Evaluation of oxidative stress and antioxidant system in the pathogenesis of proliferative vitreoretinopathy

Abstract

Purpose

To evaluate the impact of oxidative stress and the antioxidant defense system in the pathogenesis of proliferative vitreoretinopathy (PVR).

Methods

In this prospective study, three groups of patients undergoing pars plana vitrectomy (PPV) were included: Group 1 included patients with rhegmatogenous retinal detachment (RRD) complicated by grade C PVR; Group 2 included patients with RRD without PVR; and Group 3 (control group) consisted of patients undergoing PPV for macular hole or vitreomacular traction. At the initiation of PPV, approximately 0.2 ml of a vitreous sample was obtained. Samples were analyzed for total oxidant status (TOS, µmol H₂O₂ equivalent/L), total antioxidant status (TAS, mmol Trolox equivalent/L), and oxidative stress index (OSI, TOS/TAS).

Results

A total of 60 eyes from 60 patients were included (n = 20 per group). The mean TAS levels were 1.23 ± 0.62 in Group 1, 1.41 ± 0.64 in Group 2, and 1.84 ± 0.52 in Group 3 (p = 0.008). The mean TOS levels were 18.62 ± 8.56, 14.32 ± 6.57, and 10.42 ± 5.82 in Groups 1, 2, and 3, respectively (p = 0.005). There was a statistically significant difference in OSI values between the groups (Group 1: 24.4 ± 31.51; Group 2: 13.31 ± 13.79; Group 3: 6.88 ± 6.26) (p = 0.001).

Conclusion

Elevated TOS and OSI levels, along with reduced TAS levels in the vitreous samples of patients with PVR, suggest that oxidative stress and impaired antioxidant defense may play a critical role in the pathogenesis of PVR.