薬理と治療

Abstract

Objectives This study aims to investigate the effects of intake of a dietary supplement containing bilberry extract on eye fatigue resulting from deterioration in accommodative function caused by visual display terminal（VDT）work in healthy Japanese subjects. Methods This randomized, double-blind, parallel-group, placebo-controlled study was conducted on 44 healthy Japanese subjects who were experiencing eye fatigue caused by VDT work. The subjects were randomly assigned to either supplement with bilberry extract （BB group, n＝22） or placebo（P group, n＝22）group using a computerized random number generator, and each subject took one capsule per day for 12 weeks. Assessments of accommodative function and night vision and questionnaires were completed before intake and at 4, 8, and 12 weeks after intake. Safety evaluation was performed via ophthalmic examination. Somatometric parameters, physical examination, urinalysis, and blood tests were conducted before intake only. Results The final analysis included 17 subjects in the BB group and 18 subjects in the P group. The BB group had significantly higher pupillary constriction ratios, which were adjusted by calculating load in the dominant eye and both eyes, compared with the P group （P＝0.039 and P＝0.026, respectively）. No safety concerns were noted. Conclusions The consumption of a supplement containing bilberry extract for 12 weeks improved accommodative function, eye fatigue, and subjective eye-related symptoms. In the BB group, the decline in accommodative function caused by VDT work improved over the 12 weeks, subjective symptoms were alleviated, and eye fatigue was temporarily reduced. Trial registration UMIN-CTR: UMIN000029213Funding YAWATA CORPORATION