title: Cell death and ultrastructural morphology of femtosecond laser-assisted anterior capsulotomy.
abstract: OBJECTIVE
  To evaluate cell death and ultrastructural effects on capsulotomy specimens derived from femtosecond laser-assisted cataract surgery.
  
  
  METHODS
  In 26 eyes, an anterior capsulotomy was performed using a femtosecond laser. In 10 eyes (group 1), the laser-pulse energy was set to 15 μJ using a rigid curved interface and in another 10 eyes (group 2) to 5 μJ using a curved interface combined with a soft contact lens. The control group (6 eyes, group 3) underwent manual anterior capsulorhexis using forceps. All extracted capsule specimens underwent cell death analysis using the TUNEL kit, ultrastructural analyses using atomic force microscopy (AFM), and scanning electron microscopy (SEM). Counterstaining was performed with 4',6-diamidino-2-phenylindol (DAPI) and hematoxylin-eosin (HE).
  
  
  RESULTS
  Cell death was found in all capsule specimens along the cutting edge but was significantly more pronounced in group 1. DAPI and HE staining showed regular epithelial cell distribution with a demarcation line along the cutting edge of both laser groups, which was more pronounced in group 1. In AFM analysis, laser spot size in the femtosecond laser groups were in accordance with the preoperative planned size (P < 0.01). Cutting edges in SEM observations were smoother and more roundly shaped using 5 μJ (group 2).
  
  
  CONCLUSIONS
  Cutting edges of femtosecond laser-performed capsulotomies are precise and laser spot lesions are within planned size. Cell death reaction depends on the laser pulse energy settings and can be reduced to the level observed in a manual capsulorhexis.
authors.affiliation: Department of Ophthalmology, Goethe-University, Frankfurt am Main, Germany.
authors.forename: Wolfgang J
authors.initials: WJ
authors.lastname: Mayer
authors.forename: Oliver K
authors.initials: OK
authors.lastname: Klaproth
authors.forename: Marko
authors.initials: M
authors.lastname: Ostovic
authors.forename: Andreas
authors.initials: A
authors.lastname: Terfort
authors.forename: Thalia
authors.initials: T
authors.lastname: Vavaleskou
authors.forename: Fritz H
authors.initials: FH
authors.lastname: Hengerer
authors.forename: Thomas
authors.initials: T
authors.lastname: Kohnen
mesh_terms: D057866:Anterior Capsule of the Lens / Q000601:surgery* / Q000648:ultrastructure*; D019923:Capsulorhexis; D016923:Cell Death; D004847:Epithelial Cells / Q000648:ultrastructure*; D006801:Humans; D020287:In Situ Nick-End Labeling; D053685:Laser Therapy; D007908:Lens, Crystalline / Q000648:ultrastructure*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D018918:Phacoemulsification / Q000379:methods*
keywords: apoptosis; atomic force microscopy; capsulorhexis; capsulotomy; cell death; femtosecond laser; laser energy; scanning electron microscopy