Effect of Cyclotorsion Compensation in Small Incision Lenticule Extraction Surgery for the Correction of Myopic Astigmatism: A Systematic Review and Meta-Analysis

Xinwei Yang; Ying Liu; Kaimin Xiao; Qiuyi Song; Yunxi Xu; Jialing Li; Yuehua Zhou

doi:10.1007/s40123-024-00921-2

Effect of Cyclotorsion Compensation in Small Incision Lenticule Extraction Surgery for the Correction of Myopic Astigmatism: A Systematic Review and Meta-Analysis

Ophthalmol Ther. 2024 May;13(5):1271-1288. doi: 10.1007/s40123-024-00921-2. Epub 2024 Mar 18.

Authors

Xinwei Yang^#^{1

2}, Ying Liu^#³, Kaimin Xiao^#⁴, Qiuyi Song⁴, Yunxi Xu⁴, Jialing Li⁴, Yuehua Zhou^{5

6}

Affiliations

¹ Eye College, Chengdu University of Traditional Chinese Medicine, No. 37, Twelve Bridge Road, Jinniu District, Chengdu, Sichuan, China. 1434997155@qq.com.
² Refractive Surgery Department, Ineye Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China. 1434997155@qq.com.
³ Clinical School of Medicine, Chengdu University of Chinese Medicine, Chengdu, China.
⁴ Eye College, Chengdu University of Traditional Chinese Medicine, No. 37, Twelve Bridge Road, Jinniu District, Chengdu, Sichuan, China.
⁵ Eye College, Chengdu University of Traditional Chinese Medicine, No. 37, Twelve Bridge Road, Jinniu District, Chengdu, Sichuan, China. yh06236677@163.com.
⁶ Refractive Surgery Department, Ineye Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China. yh06236677@163.com.

^# Contributed equally.

Abstract

Introduction: Small incision lenticule extraction (SMILE) has made notable advancements in addressing myopic astigmatism. Nevertheless, the potential impact of cyclotorsion on surgical outcomes cannot be overlooked. This study aims to assess the effectiveness of cyclotorsion compensation technology in SMILE surgery for the correction of myopic astigmatism, examining its influence on postoperative visual quality.

Methods: A systematic review and meta-analysis were conducted. A comprehensive literature search was performed using databases, including PubMed, Web of Science, EMBASE, Cochrane Library, EBSCO, Scopus, CNKI, VIP, and Wan Fang. Studies meeting the criteria were selected and included. Data were independently extracted by three authors. Clinical outcome parameters were analyzed using Review Manager version 5.3.

Results: This meta-analysis included ten studies. The results showed that, compared with the control group (cyclotorsion compensation was not performed in SMILE), the following indicators in the cyclotorsion compensation group were: residual astigmatism (RA) [weighted mean difference (MD) = 0.73, 95% confidence interval (CI) + 0.26 to + 1.19, P = 0.002], spherical equivalent (SE) (MD = 1.99, 95% CI + 0.77 to + 3.21, P = 0.001), coma (MD = -0.06, 95% CI -0.08 to -0.04, P < 0.00001), higher-order aberrations (HOAs) (MD = -0.04, 95% CI -0.06 to -0.02, P < 0.0001), follow-up 6-month angle of error (AE) (MD = -2.67, 95% CI -3.71 to -1.63, P < 0.00001), and follow-up 6-month uncorrected distance visual acuity (UDVA) (MD = -0.05, 95% CI -0.08 to -0.01, P = 0.005), and the differences in results were statistically significant. However, the differences among correction index, index of success (IOS), targeted induced astigmatism (TIA), magnitude of error (ME), and spherical aberration (SA) were not statistically significant.

Conclusion: Cyclotorsion compensation proves to be effective and predictable for correcting myopic astigmatism. The cyclotorsion compensation group demonstrated advantages over the control group in terms of postoperative residual astigmatism, and it induced fewer coma aberrations. Whether cyclotorsion compensation can lead to better visual quality remains to be seen, and further research on correcting myopic astigmatism through cyclotorsion compensation is warranted.

Keywords: Astigmatism; Cyclotorsion compensation; Small incision lenticule extraction surgery.