| Objective: To investigate the effect of cataract phacoemulsification surgery on postoperative corneal astigmatism in cataract patients,whose preoperative corneal astigmatism were within 0.5D,using different directions(steep corneal meridian,flat corneal meridian,middle corneal meridian)of 2.4mm clear corneal incision,aiming to select the better surgical incision to reduce postoperative astigmatism,and improve visual quality.Methods: According to the results of Pentacam,a total of 86 patients(100eyes)of cataract were collected whose preoperative corneal astigmatism were within 0.5D.They were divided into three groups: A,B and C,with 2.4mm transparent corneal incisions of different axial.The incisions of 29 cases(30eyes)in group A were on steep corneal meridian,33 cases(33 eyes)in group B were on flat corneal meridian,36 cases(37 eyes)in group C were on middle corneal meridian between steep and flat corneal meridian.Postoperative follow-up was at 1 week,1 month,3 months,and comprised the best uncorrected distance visual acuity(BUDVA),the best corrected distance visual acuity(BCDVA),the changes of corneal astigmatism,and the surgically induced astigmatism(SIA),as well as the changes of astigmatism axial.We calculated theSIA by Jaffe’s vector analysis.They were calculated and compared with each group before and after surgery.We used statistical analysis to compare changes in the above factors.Results:(1)BUDVA:group A,B,and C were significantly higher than those before surgery,which had a significant difference(P<0.05).There was no significant difference between each group in 1 week and 1 month after surgery(P>0.05).When in 3 months,there was no significant difference between group A and group B(P>0.05).But there was a significant difference between group A and group C(P=0.045).The BUDVA of group A was better.(2)BCDVA:The BCDVA of three groups after surgery were significantly improved compared with preoperative,which had a significant difference(P<0.05).There was no significant difference between the three groups after surgery(P>0.05).(3)Corneal astigmatism:The corneal astigmatism was significantly increased in the three groups at 1 week after surgery(P <0.05).With the passage of time,the corneal astigmatism of three groups decreased gradually,but group A decreased rapidly.In 1 month and 3 months after surgery,group A basically returned to preoperative level,and there was no significant difference(P>0.05).Group B and C was still higher than those before surgery,which had a significant difference(P<0.05).There was a significant difference between group A and group B at 1 week after surgery(P=0.03),group A was smaller than group B.There was no significant difference between group A and group C,as well as group B and group C(P>0.05).The corneal astigmatism of group A were smaller than group B and group C when in 1 month and 3 months after surgery,which had a significant difference(P<0.05).There was no significant difference between group B and group C in any time(P>0.05).(4)SIA: Compared with group A and group B: There was no significant difference in 1 week and 3 months after surgery(P>0.05).When in 1 months after surgery,the SIA of group A was smaller than that in group B,which had a significant difference(P=0.049).When compared with group A and group C:There was no significant difference in 1 week after surgery(P>0.05).But after surgery in 1 and 3 months,the SIA of group A was smaller than that in group C,and the difference was statistically significant(P=0.021,0.040).Compared with group B and group C: There was no significant difference between group B and group C in any time after surgery.(5)Axial changes in corneal astigmatism: For group A,there was no significant difference in the axial changes of corneal astigmatism before and after surgery.For group B and C,there were significant differences before and after operation in the axial changes of corneal astigmatism(P<0.05),which turn to with-the-rule astigmatism.Conclusion:According to the Pentacam,when preoperative corneal astigmatism is within 0.5D,choosing the incision on steep corneal meridian is more effective than flat corneal meridian or middle corneal meridian,which can reduce posterior corneal astigmatism and maintain axial position stability,and to get better visual quality. |
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