To Observe The Clinical Effect Of Cataract Phacoemulsification Combined With Steep Axis Corneal Incision On Corneal Astigmatism

Purpose:Clinical effects on corneal astigmatism and visual acuity in cataract patients after ultrasound emulsification combined with steep-axis clear keratotomy versus conventional 135° keratotomy.Methods:The subject was analyzed through a retrospective clinical study.Seventy-five patients(84 eyes)who underwent cataract ultrasound-emulsification combined with intraocular lens(IOL)implantation at the Eye Hospital of Nanchang University between February 2022 and December 2022 and who had preoperative combined corneal astigmatism of 0.50 to 1.00 D were selected.The patients were randomly divided into two groups,A and B,according to the different procedures.Control group A: 37 patients(42 eyes)underwent clear corneal incision at 135°;study group B: 38 patients(42 eyes)underwent clear corneal incision at the steep axis of the cornea.Preoperative data were collected on all patients: age,gender,systemic disease,ocular disease,the uncorrected visual acuity,intraocular pressure,the best corrected visual acuity,corneal curvature K1 and K2 and axis of astigmatism measured by Pentacam,a three-dimensional anterior segment analysis system.Postoperative data:the uncorrected visual acuity(UCVA),intraocular pressure(IOP),the best corrected visual acuity(BCVA),corneal curvature K1 and K2,astigmatism axial position and surgically induced astigmatism(SIA)calculated from astigmatism size and axial position at 1 week and 1 month postoperatively.To observe the effects of the two surgical procedures on corneal astigmatism as well as visual acuity and intraocular pressure.Results:(1)There was no statistically significant difference in the basic preoperative information between the two groups of patients(P>0.05);(2)UCVA and BCVA: The postoperative UCVA and BCVA of patients in groups A and B were significantly improved,and there were statistical differences between UCVA and BCVA in each group before surgery,1 week and 1 month after surgery(P<0.001);The postoperative UCVA and BCVA in each time period in group B were better than those in group A,and the difference was statistically significant(P<0.05);(3)IOP: The postoperative IOP of patients was slightly reduced in groups A and B,and there was a statistical difference between two repeated comparisons of IOP before surgery,1 week and 1 month after surgery in each group(P<0.05);IOP was different in each time period after surgery in patients in groups A and B,and was not statistically significant(P>0.05);(4)Corneal astigmatism: In group A,the corneal astigmatism increased in each postoperative time period compared with that before surgery,and the difference between two repeated comparisons was statistically significant(P<0.001),while the corneal astigmatism decreased in 1 month after surgery compared with 1 week after surgery,the difference was not statistically significant(P>0.05);In group B,the corneal astigmatism decreased in 1 month postoperatively compared with preoperative,while it increased in 1 week postoperative compared with preoperative,and the difference between two repeated comparisons was statistically significant(P<0.05),decreased at 1 month postoperatively compared to 1 week postoperatively,with a statistically significant difference(P<0.001);Except for the preoperative corneal astigmatism of patients in groups A and B,which was not statistically different(P>0.05),the astigmatism of patients in group B was lower than that of patients in group A at all other time points,and the difference was statistically significant(P<0.05),indicating that the corneal astigmatism values of patients in group B were reduced at all postoperative time points;(5)SIA: With the extension of time,the SIA of patients in both groups A and B decreased,and the difference was statistically significant when comparing the two postoperative time periods(P<0.05);While the difference was not statistically significant when comparing the SIA of patients in both groups at all postoperative time periods(P>0.05).Conclusions:(1)When the preoperative corneal astigmatism is 0.50 to 1.00 D,both the conventional 135° clear corneal incision and the steep-axis corneal incision are safe and effective,and both significantly improve the patient’s postoperative visual acuity;(2)By comparing the two procedures,steep-axis keratotomy is superior to conventional 135° clear keratotomy in correcting astigmatism,which is conducive to improving patients’ visual quality.