Changes in vaulting and the effect on refraction after phakic posterior chamber intraocular lens implantation

PurposeTo assess the changes in vaulting over time after implantable Collamer lens (ICL) implantation and the effect of vaulting on refraction.SettingDepartment of Ophthalmology, Kitasato University, Kanagawa, Japan.MethodsThis retrospective study evaluated eyes of consecutive patients having ICL implantation. The postoperative changes in vaulting between the ICL and the crystalline at 1, 3, and 6 months and 1 year were quantitatively assessed. The relationship between the vaulting and refractive outcomes at 1 year was also evaluated.ResultsSeventy-five eyes of 47 patients were evaluated. The mean vaulting was 0.61 mm ± 0.26 (SD), 0.59 ± 0.25 mm, 0.54 ± 0.25 mm, and 0.53 ± 0.24 mm at 1 month, 3 months, 6 months, and 1 year, respectively. The mean refractive error (difference between attempted and achieved manifest spherical equivalent refraction) was 0.01 ± 0.42 diopter (D) 1 year postoperatively. There was no significant association between the amount of vaulting and the refractive error (r = 0.19, P = .11).ConclusionsVaulting of the ICL over the crystalline lens decreased slightly with time, likely as a result of pupil movement, age-related increases in crystalline lens thickness, and the fixed position of the ICL haptics. The vaulting did not significantly affect refractive outcomes, suggesting that a precise effective lens position leads to higher predictability, largely as a result of the narrow fixated location of the ICL between the back surface of the iris and the ciliary sulcus.