Diabetes is a disease that affects the body’s ability to produce or use insulin effectively to control blood sugar (glucose) levels. Too much glucose in the blood for a long time can cause damage in many parts of the body, including the small blood vessels in the eyes.
Diabetes can cause vision in your eyes to change. If blood sugar levels change quickly, it can affect the shape of the lenses in your eyes, resulting in blurry vision. Diabetes can also cause a disease called diabetic retinopathy.
Types of Diabetic Retinopathy
Diabetic retinopathy has two main categories. Each of these categories has several sub-categories. Non-proliferative diabetic retinopathy is when blood vessels leak, then close, and proliferative retinopathy occurs when new blood vessels grow.
Non-proliferative Diabetic Retinopathy
This category is also known as background retinopathy. Your retina may have some weak capillaries that either leak or close. You may have little, if any, visual symptoms. When leakage occurs in the macula, visual symptoms become more apparent. The leakage can cause swelling in the macula which could be caused by a few leaking vessels or many scattered throughout the macula. This may cause slight to very severe blurring of vision. Finally, when the capillaries close, the eye is at risk for new blood vessel growth.
Proliferative Diabetic Retinopathy
When the capillaries close, the retina becomes oxygen starved. In response, the body grows new blood vessels in an attempt to nourish the retina. In the early forms, you may notice little change in your vision. These vessels are very fragile and if the vitreous pulls hard enough on them, they can break, causing bleeding. This can cause the vision to be very blurry or completely obscured, depending on the severity. Scar tissue can also form around these vessels. If the vitreous pulls on this, it can cause a retinal detachment. This can cause severely reduced vision.
Other terms which might be mentioned during your exam are: microaneurysms – bulges in the wall of the capillaries; neovascularization – growth of small capillaries; macular – central part of vision; ischemic and cotton wool spots – when blood vessels close (ischemic) white patches of oxygen starved retina (cotton wool spots) may remain.
Diagnosis and Treatment for Diabetic Retinopathy
Patients coming for an exam are asked for a complete medical history. Knowing how long you’ve had diabetes, how you monitor and control it, as well as any specific visual problems you may be having help the doctor in the diagnosis. Your doctor will examine your retina through your dilated pupils for signs of diabetic retinopathy. Sometimes diabetic retinopathy can be treated with a laser. While the laser can’t restore vision already lost, it can help to prevent abnormal blood vessels from spreading.
Vision lost to diabetic retinopathy can be irreversible. Early detection and treatment reduce the risk of blindness by 95 percent.
What should you do to preserve your vision?
Control Your Blood Sugar and Blood Pressure. It is important for you to control your blood glucose levels by testing your blood regularly, taking your medication if needed, and following your meal plan. Many diabetics also have high blood pressure. Keeping blood pressure under control may prevent retinopathy from become worse.
Exercise Regularly. Work with your primary care physician to determine what is the best form and amount of exercise you need.
Routine Eye Exams. If diagnosed with diabetes, you should have an eye exam done through dilated pupils at least once a year or more often if your eye care provider recommends.