title: Biometry of cataractous eyes using partial coherence interferometry: clinical feasibility study of a commercial prototype I.
abstract: OBJECTIVE
  To evaluate the clinical feasibility of the prototype version of a commercial partial coherence interferometry instrument (axial length measurement, ALM, Carl Zeiss Jena) for noninvasive, high-precision biometry in cataractous eyes.
  
  
  METHODS
  Department of Ophthalmology, Vienna General Hospital, and Institute of Medical Physics, University of Vienna, Austria.
  
  
  METHODS
  The preoperative axial length in 49 eyes of 37 cataract patients was measured with the commercial (ALM) and laboratory (PCI) prototypes of the partial coherence interferometry instrument, as well as with immersion ultrasound (IUS).
  
  
  RESULTS
  Axial length measurements with the ALM and PCI did not differ significantly (P = .23). Both prototypes assessed longer axial lengths than the IUS technique (P < .0001; median 203 microm; range -476 to +635 microm). The precision of the axial length measurement was 18 microm, 28 microm, and 54 microm with the PCI, ALM, and IUS, respectively.
  
  
  CONCLUSIONS
  Partial coherence tomography is a high-precision, high-resolution, noncontact biometric technique.The commercial PCI prototype is practical in clinical use, with improved comfort for patients, no need for anesthesia, and a reduced risk of infection. However, the difference between the PCI and IUS in axial length measurement must be considered when using the constants supplied by intraocular lens (IOL) manufacturers for IOL power calculations.
authors.affiliation: Universitätsklinik für Augenheilkunde, Allgemeines Krankenhaus Wien, Vienna, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Kiss
authors.forename: Oliver
authors.initials: O
authors.lastname: Findl
authors.forename: Rupert
authors.initials: R
authors.lastname: Menapace
authors.forename: Matthias
authors.initials: M
authors.lastname: Wirtitsch
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Drexler
authors.forename: Christoph K
authors.initials: CK
authors.lastname: Hitzenberger
authors.forename: Adolf F
authors.initials: AF
authors.lastname: Fercher
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry / Q000379:methods*; D001699:Biometry / Q000379:methods*; D002386:Cataract / Q000000981:diagnostic imaging / Q000473:pathology*; D005123:Eye / Q000000981:diagnostic imaging / Q000473:pathology*; D005240:Feasibility Studies; D006801:Humans; D007368:Interferometry / Q000295:instrumentation / Q000379:methods*; D008027:Light; D008875:Middle Aged; D014463:Ultrasonography