title: Intraocular lens power calculation using IOLMaster and various formulas in short eyes.
abstract: OBJECTIVE
  To evaluate the predictability of intraocular lens (IOL) power calculations using the IOLMaster and four different IOL power calculation formulas (Haigis, Hoffer Q, SRK II, and SRK/T) for cataract surgery in eyes with a short axial length (AL).
  
  
  METHODS
  The present study was a retrospective comparative analysis which included 25 eyes with an AL shorter than 22.0 mm that underwent uneventful phacoemulsification with IOL implantation from July 2007 to December 2008 at Seoul National University Boramae Hospital. Preoperative AL and keratometric power were measured by the IOLMaster, and power of the implanted IOL was determined using Haigis, Hoffer Q, SRK II, and SRK/T formulas. Postoperative refractive errors two months after surgery were measured using automatic refracto-keratometry (Nidek) and were compared with the predicted postoperative power. The mean absolute error (MAE) was defined as the average of the absolute value of the difference between actual and predicted spherical equivalences of postoperative refractive error.
  
  
  RESULTS
  The MAE was smallest with the Haigis formula (0.37 ± 0.26 diopter [D]), followed by those of SRK/T (0.53 ± 0.25 D), SRK II (0.56 ± 0.20 D), and Hoffer Q (0.62 ± 0.16 D) in 25 eyes with an AL shorter than 22.0 mm. The proportion with an absolute error (AE) of less than 1 D was greatest in the Haigis formula (96%), followed by those in the SRK II (88%), SRK-T (84%), and Hoffer Q (80%).
  
  
  CONCLUSIONS
  The MAE was less than 0.7 D and the proportion of AE less than 1 D was more than 80% in all formulas. The IOL power calculation using the Haigis formula showed the best results for postoperative power prediction in short eyes.
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Young Rae
authors.initials: YR
authors.lastname: Roh
authors.forename: Sang Mok
authors.initials: SM
authors.lastname: Lee
authors.forename: Young Keun
authors.initials: YK
authors.lastname: Han
authors.forename: Mee Kum
authors.initials: MK
authors.lastname: Kim
authors.forename: Won Ryang
authors.initials: WR
authors.lastname: Wee
authors.forename: Jin Hak
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D055095:Optics and Photonics; D018918:Phacoemulsification; D011184:Postoperative Period; D012030:Refractive Errors / Q000175:diagnosis / Q000503:physiopathology; D012189:Retrospective Studies