Effect of fermented bilberry extracts on visual outcomes in eyes with myopia: a prospective, randomized, placebo-controlled study

J Ocul Pharmacol Ther. 2013 Apr;29(3):356-9. doi: 10.1089/jop.2012.0098. Epub 2012 Oct 31.


Purpose: To investigate clinically the effects of yeast-fermented bilberry extract on visual outcomes in myopic eyes.

Methods: In a prospective, randomized, placebo-controlled, cross-over study, we examined 30 eyes of 30 middle-aged healthy volunteers (mean age±standard deviation, 39.5±7.2 years) with myopia [manifest spherical equivalent, -2.40±1.88 diopters (D)], who were randomly assigned to 1 of 2 oral regimens: fermented bilberry extract (400 mg/day) or placebo. We quantitatively assessed visual acuity, refraction, pupil constriction rate, accommodation, and mesopic contrast sensitivity (CS), before and 1 month after treatment. Only the right eyes were tested. The amplitude of accommodation and CS were measured with an accommodometer (D'ACOMO; WOC) and a CS unit (VCTS-6500; Vistech), respectively. From the CS, the area under the log contrast sensitivity function (AULCSF) was calculated.

Results: The mean amplitude of accommodation increased significantly, from 4.62±1.88 D before treatment, to 5.33±2.03 D after treatment in the study group (Wilcoxon signed-rank test, P=0.002). Moreover, the mesopic AULCSF was significantly increased, from 1.04±0.16 before, to 1.13±0.17 after, treatment (P=0.009). However, we found no significant changes in accommodation or AULCSF in the control group (P>0.05), or any significant changes in any other parameters in either group (P>0.05).

Conclusions: The present data show that fermented bilberry extract is effective in causing increases in subjective accommodation and in mesopic CS in myopic eyes.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Adult
  • Contrast Sensitivity / drug effects
  • Cross-Over Studies
  • Double-Blind Method
  • Female
  • Fermentation
  • Humans
  • Male
  • Mesopic Vision / drug effects
  • Middle Aged
  • Myopia / drug therapy*
  • Plant Extracts / administration & dosage
  • Plant Extracts / pharmacology*
  • Prospective Studies
  • Treatment Outcome
  • Vaccinium myrtillus / chemistry*
  • Visual Acuity / drug effects


  • Plant Extracts