title: Comparison of a new optical biometry with an optical low-coherence reflectometry for ocular biometry.
abstract: OBJECTIVE
  To evaluate the repeatability and agreement of a new partial coherence interferometry optical biometer (AL-Scan, Nidek CO, Aichi, Japan) with optical low-coherence reflectometry device (Lenstar LS 900, Haag-Streit AG, Köniz, Switzerland).
  
  
  METHODS
  Three consecutive measurements with the 2 devices were performed by the same examiner in 65 eyes of 65 patients with cataract. Patients were divided into 2 groups: axial length (AL) between 22 and 26mm (Group 1) and more than 26mm (Group 2). Comparisons were performed for AL, anterior chamber depth (ACD), keratometry (K, over 2.4mm diameter for AL-Scan and 2.3mm diameter for Lenstar) and corneal diameter (CD). Repeatability was analyzed using the intraclass correlation coefficient (ICC) and the agreement was by the Bland-Altman method.
  
  
  RESULTS
  The repeatability of both devices was high for all biometry measurements (ICC over 0.970) in Group 1 and 2. The best repeatability was achieved for AL in each group. In both groups, the differences were statistically significant for all parameters (p<0.05) except for the measurement of AL and CCT (p>0.05). The Bland-Altman analysis showed good agreement between devices for all measurements in both groups. The closest agreement was for the AL measurements (ranged from -0.06 to 0.08mm in Group 1 and -0.05-0.07mm in Group 2).
  
  
  CONCLUSIONS
  The new biometer provided excellent repeatability for all ocular biometry. In addition, there was good agreement between AL-Scan and Lenstar biometers for all parameters in cataractous patients with medium and long ALs.
authors.affiliation: Türkiye Hospital, Eye Clinic, İstanbul, Turkey. Electronic address: guleremre83@hotmail.com.
authors.forename: Emre
authors.initials: E
authors.lastname: Güler
authors.affiliation: Boğazlıyan State Hospital, Eye Clinic, Yozgat, Turkey.
authors.forename: Ali Ender
authors.initials: AE
authors.lastname: Kulak
authors.affiliation: Turgut Özal University, Medical School, Department of Ophthalmology, Ankara, Turkey.
authors.forename: Yüksel
authors.initials: Y
authors.lastname: Totan
authors.affiliation: Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey.
authors.forename: Armağan
authors.initials: A
authors.lastname: Yuvarlak
authors.affiliation: Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey.
authors.forename: İbrahim Feyzi
authors.initials: İF
authors.lastname: Hepşen
mesh_terms: D000328:Adult; D000368:Aged; D000867:Anterior Chamber / Q000473:pathology* / Q000601:surgery; D001699:Biometry / Q000295:instrumentation*; D002386:Cataract / Q000175:diagnosis / Q000473:pathology*; D002387:Cataract Extraction; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular / Q000379:methods; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010783:Photometry / Q000295:instrumentation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000295:instrumentation*
keywords: AL-Scan; Agreement; Cataract; Lenstar; Repeatability