A study reveals that Pycnogenol, an antioxidant plant extract from the bark of the French maritime pine tree can improve microcirculation, retinal edema and visual acuity in the early stages of diabetic retinopathy.
Diabetic retinopathy, damage to the retina caused by leaky blood vessels, is a major cause of blindness in people with diabetes and is one of the most feared complications of diabetes. 40 percent to 45 percent of Americans diagnosed with diabetes already have some stage of diabetic retinopathy and up to 80 percent of all patients who’ve had diabetes for 10 years or more will experience some form of diabetic retinopathy.
The randomized controlled study investigated a total of 46 diabetes patients over a period of three months. The pine bark extract treatment group consisted of 24 diabetes patients, with 22 patients placed in a placebo treatment group. Each of the patients had been previously diagnosed with diabetes for at least four years prior to participating in the study and their blood glucose was well controlled by diet and oral anti-diabetic medication. Patients had early stage retinopathy characterized by capillaries in the eye leaking fluid into the retina causing swellings. At this stage only minor bleedings into the retina occur and damage to light-sensing cells may still remain largely reversible.
Subjects were treated with three 50 mg Pycnogenol tablets or placebo tablets in the morning after breakfast over a period of three months. Following treatment with the pine bark extract, the major positive observation of this study was visual improvement, which was subjectively perceived by 18 out of 24 patients in the pine bark extract group. Testing of visual acuity using the Snellen Chart (the standard eye chart used by eye care professionals to measure visual acuity) showed a significant improvement from baseline 14/20 to 17/20 after two months of treatment with pine bark extract. There were no improvements found in the control group.
The retina is considered swollen when the diameter of the macula exceeds 500 micro meters and treatment with pine bark extract significantly decreased the swellings below that level, as judged by the high resolution ultrasound imaging used in the study. Furthermore, the blood flow velocity in capillaries nourishing the light sensing cells improved. The authors suggest that both effects account for the improved vision of patients. In the control group, retinal edema was not relieved, blood flow velocity remained unaffected and no visual improvements occurred. All 22 subjects in the control group maintained the same diabetic macular swellings as they were diagnosed with at the beginning of the study.
References:
1. Robert Steigerwalt, et al. Pycnogenol® Improves Microcirculation, Retinal Edema and Visual Acuity in Early Diabetic Retinopathy. Journal of Ocular Pharmacology and Therapeutics. November 2009. doi:10.1089/jop.2009.0023.
