LASIK术后早期应用硅水凝胶角膜接触镜的临床观察

Clinical observation of silicone hydrogel contact lenses applied immediately after laser in situ keratomileusis

目的对准分子激光原位角膜磨镶术（LASIK）后早期应用硅水凝胶材质的角膜接触镜进行临床观察。方法前瞻性自身对照研究。25例近视患者（50眼）在LASIK术毕时随机选一眼给予PureVision角膜接触镜，并于术后第1天取出，观察术前及术后1d、1周、1个月、3个月的角膜荧光素染色（FL）、泪膜破裂时间（BUT）、基础泪液分泌量、主观症状评分以及术后角膜瓣并发症。戴镜眼和未戴镜眼之间以及两眼各自分别进行上述时间点不同观察指标的统计学分析。多个时间点的比较采用重复测量设计的方差分析或Kruskal—Wallis秩和检验，双眼间的比较采用配对t检验或Wilcoxon符号秩和检验，角膜瓣并发症的比较采用）（。检验。结果戴镜眼在术后1d（Z=－3．00，P〈0．01）、1周（Z=-2．32，P〈0．05）FL评分比未戴镜眼低；但与术前相比，戴镜眼和未戴镜眼在术后1d（Z=4．80，P〈0．0125；Z=6．20，P〈0．0125）、1周（Z：3．25，P〈0．0125；Z=4．26，P〈0．0125）都比术前有所升高。戴镜眼在术后1d（t=2．40，P〈0．05）、1周（t=2．09．P〈0．05）BUT比未戴镜眼延长，两眼在术后各个时间点均比术前缩短（F=3．12．P〈0．05：F=4．05，P〈0．05）。戴镜眼与未戴镜眼基础泪液分泌量在术后各个时间点差异均无统计学意义：术后1周、1个月、3个月两眼均比术前减少（F=4．64，P〈0．05；F=5．77，P〈0．05）。主观症状戴镜眼在术后1d比未戴镜眼轻（Z=2．15，P〈0．05）．两眼在术后各时间点均比术前加重（Z=2．92、2．66、2．28、2．46．P〈0．0125：Z=4．00、3．39、2．88、3．07，P〈0．0125）。两眼在术后各个时间点均未发现角膜瓣相关并发症，结论LASIK术后早期配戴硅水凝胶材质的角膜接触镜可以有效减轻早期眼表角膜的损伤、促进泪膜的稳定、缓解患者的不适感，但并不能缩短由于LASIK手术本身所带来的眼表泪液动力学改变的持续时间和症状的持续时间。

Objective To evaluate silicone hydrogel contact lenses applied immediately after laser in situ keratomileusis （LASIK）. Methods It was a prospective self-controlled study, and was based on 25 myopic patients （50 consecutive eyes） who underwent bilateral LASIK. The patients were randomly fitted with a PureVision lens in one eye and nothing in the fellow eye immediately after LASIK. The contact lenses were removed the next day. The fluoreseein staining score, tear break-up time, Schirmer I test and subjective score were assessed preoperatively and 1 day, 1 week, 1 month and 3 months postoperatively. Postoperative complications related to the corneal flap were also assessed. All values were compared between the treated eyes and the control eyes at the above time points. In addition, the parameters of the corresponding eyes were also estimated before and after surgery （1 day, 1 week, 1 month and 3 months）. The ANOVA for repeat measurements or Kruskal-Wallis ranks test were used for statistical analysis. For the differences between paired eyes, a paired-samples t test or Wilcoxon matched-samples rank sum test were used. A ehi-square test was used for the incidence of complications related to the corneal flap. Results The fluorescein staining score of the treated eyes showed improvement by 1 day （Z=-3.00, P〈0.01） and 1 week （Z=-2.32, P〈0.05） postoperatively in contrast with the control, but a significant aggravation in both eyes was found at 1 day （Z--4.80, P〈0.0125; Z=6.20, P〈0.0125） and 1 week （Z=3.25, P〈0.0125; Z=4.26, P〈0.0125） after LASIK compared to preoperative conditions. Compared to the control eye, tear break-up time of the treated eye showed an increase 1 day （t=2.40, P〈0.05） and 1 week （t=2.09, P〈0.05） after LASIK, but obvious decreases were observed on any visit after the operation for both eyes （F=3.12, P〈0.05; F=4.05, P〈0.05）. The Schirmer I test showed no statistically significant differences between the treated and control eyes postoperatively. Nevertheless, both eyes showed the same reductions （F=4.64, P〈0.05; F=5.77, P〈0.05） when compared to preoperative levels and at 1 week, 1 month, and 3 months postoperatively. Subjective scores of the treated eye were lower by 1 day （Z=2.15, P〈0.05） postoperatively compared to the control eye but there was a significant severity （Z=2.92, 2.66, 2.28, 2.46, P〈0.0125; Z=4.00, 3.39, 2.88, 3.07, P〈0.0125） at any visit after LASIK for either eye. No complications related to corneal flap were found postoperatively for any patient. Conclusion Silicone hydrogel contact lenses applied immediately after LASIK can reduce injury to the superficial cornea, increase stability of tear film and effectively alleviate patient discomfort during the early postoperative period. However, it cannot affect the time span during which dynamic ocular surface tear film changes and symptoms occur in response to LASIK.