Advertisement

Effect of corneal curvature on optical zone decentration and its impact on astigmatism and higher-order aberrations in SMILE and LASIK

  • Tommy C. Y. Chan
  • Kelvin H. Wan
  • David S. Y. Kang
  • Tiffany H. K. Tso
  • George P. M. Cheng
  • Yan Wang
Refractive Surgery
  • 65 Downloads

Abstract

Purpose

To determine the association between anterior corneal curvature and optical zone centration as well as its impact on aberration profiles in small-incision lenticule extraction (SMILE) and laser in situ keratomileusis (LASIK).

Methods

Seventy-eight eyes of 78 patients treated with SMILE (45 eyes) and LASIK (33 eyes) were included. The centration of the optical zone was evaluated on the instantaneous curvature difference map between the preoperative and 3-month postoperative scans using a superimposed set of concentric circles. The correlation between optical zone decentration and anterior keratometry values was evaluated. The effect of optical zone decentration on vector components of astigmatic correction and induction of higher-order aberrations (HOA) was assessed.

Results

The mean decentration distance was 0.21 ± 0.11 mm for SMILE and 0.20 ± 0.09 mm for LASIK (p = 0.808). There was a significant correlation between anterior keratometric astigmatism and decentration distance (r = 0.653, p < 0.001) for SMILE but not for LASIK (r = − 0.264, p = 0.138). Astigmatic correction was performed in 67 eyes. Optical zone decentration and the vector components of astigmatic correction were not correlated (p ≥ 0.420). Significant correlation was demonstrated between the decentration distance and the induced total coma (SMILE: r = 0.384, p = 0.009; LASIK: r = 0.553, p = 0.001) as well as the induced total HOA (SMILE: r = 0.498, p = 0.001; LASIK: r = 0.555, p = 0.001).

Conclusion

Anterior cornea astigmatism affected the treatment centration in SMILE but not LASIK. Subclinical decentration was associated with the induction of total coma and total HOA, but it did not affect the lower-order astigmatic correction.

Keywords

SMILE Small-incision lenticule extraction Centration Astigmatism Higher-order aberrations 

Notes

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. For this type of study, formal consent is not required.

Informed consent

Informed consent was obtained from all individual participants included in the study.

