Lipid peroxidation and total antioxidant capacity in vitreous, aqueous humor, and blood samples from patients with diabetic retinopathy

摘要

Purpose: To evaluate levels ofmalondialdehyde and the total antioxidant capacity (TAC) in the blood,aqueous humor, and vitreous bodies of diabetic and nondiabeticpatients. We also measured the blood energy charge potential (ECP). Methods: We examined 19 patients withtype 2 diabetes mellitus and diabetic retinopathy. Ten were scheduledfor cataract surgery and pars plana vitrectomy because of proliferativediabetic retinopathy (PDR). The other nine, with mild nonproliferativePDR (NPDR), and fourteen nondiabetic, age-matched subjects enrolled asa control group were scheduled for cataract surgery and vitrectomybecause of epiretinal membranes. Blood, aqueous humor and vitreous bodysamples were collected at the time of surgery. Malondialdehydeconcentrations and blood ECP were measured with high-performance liquidchromatography. The TAC of the samples was estimated with the oxygenradical absorbance capacity method. Results: The level of blood and vitreousmalondialdehyde in the PDR group was significantly higher compared tocontrols and to NPDR patients. PDR patients also had lower levels ofTAC at the vitreous body and aqueous humor level, but not at the bloodlevel, compared to controls and with NPDR patients. In all diabeticpatients, the blood ECP values were significantly lower, compared tocontrol subjects. Conclusions: Our data support thehypothesis that oxidative stress and the decrease of antioxidantdefenses are associated with the progression of diabetic retinopathy toits proliferative form. Antioxidant supply may have the effect ofcorrecting oxidative stress and inhibiting disease progression.