Retinal damage, known as retinopathy, can severely and permanently impair vision and even lead to blindness. Retinopathy is often reflective of vascular disease, such as that caused by elevated blood sugar levels (diabetic retinopathy) and high blood pressure (hypertensive retinopathy).
Fortunately, several scientifically studied integrative interventions, like B vitamins, astragalus, and Pycnogenol, can support the health of various structures in the eye and may improve symptoms of retinopathy.
Causes and Risk Factors
- People with Type 1 diabetes are more likely to develop diabetic retinopathy than people with type 2 diabetes.
- Longer duration of diabetes, higher blood glucose levels, higher blood pressure, and insulin use are also associated with an increased risk of diabetic retinopathy.
- Between 2% and 15% of people >40 years of age will have some signs of hypertensive retinopathy.
- Non-diabetic African Americans were more likely than non-diabetic whites to develop hypertensive retinopathy; however, they were also more likely to have high blood pressure, which may explain the association.
- Poorly controlled blood pressure and chronic kidney disease were both linked to a higher risk of retinopathy in non-diabetic individuals.
Signs and Symptoms
- Often, especially in the early stages of retinopathy, there are no symptoms.
- Many of the early signs of diabetic retinopathy can be detected by a doctor examining the retina with an ophthalmoscope.
- When there are symptoms, a wide spectrum of vision problems may occur, ranging from mild blurriness to sudden and dramatic loss of vision, particularly in the case of retinal detachment or hemorrhage.
- For people with diabetic or hypertensive retinopathy, treating the underlying condition damaging the retina (high blood glucose or elevated blood pressure) will help prevent progression of the retinopathy.
- One of the major goals when treating retinopathy is the destruction of dysfunctional, abnormal blood vessels. Two techniques that use this approach are cryotherapy and photocoagulation.
Novel and Emerging Therapies
- Vascular damage in diabetic retinopathy may be caused by vascular endothelial growth factor (VEGF) or protein kinase C. Inhibitors of these proteins have been studied as treatments for diabetic retinopathy.
- In clinical studies, one lipid-lowering medication – fenofibrate (Tricor®, Antara®, Lipofen®) – was found to reduce the risk of development and progression of diabetic retinopathy.
Lifestyle and Dietary Considerations
- Both diabetic and hypertensive retinopathy can in part be prevented by lowering blood pressure. Reducing sodium intake; eating a diet rich in fruits, vegetables, legumes, and low-fat dairy; consuming alcohol in moderation only; and maintaining a healthy weight can help lower blood pressure.
- Type 2 diabetics that use diet and exercise to achieve and maintain a healthy weight will often be able to lower their blood glucose and HbA1c levels. Other dietary strategies that can be beneficial include eating a consistent amount of carbohydrates at each meal and eating foods with a low glycemic index.
- B-vitamins: A study found that a combination of vitamin B12, folic acid, and pyridoxal-5’-phosphate (a form of vitamin B6) reduced retinal swelling and increased light sensitivity in individuals with diabetic retinopathy. Benfotiamine, a derivative of vitamin B1, may help combat the effects of glycation on the retina.
- Vitamin A and carotenoids: A clinical trial found that diabetics with retinopathy had improved vision after daily supplementation with lutein and zeaxanthin for three months.
- Carnosine: Carnosine, a compound comprising the amino acids histidine and beta-alanine, has been shown to counteract glycation of retinal tissue.
- Astragalus: A comprehensive review of several published studies found that astragalus was able to protect visual acuity and reduce fasting blood glucose and triglycerides in individuals with diabetic retinopathy.
- Curcumin: Subjects with diabetic retinopathy receiving curcumin as a daily supplement had less retinal swelling, improved visual acuity, and better blood flow in the retina.
- Pycnogenol: A comprehensive review examining the benefits of Pycnogenol concluded that Pycnogenol helped slow progression of diabetic retinopathy, improved visual acuity in people with diabetes, improved the strength of capillaries, and reduced capillary leakage into the retina.