Uncontrolled blood sugar levels can affect the retina of the eye and cause a complication known as diabetic retinopathy. It is generally more common in people who have been living with diabetes for several years. The risk of diabetic retinopathy increases with age and if left untreated, may lead to vision loss or blindness. Diabetic retinopathy can often be prevented by making lifestyle modifications to control blood sugar, such as weight loss, dietary changes, physical activity, and getting regular eye screenings.
Causes and stages of diabetic retinopathy
Diabetic retinopathy is a condition that causes the build-up of too much glucose that can damage the tiny vessels that supply blood to the retina. Over time, this damage may block the flow of blood and cause significant damage, like a blurred or sudden change in vision, eye pain, etc. which could also progress to blindness.
Diabetic retinopathy develops and progresses slowly over time in various stages:
- Background retinopathy - In this early stage of diabetic retinopathy, the walls of the blood vessels in the retina weaken. It causes tiny bulges called micro-aneurysms that can leak small amounts of blood into the retina. This condition is common in people with diabetes where their vision is not affected but indicates a high risk of developing vision problems in the future.
- Pre-proliferative diabetic retinopathy - This is the second stage that occurs when the damaged blood vessels swell, causing fluid and blood leakage into the retina. Sometimes, the macula, the center of the retina responsible for sharp and straight-ahead vision, can be affected. The swelling and thickening of the macula are known as macular edema. This stage usually causes distorted vision.
- Proliferative diabetic retinopathy – This stage occurs when the damaged blood vessels completely block the blood supply. It is characterized by abnormal growth and the development of new blood vessels. These new blood vessels are weak and bleed easily into the vitreous (vitreous is the gel-like fluid that fills the center of the eyes). This condition causes vision loss that may be severe.
Symptoms of diabetic retinopathy
Diabetic retinopathy rarely shows any symptoms in the early stages. But as the condition progresses, symptoms become noticeable that may include:
- Eye floaters (transparent spots or dark strings that float in the person’s vision)
- Blurred or patchy vision
- Fluctuating vision
- Impaired colour vision
- Dark or empty spots in the centre of the vision
- Sudden loss of vision
Importance of screening
Screening for diabetic retinopathy is necessary because most people with diabetes do not experience any symptoms until the condition has progressed to advanced stages. If detected early, the vision loss caused by diabetic retinopathy can often be prevented with appropriate management and treatment.
Recommendations for the screening of diabetic retinopathy are different for type 1 and type 2 diabetics.
- People with type 2 diabetes have retinopathy in the early stages when they get their diabetes diagnosed. For these people, an annual dilated eye examination is recommended shortly after diabetes is diagnosed.
- People with type 1 diabetes are advised for annual eye examinations after 3-5 years of diagnosing diabetes.
Diabetic retinopathy is shown to progress rapidly during pregnancy. Hence, pregnant women with diabetes should get a dilated eye test before conception, early in the pregnancy, and then every 3 months until childbirth. Unlike pre-existing diabetes, women with gestational diabetes are not at an increased risk of diabetic retinopathy.
People with diabetes can reduce the risk of diabetic retinopathy, or prevent it from getting worse by taking these important steps.
- Managing diabetes - One should follow a healthy diet and be physically active. It is recommended that people with diabetes exercise or walk for at least 150 minutes a week. In addition to this, they must take oral diabetes medications or insulin as prescribed by the doctor, and not miss any doses.
- Monitoring the blood sugar level - People with diabetes must check and record their blood sugar levels frequently. This will help to take measures to keep sugar levels in a healthy range.
- Testing for HbA1c level - HbA1c test reflects the average blood sugar levels for the last 3 months. One should aim to keep the HbA1c under 7 percent.
- Keeping blood pressure and cholesterol under control - Healthy diet, regular exercise, and a healthy weight help keep these levels under check. However, sometimes medication may also be required.
- Quitting smoking - Smoking may increase the risk of developing various diabetes-related complications. Quitting smoking will help to reduce the risk of diabetic retinopathy.
- Being mindful of vision changes - Any changes in vision such as floaters, dark spots, or blurred vision should be immediately discussed with an eye specialist.
Diabetic retinopathy can occur in people with either type 1 or type 2 diabetes, and it generally affects both eyes. The condition develops slowly over several years and may not show any warning signs. Therefore, people with diabetes need to have regular eye examinations to help detect the condition early and prevent complications. On diagnosing and treating the condition promptly, vision loss is usually preventable.
And for any questions on eyes and vision, you can consult an eye specialist.