title: Corneal stromal ablation with femtosecond ultraviolet pulses in rabbits.
abstract: OBJECTIVE
  To determine the effectiveness of femtosecond ultraviolet (UV) pulses in ablating corneal stroma in a rabbit model and to compare the healing response between eyes treated with femtosecond UV pulses and eyes treated with standard excimer photorefractive keratectomy.
  
  
  METHODS
  Laser Research Center, Vilnius University, Vilnius, Lithuania.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Myopic photoablation using a femtosecond UV solid-state laser system was applied to corneas of pigmented rabbits. Experiments in 16 eyes were performed for optimization of the laser system parameters (fluence, spot size, pulse repetition rate) and calibration of ablation rate. In 7 rabbits, deep femtosecond UV ablation (∼130 μm) in 1 eye and shallow ablation (∼30 μm) in the contralateral eye were performed. Nine rabbits received an approximately 30 μm ablation with femtosecond UV pulses in 1 eye and with a conventional excimer system in the contralateral eye. Two eyes were used as controls. The ablation process and surface-temperature dynamics were monitored and recorded. Surface quality and haze development were evaluated. Rabbits were humanely killed 0 to 6 months after surgery, and eyes were enucleated for histological examination.
  
  
  RESULTS
  Rabbit corneas ablated with femtosecond UV pulses or excimer laser radiation were similar in terms of the corneal wound-healing process, surface quality, and histology.
  
  
  CONCLUSIONS
  The experiments indicate the feasibility of clinical application of femtosecond UV lasers for stromal ablation. The ability to switch between laser harmonics allows fast changeover from infrared to the UV mode, implying that a wide range of ophthalmic procedures can be performed using a single solid-state laser device.
  
  
  BACKGROUND
  Ms. Gabryte and Mr. Danielius are paid employees of Light Conversion Ltd. Mr. Danielius is a shareholder of Light Conversion Ltd. No other author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: egle.danieliene@akiugydytojai.lt
authors.forename: Egle
authors.initials: E
authors.lastname: Danieliene
authors.forename: Egle
authors.initials: E
authors.lastname: Gabryte
authors.forename: Romualdas
authors.initials: R
authors.lastname: Danielius
authors.forename: Mikas
authors.initials: M
authors.lastname: Vengris
authors.forename: Agne
authors.initials: A
authors.lastname: Vaiceliunaite
authors.forename: Vaidotas
authors.initials: V
authors.lastname: Morkunas
authors.forename: Osvaldas
authors.initials: O
authors.lastname: Ruksenas
mesh_terms: D000818:Animals; D001831:Body Temperature; D003318:Corneal Opacity / Q000503:physiopathology; D003319:Corneal Stroma / Q000473:pathology / Q000601:surgery*; D004195:Disease Models, Animal; D054018:Lasers, Excimer / Q000627:therapeutic use; D053844:Lasers, Solid-State / Q000009:adverse effects / Q000627:therapeutic use*; D009216:Myopia / Q000601:surgery*; D018903:Photorefractive Keratectomy; D011817:Rabbits; D014466:Ultraviolet Rays; D014945:Wound Healing / Q000502:physiology