Table 4.
Geometric vascular parameters obtained for patients with cognitive impairment in comparison with the cognitively normal individuals.
| Vascular Parameters | Cognitive Impairment Cases n = 20 Mean (SD) | Cognitively Healthy Cases n = 19 Mean (SD) | p-Value |
|---|---|---|---|
| Fractal dimension | |||
| D0 | 1.57 (0.06) | 1.61 (0.03) | 0.03∗ |
| D1 | 1.56 (0.06) | 1.59 (0.03) | 0.03∗ |
| D2 | 1.55 (0.06) | 1.58 (0.03) | 0.02∗ |
| Caliber (μm) | |||
| CRAE | 65.88 (7.39) | 66.73 (6.46) | 0.707 |
| CRVE | 92.54 (7.15) | 92.49 (9.02) | 0.984 |
| Bifurcation | |||
| BCa | 1.65 (0.46) | 1.47 (0.35) | 0.169 |
| BCv | 1.30 (0.48) | 1.34 (0.49) | 0.812 |
| BCt | 1.55 (0.36) | 1.50 (0.28) | 0.631 |
| AFa | 0.75 (0.11) | 0.74 (0.16) | 0.765 |
| AFv | 0.74 (0.22) | 0.61 (0.19) | 0.042∗ |
| AFt | 0.77 (0.05) | 0.71 (0.10) | 0.018∗ |
| Tortuosity | |||
| cTORTa (10-4) | 4.30 (7.04) | 4.13 (0.83) | 0.485 |
| cTORTv (10-4) | 4.06 (1.06) | 3.82 (0.80) | 0.433 |
| cTORTt (10-4) | 4.17 (0.71) | 3.97 (0.64) | 0.374 |
| Ratio measures | |||
| AVR | 0.92 (0.25) | 0.86 (0.20) | 0.427 |
| LDRa | 8.98 (7.46) | 7.35 (5.86) | 0.456 |
| LDRv | 4.52 (6.06) | 2.58 (3.77) | 0.240 |
| LDRt | 9.7 (6.8) | 7.13 (4.56) | 0.173 |
The data reported was measured in the region C (i.e., area between 0.5 and 2.0 disc diameters away from the disc margin, see Figure 1) for all parameters except for the fractal parameters that were calculated in the whole area occupied by the branching pattern (FOV = 45o). The P-values were calculated by independent sample t-test. AVR, arteriole–venular ratio; BCa, arteriolar branching coefficient; BCv, venular branching coefficient; BCt total branching coefficient (i.e., arteriolar+venular); CRAE, central retinal arteriolar equivalent; CRVE, central retinal venular equivalent; LDRa, arteriolar length-to-diameter ratio; LDRv, venular length-to-diameter ratio; LDRt, total length-to-diameter ratio (i.e., arteriolar + venular); cTORTa, curvature arteriolar tortuosity cTORTv, curvature venular tortuosity; cTORTt, total tortuosity (i.e., arteriolar+venular); AFa, asymmetry arteriolar factor; AFv, asymmetry venular factor; Aft, total asymmetry factor (i.e., arteriolar+venular). Do: capacity dimension, D1: information dimension, D2: correlation dimension. ∗Significant (p < 0.05).