Comparison of tear function following laser <i>in situ</i> keratomileusis with two femtosecond laser platforms

• Main Authors: Li-Na Liu, Xing-Wu Zhong, Hai-Bo Chen, Jian-Qiang Xing, Ting-Fei Wu, Xiao-Lian Chen
• Format: Article
• Language: English
• Published: Press of International Journal of Ophthalmology (IJO PRESS) 2014-05-01
• Series: Guoji Yanke Zazhi
• Subjects: femtosecond laser; corneal staining; tear film break-up time; Schirmer's test
• Online Access: http://www.ies.net.cn/cn_publish/2014/5/201405028.pdf

AIM: To evaluate changes in tear function and corneal staining in patients who underwent laser <i>in situ </i>keratomileusis(LASIK)using two different femtosecond lasers.<p>METHODS:Forty eyes underwent FS200 and 40 eyes underwent VisuMax. The tear film break-up time(TBUT), Schirmer I test(SⅠt)and fluorescein staining were assessed preoperatively at 1wk; 1 and 3mo postoperatively. The analysis of variance(ANOVA)for repeat measurements or Kruskal—Wallis ranks test were used. For the differences between FS200 and VisuMax-operated eyes, a independent-samples <i>t</i> test or Wilcoxon matched-samples rank sum test were used.<p>RESULTS: There were no statistical differences in any clinical outcome measure between the two kinds of lasers(<i>P<</i>0.05), although there was a trend towards slightly reductions for TBUT in FS200-operated eyes. TBUT of the two groups eyes showed the same reductions(<i>F</i>=100.37, <i>P</i><0.01; <i>F</i>=112.25, <i>P</i><0.01)when compared preoperative levels to 1wk; 1 and 3mo postoperatively levels. Moreover, there were obvious decreases of the Schirmer Ⅰ test were observed on any visit after the operation for both groups(<i>F</i>=42.15, <i>P</i><0.01; <i>F</i>=37.27, <i>P</i><0.01). Furthermore, corneal staining was significantly increased at 1wk postoperatively(FS200 <i>Z</i>=4.88, <i>P</i><0.01; VisuMax <i>Z</i>=4.28, <i>P</i><0.01)after LASIK compared to preoperative conditions, and recovered to the level of preoperative at 1mo postoperatively. <p>CONCLUSION: This study shows that changes in TBUT,Schirmer I test and corneal staining are statistically similar in LASIK using FS200 and VisuMax femtosecond lasers for flap creation. However, the VisuMax-operated eyes of TBUT after LASIK have faster recovery than in FS200 eyes.