A total of 45 patients (90 eyes) with stages I and II open-angle glaucoma (OAG) were examined, 26 of these were administered lipoic acid in a daily dose of 0.075 g for 2 months and 19 were given 0.15 g daily for 1 month. Control group consisted of 31 patients with OAG who were administered only local hypotensive therapy. Vision acuity and visual field were checked up, tonometry, tonography, and campimetry carried out, and levels of nonprotein SH-groups and activity of gamma-glutamyl transpeptidase measured in the lacrimal fluid. Improvement of the biochemical parameters, visual function, and of the coefficient of efficacy of liquid discharge was more expressed in the patients administered lipoic acid in a daily dose of 0.15 g. Color campimetry results indicate improved sensitivity of the visual analyzer under the effect of treatment. Improvement was attained in approximately 45-47.5% of examined eyes, and was more often seen in patients with stage II OAG: in 57-58% eyes. The effect of lipoic acid may be explained by its antioxidant properties and direct influence on ocular tissue metabolism.