Due to the impact of abnormal glucose levels, diabetics are at risk for developing a variety of vision-related diseases. One major disease is called diabetic retinopathy because it affects the retina, causing vision loss and possible blindness. Other less common conditions that affect diabetics include cataracts and glaucoma.
Early Symptoms of Diabetic Retinopathy
The effects of diabetic retinopathy range from very mild to severe, and are categorized in four stages. Patients in the early stage of diabetic retinopathy may not notice any symptoms. Swelling begins in the tiny blood vessels in the retina due to excessive glucose. The retina is a thin membrane inside the eye that light passes through. The first three stages are called "non-proliferative" and involve swelling. Blood vessels become blocked and new vessels are formed.
Symptoms of Late-Stage Diabetic Retinopathy
The fourth stage is called proliferative retinopathy because many new abnormal blood vessels are being formed. The vessels are so fragile that they can leak, resulting in severe vision loss. As more fluid leaks into the macula (the part of the eye responsible for seeing straight ahead), the macula swells and vision becomes blurred. This condition, called macular edema, can happen during any stage but is most common during the late proliferative stage.
Less Common Vision Problems
Diabetics are more likely to develop cataracts and/or glaucoma and at an earlier age than someone without the disease. Cataracts are a clouding of the lens, causing blurriness. Glaucoma is caused by a buildup of fluid and pressure inside the eye that damages the retina and optic nerve. During the early stages, there are no symptoms. However, unless treated, glaucoma causes increasing loss of peripheral vision so that objects are viewed only through central vision, or what is called tunnel vision. The severity of diabetic-related vision diseases is strongly correlated with the patient's diet, exercise and overall ability to control the damaging effects of abnormal glucose levels and hypertension.
References
- "Coping with Vision Loss," Bill Chapman, 2001.
- "Low Vision rehabilitation: A Practical guide for Occupational Therapists," Mitchell, Scheiman, Maxine Scheiman & Stephen G. Whittaker, 2007.
- "Diabetic Retinopathy: What You Should Know (Brochure)," National Eye Institute, 2003.
