The Problem of Cyclotorsion in the Correction of Myopia and Myopic Astigmatism by the SMILE Method
https://doi.org/10.18008/1816-5095-2025-1-24-28
Abstract
For the treatment of myopia and myopic astigmatism, the most commonly performed laser refractive surgical technique is Laser in situ keratomileusis (LASIK). In recent years, minimally invasive lenticule extraction (SMILE) has emerged as a promising alternative to LASIK, requiring only a femtosecond laser to create the intrastromal lenticule. LASIK and SMILE have comparable visual outcomes in terms of safety, efficacy, and predictability. SMILE has been shown its result in less severe postoperative dry eye symptoms and faster corneal sensitivity recovery than LASIK. However, several authors have noted a clear trend toward undercorrection in SMILE, which is more pronounced in cases where preoperative astigmatism is greater. Astigmatism correction with femto-LASIK is more advantageous than with SMILE. The reason for this is cyclotorsion, which is not controlled when using the VisuMax platform. Cyclotorsia is a common problem when correcting astigmatism, as a cyclotorsional error of just a few degrees is a source of astigmatic undercorrection. Although dynamic cyclotorsion should not be a problem when performing SMILE due to the fixation of the eyes during laser treatment, static cyclotorsion must be compensated for, as proper axis alignment and pupillary centration are critical to achieving refractive results.
About the Authors
T. Yu. Shilova
Clinic of Dr. Shilova laser vision correction
Russian Federation
Russian Federation
Shilova Tatyana Yu., MD, head of the Clinic
Mosfilmovskaya str., 74B, Moscow, 119192
M. A. Shilova
Clinic of Dr. Shilova laser vision correction
Russian Federation
Russian Federation
Shilova Maria А., ophthalmosurgion
Mosfilmovskaya str., 74B, Moscow, 119192
References
1. Ang M, Tan D, Mehta JS. Small incision lenticule extraction (SMILE) versus laser in-situ keratomileusis (LASIK): study protocol for a randomized, non-inferiority trial. Trials 2012;13:75. doi: 10.1186/1745-6215-13-75.
2. Sekundo W, Kunert K, Russmann C, Gille A, Bissmann W, Stobrawa G, Sticker M, Bischoff M, Blum M. First efficacy and safety study of femtosecond lenticule extraction for the correction of myopia. J Cataract Refract Surg 2008;34(9):1513–1520. doi: 10.1016/j.jcrs.2008.05.033. Erratum in: J Cataract Refract Surg. 2008 Nov;34(11):1819.
3. Wong AHY, Cheung RKY, Kua WN, Shih KC, Chan TCY, Wan KH. Dry eyes after SMILE. Asia Pac J Ophthalmol (Phila). 2019;8(5):397–405. doi: 10.1097/01.APO.0000580136.80338.d0.
4. Han T, Zhao L, Shen Y, Chen Z, Yang D, Zhang J, Sekundo W, Shah R, Tian J, Zhou X. Twelve-year global publications on small incision lenticule extraction: a bibliometric analysis. Front Med (Lausanne) 2022;9:990657. doi: 10.3389/fmed.2022.990657.
5. Pedersen IB, Ivarsen A, Hjortdal J. Changes in Astigmatism, Densitometry, and Aberrations After SMILE for Low to High Myopic Astigmatism: A 12-Month Prospective Study. J Refract Surg. 2017;33:11–17. doi: 10.3928/1081597X-20161006-04.
6. Ivarsen A, Hjortdal J. Correction of myopic astigmatism with small incision lenticule extraction. J Refract Surg. 2014;30:240–247. doi: 10.3928/1081597X-20140320-02.
7. Zhang J, Wang Y, Wu W, Xu L, Li X, Dou R. Vector analysis of low to moderate astigmatism with small incision lenticule extraction (SMILE): results of a 1-year follow-up. BMC Ophthalmol. 2015;15:8. doi: 10.1186/1471-2415-15-8.
8. Chan TC, Ng AL, Cheng GP, Wang Z, Ye C, Woo VC, Tham CC, Jhanji V. Vector analysis of astigmatic correction after small-incision lenticule extraction and femtosecond- assisted LASIK for low to moderate myopic astigmatism. Br J Ophthalmol. 2016 Apr;100(4):553–559. doi: 10.1136/bjophthalmol-2015-307238.
9. Zhang J, Wang Y, Chen X. Comparison of Moderate- to High-Astigmatism Corrections Using WaveFront-Guided Laser In Situ Keratomileusis and Small-Incision Lenticule Extraction. Cornea. 2016;35:523–530. doi: 10.1097/ICO.0000000000000782.
10. Khalifa MA, Ghoneim AM, Shaheen MS, Piñero DP. Vector analysis of astigmatic changes after small-incision lenticule extraction and wavefrontguided laser in situ keratomileusis. J Cataract Refract Surg. 2017;43:819–824. doi: 10.1016/j.jcrs.2017.03.033.
