Abstract
Purpose: We performed a randomized, double-blind, placebo-controlled trial in mild to moderate myopia patients to evaluate the benefit of taking a nutrient supplement containing anthocyanoside oligomers for improving nocturnal visiual function and/or clinical symptoms. Methods: The subjects included have refractive error between -lD(Diopters) $\~$-8D in both eyes, symptoms of decreased night vision and asthenopia based on the scoring result of a pre-structured questionnaire, and abnormal results of mesopic contrast sensitivity(MCS) screening test showing abnormal curve of contrast sensitivity in the middle and high frequency level, between 6.0 and 30.0 CPD(Cycles per degree) at mesopic condition(-2$\~$0 log cd/$m^2$). Total 60 people who qualified the criteria above were enrolled and the subjects were instructed to take the investigational product (anthocyanoside or placebo) twice daily for a 4 week period. The enrolled subjects were investigated for nocturnal vision performance by MCS and clinical symptoms at their first visit and re-evaluated at post-intervention (4 weeks later). MCS was measured and improvement of contrast threshold level according to each CPD was calculated by subtracting initial values from final values. Age, refractive error, and MCS were compared between the placebo and anthocyanoside. Results: After 4 weeks of drug administration 22 of the anthocyanoside group showed symptom improvement compared to 1 of the placebo group (p=0.000). Contrast sensitivity levels according to each CPD before and after drug treatment showed significant improvement in the anthocyanoside group but not in the placebo group. Mean MCS change of anthocyanoside group is 2.41$\pm$1.91 which showed significant improvement compared to -0.40$\pm$2.47 of the placebo group(p=0.000). MCS changes of anthocyanoside group showed significant improvement compared to placebo group in all levels of CPD(p<0.05). During our investigation none of the subjects complained of specific side effects related to anthocyanoside use. Conclusion: Our results show that under careful selection of people with significant symptoms and definite MCS abnormalities, anthocyanoside oligomers may improve the subjective symptoms and objective MCS results.