title: Formula choice: Hoffer Q, Holladay 1, or SRK/T and refractive outcomes in 8108 eyes after cataract surgery with biometry by partial coherence interferometry.
abstract: OBJECTIVE
  To assess how intraocular lens (IOL) formula choice affects refractive outcomes after cataract surgery using IOLMaster biometry.
  
  
  METHODS
  Department of Ophthalmology, Gloucestershire Hospitals NHS Foundation Trust, Cheltenham, United Kingdom.
  
  
  METHODS
  Database study.
  
  
  METHODS
  Hypothetical prediction errors were retrospectively calculated on prospectively collected data from electronic medical records using optimized Hoffer Q, Holladay 1, and SRK/T formulas (Sofport AO and Akreos Fit IOLs) across a range of 0.5 mm or 1.0 mm axial length (AL) subgroups.
  
  
  RESULTS
  In short eyes, the Hoffer Q had the lowest mean absolute error (MAE) for ALs from 20.00 to 20.99 mm. The Hoffer Q and Holladay 1 had a lower MAE than the SRK/T for ALs from 21.00 to 21.49 mm. There were no statistically significant differences in MAE for ALs from 21.50 to 21.99 mm. In medium eyes, there were no statistically significant differences in MAE for any IOL formula for ALs from 22.00 to 23.49 mm. For ALs from 23.50 to 25.99 mm, there was a trend toward lower MAEs for the Holladay 1, with statistically significant differences in 2 subgroups. In long eyes, the SRK/T had the lowest MAE, with statistically significant differences for ALs of 27.00 mm or longer.
  
  
  CONCLUSIONS
  The Hoffer Q performed best for ALs from 20.00 to 20.99 mm, the Hoffer Q and Holladay 1 for ALs from 21.00 to 21.49 mm, and the SRK/T for ALs of 27.00 mm or longer. Using optimized constants, refractive outcomes of 40%, 75%, and 95% within ±0.25 diopter (D), ±0.50 D, and ±1.00 D, respectively, were achievable.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.
authors.affiliation: Bristol Eye Hospital, Bristol, United Kingdom. topetros@yahoo.com
authors.forename: Petros
authors.initials: P
authors.lastname: Aristodemou
authors.forename: Nathaniel E
authors.initials: NE
authors.lastname: Knox Cartwright
authors.forename: John M
authors.initials: JM
authors.lastname: Sparrow
authors.forename: Robert L
authors.initials: RL
authors.lastname: Johnston
mesh_terms: D058452:Axial Length, Eye; D001699:Biometry / Q000379:methods*; D006801:Humans; D007368:Interferometry; D007910:Lenses, Intraocular; D008027:Light; D018918:Phacoemulsification; D011184:Postoperative Period; D019591:Pseudophakia / Q000503:physiopathology*; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D016896:Treatment Outcome