title: [In vitro and in vivo investigations on the treatment of presbyopia using femtosecond lasers].
abstract: BACKGROUND
  Ultrashort (femtosecond) laser pulses can generate precise cuts in biological tissue without damaging the surface. The application of femtosecond laser technology at the lens was evaluated with respect to a possible treatment of presbyopia.
  
  
  METHODS
  Femtosecond laser lentotomy was performed on 150 pig lenses in vitro. Cutting geometry and laser settings were optimized to generate smooth cuts with a minimum of produced gas bubbles. Four rabbit lenses were treated afterwards in vivo and were controlled for 3 months post-treatment. The lenses were then extracted and evaluated.
  
  
  RESULTS
  With suitable laser settings, light scattering due to residual gas bubbles could be almost completely avoided in pig lenses. A pulse energy of less than 1.2 microJ and a cutting geometry with spot separations of more than 5 microm are important. The rabbit lenses stayed macroscopically clear for 3 months in vivo. Only the cell structures directly adjacent to the laser focus were cut; structures 5-10 microm away appeared to be intact. No cataract formation occurred during this time.
  
  
  CONCLUSIONS
  Femtosecond laser application allows precise and smooth cuts inside pig and rabbit lenses without damage to adjacent tissue.
authors.affiliation: Laserforum Köln e.V., Augenklinik am Neumarkt, Schildergasse 107, 109, 50667, Köln, Germany. info@augenportal.de
authors.forename: G
authors.initials: G
authors.lastname: Gerten
authors.forename: T
authors.initials: T
authors.lastname: Ripken
authors.forename: P
authors.initials: P
authors.lastname: Breitenfeld
authors.forename: R R
authors.initials: RR
authors.lastname: Krueger
authors.forename: O
authors.initials: O
authors.lastname: Kermani
authors.forename: H
authors.initials: H
authors.lastname: Lubatschowski
authors.forename: U
authors.initials: U
authors.lastname: Oberheide
mesh_terms: D000818:Animals; D004867:Equipment Design; D019544:Equipment Failure Analysis; D053685:Laser Therapy / Q000295:instrumentation* / Q000379:methods; D007908:Lens, Crystalline / Q000473:pathology* / Q000601:surgery*; D011305:Presbyopia / Q000473:pathology* / Q000601:surgery*; D013552:Swine; D016896:Treatment Outcome