Table 1.
Clinical and Demographic Characteristics of the Study Population
| Total Population (n = 119) | Control (n = 30) | Early (n = 29) | Intermediate (n = 30) | Late (n = 30) | P Value | |
|---|---|---|---|---|---|---|
| Age (yrs), mean (SD) | 70 (8) | 68 (10) | 68 (7) | 70 (5) | 76 (8) | 0.0005* |
| Gender, no. (%) | ||||||
| Male | 43 (36) | 12 (40) | 9 (31) | 9 (30) | 13 (43) | 0.640 |
| BMI (kg/m2), mean (SD) | 27 (5) | 26 (4) | 27 (5) | 29 (7) | 27 (4) | 0.070 |
| Ethnicity, no. (%) | ||||||
| White | 101 (85) | 22 (73) | 24 (83) | 30 (100) | 25 (83) | 0.176 |
| Black/Hispanic/Asian | 7 (6) | 2 (7) | 3 (10) | 0 | 2 (7) | |
| Unknown | 11 (9) | 6 (20) | 2 (7) | 0 | 3 (10) | |
| Smoking, no. (%) | ||||||
| Nonsmoker | 57 (48) | 18 (60) | 18 (62) | 13 (43) | 8 (27) | 0.057 |
| Former smoker | 56 (47) | 10 (33) | 11 (38) | 15 (50) | 20 (67) | |
| Smoker | 3 (3) | 1 (3) | 0 | 2 (7) | 0 | |
| NA | 3 (3) | 1 (3) | 0 | 0 | 2 (7) | |
| Age started smoking (yrs), mean (SD) | 19 (7) | 20 (7) | 16 (4) | 22 (10) | 17 (4) | 0.055 |
| Age stopped smoking (yrs), mean (SD) | 39 (13) | 37 (11) | 34 (16) | 42 (12) | 42 (13) | 0.315 |
| No. of cigarettes per day, mean (SD) | 18 (14) | 18 (10) | 9 (8) | 20 (18) | 20 (14) | 0.244 |
| AMD subtype, no. (%) | ||||||
| Choroidal neovascularization (wet) | 25 (28) | n/a | n/a | n/a | 25 (83) | 1.8 × 10−17 |
| Geographic atrophy (dry) | 4 (5) | n/a | n/a | n/a | 4 (13) |
AMD = age-related macular degeneration; BMI = body mass index; NA = not available; n/a = not applicable; no. = number; SD = standard deviation.
*
Significant differences (P < 0.05), analysis of variance for continuous variables and chi-square test for dichotomous variables.