Effect of 1.8-mm Steep-axis Clear Corneal Incision on the Posterior Corneal Astigmatism in Candidates for Toric IOL Implantation

Inclusion Criteria: 1. patients aged at least 45 years old who were scheduled for cataract surgery; (2) regular corneal astigmatism ≥ 1.0 D; (3) the imaging quality parameter (QS) of Pentacam HR was "OK"; and (4) follow-up time ≥1.0 month. Exclusion Criteria:(1) irregular corneal astigmatism; (2) corneal scar, corneal degeneration, pterygium invading the optic zone; (3) corneal endothelium count\<1,000/mm2, corneal endothelial dystrophy, iritis, glaucoma and retinal disease; (4) history of eye surgery, such as corneal refractive surgery, corneal transplantation and retinal surgery; (5) the main incision was expanded or sutures were used during surgery; and (6) some postoperative complications, such as persistent corneal edema, Descemet's membrane detachment and poor wound healing, and any others that might affect the measurement results of the Pentacam HR during the follow-up period. \-