Table 2.
Optical variables of patients with keratoconus at the initial diagnosis and the final visit before intervention.
| Total | Pediatric | Adult | p-value | |
|---|---|---|---|---|
| Number of eyes included | 288 | 37 (12.9%) | 251 (87.1%) | |
| Follow-up durationa (years) | ||||
| Median (IQR) | 1.18 (4.24) | 3.16 (2.95) | 0.75 (4.22) | 0.0447b |
| Mean ± SD | 2.98 ± 3.96 | 3.67 ± 3.28 | 2.88 ± 4.05 | |
| Min–max | 1.66–13.65 | 0.02–15.55 | ||
| CDVA (LogMAR) | ||||
| Initial diagnosis | ||||
| Median (IQR) | 0.15 (0.40) | 0.05 (0.22) | 0.15 (0.52) | 0.0546b |
| Mean ± SD | 0.30 ± 0.41 | 0.15 ± 0.21 | 0.32 ± 0.43 | |
| Final visit | ||||
| Median (IQR) | 0.22 (0.52) | 0.10 (0.40) | 0.22 (0.52) | 0.1767b |
| Mean ± SD | 0.34 ± 0.40 | 0.25 ± 0.33 | 0.35 ± 0.41 | |
| Difference | ||||
| Median (IQR) | 0.00 (0.00) | 0.00 (0.15) | 0.00 (0.00) | 0.5196b |
| Mean ± SD | 0.03 ± 0.22 | 0.10 ± 0.29 | 0.03 ± 0.20 | |
| p-value | 0.0048c* | 0.1126c | 0.0235c | |
| Sphere refractive error (diopter) | ||||
| Initial diagnosis | ||||
| Median (IQR) | − 5.00 (5.25) | − 3.75 (3.50) | − 5.25 (5.75) | 0.0539b |
| Mean ± SD | − 5.84 ± 4.68 | − 4.37 ± 3.37 | − 6.04 ± 4.80 | |
| Final visit | ||||
| Median (IQR) | − 5.38 (5.25) | − 4.75 (4.25) | − 5.50 (5.75) | 0.8349b |
| Mean ± SD | − 6.16 ± 4.79 | − 6.12 ± 4.72 | − 6.16 ± 4.81 | |
| Difference | ||||
| Median (IQR) | 0.00 (0.00) | 0.00 (2.50) | 0.00 (0.00) | 0.0071b* |
| Mean ± SD | − 0.32 ± 2.26 | − 1.75 ± 4.34 | − 0.13 ± 1.74 | |
| p-value | 0.0092c | 0.0130c | 0.1625c | |
| Cylinder refractive error (diopter) | ||||
| Initial diagnosis | ||||
| Median (IQR) | − 3.75 (3.75) | − 4.50 (3.00) | − 3.75 (4.00) | 0.2055b |
| Mean ± SD | − 3.88 ± 2.35 | − 4.33 ± 2.02 | − 3.81 ± 2.39 | |
| Final visit | ||||
| Median (IQR) | − 4.00 (4.25) | − 5.00 (4.00) | − 3.75 (4.25) | 0.0238b |
| Mean ± SD | − 4.10 ± 2.57 | − 5.21 ± 2.63 | − 3.95 ± 2.53 | |
| Difference | ||||
| Median (IQR) | 0.00 (0.25) | 0.00 (1.50) | 0.00 (0.25) | 0.1396b |
| Mean ± SD | − 0.23 ± 1.34 | − 0.88 ± 1.78 | − 0.14 ± 1.24 | |
| p-value | 0.0037c* | 0.0238c | 0.0407c | |
| Spherical equivalence (diopter) | ||||
| Initial diagnosis | ||||
| Median (IQR) | − 6.81 (5.13) | − 5.75 (3.75) | − 7.00 (5.13) | 0.1352b |
| Mean ± SD | − 7.85 ± 4.88 | − 6.54 ± 3.43 | − 8.03 ± 5.03 | |
| Final visit | ||||
| Median (IQR) | − 7.50 (5.88) | − 8.13 (4.00) | − 7.38 (6.25) | 0.5219b |
| Mean ± SD | − 8.23 ± 5.01 | − 8.73 ± 5.01 | − 8.16 ± 5.02 | |
| Difference | ||||
| Median (IQR) | 0.00 (0.13) | 0.00 (3.00) | 0.00 (0.00) | 0.0066b* |
| Mean ± SD | − 0.44 ± 2.39 | − 2.19 ± 4.50 | − 0.20 ± 1.81 | |
| p-value | 0.0015c* | 0.0052c* | 0.0572c | |
| Steep K (diopter) | ||||
| Initial diagnosis | ||||
| Median (IQR) | 48.63 (6.25) | 48.75 (6.75) | 48.63 (6.25) | 0.8570b |
| Mean ± SD | 49.57 ± 5.00 | 49.64 ± 4.85 | 49.56 ± 5.03 | |
| Final visit | ||||
| Median (IQR) | 48.75 (6.50) | 49.00 (8.00) | 48.75 (6.00) | 0.5463b |
| Mean ± SD | 49.73 ± 5.30 | 50.38 ± 5.47 | 49.64 ± 5.28 | |
| Difference | ||||
| Median (IQR) | 0.00 (0.00) | 0.00 (0.50) | 0.00 (0.00) | 0.0934b |
| Mean ± SD | 0.16 ± 2.04 | 0.74 ± 1.81 | 0.08 ± 2.07 | |
| p-value | 0.1769c | 0.0339c | 0.5833c | |
| Flat K (diopter) | ||||
| Initial diagnosis | ||||
| Median (IQR) | 44.25 (3.92) | 44.00 (4.10) | 44.38 (4.00) | 0.2688b |
| Mean ± SD | 45.27 ± 4.08 | 44.71 ± 3.60 | 45.36 ± 4.15 | |
| Final visit | ||||
| Median (IQR) | 44.25 (3.88) | 43.75 (5.00) | 44.25 (3.75) | 0.4998b |
| Mean ± SD | 45.42 ± 4.25 | 45.31 ± 4.15 | 45.43 ± 4.27 | |
| Difference | ||||
| Median (IQR) | 0.00 (0.00) | 0.00 (0.75) | 0.00 (0.00) | 0.3702b |
| Mean ± SD | 0.14 ± 1.45 | 0.60 ± 1.58 | 0.08 ± 1.42 | |
| p-value | 0.1065c | 0.0365c | 0.4810c | |
afrom the initial diagnosis of KC to the final visit before intervention. bWilcoxon rank-sum test. cWilcoxon signed-rank test. K: keratometry readings. CDVA: corrected distance visual acuity. SD: standard deviation.
*Statistical significance according to the sequential Bonferroni-type procedure, because the smallest p was < i/46* 0.05 for the 46 multiple tests in Tables 1 and 2, and i is the ranking of the p values of multiple tests from smallest to largest as p(i).