Changes in Schlemm’s canal, trabecular meshwork, and relevant parameters in the early stage after SMILE of myopia patients

Abstract

AIM: To observe the changes in Schlemm's canal (SC), trabecular meshwork (TM), and anterior chamber relevant parameters after small incision lenticule extraction (SMILE) of myopia patients. METHODS: A total of 58 eyes from 30 patients who underwent SMILE were divided into a low and moderate myopia group (group A, 32 eyes) and a high myopia group (group B, 26 eyes). The diameter and area of the SC, the width and thickness of TM obtained by CIRRUS HD-OCT5000, and the related anterior chamber parameters obtained by Pentacam anterior segment analysis system, accommodation amplitude (AMP) were observed pre- and postoperatively. The preoperative intraocular pressure (IOP) and postoperative correction of intraocular pressure (IOPcc) were measured. RESULTS: The diameter and area of the SC in the two groups were significantly increased postoperatively (all P<0.01). The TM width of the patients in the two groups were increased at 1mo after surgery (both P<0.01), but the TM thickness did not change (P>0.05). The corneal curvature, central anterior chamber depth, and anterior chamber volume decreased after SMILE surgery (all P<0.01). There was a weak negative correlation between the SC area change and AMP change in group A (r=-0.362, P<0.01). The postoperative IOP decreased after correction by Shah formula (P<0.05). CONCLUSION: SC and TM in myopia patients change in the early postoperative stage of SMILE and the IOP is decline.