Table 1.
Impact of oral supplements on the decline rate of central residual effective radius after adjustment for age, sex, and baseline central residual effective radius
| Placebo | Antioxidants* | Zinc† | Antioxidants plus Zinc | |
|---|---|---|---|---|
| Number of patients | 39 | 33 | 48 | 38 |
| Age, years, mean (SD) | 70.3 (5.8) | 68.5 (5.2) | 71.8 (4.9) | 71.0 (5.4) |
| Sex, female, n (%) | 22 (56.4) | 12 (36.4) | 31 (64.6) | 25 (65.8) |
| Duration of follow-up, years, mean (SD) | 4.4 (2.7) | 4.5 (2.6) | 3.5 (2.0) | 3.6 (2.3) |
| Advanced AMD in the fellow eye at any visit, n (%) | 26 (66.7) | 23 (69.7) | 32 (66.7) | 24 (63.2) |
| Baseline central residual effective radius, mm, mean (SD) | 0.40 (0.09) | 0.39 (0.11) | 0.38 (0.11) | 0.38 (0.12) |
| Decline rate of central residual effective radius, mm/yr, mean (95% CI) | 0.041 (0.033–0.051) | 0.039 (0.029–0.049) | 0.039 (0.030–0.048) | 0.036 (0.037–0.046) |
| P compared with the decline rate in placebo‡ | NA | 0.85 | 0.70 | 0.67 |
AMD, age-related macular degeneration; CI, confidence interval; FE-Advanced AMD, the fellow eye had advanced AMD; FE-None, the fellow eye did not have advanced AMD; GA, geographic atrophy.
*
Antioxidants = 500 mg of ascorbic acid; 400 IU of dl-alpha-tocopherol acetate; and 15 mg of beta carotene
†
Zinc = 80 mg as zinc oxide and copper; and 2 mg as cupric oxide.
‡
P value of interaction between treatment group and year after adjusting for age, sex, and baseline central residual effective radius. Overall P = 0.97.