title: [Morphological analysis of corneal refractive lenticules--is there a correlation with refractive results?].
abstract: BACKGROUND
  ReLEx®flex is a corneal refractive procedure performed by removing corneal lenticules with a femtosecond (fs) laser system. Using electron microscopy, tissue parameters of extracted lenticules were analysed for potential correlations to the refractive results. Furthermore, the effect of previous contact lens (CL) wear on refractive stability (regression) was tested.
  
  
  METHODS
  19 lenticules from 11 patients (age 24-56 years, 8 f, 3 m) were prepared for EM. The central areas of the samples were photographed and the distance between the collagen fibres and their diameters were digitally measured. ANOVA analysis was used to correlate postoperative refractional stability with time of preoperative CL use, fibre diameter and the coefficient of variation (CV) of fibre distance.
  
  
  RESULTS
  14 of 19 lenticules were from patients who had worn CL preoperatively. The cumulative duration of CL wear averaged around 31.2 ± 35.5 thousand hours. Preoperative CL use significantly influenced the postoperative regression: the longer time patients had worn CL, the greater was the regression towards myopia (p = 0.01). Additionally, the morphological parameters collagen fibre diameter (p = 0.09) and CV of fibre distance (p = 0.07) had an impact on regression.
  
  
  CONCLUSIONS
  Prolonged CL use and alterations in ultrastructural patterns affected the refractive stability after ReLExflex. Although the pathophysiological relationships between CL use, corneal morphological parameters, and refractive stability are still poorly understood, these findings could potentially be used as prognostic markers for postoperative refraction after ReLExflex.
authors.affiliation: Klinik für Augenheilkunde, Universitätsklinikum, Albert-Ludwigs-Universität Freiburg im Breisgau.
authors.forename: T
authors.initials: T
authors.lastname: Lapp
authors.affiliation: Klinik für Augenheilkunde, Universitätsklinikum, Albert-Ludwigs-Universität Freiburg im Breisgau.
authors.forename: C
authors.initials: C
authors.lastname: Auw-Hädrich
authors.affiliation: Klinik für Augenheilkunde, Universitätsklinikum, Albert-Ludwigs-Universität Freiburg im Breisgau.
authors.forename: F
authors.initials: F
authors.lastname: Sadler
authors.affiliation: Klinik für Augenheilkunde, Universitätsklinikum, Albert-Ludwigs-Universität Freiburg im Breisgau.
authors.forename: D
authors.initials: D
authors.lastname: Böhringer
authors.affiliation: Augenklinik, Helios Klinikum Erfurt.
authors.forename: M
authors.initials: M
authors.lastname: Blum
authors.affiliation: Klinik für Augenheilkunde, Universitätsklinikum, Albert-Ludwigs-Universität Freiburg im Breisgau.
authors.forename: T
authors.initials: T
authors.lastname: Reinhard
authors.affiliation: Klinik für Augenheilkunde, Universitätsklinik Halle.
authors.forename: J
authors.initials: J
authors.lastname: Heichel
authors.affiliation: Augenklinik, Helios Klinikum Erfurt.
authors.forename: K S
authors.initials: KS
authors.lastname: Kunert
mesh_terms: D000328:Adult; D003261:Contact Lenses; D003319:Corneal Stroma / Q000473:pathology* / Q000601:surgery*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D020287:In Situ Nick-End Labeling; D066298:In Vitro Techniques; D020731:Keratomileusis, Laser In Situ / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D011183:Postoperative Complications / Q000473:pathology / Q000503:physiopathology; D012029:Refraction, Ocular / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013223:Statistics as Topic; D014792:Visual Acuity / Q000502:physiology