title: Accuracy of intraocular lens power calculation using partial coherence interferometry in patients with high myopia.
abstract: OBJECTIVE
  Ultrasound-A-scan-biometry intraocular lens power calculation for cataract surgery sometimes shows lack of accuracy in patients with high myopia. The purpose of this retrospective study was to assess the accuracy of lens power calculation with optical biometry using the Zeiss IOLMaster across a large range of myopia levels.
  
  
  METHODS
  We included 37 consecutive, myopic eyes with an axial length >26.5mm (31 patients, 62±13years old, average preoperative refraction of -14.46±6.61D, range -3.5 to -32.0D which underwent phacoemulsification and implantation of an intraocular lens following biometry using the IOLMaster. For lens power calculation, the Haigis formula was used in all cases. For comparison, refraction was back-calculated using the SRK/T and Holladay I formulae.
  
  
  RESULTS
  The preoperative mean axial length was 29.37±2.44 mm with a range of 26.50-35.52mm. Thirty eyes (81.1%) showed a postoperative spherical equivalent which differed 1.00D or less from the predicted value, in 20 cases (54.1%) the postoperative refractive error was within±0.50D. The mean absolute error (MAE) was 0.70±0.59D (Holladay I, 0.85±0.68; SRK/T, 1.01±0.61D).
  
  
  CONCLUSIONS
  Optical biometry for intraocular lens power calculation seems to deliver reliable results for cataract surgery in patients with high myopia, although our data describe an increasing lack of accuracy beyond an axial length of 30mm. The Haigis formula provided the best predictability of postoperative refractive outcome for myopic eyes in general.
authors.affiliation: Department of Ophthalmology, RWTH Technical University of Aachen, Aachen Department of Ophthalmology, University of Cologne, Cologne, Germany. gf.roessler@gmx.de
authors.forename: Gernot F
authors.initials: GF
authors.lastname: Roessler
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Dietlein
authors.forename: Niklas
authors.initials: N
authors.lastname: Plange
authors.forename: Anna-Katharina
authors.initials: AK
authors.lastname: Roepke
authors.forename: Sven
authors.initials: S
authors.lastname: Dinslage
authors.forename: Peter
authors.initials: P
authors.lastname: Walter
authors.forename: Babac A
authors.initials: BA
authors.lastname: Mazinani
mesh_terms: D000368:Aged; D001699:Biometry / Q000379:methods; D002386:Cataract / Q000150:complications; D006801:Humans; D007368:Interferometry / Q000379:methods; D019654:Lens Implantation, Intraocular / Q000379:methods; D007910:Lenses, Intraocular; D008875:Middle Aged; D009216:Myopia / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D018918:Phacoemulsification / Q000379:methods*; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology