Prospects for the use of direct antioxidant ionol (2,6-di-tert-butyl-4-methylphenol) for conservative treatment of cataract

Aim. To estimate the effect of ionol (2,6-di-teRt-butyl-4-methylphenol) on the dynamics of lens opacities and its free-radical status in experimental cataract.

Methods. Cataract was induced by a single injection of diquat dibromide solution into the vitreous body of 80 rabbits (160 eyes) at a dose of 600 nmol, 5 rabbits were included into the control intact group. Animals with induced cataract were divided into 4 groups each including 20 animals (40 eyes) who were treated with TID instillation in conjunctival cavity of: olive oil (control), «Oftan Catachrom», solution of α-tocopherol acetate, 2.2% ionol oil solution. Treatment was started on day 7. The duration of the experiment was 56 days. Dynamics of lens opacities was assessed by the following criteria: progress, stabilization and regression. In the lens homogenate the concentration of malonic dialdehyde, level of non-protein thiol (SH) groups, activity of glutathione peroxidase and glutathione transferase were determined. The results were analyzed by ANOVA, paired comparison was performed by the Newman-Keysl criterion.

Results. Application of ionol reduced malonic dialdehyde concentration in the lens compared to the series without treatment on days 14, 28, 42 and 56 (by 74.3, 90.0, 89.3, and 80.2%, p <0.05). Use of ionol prevented the depletion of antioxidant enzymes. On day 56, glutathione peroxidase activity exceeded control by more than 400%, and glutathione transferase - by 983.4% (p <0.05). The content of SH-groups by day 56 exceeded the control by 5 times. «Oftan Catachrom» and tocopherol showed no significant effect on free-radical status of the lens. With ionol, marked anti-cataract effect was registered. By day 28, stabilization of the process was noted in 44.3% of cases, and in 11.3% of cases the regression of lens opacities started. Further on, this trend persisted and by the end of the study, in half of the cases regression of lens opacities was noted, and in one third - their stabilization. «Oftan Catachrom» treatment stabilized the process of cataract formation only in 33%, and regression was not observed. Tocopherol did not have a significant effect on the cataractogenesis process.

Conclusion. The received results testify to the pathogenetic validity of the use of the direct antioxidant ionol for the treatment of cataract.