An observation of the relation between basal tear volume and corneal sensitivity after LASIK and LASEK

Objective To observe the relation between basal tear volume and corneal sensitivity after laser in situ keratomileusis (LASIK) and laser subepithelial keratomileusis (LASEK). Methods The design of this study was prospective case series.The subjects included 24 eyes of 24 patients who underwent LASIK and 21 eyes of 21 patients who underwent LASEK.The central corneal sensitivity (CCS) was measured with the Cochet & Bonnet esthesiometer.The lower tear meniscus area (LTMA) was evaluated with the RTVue (Fourier-Domain Optical Coherence Tomography). For LASIK,the CCS and the LTMA were observed preoperatively,1 day and 3 weeks postoperatively.For LASEK,the CCS and the LTMA were observed preoperatively,1 week and 3 weeks postoperatively.The ANOVA was used to analyze the differences in the CCS and the LTMA between the different time points. Results The difference in the LTMA between the different time points was not significant for both LASIK (F =0.08,P =0.9271) and LASEK (F=0.51,P =0.6077).The difference in the CCS between the different time points was significant for both LASIK (F =70.23,P=0.0001)and LASEK (F =6.76,P =0.0061).For LASIK,the CCS was significantly decreased 1 day and 3weeks postoperatively than preoperatively (P ＜0.05),and the CCS was significantly decreased 3weeks than 1 day postoperatively (P ＜0.05).For LASEK,the CCS was significantly decreased 1 week postoperatively than the other two time points (preoperatively and 3 weeks postoperatively,P ＜0.01),but the CCS was not significantly different between preoperatively and 3 weeks postoperatively (P ＞0.05).Conclusions The basal tear secretion is not affected by the change in corneal sensitivity after laser refractive surgery. Key words: Corneal surgery; Laser; Myopia; Tear; Optical coherence tomography; Corneal sensitivity