title: Effect of a suction device for femtosecond laser on anterior chamber depth and crystalline lens position measured by OCT.
abstract: OBJECTIVE
  To investigate the position and stability of the crystalline lens after application of a suction device containing a contact lens and a vacuum unit for the treatment of presbyopia using a femtosecond laser.
  
  
  METHODS
  Twenty presbyopic (44.4+/-4.3 years) and 5 pre-presbyopic patients (31.6+/-3.8 years) were included. The anterior chamber depth, along with the position of the lens, was investigated before and after application of the suction device with optical coherence tomography (Visante OCT; Carl Zeiss Meditec AG). The type of suction device is routinely used for femtosecond LASIK with the VisuMax laser (Carl Zeiss Meditec AG).
  
  
  RESULTS
  In both groups, there was a reduction in anterior chamber depth of approximately 700 microm due to the suction device, and the anterior chamber depth achieved was stable. The maximum variation was 160 microm. At the periphery of the crystalline lens, there were movements up to 310 microm axially and 470 microm laterally.
  
  
  CONCLUSIONS
  The study proves that once the suction device has been applied, the crystalline lens is stable enough to undergo presbyopic laser therapy. However, the reduction in anterior chamber depth induced by the suction device showed significant individual variation. The exact position of the lens should therefore be measured immediately before laser surgery.
authors.affiliation: Department of Ophthalmology, Helios Klinikum Erfurt, Erfurt, Germany. kathleen.kunert@helios-kliniken.de
authors.forename: Kathleen S
authors.initials: KS
authors.lastname: Kunert
authors.forename: Marcus
authors.initials: M
authors.lastname: Blum
authors.forename: Matthias
authors.initials: M
authors.lastname: Reich
authors.forename: Manfred
authors.initials: M
authors.lastname: Dick
authors.forename: Christoph
authors.initials: C
authors.lastname: Russmann
mesh_terms: D000328:Adult; D000867:Anterior Chamber / Q000473:pathology*; D005260:Female; D006801:Humans; D054018:Lasers, Excimer / Q000627:therapeutic use*; D007908:Lens, Crystalline / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011305:Presbyopia / Q000601:surgery*; D011446:Prospective Studies; D013396:Suction / Q000295:instrumentation*; D041623:Tomography, Optical Coherence