Table 1.
Basic descriptive statistics for ONSD, ETD, and the ONSD/ETD ratio measured using ultrasonography for healthy Korean adults.
| Mean ± SD (95% CI) | Median (IQR) | Minimum | Maximum | |
|---|---|---|---|---|
| ONSD | ||||
| Right (mm) | 4.12 ± 0.37 (4.09–4.15) | 4.10 (3.80–4.40) | 3.10 | 5.20 |
| Left (mm) | 4.11 ± 0.37 (4.08–4.14) | 4.10 (3.80–4.30) | 3.20 | 5.40 |
| Overall (mm) | 4.11 ± 0.35 (4.09–4.14) | 4.10 (3.85–4.35) | 3.30 | 5.20 |
| ETD | ||||
| Right (mm) | 22.95 ± 0.95 (22.87–23.02) | 22.90 (22.30–23.50) | 20.90 | 25.60 |
| Left (mm) | 22.87 ± 0.95 (22.79–22.94) | 22.80 (22.20–23.40) | 20.70 | 25.90 |
| Overall (mm) | 22.91 ± 0.93 (22.83–22.98) | 22.85 (22.25–23.45) | 20.90 | 25.70 |
| ONSD/ETD ratio | ||||
| Right | 0.18 ± 0.02 (0.18) | 0.18 (0.17–0.19) | 0.13 | 0.23 |
| Left | 0.18 ± 0.02 (0.18) | 0.18 (0.17–0.19) | 0.14 | 0.24 |
| Overall | 0.18 ± 0.02 (0.18) | 0.18 (0.17–0.19) | 0.14 | 0.23 |
The overall ONSD value is the mean of the values for the left and right eyes.
ONSD, optic nerve sheath diameter; ETD, eyeball transverse diameter; SD, standard deviation; CI, confidence interval; IQR, interquartile range.