title: Biometry and intraocular lens power calculation.
abstract: OBJECTIVE
  Heightened patient expectations for precise postoperative refractive results have spurred the continued improvements in biometry and intraocular lens calculations. In order to meet these expectations, attention to proper patient selection, accurate keratometry and biometry, and appropriate intraocular lens power formula selection with optimized lens constants are required. The article reviews recent studies and advances in the field of biometry and intraocular lens power calculations.
  
  
  RESULTS
  Several noncontact optical-based devices compare favorably, if not superiorly, to older ultrasonic biometric and keratometric techniques. With additional improvements in the internal acquisition algorithm, the new IOL Master software version 5 upgrade should lessen operator variability and further enhance signal acquisition. The modern Haigis-L and Holladay 2 formulas more accurately determine the position and the shape of the intraocular lens power prediction curve.
  
  
  CONCLUSIONS
  Postoperative refractive results depend on the precision of multiple factors and measurements. The element with the highest variability and inaccuracy is, ultimately, going to determine the outcome. By understanding the advantages and limitations of the current technology, it is possible to consistently achieve highly accurate results.
authors: Pepose Vision Institute, Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St Louis, Missouri 63017, USA.
authors: Alexander C
authors: AC
authors: Lee
authors: Mujtaba A
authors: MA
authors: Qazi
authors: Jay S
authors: JS
authors: Pepose
mesh_terms: D001699:Biometry / Q000379:methods*; D002386:Cataract / Q000150:complications*; D006801:Humans; D019654:Lens Implantation, Intraocular / Q000295:instrumentation*; D007910:Lenses, Intraocular; D009907:Optometry / Q000379:methods*; D011474:Prosthesis Design; D019591:Pseudophakia / Q000150:complications* / Q000503:physiopathology; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000150:complications / Q000503:physiopathology / Q000534:rehabilitation*