the lens shrinks back to its normal state, causing a hyperopic shift in refractive error. This constant state of flux can make it difficult to determine a valid refractive error if the glucose level is poorly controlled.