In Vivo Prediction of Air-Puff Induced Corneal Deformation Using LASIK, SMILE, and PRK Finite Element Simulations

Mathew Francis*, Pooja Khamar, Rohit Shetty, Kanchan Sainani, Rudy M. M. A. Nuijts, Bart Haex, Abhijit Sinha Roy

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

17 Citations (Web of Science)

Abstract

PURPOSE. To simulate deformation amplitude after laser-assisted in situ keratomileusis (LASIK), small incision lenticule extraction (SMILE), and photorefractive keratectomy (PRK) with finite element models.

METHODS. Finite element simulations of air-puff applanation on LASIK, SMILE, and PRK models were performed on a cohort of normal eyes, which had undergone refractive treatments. Short-and long-term wound healing responses were considered for SMILE and LASIK models based on evidence of microdistortions in Bowman's layer and crimping of collagen fibers. First, inverse simulations were performed to derive the preoperative properties of the cornea. Using these properties and planned refractive treatment, postoperative air-puff deformation amplitude was predicted and compared with the in vivo measurements.

RESULTS. The predicted postoperative corneal stiffness parameters agreed very well with in vivo values of SMILE, LASIK, and PRK eyes. Intraclass correlations (ICC) were greatest in PRK eyes (ICC > 0.95). This agreement was lower for peak deformation amplitude and peak deflection amplitude in SMILE and LASIK eyes (ICC <0.9). In PRK eyes, peak deformation and deflection amplitude predictions were the best relative to in vivo magnitudes. Also, linear correlation (r) between in vivo measurement and predicted biomechanical parameters indicated strong agreement between them (SMILE: r >= 0.89, LASIK: r >= 0.83, PRK: r >= 0.87).

CONCLUSIONS. The is the first study to present predictive simulations of corneal deformation changes after different procedures. Patient-specific preoperative corneal biomechanical properties and finite element models were a significant determinant of accurate postoperative deformation amplitude prediction.

Original languageEnglish
Pages (from-to)5320-5328
Number of pages9
JournalInvestigative Ophthalmology & Visual Science
Volume59
Issue number13
DOIs
Publication statusPublished - Nov 2018

Keywords

  • cornea
  • SMILE
  • LASIK
  • PRK
  • finite
  • element modeling
  • prediction
  • INCISION LENTICULE EXTRACTION
  • LASER-ASSISTED LASIK
  • REFRACTIVE SURGERY
  • BIOMECHANICAL PROPERTIES
  • SCHEIMPFLUG TECHNOLOGY
  • SITU KERATOMILEUSIS
  • TENSILE-STRENGTH
  • TONOMETRY
  • STIFFNESS
  • MYOPIA

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