Lipid peroxidation in proliferative vitreoretinopathies.

OBJECTIVE

To study the lipid hydroperoxide activity in vasoproliferative and fibroproliferative retinal disorders.

METHODS

Vitreous body samples from patients undergoing vitrectomy because of proliferative vitreoretinopathy (PVR; n = 12) or proliferative diabetic retinopathy (PDR; n = 15), and rhegmatogenous retinal detachment/macular hole/epiretinal membranes as the comparison group (CG; n = 14), were analysed for protein content and basal and induced lipid peroxidation (LPO), as determined by the thiobarbituric acid reactive substances (TBARS) test and LPO 586 commercial kit. The antioxidant activity for superoxide dismutase (SOD) and catalase (CAT) was also assayed.

RESULTS

Malondialdehyde (MDA)-like metabolites and 4-hydroxynonenal (4-HNE) mean values were first measured to assess basal LPO, and found to be significantly higher in the PVR and PDR cases than in the CG (p < or = 0.0001). LPO induced by nicotine adenine dinucleotide phosphate iron (NADPH-Fe) was then assayed and the data showed that MDA mean values were 5-fold greater for the PVR and PDR eyes than in the case of basal LPO (p < or = 0.0001). SOD activity was significantly smaller in the PVR (p = 0.0010) and PDR (p < or = 0.0001) groups than in the CG. CAT levels displayed significantly lower values in the PVR and PDR cases than in the CG (p < or = 0.0001). No significant differences in free radical (FR) formation and antioxidant status between PVR and PDR patients were observed.

CONCLUSIONS

Fibrovascular proliferative vitreoretinopathies correlate with increased FR formation and decreased antioxidant activity in the human vitreous body.