The influence factors and management of anterior chamber gas bubble emergence during femtosecond flap creation for LASIK

AIM: To study the influence factors and management of anterior chamber gas bubble during femtosecond flap creation for laser-assisted in situ keratomileusis(LASIK). METHODS: Totally 9 671 eyes of 4 859 patients with femtosecond LASIK were included in this study. Preoperative, intraoperative and postoperative parameters of anterior chamber gas bubble patients were analyzed and compared. RESULTS: A total of 51 cases(0.53%)occurred anterior chamber gas bubble during femtosecond flap creation. There was no statistical difference between uncorrected visual acuity of postoperative 1mo(-0.076±0.09)and preoperative best corrected visual acuity(-0.08±0.04; t=-0.34,P=0.74). And 33 eyes(65%)did not affect the pupil tracking, but there were 18 eyes(35%)unable to track the pupil successfully. There was no statistical difference in uncorrected visual acuity of postoperative 1mo between trace group(-0.06±0.08)and no trace group(-0.11±0.09; t=1.82, P=0.07). The highest incidence of anterior chamber gas bubble was at 9 point, followed by 3 point. There were no statistical differences in spherical equivalent refraction, corneal curvature, corneal diameter, anterior chamber volume, anterior chamber depth and intraoperative femtosecond laser energy between anterior chamber gas bubble eyes and the contralateral eyes(P>0.05). CONCLUSION: Anterior chamber gas bubble formation during femtosecond flap creation for LASIK is an uncommon event. It may affect the eye tracking. There is no obvious effect on early postoperative visual acuity if intraoperative disposed properly. The direct or indirect factors of anterior chamber gas bubble formation are unclear