The present study aims to support previous research on the effects of antioxidant therapy on the outcome of diabetic retinopathy and local oxidative stress values. The researchers intend to evaluate 56 patients with proliferative diabetic retinopathy undergoing the vitrectomy procedure, who will be assigned to a placebo group or combination antioxidant therapy. Each group will receive the intervention for 2 months. This intervention consists of taking one tablet (placebo or antioxidant therapy) orally, once a day. At the beginning of the study, only blood samples will be collected to evaluate the state of oxidative and metabolic stress at a systemic level. After 2 months of intervention, blood samples will be taken again on the day of the intervention, adding the samples of aqueous and vitreous humor obtained during the vitrectomy. The results obtained between both groups and the different analysis matrices will be compared.
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 is a result from an imbalance between oxidants production and cellular antioxidant defenses, which provokes DNA damage. The treatment of diabetic retinopathy simply includes glycemic, lipemic and blood pressure control. Only when the view is compromised is when a vitrectomy is performed, which usually occurs in the more advanced stages such as the proliferative stage. Antioxidant therapy has been used as a coadjuvant for these interventions, complementing the action and efficacy of the treatment established for diabetic retinopathy in the early stages. However, in order to obtain vitreous and aqueous humor, the vitrectomy procedure is required, which is only carried out in the proliferative stage. Diabetic retinopathy is a specific and chronic complication of diabetes mellitus and is known to have a prevalence of 43.6% internationally and 31.5% in the Mexican population. It represents the main cause of visual blindness and weakness in the economically active population, which also affects the quality of life and the productivity of the people who suffer it. The researchers intend to evaluate whether antioxidant therapy influences the levels of oxidative stress markers at the ocular level.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
40
It consists of a tablet with lutein (10 mg), astaxanthin (4 mg), Zeaxanthin (1 mg), vitamin C (L-ascorbic acid 180 mg), vitamin E (DL-alpha tocopherol 30 mg), zinc (zinc oxide 20 mg), copper (copper sulfate 1 mg), taken once a day for 12 months
It consists in a capsule with 100 mg of magnesium oxide
Institute of Experimental and Clinical Therapeutics,
Guadalajara, Jalisco, Mexico
Compare levels of markers of oxidative stress in aqueous humor and vitreous humor
The investigators will measure oxidative stress markers in aqueous and vitreous humor taken during vitrectomy procedure and compare such results between both intervention groups.
Time frame: 1 measure will be made after 2 months of intervention
Changes in concentration of plasma 8-isoprostanes after intervention.
The investigators will consider changes presented in plasma concentrations of 8-isoprostanes from baseline to the end of the intervention. The investigators expect to find a decrease in 8-isoprostanes concentrations in the supplemented group.
Time frame: 2 measures will be made, 1 at baseline, and one after completion of 2 months of intervention
Changes in concentration of total antioxidant capacity (TAC) after intervention from baseline.
The investigators will consider changes presented in plasma concentrations of total antioxidant capacity (TAC) from baseline to the end of the intervention. The investigators expect to find TAC augmentation in the supplemented group.
Time frame: 2 measures will be made, 1 at baseline, and one after completion of 2 months of intervention
Correlate the levels of 8-isoprostanes in systemic samples, aqueous humor and vitreous humor with the glycosylated hemoglobin value of patients with proliferative diabetic retinopathy.
The investigators will consider levels of 8-isoprostanes in serum, aqueous humor and vitreous humor after intervention and baseline glycated hemoglobin
Time frame: 1 measure of glycated hemoglobin will be taken at baseline
Correlate the levels of total antioxidant capacity (TAC) in systemic samples, aqueous humor and vitreous humor with the glycosylated hemoglobin value of patients with proliferative diabetic retinopathy.
The investigators will consider levels of total antioxidant capacity in serum, aqueous humor and vitreous humor after intervention and baseline glycated hemoglobin
Time frame: 1 measure of glycated hemoglobin will be taken at baseline
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