title: Deep Laser-Assisted Lamellar Anterior Keratoplasty With Microkeratome-Cut Grafts.
abstract: OBJECTIVE
  The goals of this laboratory study were to evaluate the interface quality in laser-assisted lamellar anterior keratoplasty (LALAK) with microkeratome-cut grafts and achieve good graft-host apposition.
  
  
  METHODS
  Simulated LALAK surgeries were performed on 6 pairs of eye-bank corneoscleral discs. Anterior lamellar grafts were precut with microkeratomes. Deep femtosecond (FS) laser cuts were performed on host corneas followed by excimer laser smoothing. Different parameters of FS laser cuts and excimer laser smoothing were tested. Optical coherence tomography was used to measure corneal pachymetry and evaluate graft-host apposition. The interface quality was quantified in a masked fashion using a 5-point scale based on scanning electron microscopy images.
  
  
  RESULTS
  Deep FS laser cuts at 226 to 380 μm resulted in visible ridges on the host bed. Excimer laser smoothing with a central ablation depth of 29 μm and saline as a smoothing agent did not adequately reduce ridges (score = 4.0). Deeper excimer laser ablation of 58 μm and Optisol-GS as a smoothing agent smoothed ridges to an acceptable level (score = 2.1). Same sizing of the graft and host cut diameters with an approximately 50-μm deeper host side cut relative to the central graft thickness provided the best graft-host fit.
  
  
  CONCLUSIONS
  Deep excimer laser ablation with a viscous smoothing agent was needed to remove ridges after deep FS lamellar cuts. The host side cut should be deep enough to accommodate thicker graft peripheral thickness compared with the center. This LALAK design provides smooth lamellar interfaces, moderately thick grafts, and good graft-host fits.
authors.affiliation: *Center for Ophthalmic Optics & Lasers, Casey Eye Institute and Department of Ophthalmology, Oregon Health & Science University, Portland, OR; and†Department of Ophthalmology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yokogawa
authors.forename: Maolong
authors.initials: M
authors.lastname: Tang
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Liang
authors.initials: L
authors.lastname: Liu
authors.forename: Winston
authors.initials: W
authors.lastname: Chamberlain
authors.forename: David
authors.initials: D
authors.lastname: Huang
mesh_terms: D003315:Cornea / Q000601:surgery* / Q000648:ultrastructure; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000033:anatomy & histology; D016039:Corneal Transplantation / Q000379:methods*; D005125:Eye Banks; D005583:Fourier Analysis; D006801:Humans; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008855:Microscopy, Electron, Scanning; D012590:Sclera / Q000601:surgery* / Q000648:ultrastructure; D014019:Tissue Donors; D041623:Tomography, Optical Coherence