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Steinberg J, Mehlan J, Mudarisov B, Katz T, Druchkiv V, J Linke S, Frings A. Safety and Precision of Two Different Flap-morphologies Created During Low Energy Femtosecond Laser-assisted LASIK. JOVR [Internet]. 2023Feb.13 [cited 2024May2];18(1):3–14. Available from: https://knepublishing.com/index.php/JOVR/article/view/12720

https://doi.org/10.18502/jovr.v18i1.12720

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authors

  • Johannes Steinberg

    Johannes Steinberg

    MD. Department of Ophthalmology, University Hospital Hamburg-Eppendorf, Martinistr. 52, Hamburg 20251, Germany.
  • Juliane Mehlan

    Juliane Mehlan

    MD. Department of Ophthalmology, University Hospital Hamburg-Eppendorf, Martinistr. 52, Hamburg 20251, Germany.
  • Bulat Mudarisov

    Bulat Mudarisov

    MD. Department of Ophthalmology, University Hospital Hamburg-Eppendorf, Martinistr. 52, Hamburg 20251, Germany.
  • Toam Katz

    Toam Katz

    MD. Department of Ophthalmology, University Hospital Hamburg-Eppendorf, Martinistr. 52, Hamburg 20251, Germany.
  • Vasyl Druchkiv

    Vasyl Druchkiv

    MD. Department of Ophthalmology, University Hospital Hamburg-Eppendorf, Martinistr. 52, Hamburg 20251, Germany.
  • Stephan J Linke

    Stephan J Linke

    MD. Department of Ophthalmology, University Hospital Hamburg-Eppendorf, Martinistr. 52, Hamburg 20251, Germany.gw
  • Andreas Frings

    Andreas Frings

    Univ.-Augenklinik Düsseldorf, Düsseldorf, Germany

Published Date

  • Feb 13, 2023
This journal is publishing all the articles under Creative Commons Attribution License CC BY 4.0.

Safety and Precision of Two Different Flap-morphologies Created During Low Energy Femtosecond Laser-assisted LASIK

Journal of Ophthalmic and Vision Research (JOVR) / Jan–Mar 2023, Volume 18, Issue 1 / Pages 3–14

Abstract

Purpose: Currently, two major principles exist to create LASIK flaps: firstly, a strictly horizontal (2D) cut similar to the microkeratome-cut and secondly an angled cut with a “step-like” edge (3D). The strictly horizontal (2D) cut method can be performed using apparatus such as the low-energy FEMTO LDV Z8 laser and its predecessors which are specific to this type. Alternatively, the low-energy FEMTO LDV Z8 laser’s 3D flap design creates an interlocking flap-interface surface which potentially contributes toward flap stability. In addition, the FEMTO LDV Z8 offers flap-position adjustments after docking (before flap-creation). The current study analyzed precision, safety, efficacy, as well as patient self-reported pain and comfort levels after applying two different types of LASIK flap morphologies which were created with a low-energy, high-frequency femtosecond (fs) laser device.
Methods: A prospective, interventional, randomized, contralateral eye, single-center comparison study was conducted from November 2019 to March 2020 at the Hamburg vision clinic/ zentrumsehstärke, Hamburg, Germany. Eleven patients and 22 eyes received low-energy fs LASIK treatment for myopia or myopic astigmatism in both eyes. Before the treatment, the eyes were randomized (one eye was treated with the 2D, the other eye with the 3D method).
Results: The mean central flap thickness one month after surgery was 110.7 ± 1.6 μm (2D) and 111.2 ± 1.7 μm (3D); P = 0.365 (2D vs 3D). Flap thickness measured at 13 different points resulted in no statistically significant differences between any of the measurement points within/between both groups; demonstrating good planarity of the flap was achieved using both methods. Despite not being statistically significant, the surgeons recognized an increase in the presence of an opaque bubble layer in the 3D flap eyes during surgery and some patients reported higher, yet not statistically significant, pain scores in the 3D flap eyes during the first hours after the treatment. Overall, safety- and efficacy indices were 1.03 and 1.03, respectively.
Conclusion: In this prospective, randomized, contralateral eye study, the low-energy fs laser yielded predictable lamellar flap thicknesses and geometry at one-month followup. Based on these results, efficacy and safety of the corresponding laser application, that is, 2D vs 3D, are equivalent

Keywords:

Cornea, Femtosecond Laser, Flap Morphology, LASIK, Refractive Surgery

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