Corneal astigmatism changes after cataract surgery with different incision locations on steep meridian

ObJective To evaluate surgically induced astigmatism (SIA) when locate the clear corneal incision on the preoperative steep meridian of the cornea in the cataract surgery.Methods According to where the corneal incision was chosen by rounding the steep corneal meridian to the closest 10 degrees,100 patients (121 eyes) who had received phacoemulsification and IOL implantation with 3.0mm clear corneal incision,were divided into 3 groups:Group A,superior corneal incision,38 eyes; Group B,temporal incision,42 eyes; Group C,superotemporal incision,41 eyes.Pentacam results were obtained preoperatively,at postoperative 1 week,1 month and 3 months.Corneal astigmatism changes and SIA were analyzed with vector method.Results Compared with the preoperative corneal astigmatism,the postoperative astigmatism decreased significantly in 3 groups (P ＜0.01).The corneal astigmatism had significant difference between 1 week and I month (P =0.024),but not between 1 month and 3 months (P ＞0.05).The SIA was (0.48±0.06)D,(0.26±0.04)D,(0.33±0.04)D respectively,the difference was significant among 3 groups (P ＜0.01).Conclusions Choosing the corneal incision based on the preoperative steep meridian significantly decrease residual astigmatism.It is feasible to utilize the SIA reasonably for individually incision design in cataract surgerv. Key words: Surgically induced astigmatism;  Cataract surgery;  Corneal astigmatism