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

Purpose: To assess the changes in vaulting over time after implantable Collamer lens (ICL) implantation and the effect of vaulting on refraction.

Setting: Department of Ophthalmology, Kitasato University, Kanagawa, Japan.

Methods: This 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.

Results: Seventy-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).

Conclusions: Vaulting 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.