Short‐term changes in and preoperative factors affecting vaulting after posterior chamber phakic Implantable Collamer Lens implantation

Abstract

Background To describe the very early vault changes in the first month after Implantable Collamer Lens (ICL) implantation and to evaluate the effect of preoperative biometric factors on vault. Methods Eighty-three eyes from eighty-three subjects with complete data who met follow-up requirements were recruited in this retrospective study between May 2019 and March 2020. We quantitatively assessed the postoperative vault at 2 h, 1 day, 1 week, and 1 month following implantation. Associations between the postoperative vault and age, ICL size, spherical equivalent (SE), axial length (AL), central corneal thickness (CCT), flat keratometry (K), steep K, mean K, anterior chamber depth (ACD), crystalline lens thickness (LT), white-to-white (WTW) diameter obtained by three devices, horizontal and vertical sulcus-to-sulcus (STS) diameter, bright and dark pupil sizes (BPS and DPS) and DPS-BPS were investigated using Spearman’s correlation analysis and stepwise multiple regression analysis. Results The mean vault values at 2 h, 1 day, 1 week, and 1 month after ICL implantation were 672.05 ± 30.72, 389.15 ± 28.33, 517.23 ± 30.76 and 530.12 ± 30.22 μm, respectively. Significant differences were found in the vault values at 2 h, 1 day and 1 week after the operation. The ICL size (β = 0.942; p < 0.001), followed by horizontal STS (β = -0.517; p < 0.001), crystalline LT (β = -0.376; p < 0.001) and vertical STS (β = -0.257; p = 0.017), significantly influenced the vault at 1 month after the operation. The multiple regression equation was expressed as follows: central vault (µm) = -1369.05 + 657.121 × ICL size- 287.408 × horizontal STS − 432.497 × crystalline LT − 137.33 × vertical STS (adjusted R2 = 0.643). Conclusions After ICL implantation, the vault decreased and then increased, but it did not return to the vault value 2 h after surgery. The ICL size, horizontal and vertical STS and crystalline LT are key factors for predicting postoperative vaulting.

Analysis of perioperative problems related to intraocular Implantable Collamer Lens (ICL) implantation

“…At 1 month after surgery, ICL size had the greatest impact on the arch height, followed by horizontal sulcus-to-sulcus diameter (STS), crystalline lens thickness (LT), and vertical STS. The influence of other factors such as white-to-white diameter (WTW) and preoperative spherical equivalent refractive error had no effect [55][56][57][58]. Although WTW can indirectly predict STS, the WTW diameter was further away from 11.08 to 12.51 mm, or the ACD was further away from 2.81 to 3.74 mm, the correlation between the STS and WTW diameters was weaker [59].…”

Clinical Prediction of Inadequate Vault in Eyes With Thick Lens After Implantable Collamer Lens Implantation Using Iris Morphology

“…For concave shape iris, it had a tendency to demonstrate low vault value after ICL implantation; while for convex shape iris, most of eyes acquired a high vault value. With regards to the parameters about the lens, previous studies have reported that the LT and LR had significantly negative correlation with vault value in previous studies ( 10 , 11 , 19 , 20 ). However, eyes in our study obtained both high and low vault value even though they all had the LT > 4.0 mm.…”

“…Herein, the iris shape demonstrated significant correlation with the vault value. As is known, the ICL size had a positive association with postoperative vault ( 11 ). Therefore, it seemed rational to choose a relative larger size ICL when facing the increased LT or LR.…”

“…After the second intervention, all these eyes obtained an ideal vault and no decreased visual acuity or other complications were reported during the follow up time. The method that ICL exchanging to a larger size ICL for low vault was supported by the positive correlation between ICL size and vault value ( 11 , 24 ). As for high vault after ICL implantation, we made a rotation of the ICL from horizontal to oblique or vertical orientation and obtained an ideal vault eventually.…”

“…Other detailed anatomic dimensional parameters, including angel-to-angle (ATA), anterior chamber area or ciliary sulcus diameter [sulcus to sulcus (STS)], crystalline lens rise (LR) and thickness (LT) are also important to optimize the method of ICL sizing and improve the accuracy and precision of vault prediction ( 6 – 9 ). One of interesting findings is that the LT had a negative correlation with the vault value ( 10 , 11 ). However, not all eyes with thick lens obtained a low vault since the prediction of vault required the integration of multiple factors.…”