Oral antioxidant therapy for marginal dry eye

Objective: To assess the efficacy of an orally administered antioxidant dietary supplement for managing marginal dry eye. Design: A prospective, randomised, placebo controlled trial with cross-over. Setting: Eye Clinic, Department of Vision Sciences, Glasgow Caledonian University. Subjects: Forty marginal dry eye sufferers composed of 30 females and 10 males (median age 53 y; range 38-69 y). Interventions: Baseline assessments were made of tear volume sufficiency (thread test), tear quality (stability), ocular surface status (conjunctival impression cytology) and dry eye symptoms (questionnaire). Each subject was administered courses of active treatment, placebo and no treatment, in random order for I month each and results compared to baseline. Results: Tear stability and ocular surface status were significantly improved following active treatment (P < 0.05). No changes from baseline were detected following administration of placebo and no treatment (P >0.05). Absolute increase in tear stability correlated with absolute change in goblet cell population density. Tear volume was not improved following any treatment period and dry eye symptom responses were subject to placebo effect. Conclusions: Oral antioxidants improved both tear stability and conjunctival health, although it is not yet understood whether increased ocular surface health mediates increased tear stability or vice versa. Sponsors: This study was supported by a PhD scholarship funded by the Department of Vision Sciences, Glasgow Caledonian University, Scotland. Antioxidant supplements and placebos were kindly donated by Vitabiotics.