The rate of vault changes after ICL V4c implantation and its correlation with anterior segment parameters

Purpose To investigate the rate of vault changes after implantation of ICL V4c and the correlation with anterior segment parameters. Methods A total of 64 eyes were studied from the 37 myopic subjects recruited. CASIA2 was used to record the vault at 1 week, 1 month, 3 months and 6 months after the operation as well as the preoperative anterior segment parameters including pupil diameter, lens vault, anterior chamber depth, anterior chamber width, iris area (IA), iris thickness, angle opening distance, angle recess area, trabecular iris space area, and trabecular iris angle. The rates of vault change in different time intervals were compared and the correlations between the rates and anterior segment parameters were analyzed. P < 0.05 was considered statistically significant. Results The rate of vault decrease was -19.53 +/- 111.28 mu m/month between 1 week and 1 month, -19.90 +/- 29.71 mu m/month between 1 month and 3 months and -4.25 +/- 18.10 mu m/month between 3 months and 6 months; hence the rate was shown to slow down significantly from 3 months post-operation (P = 0.024). The average rate of vault changes showed a significant positive correlation with IA (R-2 = 0.140, F = 4.980, P = 0.01). No significant correlation was found with other anterior segment parameters (all P > 0.05). Conclusion The rate of decreasing vault significantly slowed down from 3 months post-operation. A larger IA may imply a lower decreasing rate of vault change.