Effect of laser <i>in situ</i> keratomileusis with corneal flap created by femtosecond laser on tear film detected by Keratograph in different age groups

AIM:To explore the changes of tear film detected by Keratograph in the patients after laser <i>in situ </i>keratomileusis(LASIK)with corneal flap created by femtosecond laser. <p>METHODS: Totally 75 myopic patients(150 eyes)were enrolled who underwent femtosecond laser LASIK from July 2014 to June 2015, including patients<30, 30～40, over 40 years old and 25 cases(50 eyes)in each group. Tear break-up time(BUT), tear meniscus height(TMH), McMonnies Dry Eye Disease Questionnaire(McMonnies Questionnaire, MQ)were checked preoperatively and postoperatively at 1wk, 1, 2 and 3mo. <p>RESULTS: Before surgeries, the dry eye symptoms score of three groups had no significant difference(<i>P</i>>0.05). After surgeries, there were significant difference at each follow-up time among the three groups on symptoms score(<i>P</i><0.05), with <30 years old group the lowest and over 40 years old group the highest. Dry eye symptom scores rise obviously at postoperatively 1wk and then declined gradually. The scores of <30, 30～40 years old group fell to the preoperative levels at 2mo, while that happened in over 40 group at 3mo after surgeries. BUT and TMH of three groups had significant differences at each follow-up point(<i>P</i><0.05), with <30 years old group the highest, over 40 years old group the lowest. A 1wk after surgeries, the indexes declined obviously and then rise. BUT of <30, 30～40 years old group recovered to preoperative levels at 3mo, with over 40 years old group not recovered. TMH of <30 years group recovered to preoperative levels at 2mo, with 30～40 and over 40 years old group recovered at 3mo. <p>CONCLUSION: LASIK can affect the dry eye symptoms and the stability of tear film, which decreased by postoperative time. And the index recovered to preoperative levels earlier in younger patients