Values of optic disc variables in 38 normal subjects
| Variable (unit) | Mean (SD) |
| Optic disc size (mm2) | 2.325 (0.441) |
| Contour modulation (mm) | 0.144 (0.041) |
| Contour variation (mm) | 0.424 (0.750) |
| Mean contour depth (mm) | 0.066 (0.145) |
| Effective area (mm2) | 0.834 (0.546) |
| ½ depth area (mm2) | 0.245 (0.176) |
| ½ depth volume (mm3) | −0.035 (0.038) |
| NRA(mm2) | 1.490 (0.470) |
| Volume above (mm3) | 0.326 (0.174) |
| Volume below (mm3) | −0.198 (0.185) |
| C/D ratio | 0.348 (0.195) |
| Average depth (mm) | −0.205 (0.103) |
| Maximum depth (mm) | −0.537 (0.222) |