飞秒激光小切口角膜基质透镜取出术与准分子激光原位角膜磨镶术治疗近视对角膜内皮细胞密度影响的比较

目的　比较飞秒激光小切口角膜基质透镜取出术（ｓｍａｌｌｉｎｃｉｓｉｏｎｌｅｎｔｉｃｕｌｅｅｘｔｒａｃｔｉｏｎ，ＳＭＩＬＥ）与准分子激光原位角膜磨镶术（ｌａｓｅｒｉｎｓｉｔｕｋｅｒａｔｏｍｉｌｅｕｓｉｓ，ＬＡＳＩＫ）治疗近视对角膜内皮细胞密度的影响。方法　选取我院自愿接受ＳＭＩＬＥ手术和ＬＡＳＩＫ手术且常规术前检查确认为适应证的患者作为研究对象，接受ＳＭＩＬＥ手术者共９３例（１８６眼）为观察组，接受ＬＡＳＩＫ手术者共９６例（１９２眼）为对照组。比较两组患者手术前后视力、眼压和中央角膜厚度的变化情况，并于术前和术后１ｄ、１０ｄ、１个月、３个月、６个月进行角膜内皮细胞计数仪检查，观察并统计分析两组患者角膜内皮细胞密度、变异系数、六角形细胞百分比、平均细胞面积。结果　手术后两组患者各时间点裸眼视力差异均无统计学意义（均为Ｐ＞０．０５）；术后１个月，观察组眼压和中央角膜厚度改变率分别为（－２７．１０±１１．２０）％和（－１４．５０±４．３０）％，对照组分别为（－２９．２０±９．６０）％和（－１７．９０±４．３０）％，观察组眼压和中央角膜厚度改变率均较对照组低（均为Ｐ＜０．０５）。术后６个月，观察组眼压和中央角膜厚度改变率分别为（－２４．５０±１０．９０）％和（－１３．６０±４．３０）％，对照组分别为（－２７．００±１０．８０）％和（－１５．６０±４．４０）％，较术后１个月时有所减少（均为Ｐ＜０．０５），说明眼压和中央角膜厚度有一定回升趋势；角膜内皮细胞密度、平均细胞面积、变异系数及六角形细胞百分比两组患者手术前后各时间点比较差异均无统计学意义（均为Ｐ＞０．０５），组间各时间点比较差异均无统计学意义（均为Ｐ＞０．０５）。结论　ＳＭＩＬＥ与ＬＡＳＩＫ治疗近视均具有较高的安全性、有效性和稳定性。与ＬＡＳＩＫ相比，ＳＭＩＬＥ术后角膜弹性的改变较少，角膜内皮细胞密度无明显变化，不会对角膜内皮细胞造成过重损伤。

Effects of SMILE and LASIK on corneal endothelial cell density in treatment of myopia

Objective To compare the effects of Femtosecond laser small incision lenticule extraction ( SMILE ) and excimer laser in-situ keratomileusis ( LASIK) on the corneal endothelial cell density in the treatment of myopia. Methods Ninty-three patients ( 186 eyes) who underwent SMILE and meet the indication by routine preoperative exanunation were selected as the observation group. 96 cases ( 192 eyes) underwent LASIK were selected as the control group. The visual acuity,intraocular pressure ( IOP) and corneal central thickness ( CCT) were compared, and the density of corneal endothelial cells .variation coefficients , percentage of hexagonal cells and average areas of corneal endothelial cells in the two groups were exanuned before operation and I day,10 days , I month , 3 months ,6 months after operation. Results There was no significant difference in UCVA at each time point after operation between the two groups ( all P > 0. 05 ) ;At I months after operation . the change rate of IOP and CCT in the observation group were ( - 27. 10 + 11. 20) % and ( - 14. 50 + 4. 30 ) % , respectively , and ( - 29. 20 + 9. 60) % and ( - 17. 90 + 4. 30 ) % in the control group, respectively. The change rate of IOP and CCT in the observation group were lower than those in the control group ( all P < 0. 05 ). At 6 months. the change rate of IOP and CCT were ( - 24. 50 + 10. 90 ) % and ( - 13. 60 + 4. 30 ) % in the observation group , respectively , and ( - 27. 00 + 10. 80 ) % and ( - 15. 60 +4. 40 ) % in the control group , respectively , which were less than those at I month after operation( all P < 0. 05 ) in both groups , showed a tendency to rise of IOP and CCT. There was no significant difference in corneal endothelial cell density , average cell area , variation coefficients and percentage of hexagonal cells before and after operation in two groups( all P > 0. 05 ) . There was no significant difference at each time point between inter-groups( all P > 0. 05) . Conclusion Both SMILE and LASIK are safe , effective and stable. Compared with LASIK , the changes of corneal thickness and elasticity after SMILE are less ,the density of corneal endothelial cells is not affected, and has no more damage on the corneal endothelial cells.