Effect Of ICL Implantation Combined With Steep-axis Incision Of Corneal Limbus Of Different Lengths To Correct Astigmatism

Objective:To analyze the effect of ICL implantation combined with steep-axis incision of corneal limbus of different lengths to correct astigmatism in patients with ametropia by standard vector analysis.Methods:Prospective study.A total of 66 patients(109 eyes)with high myopia and astigmatism admitted to our Hospital from November 2019 to March 2020 were collected.All patients were treated with a maximum limbal refractive meridian incision.According to the results of mydriatic optometry before surgery,the patients were divided into 5 groups: the 3.0mm group: 0.5D≤astigmatism<1.0D;the 3.5mm group:1.0D≤astigmatism<1.5D;the 4.0mm group: 1.5D≤astigmatism<2.0D;the 4.5mm group: 2.0D≤astigmatism<2.5D;the 5.0mm group: 2.5D≤astigmatism<3.0D.The UCVA,BCVA,SE,safety index and effectiveness index of 5 groups were compared before and 6 months after surgery.Standard vector analysis was used to evaluate the indexes about astigmatism before and after surgery.Results:1.Six months after surgery,the UCVA differences among the 5 groups were statistically significant(F=8.588,P<0.001).The UCVA of the 3.0mm group was better than that of the 4.5mm group after surgery,with statistically significant differences(P=0.011).Postoperative UCVA in 5 groups was significantly higher than that before surgery,and the difference was statistically significant(t=26.74,28.85,17.09,20.42,17.41,P < 0.01).No loss of BCVA was observed in the 5 groups after operation.The SE differences among the 5 groups were not statistically significant(F=0.975,P=0.424).2.Six months after surgery,the safety indexes of 5 groups were 1.13±0.11,1.10±0.13,1.10± 0.12,1.06±0.08 and 1.09±0.13,respectively,with no statistical significance(F=1.198,P=0.316).The validity indexes of 5 groups wrer 1.13±0.11,1.09±0.15,1.10±0.12,0.98±0.17,1.02±0.20,respectively,with statistically significant differences(F=3.468,P=0.011),and the 3.0mm group was better than the 4.5mm group,the difference was statistically significant(P=0.03).3.Six months after surgery,there were 13 eyes(12%)without astigmatism among 5 groups,69 eyes(63%)with astigmatism≤0.50 D,and 99 eyes(91%)with astigmatism ≤1.0D.The differences of |SIRC|and |EV|,EM,CR among the 5 groups were statistically significant(P<0.05).The postoperative |SIRC| of 5 groups were(0.47±0.21)D,(0.63±0.25)D,(0.90±0.32)D,(1.47±0.45)D,(2.16±1.07)D,respectively.A fter six months,between the 3.0mm group and the other four groups,comparative difference of |EV| was statistically significant(P< 0.05).The EM is positive in all 5groups,which is considered undercorrection.There was statistically significant difference in EM between 3.0mm group and the other 4 groups(P<0.05).There was statistically significant difference in CR between 3.0mm group and 3.5mm group(P=0.019).There was no significant difference in EA and ER among 5 groups(P=0.553,0.161).4.After six months,the |SIRC| was significantly correlated with incision length(r=0.803,<0.001).Conclusion:ICL implantation combined with steep-axis incision of corneal limbus of different lengths is safe and effective in the correction of high myopia with astigmatism,but the correction effect of low to moderate astigmatism is better.The amount of surgically corrected astigmatism was positively correlated with the length of limbal incision.