Table 2. CRAE, CRVE, Retinal Vessel Tortuosity Index, and Multifractal Characteristics of the Study Population .
| Characteristic | Study Population, mean (SD) | P valuea | ||
|---|---|---|---|---|
| Combined | Girls | Boys | ||
| CRAE, μm | 180.9 (14.4) | 182.4 (13.6) | 179.3 (15.2) | .10 |
| CRVE, μm | 251.1 (19.6) | 253.4 (18.1) | 248.3 (20.9) | .04 |
| Tortuosity indexb | 0.889 (0.012) | 0.890 (0.012) | 0.887 (0.013) | .07 |
| D0 | 1.56 (0.03) | 1.56 (0.03) | 1.56 (0.03) | .63 |
| D1 | 1.52 (0.03) | 1.52 (0.03) | 1.52 (0.04) | .65 |
| D2 | 1.51 (0.03) | 1.51 (0.03) | 1.50 (0.04) | .66 |
| Curve asymmetry | 0.27 (0.05) | 0.27 (0.05) | 0.27 (0.06) | .69 |
| Singularity length | 0.76 (0.07) | 0.76 (0.07) | 0.76 (0.07) | .77 |
Abbreviations: CRAE, central retinal arteriolar equivalent; CRVE, central retinal venular equivalent; D0, capacity dimension; D1, information dimension; D2, correlation dimension.
a
Calculated using a 2-sided t test.
b
Computed as the mean tortuosity of the branch segments, where the tortuosity of a branch segment is the ratio of the line traced on each tree along the vessel axis from 0.5 to 2.0 times the optic disc diameter and the line connecting the end points.