Table 1

Age Related Eye Disease Study (AREDS) definitions and details

AREDS categories
All categories had a best visual acuity of at least 6/9 (the study eye) at baseline.
Category 1: Range from completely normal macula to a few small drusen.
Category 2: Multiple small drusen, single or non-extensive intermediate size drusen, pigment abnormalities.
Category 3: Absence of advanced age related macular degeneration (AMD) in both eyes, with at least one large drusen at macular centre, or extensive intermediate drusen or geographic atrophy (GA) not involving the central macula.
Category 4: No advanced AMD in one eye, with vision impairment from AMD in fellow eye
Definitions of AREDS outcomes
Neovascular events: Progression to advanced AMD for a study eye was defined by:
(1) laser photocoagulation or other treatment for choroidal neovascularisation, or
(2) any of the following: GA involving the macula centre, non-drusenoid retinal pigment epithelial (RPE) detachment, serous or haemorrhagic retinal detachment, haemorrhage under the retina or RPE, and/or subretinal fibrosis.
Visual acuity events: A decrease in best corrected visual acuity score from baseline, of 15 or more letters in a study eye (a doubling or more of the visual angle, from baseline equivalent 6/9 or better, to 6/18 or worse).
Incremental output: the difference between treatment and placebo outcomes.
Study population characteristics
(1) AREDS: 96% European origin, age range 55–80 years, median age 69 years. Study population garnered from medical records, patient lists, screening at public gatherings, other. Size 4757.
(2). Blue Mountains Eye Study: 98% European origin, age range 49–97 years, median age 66 years. Population based study. Size 3654.
AREDS zinc and antioxidant formulation: Zinc 80 mg (+ copper 2 mg), vitamin C 500 mg, vitamin E 400 IU, β carotene 15 mg.
Compliance levels in AREDS study: around 75% of tablets taken by 71% of patients.
Adverse events: Increased frequency of yellow skin reported by taking antioxidants.
No differences noted between groups for other potential adverse events.