11. Kanellopoulos AJ. Topography-Guided LASIK Versus Small Incision Lenticule Extraction (SMILE) for Myopia and Myopic Astigmatism: A Randomized, Prospective, Contralateral Eye Study. J Refract Surg. 2017;33:306–312. doi: 10.3928/1081597X-20170221-01.
12. Ganesh S, Brar S, Pawar A. Results of Intraoperative Manual Cyclotorsion Compensation for Myopic Astigmatism in Patients Undergoing Small Incision Lenticule Extraction (SMILE). J Refract Surg. 2017;33:506–512. doi: 10.3928/1081597X-20170328-01.
13. Bharti S, Bains HS. Active cyclotorsion error correction during LASIK for myopia and myopic astigmatism with the NIDEK EC-5000 CX III laser. J Refract Surg (Thorofare, NJ : 1995). 2007;23(9 Suppl):S1041–S1045. doi: 10.3928/1081-597X-20071102-11.
14. Febbraro JL, Koch DD, Khan HN, Saad A, Gatinel D. Detection of static cyclotorsion and compensation for dynamic cyclotorsion in laser in situ keratomileusis. J Cataract Refract Surg. 2010 Oct;36(10):1718–1723. doi: 10.1016/j.jcrs.2010.05.019.
15. Alió Del Barrio JL, Vargas V, Al-Shymali O, Alió JL. Small incision lenticule extraction (SMILE) in the correction of myopic astigmatism: outcomes and limitations — an update. Eye Vis (Lond). 2017 Nov 15;4:26. doi: 10.1186/s40662-017-0091-9.
16. Kim BK, Mun SJ, Lee DG, Kim JR, Kim HS, Chung YT. Full-Thickness Astigmatic Keratotomy Combined With Small-Incision Lenticule Extraction to Treat High-Level and Mixed Astigmatism. Cornea. 2015;34:1582–1587. doi: 10.1097/ICO.0000000000000613.
17. World Health Organization. General Guidelines for Methodologies on Research and Evaluation of Traditional Medicine. 2000. Available from URL: http://apps.who.int/medicinedocs/pdf/whozip42e/whozip42e.pdf
18. Reinstein DZ, Archer TJ, Randleman JB. JRS Standard for reporting astigmatism outcomes of refractive surgery. J Refract Surg. 2014;30:654–659. doi: 10.3928/1081597X-20150128-01.
19. Alpins NA. New method of targeting vectors to treat astigmatism. J Cataract Refract Surg. 1997;23:65–75. doi: 10.1016/s0886-3350(97)80153-8.
20. Xia L, Zhang J, Wu J, Yu K. Comparison of corneal biological healing after femtosecond LASIK an small incision lenticule extraction procedure. Curr Eye Res. 2016;41(9):1202–1208. doi: 10.3109/02713683.2015.1107590.
21. Xia LK, Ma J, Liu HN, Shi C, Huang Q. Three-year results of small incision lenticule extraction and wavefront-guided femtosecond laser-assisted laser in situ keratomileusis for correction of high myopia and myopic astigmatism. Int J Ophthalmol. 2018;11(3):470–477. doi: 10.18240/ijo.2018.03.18.
22. Swami AU, Steinert RF, Osborne WE, White AA. Rotational malposition during laser in situ keratomileusis. Am J Ophthalmol. 2002 Apr;133(4):561-562. doi: 10.1016/s0002-9394(01)01401-5.
23. Randleman JB, White AJ Jr, Lynn MJ, Hu MH, Stulting RD. Incidence, outcomes and risk factors for retreatment after wavefront-optimized ablations with PRK and LASIK. J Refract Surg. 2009;25:273–276.
24. Reinstein DZ, Gobbe M, Gobbe L, Archer TJ, Carp GI. Optical Zone Centration Accuracy Using Corneal Fixation-based SMILE Compared to Eye Tracker-based Femtosecond Laser-assisted LASIK for Myopia. J Refract Surg. 2015 Sep;31(9):586–592. doi: 10.3928/1081597X-20150820-03.
25. Alpins N. Astigmatism analysis by the Alpins method. J Cataract Refract Surg. 2001;27:31–49. doi: 10.1016/s0886-3350(00)00798-7.
26. Hori-Komai Y, Sakai C, Toda I, Ito M, Yamamoto T, Tsubota K. Detection of cyclotorsional rotation during excimer laser ablation in LASIK. J Refract Surg. 2007 Nov;23(9):911–915. doi: 10.3928/1081-597X-20071101-08.
27. Shilova T.Yu. Method of cyclotorsion control during myopia correction in combination with astigmatism by the RELEX SMILE method. Patent RU 2780135, 19.09.22.
Review
For citations:
Shilova T.Yu., Shilova M.A. The Problem of Cyclotorsion in the Correction of Myopia and Myopic Astigmatism by the SMILE Method. Ophthalmology in Russia. 2025;22(1):24-28. (In Russ.) https://doi.org/10.18008/1816-5095-2025-1-24-28
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