Table 3. Comparison of Corvis ST tonometer measured variables in each measurement.
CCT: central corneal thickness, sd: standard deviation, CV: coefficient of variance, ICC: intraclass correlation.
| Measurement | average | CV (%) | ICC | |||
|---|---|---|---|---|---|---|
| 1st | 2nd | 3rd | ||||
| CCT, (mean ± sd) [range], μm | 547.5±33.1 [453 to 643] | 547.2±32.7 [458 to 645] | 547.9±32.5 [453.0 to 643.0] | 547.5±32.3 [454.7 to 643.7] | 0.9±0.9 [0.0 to 5.1] | 0.99 |
| IOP-C, (mean ± sd) [range], mmHg | 13.9±3.0 [5.0 to 23.0] | 13.9±3.0 [4.5 to 19.5] | 13.8±3.4 [4.0 to 22.0] | 13.8±3.0 [4.5 to 20.5] | 6.1±5.4 [0.0 to 30.0] | 0.97 |
| A time-1, (mean ± sd) [range], ms | 7.3±0.3 [6.6 to 8.4] | 7.3±0.3 [6.5 to 8.0] | 7.3±0.3 [6.5 to 8.3] | 7.3±0.3 [6.5 to 8.1] | 1.2±1.0 [0.2 to 7.0] | 0.95 |
| A length-1, (mean ± sd) [range], mm | 1.8±0.3 [1.3 to 2.3] | 1.8±0.3 [1.3 to 2.4] | 1.8±0.3 [1.2 to 2.4] | 1.8±0.2 [1.4 to 2.3] | 13.7±7.1 [1.0 to 30.4] | 0.13 |
| A velocity-1, (mean ± sd) [range], m/s | 0.15±0.03 [0.05 to 0.23] | 0.15±0.03 [0.09 to 0.24] | 0.15±0.03 [0.07 to 0.22] | 0.15±0.02 [0.09 to 0.21] | 13.9±9.3 [0.0 to 47.6] | 0.39 |
| A time-2, (mean ± sd) [range], ms | 21.9±0.4 [20.1 to 23.0] | 21.9±0.4 [20.7 to 22.8] | 21.8±0.7 [17.8 to 23.3] | 21.9±0.4 [20.4 to 23.0] | 0.9±1.6 [0.1 to 12.4] | 0.75 |
| A length-2, (mean ± sd) [range], mm | 1.9±0.5 [1.0 to 2.9] | 1.8±0.5 [0.9 to 2.7] | 1.9±0.5 [0.6 to 2.7] | 1.8±0.3 [1.0 to 2.7] | 24.2±9.8 [3.4 to 52.8] | 0.18 |
| A velocity-2, (mean ± sd) [range], m/s | 0.38±0.07 [-0.23 to -0.56] | 0.39±0.09 [-0.17 to -0.71] | 0.38±0.09 [-0.68 to 0.07] | 0.39±0.07 [0.20 to 0.60] | 12.7±12.6 [1.4 to 111.9] | 0.75 |
| highest concavity time, (mean ± sd) [range], ms | 16.8±0.6 [15.3 to 18.3] | 16.8±0.4 [15.7 to 17.8] | 16.8±0.5 [14.1 to 18.3] | 16.8±0.4 [15.6 to 18.0] | 1.9±1.5 [0.0 to 10.4] | 0.66 |
| highest concavity curvature, (mean ± sd) [range], mm | 7.0±0.8 [5.5 to 9.7] | 7.0±1.1 [1.7 to 9.5] | 6.9±0.9 [1.7 to 8.8] | 7.0±0.7 [4.8 to 8.7] | 8.1±8.7 [0.5 to 59.0] | 0.68 |
| peak distance, (mean ± sd) [range], mm | 3.9±1.2 [2.1 to 5.4] | 4.0±1.2 [2.3 to 5.6] | 3.9±1.3 [2.2 to 5.6] | 8.7±0.8 [2.3 to 5.5] | 24.3±18.8 [0.1 to 49.9] | 0.37 |
| maximum deformation amplitude, (mean ± sd) [range], mm | 1.1±0.1 [0.9 to 1.3] | 1.1±0.1 [0.9 to 1.3] | 1.1±0.1 [0.8 to 1.4] | 5.5±1.1 [0.9 to 1.3] | 3.2±1.9 [0.0 to 11.0] | 0.95 |