Regional changes in corneal shape over a 6-month follow-up after femtosecond-assisted LASIK

Purpose To assess the regional changes in corneal shape after femtosecond laser–assisted laser in situ keratomileusis (FS-LASIK) in patients with different myopia extents. Setting Eye Hospital, Wenzhou Medical University, Wenzhou, China. Design Retrospective case series. Methods A retrospective study of myopic eyes treated with FS-LASIK was conducted to assess the shape changes within different corneal regions after surgery. Corneal curvature was measured in the central region (0 mm to 3.0 mm diameter), pericentral region (3.0 mm to 6.0 mm diameter) and peripheral region (6.0 mm to 9.0 mm diameter) preoperatively and from 1 week to 6 months postoperatively. Results The study comprised 608 myopic eyes. During the 6-month follow-up, the anterior cornea became steeper in the central and pericentral regions, but flatter in the peripheral region ( P P P P P P  > .05). Conclusions Postoperative corneal shape changes were different in different regions. There were shape changes in individual corneal regions during the 6-month follow-up period that represented reverse trends; however, the changes were much smaller than the short-term changes observed 1 week after surgery.