According to Prevent Blindness America, diabetes is the leading cause of new cases of blindness in adults—and all people with diabetes are at risk for vision loss and blindness from diabetic eye disease. African Americans, Native Americans, Alaska Natives, Hispanics, Latinos, and older adults with diabetes are especially at higher risk. In addition, an emerging body of research in diabetes, vision, and health care indicates that significant differences in the quality and equality of eye care exist throughout the United States, specifically in the African American and Latino communities. According to the National Eye Institute, 7.7 million people who are 40 years of age or older are affected by a diabetic eye disease. The National Eye Institute projects that this number will increase to 11 million people by the year 2030.
Although people with diabetes are more likely to develop cataracts at a younger age and are twice as likely to develop glaucoma as people who do not have diabetes, the primary vision problem caused by diabetes is diabetic retinopathy, the leading cause of new cases of blindness and low vision in adults aged 20-65. “Retinopathy” is a general term that describes damage to the retina. The retina is a thin, light-sensitive tissue that lines the inside surface of the eye. Nerve cells in the retina convert incoming light into electrical impulses. These electrical impulses are carried by the optic nerve to the brain, which interprets them as visual images. Diabetic retinopathy occurs when there is damage to the small blood vessels that nourish tissue and nerve cells in the retina. Proliferative diabetic retinopathy affects approximately 1 in 20 individuals with the disease.
Diabetic macular edema [edema = a swelling or accumulation of fluid] (DME) can occur in people with diabetes when retinal blood vessels begin to leak into the macula, the part of the eye responsible for detailed central vision. These leakages cause the macula to thicken and swell, which, in turn, creates a progressive distortion of central vision. Although this swelling does not always lead to severe vision loss or blindness, it can cause a significant loss of central, or detail, vision, and is the primary cause of vision loss in people with diabetic retinopathy. DME can occur at any stage of diabetic retinopathy, but it is more likely to occur as the disease progresses.