A clinical study of cataract phacoemulsification and implantation of multifocal intraocular lens with paired clear corneal incision guided by K values

Objective To observe the effect of phacoemulsification with paired clear corneal incision guided by K values on the correction of preoperative corneal astigmatism and the visual function after implantation of multifocal intraocular lens,and evaluate the feasibility and security of this surgical method.Methods Forty-eight patients (96 eyes) with age-related cataract and corneal astigmatism≤l.50D were enrolled in this study.According to the preoperative comeal astigmatism measured by IOL-Master,they were divided into two groups; 30 patients (41 eyes) whose preoperative corneal astigmatism was 1.00D to 1.50D,as observation group,37 patients (55 eyes) whose astigmatism less than 1.0D were included in control group.The observation group received the clear comeal incision on the steepest meridian axis guided by K values during phacoemulsification and implanted IQ ReSTOR +3D multifocal intraocular lens,an additional symmetric clear corneal incision was made on the opposite side.And the control group only received the clear corneal incision on the steepest meridian axis guided by K values during phacoemulsification and implanted IQ ReSTOR + 3D multifocal intraocular lens.Three months after surgery,corneal astigmatism change,naked and corrected visual acuity in near-,intermediate-and far-distance,contrast sensitivity and patient questionnaires were observed.Results The mean preexisting astigmatism in the two groups significantly reduced postoperatively (after 3 months).Between the two groups,there were significant statistical differences (P ＜0.05),but there were no significant statistical difference in postoperative residual astigmatism (P ＞0.05).No significant statistical difference existed in uncorrected and corrected visual acuity in near-,intermediate-and far-distance (P ＞0.05).The postoperative contrast sensitivity in the two groups were normal,there was no significant difference in low frequencies and high frequencies (P ＞0.05),only there was statistical difference in medium frequency (P ＜0.05),the observation group lower than those of the control group.There was no statistically significant difference in the off-near glass rate,night blurred vision,glare and halos in two groups.Conclusions The cataract patients with high astigmatism who receive phacoemulsification with paired clear corneal incision guided by K values and implantation of multifocal intraocular lens can obtain good results,such as visual acuity in near-,intermediate-and far-distance,and quality of vision.This surgical method can develop clinical application range of the multifocal intraocular lens. Key words: Phacoemulsification; Corneal K value; Paired clear corneal incision; Astigmatism; Multifocal intraocular lens