AIM: To investigate the changes of corneal curvature after non-phacoemulsification in small-incision cataract surgery with intraocular lens implantation and discuss the essence of iatrogenic astigmatism.

METHODS: In this study, the horizontal corneal curvature(HCC)and vertical corneal curvature(VCC)of 99 patients(116 eyes)were documented before and after cataract surgery,with the postoperative follow-up of 3d; 1, 2wk; 1, 3, 6mo; 1, 2, 3a. The difference value of the HCC and the VCC between preoperation and postoperation were calculated and statistically analyzed.

RESULTS: The VCC was deceased by 2.01D, while the HCC was increased by 1.62D on the 3d after surgery; the difference value of the HCC and VCC were both decreased acutely in the 3mo postoperationly(the difference value of the VCC was -0.52D and HCC was 0.46D); the difference value of the HCC and VCC both were decreased mildly after 3mo of postoperation, There was no significant difference between the difference value of HCC(0.29D)and VCC(-0.29D)at 6mo(P=0.801); VCC was still smaller than that of preoperation(-0.26D), and HCC was larger than that of preoperation(0.25D)at the 3a. Paired t test was performed in these curvature differences, which both decreased apparently from 3d to 6mo after surgery(P<0.001), while they stayed still from 6mo to 3a postoperatively(VCC: P=0.284; HCC:P=1.000).

CONCLUSION: It remains astigmatism for a short time after small-incision cataract surgery and the treatment requires improvement so as to minimize the astigmatism as much as possible.