Combined Antioxidant Therapy on Oxidative Stress, Mitochondrial Dysfunction Markers in Diabetic Retinopathy
Condition: Diabetic Retinopathy
MeSH terms: Retinal Diseases; Diabetic Retinopathy
Study type: Interventional
Phase: Phase 3

Summary: 
      The present study aims to support previous research on antioxidant therapy effects in
      diabetic retinopathy outcome. The investigators intend to assess 180 patients with diabetic
      retinopathy in different stages (moderate, severe and proliferative), whom either will be
      assigned to placebo group or combined antioxidant therapy. Each group will receive the
      intervention for 12 months. Such intervention consists in taking one tablet (placebo or
      antioxidant therapy) orally, a day.

      At baseline, blood and urine samples will be collected in order to assess metabolic and
      oxidative stress status, mitochondrial function or dysfunction, liver and kidney function. In
      addition, fluorescein angiography will be done for the categorization of diabetic
      retinopathy. After six months and at the end of the intervention, blood and urine
      measurements as well as angiographies will be done for comparing the outcomes between both
      groups and correlate oxidative stress status, mitochondrial dysfunction with grade of
      retinopathy.
    

Detailed description: 
      Diabetic retinopathy is a diabetes microvascular complication due to an insufficient oxygen
      supply to its endothelial cells in states of constant hyperglycemia. This entity is
      classified in two main categories: non-proliferative diabetic retinopathy and proliferative
      diabetic retinopathy, the latter is characterized for the presence of neovascularization as
      oppose to the first one.

      Oxidative stress has been considered as one of the main factors in the development of
      diabetic retinopathy. It results from an imbalance between oxidants production and cellular
      antioxidant defenses, which provokes DNA damage in the mitochondrion altering its capacity to
      produce ATP (Adenosine Triphosphate) resulting in what is known as mitochondrial dysfunction.

      Diabetic retinopathy management merely comprises glycemic, lipemic and blood pressure
      control. Secondary intervention includes anti-platelet agents, protein-kinase C inhibitors,
      aldolase reductase inhibitors, laser and vitrectomy. Antioxidant therapy has been used as a
      co-adjuvant for these interventions, as antioxidant substances that complement action and
      efficacy of the established treatment for diabetic retinopathy.

      Diabetic retinopathy is the principal cause of blindness in persons between 20 and 70 years
      of age. Its prevalence is, approximately, 25% 5 years after diagnosis.

      Which is why the investigators intend to prove if the antioxidant therapy is able to change
      retinopathy outcomes in oxidative stress, mitochondrial dysfunction and/or grade of
      retinopathy.
    

Intervention name(s): Combined antioxidant therapy; Placebo
Intervention type(s): Drug; Other
Intervention description(s): It consists in a tablet with lutein (10 mg), astaxanthin (4 mg), Zeaxanthin (1mg), vitamin C (L-ascorbic acid 180mg), vitamin E (DL-alpha tocopherol 30mg), zinc (zinc oxide 20mg), copper (copper sulfate 1mg), taken once a day for 12 months; It consists in a capsule with 100mg of magnesium oxide.
Other intervention name(s): Drusen Laz; Magnesia
Intervention MeSH terms: Antioxidants
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: diabetic retinopathy; oxidative stress; mitochondrial dysfunction; oxidative markers; diabetes; antioxidant therapy