Corneal astigmatism and optical quality after phacoemulsification and multifocal intraocular lens implantation: single versus double clear corneal incisions

Objective The purpose of this study is to evaluate the astigmatism,visual acuity,contrast sensitivity,and stereoscopic acuity after phacoemulsification and multifocal intraocular lens(IOL) implantation using single clear corneal incisions or paired opposite clear corneal incisions on the steep axis in cataract patients with pre-existing astigmatism of 0.5 D ～ 1.75 D.Methods Sixty eyes of 52 patients were involved in this prospective clinical study.(1) CCIs group: patients who had pre-existing astigmatism less than 1.00D underwent 3.0 mm single 0pposite clear corneal incisions.(2) OCCIs group: patients who had pre-existing astigmatism between 1.00 D ～ 1.75 D underwent 3.0 mm paired 0pposite clear corneal incisions.We recorded refractory changes in all patients at 1 day,1 week,1 month and 3 months,and compared the refractory changes between OCCIs and CCIs at 3 months.Uncorrected distance and near visual acuity,contrast sensitivity,and stereoscopic acuity of OCCIs group were also compared with those of CCIs group.Results(1) The astigmatism started to improved in all patients at postoperative day 1 and continue to improve through 1 week,1 month and 3 months in the follow-up(P 0.05).(2) At 3 months,mean astigmatism was 0.86 ± 0.35 D and 0.41 ± 0.28 D in OCCIs group and CCIs group,respectively.There was significant difference between the two groups(P 0.001).(3) There was no difference in uncorrected distance visual acuity,uncorrected near visual acuity,contrast sensitivity,stereoscopic acuity between the two groups at 3 months after the operation.Conclusion Clear corneal incisions on the steep axis can reduce pre-existing corneal astigmatism.Paired OCCIs provide an enhanced refractory correction in cataract surgery.It helps to provide better postoperative visual quality for the patients who has pre-existing astigmatism between 0.50 D ～ 1.75 D and wishes to implant multifocal intraocular lens.