title: Penetrating and Intrastromal Corneal Arcuate Incisions in Rabbit and Human Cadaver Eyes: Manual Diamond Blade and Femtosecond Laser-Created Incisions.
abstract: OBJECTIVE
  To compare morphologic differences between freehand diamond or femtosecond laser-assisted penetrating and intrastromal arcuate incisions.
  
  
  METHODS
  Freehand diamond blade, corneal arcuate incisions (180° apart, 60° arc lengths) and 150 kHz femtosecond laser (80% scheimpflug pachymetry depth corneal thickness) arcuate incisions were performed in rabbits. Intrastromal arcuate incisions (100 μm above Descemet's membrane, 100 μm below epithelium) were performed in rabbit corneas (energy 1.2 μJ, spot line separation 3 × 3 μm, 90° side cut angle). Eyes were examined by slit lamp and light microscopy up to 47 days post-procedure. Freehand diamond blade penetrating incisions, and femtosecond laser penetrating and intrastromal arcuate incisions (energy 1.8 μJ, spot line separation 2 × 2 μm) were performed in cadaver eyes. Optical coherence tomography was performed immediately after surgery and the corneas were fixed for light scanning and transmission electron microscopy.
  
  
  RESULTS
  The rabbit model showed anterior stromal inflammation with epithelial hyperplasia in penetrating blade and laser penetrating wounds. The laser intrastromal and penetrating incisions showed localized constriction of the stromal layers of the cornea near the wound. In cadaver eyes, penetrating wound morphology was similar between blade and laser whereas intrastromal wounds did not affect the cornea above or below incisions.
  
  
  CONCLUSIONS
  Penetrating femtosecond laser arcuate incisions have more predictable and controlled outcomes shown by less post-operative scarring than incisions performed with a diamond blade. Intrastromal incisions do not affect uncut corneal layers as demonstrated by histopathology. The femtosecond laser has significant advantages in its ability to make intrastromal incisions which are not achievable by traditional freehand or mechanical diamond blades.
authors.affiliation: Employee of Abbott Medical Optics Inc. (B.G., L.C.H., J.H., M.S.-S.), Santa Ana, CA; Gavin Herbert Eye Institute (P.S.B., A.G.), University of California Irvine, Irvine, CA; and Consultant for Abbott Medical Optics Inc. (P.S.B., A.G.), Santa Ana, CA.
authors.forename: Brad
authors.initials: B
authors.lastname: Gray
authors.forename: Perry S
authors.initials: PS
authors.lastname: Binder
authors.forename: Ling C
authors.initials: LC
authors.lastname: Huang
authors.forename: Jim
authors.initials: J
authors.lastname: Hill
authors.forename: Mercedes
authors.initials: M
authors.lastname: Salvador-Silva
authors.forename: Arlene
authors.initials: A
authors.lastname: Gwon
mesh_terms: D000818:Animals; D002102:Cadaver; D002921:Cicatrix; D055954:Corneal Endothelial Cell Loss / Q000209:etiology / Q000473:pathology; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000473:pathology / Q000601:surgery*; D048988:Corneal Surgery, Laser / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D004728:Endothelium, Corneal / Q000473:pathology / Q000601:surgery; D006801:Humans; D006965:Hyperplasia / Q000209:etiology / Q000473:pathology; D007646:Keratotomy, Radial / Q000295:instrumentation*; D008854:Microscopy, Electron; D011817:Rabbits; D000072776:Slit Lamp Microscopy; D013525:Surgical Instruments / Q000009:adverse effects; D000072836:Surgical Wound / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D041623:Tomography, Optical Coherence; D014945:Wound Healing