Abstract:AIM: To compare the short-term and long-term effects of sub-Bowmans keratomileusis(SBK), femtosecond laser SBK(FS-SBK)and small incision lenticule extraction(SMILE)treatments on corneal endothelial cells density(ECD)in myopia.
METHODS: Thirty-four myopia patients(34 eyes)were performed with SBK, and 41 patients(41 eyes)underwent FS-SBK, 49 patients(49 eyes)underwent SMILE. The corneal endothelial cells, in terms of central corneal ECD, the coefficient of variation(CV)and the percentage of hexagonal endothelial cells, were measured by non-contact corneal endothelial microscope(Topcon SP-1P )at 1wk and 1a preoperative, and postoperative, separately.
RESULTS:There were no significant differences in the visual acuity and diopter among three groups at preoperative, 1wk and at 1a postoperative, separately(all P>0.05). The central corneal ECDs statistically decreased at 1wk postoperative in three groups, compared to preoperatively(all P<0.01), while the ECDs recovered at 1a postoperative. The changes of CVs and the percentage of hexagonal endothelial cells at 1wk,1a after operation were not statistically significantly different compared with preoperative results in the three groups(all P>0.05).The differences of ECD, CVs, and the percentage of hexagonal endothelial cells among three groups at preoperatively and postoperatively were not statistically significant(all P>0.05).
CONCLUSION: The SBK, FS-SBK and SMILE used to treat myopia were safe for the corneal endothelium. The central corneal ECDs decreased slightly at early period after operation, and recovered 1a later in all groups. The CVs and percentages of hexagonal endothelial cells in three groups do not change at short-term and long-term postoperatively. The differences of ECD, CVs, and the percentage of hexagonal endothelial cells among three groups were not found at postoperative.