FangJun Bao1, Si Cao2, JunJie Wang1, Yuan Wang2, Wei Huang2, Rong Zhu2, XiaoBo Zheng1, JinHai Huang2, ShiHao Chen2, YiYu Li3, QinMei Wang4, Ahmed Elsheikh5. 1. Eye Hospital, Wenzhou Medical University, Wenzhou, China; Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, China. 2. Eye Hospital, Wenzhou Medical University, Wenzhou, China. 3. Eye Hospital, Wenzhou Medical University, Wenzhou, China. Electronic address: liiyiiyuu@263.net. 4. Eye Hospital, Wenzhou Medical University, Wenzhou, China; Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, China. Electronic address: wangqm55@126.com. 5. School of Biological Science and Biomedical Engineering, Beihang University, Beijing, China; School of Engineering, University of Liverpool, London, England; National Institute for Health Research (NIHR) Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, England.
Abstract
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 < .01), representing a partial, gradual, yet significant reversal of the immediate change in corneal shape after laser ablation. In contrast, the posterior surface experienced significantly less change than the anterior surface, with the cornea becoming slightly flatter (P < .01) in the central region at 1 week postoperatively, and steeper elsewhere (P < .05), and then remaining stable during the rest of the follow-up. On the other hand, the anterior astigmatism had significant decreases in the central region (P < .01) and slight increases in the peripheral region (P < .01) 1 week postoperatively, and that remained stable over the follow-up period. In contrast, there were little or non-significant changes in the posterior astigmatism throughout the follow-up (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.
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 < .01), representing a partial, gradual, yet significant reversal of the immediate change in corneal shape after laser ablation. In contrast, the posterior surface experienced significantly less change than the anterior surface, with the cornea becoming slightly flatter (P < .01) in the central region at 1 week postoperatively, and steeper elsewhere (P < .05), and then remaining stable during the rest of the follow-up. On the other hand, the anterior astigmatism had significant decreases in the central region (P < .01) and slight increases in the peripheral region (P < .01) 1 week postoperatively, and that remained stable over the follow-up period. In contrast, there were little or non-significant changes in the posterior astigmatism throughout the follow-up (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.