Li H, Chen M, Tian L, Li D W, Peng Y S, Zhang F F
Qingdao Eye Hospital, Shandong Eye Institute, Shandong Academy of Medical Science, Qingdao 266071, China.
Zhonghua Yan Ke Za Zhi. 2018 Jan 11;54(1):39-47. doi: 10.3760/cma.j.issn.0412-4081.2018.01.008.
To explore the change of optical zone after femtosecond laser assisted laser in sitn keratomileusis(FS-LASIK) so as to provide the reference for measurement and design of clinical optical zone. This retrospective case series study covers 41 eyes of 24 patients (7 males and 17 females, aged from 18 to 42 years old) with myopia and myopic astigmatism who have received FS-LASIK surgery at Corneal Refractive Department of Qingdao Eye Hospital and completed over 6 months of clinical follow-up. Pentacam system (with the application of 6 corneal topographic map modes including: the pure axial curvature topographic map, the pure tangential curvature topographic map, the axial curvature difference topographic map, the tangential curvature difference topographic map, the postoperative front elevation map and the corneal thickness difference topographic map), combined with transparent concentric software (a system independently developed by Qingdao Eye Hospital) was used to measure the optical zone at 1, 3 and 6 months postoperatively, the optical zone diameters measurement results among different follow-up times in group were analyzed with the repeated measures analysis of variance, and the actual measured values and the theoretical design values of the optical zone were analyzed with independent-samples t-testing. Spearman correlation coefficient () have been applied to evaluate the relationship between postoperative optical zone measurement values and the potential influencing factors. The optical zone diameters measured by pure axial curvature topographic map at 1, 3 and 6 months after FS-LASIK showed (6.55±0.50)mm, (6.50±0.53)mm and (6.48±0.53)mm respectively. The differences between values are of no statistical significance (1.60, 0.21), the optical zone diameter measured by pure tangential curvature topographic map at 1, 3 and 6 months after FS-LASIK showed (5.44±0.46)mm, (5.46±0.52)mm and (5.44±0.50)mm respectively, the differences between values are of no statistical significance (0.17, 0.85). The optical zone diameters measured by postoperative front elevation map at 1, 3 and 6 months after FS-LASIK showed (5.06±0.28)mm, (5.12±0.32)mm and (5.17±0.28)mm respectively. The differences between the values of 3 and 6 months postoperatively are of no statistical significance (6.14, 0.15), the optical zone diameters measured by axial curvature difference topographic map at 1, 3 and 6 months after FS-LASIK showed (6.51±0.37)mm, (6.45±0.41)mm and (6.41±0.40)mm respectively, and the differences between the values of 3 and 6 months postoperatively are of no statistical significance (7.25, 0.05). The optical zone diameters measured by tangential curvature difference topographic map at 1, 3 and 6 months after FS-LASIK showed (5.21±0.23)mm, (5.16±0.19)mm and (5.17±0.20) mm respectively, and the differences between the values of 1 and 3 months postoperatively are of statistical significance (1.75, 0.04). The optical zone diameters measured by corneal thickness difference topographic map at 1, 3 and 6 months after FS-LASIK showed (6.53±0.40)mm, (6.39±0.43)mm and (6.41±0.47)mm respectively, and the differences between the values of 1 and 3 months postoperatively are of statistical significance (1.67, 0.032). The actual measured optical zone values from the 6 different modes of Pentacam system are less than the theoretical design values (7.75 mm), and the differences were statistical significance (-15.42, -29.39, -59.27, -21.47, -81.69, -18.22, 0.01). The optical zone measurement values tend to be stable at 3 months after FS-LASIK. The actual measured values from all the 6 different modes of Pentacam system were less than the theoretical design values. The results from pure tangential curvature topographic map, the tangential curvature difference topographic map and the postoperative front elevation map showed greater variation with clear border, which was beneficial for eccentric research. The results from pure axial curvature topographic map, the axial curvature difference topographic map and the corneal thickness difference topographic map were close to the theoretically designed values. Furthermore, the axial curvature difference topographic map showed clearer border and less variation thus maybe more favorable for measuring optical zone in clinical application..
探讨飞秒激光制瓣准分子原位角膜磨镶术（FS-LASIK）后光学区的变化情况，为临床光学区的测量与设计提供参考。本回顾性病例系列研究纳入了在青岛眼科医院角膜屈光科接受FS-LASIK手术且完成6个月以上临床随访的24例患者（男7例，女17例，年龄18～42岁）的41只眼，均为近视及近视散光。采用Pentacam系统（应用6种角膜地形图模式：单纯轴向曲率地形图、单纯切向曲率地形图、轴向曲率差值地形图、切向曲率差值地形图、术后前表面高度图、角膜厚度差值地形图），联合透明同心软件（青岛眼科医院自主研发的系统）测量术后1、3、6个月的光学区，对组内不同随访时间的光学区直径测量结果采用重复测量方差分析，光学区实际测量值与理论设计值采用独立样本t检验。应用Spearman相关系数（）评估术后光学区测量值与潜在影响因素的关系。FS-LASIK术后1、3、6个月单纯轴向曲率地形图测量的光学区直径分别为（6.55±0.50）mm、（6.50±0.53）mm、（6.48±0.53）mm，各值间差异无统计学意义（1.60，0.21）；FS-LASIK术后1、3、6个月单纯切向曲率地形图测量的光学区直径分别为（5.44±0.46）mm、（5.46±0.52）mm、（5.44±0.50）mm，各值间差异无统计学意义（0.17，0.85）；FS-LASIK术后1、3、6个月术后前表面高度图测量的光学区直径分别为（5.06±0.28）mm、（5.12±0.32）mm、（5.17±0.28）mm，术后3、6个月的值间差异无统计学意义（6.14，0.15）；FS-LASIK术后1、3、6个月轴向曲率差值地形图测量的光学区直径分别为（6.51±0.37）mm、（6.45±0.41）mm、（6.41±0.40）mm，术后3、6个月的值间差异无统计学意义（7.25，0.05）；FS-LASIK术后1、3、6个月切向曲率差值地形图测量的光学区直径分别为（5.21±0.23）mm、（5.16±0.19）mm、（5.17±0.20）mm，术后1、3个月的值间差异有统计学意义（1.75，0.04）；FS-LASIK术后1、3、6个月角膜厚度差值地形图测量得光学区直径分别为（6.53±0.40）mm、（6.39±0.43）mm、（6.41±0.47）mm，术后1、3个月的值间差异有统计学意义（1.67，0.032）。Pentacam系统6种不同模式的光学区实际测量值均小于理论设计值（7.75mm），差异有统计学意义（-15.42，-29.39，-59.27，-21.47，-81.69，-18.22，0.01）。FS-LASIK术后3个月光学区测量值趋于稳定。Pentacam系统6种不同模式的实际测量值均小于理论设计值。单纯切向曲率地形图、切向曲率差值地形图及术后前表面高度图的结果变异较大但边界清晰，有利于偏心研究。单纯轴向曲率地形图、轴向曲率差值地形图及角膜厚度差值地形图的结果接近理论设计值。此外，轴向曲率差值地形图边界更清晰、变异更小，可能更有利于临床应用中光学区的测量。
