title: [Selection of accurate IOL formula in patients with cataract and high hyperopia].
abstract: OBJECTIVE
  To audit intraocular lens (IOL) power predictions for cataract surgery in high hyperopia by comparing the accuracy of different formulae of Haigis, SRKII, Hoffer Q, Hollady, and SRK/T.
  
  
  METHODS
  A comparative study was used in 31 eyes with cataract and high hyperopia underwent phacoemulsification and posterior chamber IOL implantation. Eyes were examined with A-scan and IOL Master before the operation. Postoperative refraction was examined 3 months after surgery. We compared the accuracy of prediction between these different formulae using IOL Master, and then compared the errors using the two different methods for axial length measurement.
  
  
  RESULTS
  (1) Using IOL Master, the Haigis formula showed the smallest mean prediction errors (0.37 +/- 0.14), followed by the Hoffer Q, Holladay, SRK/T, and SRK II formulae (-0.70 +/- 0.12, -0.97 +/- 0.15, -1.25 +/- 0.14, -1.46 +/- 0.13). The Haigis formula generated a slightly myopic result, but the other formulae generated hyperopic result at different degrees. (2) The A-scan led to a prediction error that was toward positive values (equivalent to underestimating axial length), whereas the IOL Master error was towards the negative. Hoffer Q formula appeared to be more accurate when measuring axial lengths with A-Scan, whereas Haigis formula was more accurate when combined with IOL Master (0.37 +/- 0.14).
  
  
  CONCLUSIONS
  For selection of IOL formula in cataract patients with high hyperopia, the Haigis would be the most accurate in IOL Master analysis, but the Hoffer Q was better when using A-scan.
authors.affiliation: Department of Ophthalmology, Second Hospital, xi'an Jiaotong University, xi'an 710004, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Bai
authors.forename: Zhen-ping
authors.initials: ZP
authors.lastname: Zhang
authors.forename: Gui-lan
authors.initials: GL
authors.lastname: Yi
authors.forename: Wen-jie
authors.initials: WJ
authors.lastname: Wu
authors.forename: Hao-tian
authors.initials: HT
authors.lastname: Lin
authors.forename: Pi-song
authors.initials: PS
authors.lastname: Yan
mesh_terms: D000328:Adult; D000368:Aged; D002386:Cataract / Q000628:therapy*; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000601:surgery*; D019654:Lens Implantation, Intraocular / Q000379:methods*; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D012029:Refraction, Ocular