Table 1.
Retinal arteriolar, venular and capillary parameters at different levels of diabetic retinopathy severity.
| DR severity level | Non-severe DR (n = 29) | Severe DR (n = 20) | p-trend (No DR to Proliferative DR)a | p-value (non-severe DR vs severe DR)b | |||
|---|---|---|---|---|---|---|---|
| No DR (n = 9) | Mild NPDR (n = 10) | Moderate NPDR (n = 10) | Severe NPDR (n = 8) | Proliferative DR (n = 12) | |||
| Arteriolar and venular (SIVA) parameters, mean (SD) | |||||||
| CRAE | 143.3 (23.8) | 157.3 (15.3) | 151.4 (20.3) | 137.5 (15.1) | 134.6 (17.8) | 0.046 | |
| 151.3 (19.7) | 135.7 (16.4) | 0.009 | |||||
| CRVE | 219.9 (32.1) | 220.2 (18.9) | 211.9 (36.6) | 213.2 (19.1) | 198.1 (30.6) | 0.093 | |
| 216.9 (29.3) | 204.1 (27.1) | 0.163 | |||||
| AVR | 0.657 (0.098) | 0.715 (0.056) | 0.727 (0.128) | 0.645 (0.040) | 0.686 (0.075) | 0.454 | |
| 0.704 (0.100) | 0.669 (0.065) | 0.123 | |||||
| FDt | 1.368 (0.114) | 1.349 (0.091) | 1.398 (0.086) | 1.364 (0.089) | 1.300 (0.148) | 0.318 | |
| 1.373 (0.094) | 1.325 (0.129) | 0.219 | |||||
| FDa | 1.131 (0.104) | 1.151 (0.085) | 1.175 (0.072) | 1.126 (0.107) | 1.093 (0.106) | 0.324 | |
| 1.155 (0.084) | 1.106 (0.105) | 0.150 | |||||
| FDv | 1.192 (0.089) | 1.138 (0.075) | 1.206 (0.077) | 1.172 (0.090) | 1.134 (0.113) | 0.384 | |
| 1.179 (0.082) | 1.149 (0.104) | 0.282 | |||||
| Capillary (OCT-A) parameters, mean (SD) | |||||||
| SVP CDI | 0.360 (0.021) | 0.356 (0.022) | 0.347 (0.009) | 0.340 (0.023) | 0.333 (0.010) | <0.001 | |
| 0.354 (0.018) | 0.336 (0.016) | 0.001 | |||||
| DVP CDI | 0.360 (0.019) | 0.356 (0.025) | 0.352 (0.019) | 0.346 (0.021) | 0.345 (0.021) | 0.048 | |
| 0.356 (0.021) | 0.345 (0.020) | 0.093 | |||||
| SVP FDc | 1.515 (0.072) | 1.581 (0.049) | 1.564 (0.076) | 1.546 (0.040) | 1.601 (0.050) | 0.059 | |
| 1.555 (0.070) | 1.579 (0.053) | 0.290 | |||||
| DVP FDc | 1.537 (0.090) | 1.612 (0.060) | 1.599 (0.070) | 1.556 (0.074) | 1.533 (0.125) | 0.350 | |
| 1.584 (0.078) | 1.542 (0.106) | 0.089 | |||||
Abbreviations: DR = diabetic retinopathy; NPDR = non-proliferative diabetic retinopathy; SIVA = Singapore I Vessel Assessment; CRAE = central retinal arteriolar equivalent; CRVE = central retinal venular equivalent; AVR = arteriole-venule ratio; FDt = total fractal dimension; FDa = arteriole fractal dimension; FDv = venule fractal dimension; OCT-A = optical coherence tomography angiography; SVP = superficial vascular plexus; CDI = capillary density index; DVP = deep vascular plexus; FDc = capillary fractal dimension.
ap-trends calculated using the Wilcoxon-type test for trend.
bp-values calculated using the Mann-Whitney U test.