The Use of Alpha Lipoic Acid for the Treatment and Prevention of Diabetic Retinopathy (ALA-TPD)

The purpose of this study is to evaluate the role of alpha lipoic acid in patients who have moderate non-proliferative diabetic retinopathy. The primary aim of this study is to test the hypothesis that the addition of alpha lipoic acid in a diabetic patient's therapeutic regimen can decrease the progression of diabetic retinopathy and preserve visual acuity.

Increased production of free radicals and depletion of antioxidants are commonly observed in diabetic patients. Based on animal studies, increased production of free radicals tends to persist even after blood glucose is tightly controlled. The rationale of using a potent antioxidant is based on the observation that increased oxidative stress associated with hyperglycemia can contribute to cellular injury leading to apoptosis; consequently, leading to diabetic retinopathy. Evidence from animal model showed that alpha lipoic acid (a potent antioxidant) was effective for decreasing the progression of diabetic retinopathy and in reducing free radicals. Therefore, we hypothesize that therapy that can exert a powerful antioxidant activity can provide a therapeutic modality needed to target the pathogenesis of diabetic retinopathy. This study will be a 12-month pilot study demonstrating the role of alpha lipoic acid in patients who have moderate non-proliferative diabetic retinopathy. Eligible patients will be randomized to two groups, treatment and control groups. Patients in the treatment group will receive 600 mg of alpha lipoic acid daily with routine care while patient in control group will only follow routine care. Optical coherence tomography (OCT)and electronic visual acuity testing algorithm (ETDRS) will be used to measure changes in retinal thickness and visual acuity respectively. Blood changes in macrophage colony stimulating factor (M-CSF), vascular endothelia growth factor (VEGF), Interferon 2 alpha, interleukin 6 and 8 will also be evaluated and compared between the two groups. Descriptive statistics and intention to treat analysis will be used to compare treatment and control groups.

Diabetes, Diabetic Retinopathy, Retinopathy, Free radical, Retinal diseases, Antioxidants, Protective agents, Thioctic acid

Alpha lipoic acid assignment group will follow routine care and receive 600 mg oral administration of lipoic acid daily.

Decreased progression of diabetic retinopathy as measured and graded by using Standard ETDRS 7 -field color stereoscopic funds photograph, and also by measuring the serum levels of interleukin 6 and 8, VEGF, interferon 2 alpha and M-CSF using ELISA technique

Inclusion Criteria: Individual with diabetes mellitus type I or type II mild to moderate non-proliferative diabetic retinopathy which will be based on ETDRS grading scale Patient must be 18 years and older Exclusion Criteria: Patients with severe non-proliferative or proliferative diabetic retinopathy Patients with macular edema Eye diseases that may interfere with visualization of the fundus such as preretinal hemorrhage, cataract, vitreous hemorrhage Patient that has undergone any type of interventional therapy for diabetic retinopathy (Such as laser photocoagulation, vitrectomy) Amblyopia Glaucoma Patient with cataract surgery within a period of 4 months Patients with other retinal diseases Patients on chronic administration of alpha lipoic acid Known intolerance/hypersensitivity to alpha lipoic acid Patient with history of dialysis in cases of renal insufficiency and history of kidney transplantation Malignancies or life threatening diseases as determined by the investigators Current history of drug or alcohol abuse Pregnant and breast feeding women Cognitively impaired patients Participation in a clinical trial within the last 30 days