title: Quality of corneal lamellar cuts quantified using atomic force microscopy.
abstract: OBJECTIVE
  To quantify the cut quality of lamellar dissections made with the femtosecond laser using atomic force microscopy (AFM).
  
  
  METHODS
  Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Experiments were performed on 3 pairs of human cadaver eyes. The cornea was thinned to physiologic levels by placing the globe, cornea side down, in 25% dextran for 24 hours. The eyes were reinflated to normal pressures by injecting a balanced salt solution into the vitreous cavity. The eyes were placed in a holder, the epithelium was removed, and the eyes were cut with a Visumax femtosecond laser. The energy level was 180 nJ for the right eye and 340 nJ for the left eye of each pair. The cut depths were 200 μm, 300 μm, and 400 μm, with the cut depth maintained for both eyes of each pair. A 12.0 mm trephination was then performed. The anterior portion of the lamellar surface was placed in a balanced salt solution and imaged with AFM. As a control, the posterior surface was placed in 2% formalin and imaged with environmental scanning electron microscopy (SEM). Four quantitative parameters (root-mean-square deviation, average deviation, skewness, kurtosis) were calculated from the AFM images.
  
  
  RESULTS
  From AFM, the 300 μm low-energy cuts were the smoothest. Similar results were seen qualitatively in the environmental SEM images.
  
  
  CONCLUSIONS
  Atomic force microscopy provided quantitative information on the quality of lamellar dissections made using a femtosecond laser, which is useful in optimizing patient outcomes in refractive and lamellar keratoplasty surgeries.
authors.affiliation: From the Biomedical Atomic Force Microscopy Laboratory (Ziebarth, Dias), Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, and the Bascom Palmer Eye Institute (Hürmeriç, Shousha, Culbertson, Yoo) and the Department of Physiology and Biophysics (Yau, Moy), University of Miami Miller School of Medicine, Miami, Florida, USA. Electronic address: nziebarth@miami.edu.
authors.forename: Noël M
authors.initials: NM
authors.lastname: Ziebarth
authors.affiliation: From the Biomedical Atomic Force Microscopy Laboratory (Ziebarth, Dias), Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, and the Bascom Palmer Eye Institute (Hürmeriç, Shousha, Culbertson, Yoo) and the Department of Physiology and Biophysics (Yau, Moy), University of Miami Miller School of Medicine, Miami, Florida, USA.
authors.forename: Janice
authors.initials: J
authors.lastname: Dias
authors.affiliation: From the Biomedical Atomic Force Microscopy Laboratory (Ziebarth, Dias), Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, and the Bascom Palmer Eye Institute (Hürmeriç, Shousha, Culbertson, Yoo) and the Department of Physiology and Biophysics (Yau, Moy), University of Miami Miller School of Medicine, Miami, Florida, USA.
authors.forename: Volkan
authors.initials: V
authors.lastname: Hürmeriç
authors.affiliation: From the Biomedical Atomic Force Microscopy Laboratory (Ziebarth, Dias), Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, and the Bascom Palmer Eye Institute (Hürmeriç, Shousha, Culbertson, Yoo) and the Department of Physiology and Biophysics (Yau, Moy), University of Miami Miller School of Medicine, Miami, Florida, USA.
authors.forename: Mohamed Abou
authors.initials: MA
authors.lastname: Shousha
authors.affiliation: From the Biomedical Atomic Force Microscopy Laboratory (Ziebarth, Dias), Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, and the Bascom Palmer Eye Institute (Hürmeriç, Shousha, Culbertson, Yoo) and the Department of Physiology and Biophysics (Yau, Moy), University of Miami Miller School of Medicine, Miami, Florida, USA.
authors.forename: Chiyat Ben
authors.initials: CB
authors.lastname: Yau
authors.affiliation: From the Biomedical Atomic Force Microscopy Laboratory (Ziebarth, Dias), Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, and the Bascom Palmer Eye Institute (Hürmeriç, Shousha, Culbertson, Yoo) and the Department of Physiology and Biophysics (Yau, Moy), University of Miami Miller School of Medicine, Miami, Florida, USA.
authors.forename: Vincent T
authors.initials: VT
authors.lastname: Moy
authors.affiliation: From the Biomedical Atomic Force Microscopy Laboratory (Ziebarth, Dias), Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, and the Bascom Palmer Eye Institute (Hürmeriç, Shousha, Culbertson, Yoo) and the Department of Physiology and Biophysics (Yau, Moy), University of Miami Miller School of Medicine, Miami, Florida, USA.
authors.forename: William W
authors.initials: WW
authors.lastname: Culbertson
authors.affiliation: From the Biomedical Atomic Force Microscopy Laboratory (Ziebarth, Dias), Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, and the Bascom Palmer Eye Institute (Hürmeriç, Shousha, Culbertson, Yoo) and the Department of Physiology and Biophysics (Yau, Moy), University of Miami Miller School of Medicine, Miami, Florida, USA.
authors.forename: Sonia H
authors.initials: SH
authors.lastname: Yoo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D003319:Corneal Stroma / Q000601:surgery* / Q000648:ultrastructure*; D016039:Corneal Transplantation; D004210:Dissection / Q000379:methods*; D006801:Humans; D053685:Laser Therapy / Q000379:methods*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D010865:Pilot Projects; D014019:Tissue Donors