Higher-Order Aberration Changes After Implantable Collamer Lens Implantation for Myopia

Abstract

PURPOSE: To investigate the changes in higher-order aberrations (HOAs) induced by implantation of Implantable Collamer Lenses (STAAR Surgical) and to explain them in relation to the surgical incision and optical properties. DESIGN: Prospective, observational case study. METHODS: This study included 56 eyes undergoing Implantable Collamer Lens insertion for myopic correction. The corneal incision size was determined according to the amount of astigmatism. HOAs were measured before surgery and :3 months after surgery in 25 eyes having small superior incision (<3.2 mm) surgery and in 31 eyes with large superior incision (3.2 to 4.5 mm) surgery. Changes in spherical aberration, coma, trefoil, and total HOAs (third to sixth order) were analyzed. Laboratory measurements of aberration profiles of Implantable Collamer Lenses with different optical powers were performed to validate clinical measurements. RESULTS: In the small-incision group, trefoil (Z(3)(-3)) and spherical aberration changed significantly (P = .004). In the large-incision group, in addition to trefoil and spherical aberration, total HOA changed significantly (mean change, 0.13 +/- 0.17; P = .001). Significant correlations were observed among the incision size, the astigmatism induced, and the trefoil induced. Induced trefoil showed a predominant pattern at the orientation of the incision meridian.. Optical measurement of aberrations of the Implantable Collamer Lenses confirmed the postoperative negative spherical aberration. CONCLUSIONS: HOA changes after Implantable Collamer Lens insertion were increased trefoil and induced negative spherical aberration. These changes may be explained by the effect of the corneal incision and the negative spherical aberration in the Implantable Collamer Lens, respectively. (Am J Ophthalmol 2011;151: 653-662. (C) 2011 by Elsevier Inc. All rights reserved.)