Table 2. Changes in Optical Coherence Tomography Angiography Parameters With Increasing Diabetic Retinopathy Severity in Eyes With or Without PPL.
| Parameter | Mean (SD) | P value | |||
|---|---|---|---|---|---|
| Mild NPDR | Moderate NPDR | Severe NPDR or PDR | Univariate analysis (ANOVA) | GEEsa | |
| Without PPL | |||||
| No. | 99 | 36 | 74 | NA | NA |
| Parafovea, % | |||||
| VD SCP | 38.1 (4.7) | 36.4 (4.6) | 34.1 (4.1) | <.001 | <.001 |
| VD ICP | 45.2 (3.0) | 45.3 (1.6) | 45.0 (1.7) | .88 | .80 |
| VD DCP | 45.8 (3.0) | 45.8 (2.2) | 44.5 (1.7) | .002 | <.001 |
| Choriocapillaris flow density, % | 69.7 (6.2) | 67.6 (5.6) | 67.1 (5.6) | .01 | .006 |
| With PPL | |||||
| No. | 84 | 35 | 24 | NA | NA |
| Parafovea, % | |||||
| VD SCP | 34.1 (4.1) | 35.2 (4.1) | 36.0 (4.3) | .42 | .47 |
| VD ICP | 45.0 (1.7) | 45.5 (1.4) | 45.2 (2.0) | .60 | .54 |
| VD DCP | 44.5 (1.7) | 45.4 (1.4) | 44.9 (1.5) | .81 | .67 |
| Choriocapillaris flow density, % | 67.1 (5.6) | 69.3 (4.6) | 68.3 (5.6) | .49 | .67 |
Abbreviations: ANOVA, analysis of variance; DCP, deep capillary plexus; GEEs, generalized estimating equations; ICP, intermediate capillary plexus; NA, not applicable; NPDR, nonproliferative diabetic retinopathy; PDR, proliferative diabetic retinopathy; PPL, predominantly peripheral lesions; SCP, superficial capillary plexus; VD, vessel density.
a
Correcting for age, signal strength index, spherical equivalent, type of diabetes, diabetes duration, and correlation of both eyes in the same individual.