Objective: To investigate the various factors that influencing the flap thickness after laser operation in situ keratomileusis (LASIK).
Methods: 369 LASIK eyes (192 cases; among them, 15 patients for surgery monocular) with M2 130 microkeratome heads, grouped by left or right eye were analyzed by Chi-square test and logistic regression analysis based on age, sex, occupation, family history of myopia and ophthalmologic examination results before and after LASIK. The result of analysis of one-way variance which P < 0.05 as the variance to described with logistic regression analysis.
Results: Results from logistic regression analysis showed that the flap thickness after LASIK of right eye group was related to two factors: the preoperative refractive power (P = 0.017, OR = 0.832,95% CI: 0.715-0.968), and the corneal thickness (P = 0.000, OR = 1.023, 95% CI: 1.011-1.036) while left eye group was related to three factors: the preoperative astigmatism power (P = 0.044, OR = 2.094, 95% CI: 1.021-4.294), negative pressure suction time (P = 0.019, OR = 1.418, 95% CI: 1.059-1.898) and the corneal thickness (P = 0.000, OR = 1.049, 95% CI: 1.025-1.073).
Conclusion: Corneal thickness, the preoperative astigmatism power and the negative pressure suction time tended to make the flap thicker while the preoperative refractive power tended to make the flap thinner. Results showed that the flap thickness performed at the first time was more obvious than at the second time.