AIM:To compare the effect of AT TORBI 709M and Tecnis ZMT intraocular lenses on astigmatism correction in patients with corneal astigmatism at 3 mo after operation based on the standard astigmatism vector analysis.

METHODS: This was a retrospective case-control study. The clinical data of 69 patients(69 eyes)with corneal astigmatism who underwent phacoemulsification and implantation of toric intraocular lens(IOL)from June 2021 to December 2021 in Day Surgery Center of Xi'an No.1 Hospital was analyzed. The patients were divided into two groups. In group one, 38 cases(38 eyes)were implanted with AT TORBI 709M, and 31 patients(31 eyes)with Tecnis ZMT in group two. The axial length, preoperative astigmatism and axis, and the degree of intraocular lens were recorded. The uncorrected distance visual acuity(UCDVA), best corrected distance visual acuity(BCDVA), diopter, residual astigmatism and axis were recorded preoperatively and at 1 wk, 1 and 3 mo postoperatively. The postoperative surgical indicators, including spherical equivalent(SE), target induced astigmatism vector(TIA), surgically induced astigmatism vector(SIA), magnitude of error(ME), absolute value of angle of error(|AE|), absolute value of difference vector(|DV|), correction index(CI), and index of success(IOS)were evaluated by the standard astigmatism vector analysis.

RESULTS:Postoperative UCDVA and BCDVA were significantly improved(all P<0.001), and there were statistically significant differences compared to preoperative UCDVA and BCDVA(all P<0.001). While, there was no significant difference in UCDVA and BCDVA between the two groups(P=0.275, 0.124). The standard astigmatism vector analysis showed that a good astigmatism correction was achieved in both AT TORBI 709M group and Tecnis ZMT group, and both |DV| and IOS were close to 0(P=0.329, 0.288). The CI of the AT TORBI 709M group was closer to 1, indicating a better astigmatism correction, while the CI of the Tecnis ZMT group was higher than 1, suggesting an overcorrection of astigmatism. However, the difference between the two groups was not statistically significant(P=0.193). The mean residual astigmatism at 3 mo postoperatively was -0.11±0.91 D in the AT TORBI 709M group and -0.46±0.76 D in the Tecnis ZMT group, respectively, showing no statistically significance difference(t=1.732, P=0.088).

CONCLUSION:Both the flat loop AT TORBI 709M and the double C-loop Tecnis ZMT intraocular lenses can effectively improve postoperative visual acuity in patients with regular corneal astigmatism, showing good rotational stability and comparable correction abilities for both astigmatism with the rule and against-the-rule astigmatism.