title: The Roche European American Cataract Trial (REACT): a randomized clinical trial to investigate the efficacy of an oral antioxidant micronutrient mixture to slow progression of age-related cataract.
abstract: BACKGROUND
  Funding surgery worldwide for age-related cataract (ARC), a leading cause of blindness, is a huge economic burden. Non-surgical means of slowing ARC progression could benefit patients and reduce this burden.
  
  
  OBJECTIVE
  To determine if a mixture of oral antioxidant micronutrients [mg/day] (beta-carotene [18], vitamin C [750], and vitamin E [600]) would modify progression of ARC.
  
  
  METHODS
  REACT was a multi-centered, prospective, double-masked, randomized, placebo-controlled, 3-year trial.
  
  
  METHODS
  Consecutive adult American and English outpatients with early ARC were recruited.
  
  
  METHODS
  Four-hundred-and-forty-five patients were eligible; 297 were randomized; 231 (78%) were followed for two years; 158 (53%) were followed for three years; 36 (12%) were followed for four years. Twelve patients died during the trial (9 on vitamins; 3 on placebo (p = 0.07)). There were no serious safety issues.
  
  
  METHODS
  After a three-month placebo run-in, patients were randomized by clinical center to the vitamin or placebo groups and followed every four months.
  
  
  METHODS
  Cataract severity was documented with serial digital retroillumination imagery of the lens; progression was quantified by image analysis assessing increased area of opacity. This measure of area, 'increase % pixels opaque' (IPO), was the main outcome measure.
  
  
  RESULTS
  There were no statistically significant differences between the treatment groups at baseline. The characteristics of dropouts and the mean follow-up times by treatment group were the same. After two years of treatment, there was a small positive treatment effect in U.S. patients (p = 0.0001); after three years a positive effect was apparent (p = 0.048) in both the U.S. and the U.K. groups. The positive effect in the U.S. group was even greater after three years: (IPO = 0.389 (vitamin) vs. IPO = 2.517 (placebo); p = 0.0001). There was no statistically significant benefit of treatment in the U.K. group. In spite of nearly perfect randomization into treatment groups, the U.S. and U.K. cohorts differed significantly.
  
  
  CONCLUSIONS
  Daily use of the afore-mentioned micronutrients for three years produced a small deceleration in progression of ARC.
authors.affiliation: Center for Ophthalmic Research, Department of Surgery, Brigham and Women's Hospital, Boston, MA, USA. ltchylack@rics.bwh.harvard.edu
authors.forename: Leo T
authors.initials: LT
authors.lastname: Chylack
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Brown
authors.forename: Anthony
authors.initials: A
authors.lastname: Bron
authors.forename: Mark
authors.initials: M
authors.lastname: Hurst
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Köpcke
authors.forename: Uta
authors.initials: U
authors.lastname: Thien
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schalch
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000375:Aging; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage*; D002386:Cataract / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D018450:Disease Progression; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D018977:Micronutrients / Q000008:administration & dosage*; D011446:Prospective Studies; D006113:United Kingdom; D014481:United States; D014810:Vitamin E / Q000008:administration & dosage*; D019207:beta Carotene / Q000008:administration & dosage*
chemical_list: D000975:Antioxidants; D018977:Micronutrients; D019207:beta Carotene; D014810:Vitamin E; D001205:Ascorbic Acid