摘要目的 评价和比较准分子激光手术不同方式制作角膜瓣厚度的预测性和均匀性以及短期变化.方法 选取3组准分子激光手术连续病例:准分子激光角膜上皮瓣下磨镶术(LASEK)组40例(80只眼),板层角膜刀准分子激光原位角膜磨镶术(LASIK)组78例(155只眼),飞秒激光LASIK组42例(82只眼).LASIK手术采用90μm Moria M_2自动旋转式微型角膜刀或Zeiss VisuMax 飞秒激光制作100 μm角膜瓣.采用眼前节光学相干断层(OCT)扫描系统,由同一检查医师于术后1h、1d、1周、1个月和3个月测量角膜上皮瓣或基质瓣厚度,采集水平子午线、垂直子午线、45°和135°子午线上距离角膜顶点1.5、2.5、3.5mm及角膜顶点共25个点的角膜瓣厚度.统计方法为t检验或方差分析,P<0.05为差异有统计学意义.结果 眼前节OCT测得角膜上皮瓣厚度:术后1h、1d、1周、1个月、3个月分别为(57.91±6.76)、(54.94±4.65)、(54.96±2.70)、(55.26±4.27)、(53.86±5.56)μm,差异有统计学意义(F-=20.25,P<0.05).板层角膜刀组角膜顶点处平均厚度为(129.16±12.10)μm,飞秒激光组为(112.69±5.12)μm,飞秒激光制瓣预测性优于板层角膜刀.板层角膜刀组和飞秒激光组实际瓣厚度与平均瓣厚度差值绝对值的均数分别为(13.16±4.78)μm和(5.26±1.21)μm,飞秒激光制瓣重复性优于板层角膜刀.角膜瓣厚度空间特征:板层角膜刀组角膜瓣呈现中央薄而周边厚的形态,飞秒激光组不同离心度位置角膜瓣厚度均匀一致,差异无统计学意义(F=1.08,P>0.05).结论 眼前节OCT是无创、简捷并可靠的角膜瓣形态检测手段.角膜瓣的眼前节OCT检查表明,飞秒激光制瓣比常规板层角膜刀在预测性和均匀性方面更有优势.

abstractsObjective To assess and compare the accuracy and regularity and short-term change of corneal flap in different flap preparation styles.Methods Eighty eyes of 40 cases were treated with laser-assisted subepithelial keratectomy.One hundred and fifty-five eyes of 78 cases were treated with laser in situ keratomileusis with 90 μm microkeratome flap preparation and eighty-two eyes of 42 cases were treated with laser in situ keratomileusis with 100 μm femtosecond laser flap preparation.Anterior segment optical coherence tomography Was used to assess the thickness of epithelial or stromal flaps created with M2 microkeratome or VisuMaX femtosecond laser by the same investigator 1 hour,1 day,1 week,1 month and3 months postoperatively,respectively.The thickness of twenty-five measuring points across each flap in LASIK,which were 1.5mm,2.5 mm and 3.5 mm away from vertex of cornea on the horizontal,vertical,45°and 135°meridian respectively and the vertex of cornea itself,Was evaluated.The results were analyzed with t-test or ANOVA by SPSS software.Results The thickness of epithelial flaps Was(57.91±6.76),(54.94±4.65),(54.96±2.70),(55.26±4.27)and(53.86±5.56)μm at 1 hour,1 day,1 week, 1 month and 3 months respectively,with statistical significant difference between 1 hour and the other time points(F=20.25,P<0.05).The average thickness of stromal flaps on the vertex of cornea in microkeratome group was (129.16 ±12.10)μm,while(112.69±5.12)μm in the femtosecond laser group,which means the accuracy of flap preparation with femtosecond laser is better than with microkeratome.The absolute difference between actual and average thickness was (13.16±4.78)and (5.26±1.21)μm in the microkeratome group and femtosecond laser group,which means the reproducibility of flap preparation with femtosecond laser is better than with microkeratome as well. Flap morphology showed the feature of thin central area and thick peripheral area in microkeratome flap and uniformity in femtosecond laser flap.which illustrated the better regularity of femtosecond laser flap preparation.Conclusions Anterior segment optical coherence tomography is a safe.quick and reliable facility to examine and assess flap morphology.Our results showed the accuracy and regularity of femtosecond laser flap preparation outweighed microkeratome flap preparation.