Introduction This study evaluated vault changes in eyes implanted with an implantable Collamer lens (ICL) with a central hole (ICL V4c) for myopia and astigmatism correction as well as factors related to vault changes over time. Methods This retrospective study enrolled 169 myopic eyes from 169 patients (137 women and 32 men) who underwent ICL V4c implantation to correct myopia and astigmatism. Vault values were measured quantitatively using a rotating Scheimpflug camera. Each patient underwent at least four postoperative follow-up visits at 1 month, 6 months, 1 year, and more than 2 years. We compared postoperative values between groups and identified factors affecting vault changes over time. Results The mean vaults at 1 month (baseline), 6 months, 1 year, and the last follow-up time following ICL implantation were 540.83 ± 186.13, 520.00 ± 196.08, 503.79 ± 198.30, and 471.42 ± 211.35 μm, respectively. Eyes with baseline vaults of 250–750 and ≥ 750 μm exhibited a trend of vault decrease over time, and the differences were statistically significant ( P < 0.05) at 6 months and 1 year postoperatively, respectively. The variables relevant to the value of vault decrease between baseline and last follow-up time were anterior chamber depth (ACD) and ICL power (adjusted R 2 = 0.121, P < 0.001). Conclusions We found a trend of decreased mean objective vault values over time, which was more obvious in eyes with higher baseline vault values. The vault value of the ICL decreased more in eyes with shallower ACDs, higher ICL power, or both. Moreover, the decrease in vault values became statistically significant earlier in eyes with higher baseline vaults or shallower ACDs.

Purpose To compare school-age children’s objective and subjective refraction using a binocular wavefront optometer (BWFOM) with autorefraction and retinoscopy before and after cycloplegia. Methods Eighty-six eyes from 86 children (6–15 years old) were enrolled in this cross-sectional study. BWFOM objective and subjective refractions were compared with autorefraction and retinoscopy under cycloplegia. BWFOM refraction was evaluated before and after cycloplegia. Measurements were compared using a paired t-test; agreement was assessed using Bland–Altman plots. Results Under cycloplegia, the sphere, spherical equivalence, and J45 were significantly more negative on BWFOM objective refraction than autorefraction (− 1.39 ± 2.20 D vs. − 1.28 ± 2.23 D, P = 0.003; − 1.84 ± 2.38 D vs. − 1.72 ± 2.43 D, P = 0.001; − 0.02 ± 0.17 D vs. 0.03 ± 0.21 D, P = 0.004). The subjective sphere of BWFOM was less myopic, and the cylinder and the J45 were more negative than those with retinoscopy (− 1.17 ± 2.09 D vs. − 1.25 ± 2.20 D, P = 0.02; − 0.91 ± 0.92 D vs. − 0.76 ± 0.92 D, P < 0.001; − 0.01 ± 0.15 D vs. 0.03 ± 0.21 D, P = 0.028). For both BWFOM objective and subjective refraction, sphere and spherical equivalence with noncycloplegia were more myopic than those with cycloplegia (objective: − 1.76 ± 2.10 D vs. − 1.39 ± 2.20 D, − 2.21 ± 2.30 D vs. − 1.84 ± 2.38 D, P < 0.001; subjective: − 1.57 ± 1.92 D vs. − 1.17 ± 2.09 D, − 2.01 ± 2.13 D vs. − 1.62 ± 2.27 D, P < 0.001). Bland–Altman plots showed good agreement in spherical equivalence between BWFOM objective refraction and autorefraction (mean difference = 0.12 D, 95% confidence interval [CI] − 0.52 to 0.76), subjective refraction with retinoscopy (mean difference =  − 0.01 D, 95% CI − 0.65 to 0.64), and BWFOM refractions with or without cycloplegia (objective: mean difference =  − 0.37 D, 95% CI − 1.31 to 0.57; subjective: mean difference =  − 0.39 D, 95% CI − 1.30 to 0.51). The time cost by BWFOM was significantly less than the total time of autorefraction and retinoscopy (264.88 ± 90.67 s vs. 315.89 ± 95.31 s, P < 0.001). Conclusion BWFOM is a new device that realizes both objective and subjective refraction. For children’s refractive errors, it is more convenient and quicker to obtain the proper prescription at a 0.05-D interval, and it is more accurate than autorefraction and retinoscopy under cycloplegia.