Summary of vessel diameter and blood flow measures stratified by disease stagea
| Control (Mean) (SD) (n = 20 OA, 24 ICA) | Early AMD (Mean) (SD) (n = 9 OA, 15 ICA) | Interm. AMD(Mean) (SD) (n = 7 OA, 8 ICA) | Late AMD (Mean) (SD) (n = 12 OA, 17 ICA) | All AMD (Mean) (SD) (n = 28 OA, 40 ICA) | |
|---|---|---|---|---|---|
| OA diameter (mm) | 1.1 (0.19) | 0.9 (0.25)P = .11 | 1.0 (0.26)P = .42 | 0.8 (0.25)P < .01b | 0.9 (0.26)P < .01b |
| OA volume flow (mL/min) | 7.0 (3.0) | 6.5 (4.2)P = .74 | 5.6 (3.1)P = .37 | 3.8 (1.8)P < .01b | 5.1 (3.2)P = .07 |
| OA flow velocity (cm/s)c | 13.1 (4.0) | 16.0 (4.5)P < .01b | 11.9 (4.3)P = .91 | 15.0 (5.7)P = .03b | 14.6 (5.1)P = .02b |
| OA RI | 0.70 (0.10) | 0.82 (0.10)P < .01b | 0.81 (0.06)P < .01b | 0.80 (0.07)P < .01b | 0.81 (0.08)P < .01b |
| ICA diameter (mm) | 4.3 (0.51) | 4.2 (0.52)P = .38 | 4.6 (0.63)P = .47 | 4.2 (0.44)P = .55 | 4.3 (0.52)P = .67 |
| ICA volume flow (mL/min)c | 163.1 (44.8) | 154.3 (44.2)P = .98 | 167.0 (23.4)P = .49 | 166.6 (27.7)P = .19 | 162.2 (33.8)P = .46 |
| ICA flow velocity (cm/s)c | 18.3 (3.5) | 18.7 (3.7)P = .07 | 17.8 (4.5)P = .58 | 20.6 (5.2)P < .01b | 19.4 (4.6)P < .01b |
| ICA RI | 0.61 (0.09) | 0.66 (0.09)P = .18 | 0.70 (0.04)P < .01b | 0.65 (0.11)P = .29 | 0.67 (0.09)P = .07 |
Note:—RI indicates resistance index; Interm., intermediate.
a Values represent group mean and group SD, and reported P values indicate significance relative to controls based on a GEE analysis followed by post hoc least significant difference comparisons between disease groups and controls. The sample size for ophthalmic artery measurements was 48 hemisphere measurements from 30 subjects. The sample size for the ICA measurements was 64 hemispheres of 33 subjects.
↵b Tests that were significant at the P < .05 level (uncorrected).
↵c Adjusted for age, which was statistically significant (P < .05) in the GEE model.