References

  1. 1.
    Bueeler M, Mrochen M, Seiler T (2003) Maximum permissible lateral decentration in aberration-sensing and wavefront-guided corneal ablation. J Cataract Refract Surg 29:257–263CrossRefGoogle Scholar
  2. 2.
    Mrochen M, Kaemmerer M, Mierdel P, Seiler T (2001) Increased higher-order optical aberrations after laser refractive surgery: a problem of subclinical decentration. J Cataract Refract Surg 27:362–369CrossRefGoogle Scholar
  3. 3.
    Prakash G, Agarwal A, Ashok Kumar D, Jacob S (2011) Comparison of laser in situ keratomileusis for myopic astigmatism without iris registration, with iris registration, and with iris registration-assisted dynamic rotational eye tracking. J Cataract Refract Surg 37:574–581.  https://doi.org/10.1016/j.jcrs.2010.11.025 CrossRefGoogle Scholar
  4. 4.
    Chan TCY, Ng ALK, Cheng GPM, Woo VCP, Zhang J, Wang Y, Jhanji V (2017) Effect of the learning curve on visual and refractive outcomes of small-incision lenticule extraction. Cornea 36:1044–1050.  https://doi.org/10.1097/ICO.0000000000001246 CrossRefGoogle Scholar
  5. 5.
    Liu M, Sun Y, Wang D, Zhang T, Zhou Y, Zheng H, Liu Q (2015) Decentration of optical zone center and its impact on visual outcomes following SMILE. Cornea 34:392–397.  https://doi.org/10.1097/ICO.0000000000000383 CrossRefGoogle Scholar
  6. 6.
    Yu Y, Zhang W, Cheng X, Cai J, Chen H (2017) Impact of treatment decentration on higher-order aberrations after SMILE. J Ophthalmol 2017:9575723.  https://doi.org/10.1155/2017/9575723 Google Scholar
  7. 7.
    Li M, Zhao J, Miao H, Shen Y, Sun L, Tian M, Wadium E, Zhou X (2014) Mild decentration measured by a Scheimpflug camera and its impact on visual quality following SMILE in the early learning curve. Invest Ophthalmol Vis Sci 55:3886–3892.  https://doi.org/10.1167/iovs.13-13714 CrossRefGoogle Scholar
  8. 8.
    Wong JX, Wong EP, Htoon HM, Mehta JS (2017) Intraoperative centration during small incision lenticule extraction (SMILE). Medicine (Baltimore) 96:e6076.  https://doi.org/10.1097/MD.0000000000006076 CrossRefGoogle Scholar
  9. 9.
    Shah R, Shah S, Sengupta S (2011) Results of small incision lenticule extraction: all-in-one femtosecond laser refractive surgery. J Cataract Refract Surg 37:127–137.  https://doi.org/10.1016/j.jcrs.2010.07.033 CrossRefGoogle Scholar
  10. 10.
    Reinstein DZ, Gobbe M, Gobbe L, Archer TJ, Carp GI (2015) Optical zone centration accuracy using corneal fixation-based SMILE compared to eye tracker-based femtosecond laser-assisted LASIK for myopia. J Refract Surg 31:586–592.  https://doi.org/10.3928/1081597X-20150820-03 CrossRefGoogle Scholar
  11. 11.
    Alpins N (2001) Astigmatism analysis by the Alpins method. J Cataract Refract Surg 27:31–49CrossRefGoogle Scholar
  12. 12.
    Güell JL, Verdaguer P, Gris O, Manero F, Elies D (2013) Laser corneal refractive surgery: an update. In: Güell JL (ed) Cataract. ESASO course series, vol 3. Karger, Basel, pp 116–128Google Scholar
  13. 13.
    Osman IM, Awad R, Shi W, Abou Shousha M (2016) Suction loss during femtosecond laser-assisted small-incision lenticule extraction: incidence and analysis of risk factors. J Cataract Refract Surg 42:246–250.  https://doi.org/10.1016/j.jcrs.2015.10.067 CrossRefGoogle Scholar
  14. 14.
    Lazaridis A, Droutsas K, Sekundo W (2014) Topographic analysis of the centration of the treatment zone after SMILE for myopia and comparison to FS-LASIK: subjective versus objective alignment. J Refract Surg 30:680–686.  https://doi.org/10.3928/1081597x-20140903-04 CrossRefGoogle Scholar
  15. 15.
    Zhang J, Wang Y, Chen X (2016) Comparison of moderate- to high-astigmatism corrections using wavefront-guided laser in situ keratomileusis and small-incision lenticule extraction. Cornea 35:523–530.  https://doi.org/10.1097/ICO.0000000000000782 CrossRefGoogle Scholar
  16. 16.
    Pedersen IB, Ivarsen A, Hjortdal J (2017) Changes in astigmatism, densitometry, and aberrations after SMILE for low to high myopic astigmatism: a 12-month prospective study. J Refract Surg 33:11–17.  https://doi.org/10.3928/1081597X-20161006-04 CrossRefGoogle Scholar
  17. 17.
    Ganesh S, Brar S, Pawar A (2017) Results of intraoperative manual cyclotorsion compensation for myopic astigmatism in patients undergoing small incision lenticule extraction (SMILE). J Refract Surg 33:506–512.  https://doi.org/10.3928/1081597X-20170328-01 CrossRefGoogle Scholar
  18. 18.
    Wang L, Koch DD (2008) Residual higher-order aberrations caused by clinically measured cyclotorsional misalignment or decentration during wavefront-guided excimer laser corneal ablation. J Cataract Refract Surg 34:2057–2062.  https://doi.org/10.1016/j.jcrs.2008.08.015 CrossRefGoogle Scholar
  19. 19.
    Buhren J, Yoon G, Kenner S, MacRae S, Huxlin K (2007) The effect of optical zone decentration on lower- and higher-order aberrations after photorefractive keratectomy in a cat model. Invest Ophthalmol Vis Sci 48:5806–5814.  https://doi.org/10.1167/iovs.07-0661 CrossRefGoogle Scholar
  20. 20.
    Ivarsen A, Asp S, Hjortdal J (2014) Safety and complications of more than 1500 small-incision lenticule extraction procedures. Ophthalmology 121:822–828.  https://doi.org/10.1016/j.ophtha.2013.11.006 CrossRefGoogle Scholar
  21. 21.
    Lieberman DM, Grierson JW (2000) The lids influence on corneal shape. Cornea 19:336–342CrossRefGoogle Scholar
  22. 22.
    Qu J, Lu F, Wu J, Wang Q, Xu C, Zhou X, He JC (2007) Wavefront aberration and its association with intraocular pressure and central corneal thickness in myopic eyes. J Cataract Refract Surg 33:1447–1454.  https://doi.org/10.1016/j.jcrs.2007.04.012 CrossRefGoogle Scholar
  23. 23.
    Mosquera SA, Verma S, McAlinden C (2015) Centration axis in refractive surgery. Eye Vision 2:4.  https://doi.org/10.1186/s40662-015-0014-6 CrossRefGoogle Scholar
  24. 24.
    Liu M, Zhang T, Zhou Y, Sun Y, Wang D, Zheng H, Liu Q (2015) Corneal regeneration after femtosecond laser small-incision lenticule extraction: a prospective study. Graefes Arch Clin Exp Ophthalmol 253:1035–1042.  https://doi.org/10.1007/s00417-015-2971-9 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Ophthalmology and Visual SciencesThe Chinese University of Hong KongHong KongHong Kong
  2. 2.Eyereum Eye ClinicSeoulSouth Korea
  3. 3.Hong Kong Laser Eye CenterHong KongHong Kong
  4. 4.Tianjin Eye Hospital & Eye InstituteTianjinChina

Personalised recommendations