Objective: To evaluate the effect of a multivitamin/mineral supplement on development or progression of age-related lens opacities.
Design: Randomized, double-masked, single center, placebo-controlled clinical trial.
Participants: One thousand twenty participants, 55 to 75 years old and with early or no cataract, were randomly assigned to a daily tablet of a multivitamin/mineral formulation or a placebo.
Methods: Baseline and annual lens photographs were graded for severity of lens opacities according to a modification of the Age-Related Eye Disease Study system for classifying cataracts.
Main outcome measures: The primary outcome was a prespecified increase from baseline in nuclear, cortical, or posterior subcapsular cataract (PSC) opacity grades or cataract surgery. Secondary outcomes included an increase in type-specific opacity grades, cataract surgery, and visual acuity (VA) loss from baseline > or =15 letters.
Results: Participants were observed for an average of 9.0+/-2.4 years. There was a decrease in total lens events in participants assigned to the multivitamin/mineral formulation compared with those assigned to the placebo (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.68-0.98; P = 0.03). Nuclear events were significantly less common (HR, 0.66; 95% CI, 0.50-0.88; P = 0.004) and PSC events significantly more common (HR, 2.00; 95% CI, 1.35-2.98; P<0.001) in participants taking the multivitamin/mineral formulation than in those assigned to the placebo. No statistically significant treatment effects were seen for cortical opacities, moderate VA loss, or cataract surgery.
Conclusions: Lens events were less common in participants who took the multivitamin/mineral formulation, but treatment had opposite effects on the development or progression of nuclear and PSC opacities, the 2 most visually important opacity subtypes.