Table 7.
Within-Subject Variance [Sw ± 1.96 Standard Error (Se)] for Spectralis Optical Coherence Tomography Retinal Nerve Fiber Layer (RNFL) Thickness and Neuroretinal Rim Measurements in Normal versus Glaucomatous Eyes
| Normal Patients (n=27) | ||||||
| Region of Interest | RNFL Thickness (μm) | Neuroretinal Rim | ||||
| MDB Thickness (μm) | MDB Area (mm2) | Rim Area (mm2) | Rim Volume (mm3) | Rim Thickness (μm) | ||
| Overall global | 1.2 ± 0.2 | 6.9 ± 4.5 | 0.084 ± 0.022 | 0.139 ± 0.079 | 0.007 ± 0.002 | 12.5 ± 7.3 |
| Superior quadrant | 2.6 ± 1.3 | 11.0 ± 2.7 | 0.057 ± 0.016 | 0.052 ± 0.019 | 0.007 ± 0.002 | 13.9 ± 6.5 |
| Temporal quadrant | 1.6 ± 0.4 | 11.6 ± 3.9 | 0.034 ± 0.008 | 0.071 ± 0.032 | 0.004 ± 0.002 | 14.5 ± 7.1 |
| Inferior quadrant | 2.1 ± 0.5 | 9.1 ± 3.1 | 0.039 ± 0.014 | 0.043 ± 0.017 | 0.006 ± 0.003 | 13.6 ± 5.1 |
| Nasal quadrant | 1.5 ± 0.3 | 8.0 ± 3.5 | 0.054 ± 0.023 | 0.028 ± 0.006 | 0.006 ± 0.003 | 10.5 ± 6.3 |
| ST sector | 2.9 ± 1.2 | 12.8 ± 3.1 | 0.032 ± 0.007 | 0.031 ± 0.014 | 0.004 ± 0.001 | 15.4 ± 4.5 |
| IT sector | 2.5 ± 0.6 | 12.4 ± 3.1 | 0.026 ± 0.008 | 0.028 ± 0.020 | 0.005 ± 0.002 | 18.3 ± 7.6 |
| SN sector | 2.8 ± 1.2 | 13.4 ± 4.1 | 0.038 ± 0.009 | 0.027 ± 0.011 | 0.006 ± 0.003 | 19.2 ± 9.8 |
| IN sector | 2.4 ± 0.5 | 14.0 ± 7.4 | 0.028 ± 0.010 | 0.026 ± 0.008 | 0.005 ± 0.001 | 17.6 ± 10.8 |
| Glaucoma Patients (n=40) | ||||||
| Region of Interest | RNFL Thickness (μm) | Neuroretinal Rim | ||||
| MDB Thickness (μm) | MDB Area (mm2) | Rim Area (mm2) | Rim Volume (mm3) | Rim Thickness (μm) | ||
| Overall global | 1.5 ± 0.5 | 7.5 ± 4.1 | 0.067 ± 0.013 | 0.171 ± 0.090 | 0.014 ± 0.011 | 9.6 ± 3.1 |
| Superior quadrant | 2.4 ± 0.7 | 21.6 ± 14.3 | 0.052 ± 0.022 | 0.063 ± 0.027 | 0.007 ± 0.005 | 16.6 ± 5.9 |
| Temporal quadrant | 1.8 ± 0.6 | 9.1 ± 2.4 | 0.024 ± 0.005 | 0.055 ± 0.017 | 0.006 ± 0.005 | 10.4 ± 2.9 |
| Inferior quadrant | 2.5 ± 0.6 | 14.7 ± 4.9 | 0.040 ± 0.012 | 0.087 ± 0.034 | 0.004 ± 0.001 | 12.0 ± 2.9 |
| Nasal quadrant | 2.3 ± 0.6 | 6.4 ± 1.4 | 0.033 ± 0.014 | 0.035 ± 0.014 | 0.003 ± 0.002 | 8.9 ± 2.4 |
| ST sector | 3.3 ± 0.9 | 21.2 ± 12.2 | 0.033 ± 0.008 | 0.037 ± 0.014 | 0.004 ± 0.003 | 14.2 ± 4.3 |
| IT sector | 3.5 ± 0.9 | 18.2 ± 6.7 | 0.022 ± 0.007 | 0.053 ± 0.022 | 0.002 ± 0.001 | 14.9 ± 5.3 |
| SN sector | 3.0 ± 0.9 | 28.8 ± 17.4 | 0.037 ± 0.011 | 0.030 ± 0.012 | 0.004 ± 0.003 | 21.0 ± 8.6 |
| IN sector | 2.9 ± 0.9 | 18.4 ± 7.8 | 0.027 ± 0.010 | 0.041 ± 0.017 | 0.003 ± 0.001 | 12.5 ± 3.5 |
Note: Sw is defined as the square root of the within-subject variance, defined as the within-subject sum of squares divided by its degrees of freedom.
Abbreviations: Sw, within-subject standard deviation; se, standard error; RNFL, retinal nerve fiber layer; MDB, minimum distance band; ST, superior-temporal; IT, inferior-temporal; SN, superior-nasal; IN, inferior-nasal.