title: Updated practical intraocular lens power calculation after refractive surgery.
abstract: OBJECTIVE
  Since its introduction in the 1980s, more than 40 million people worldwide have undergone some form of kerato-refractive surgery. Many of these individuals are now candidates for cataract surgery and pose the challenge of attaining first-rate refractive outcomes in nonvirgin eyes. Numerous approaches have been developed to estimate intraocular lens (IOL) power in eyes postrefractive surgery. This review highlights the most practical, relevant options for accurate IOL power determination in these cases.
  
  
  RESULTS
  With refined techniques and advances in instrumentation, more accurate assessments of true corneal power and thus, IOL power, are possible in postrefractive eyes. Optical coherence tomography and other corneal tomography instruments have markedly improved accuracy in this process. However, when expensive, modern equipments are not readily available, and online IOL calculators such as the American Society of Cataract and Refractive Surgery (ASCRS) calculator have become efficient, reliable options. Recent evidence confirms the accuracy of these online calculators.
  
  
  CONCLUSIONS
  Emerging literature supports the use of methods that do not rely on prior refractive data in IOL power determination. Online IOL calculators provide user-friendly, efficient options that greatly facilitate accurate IOL power determination for cataract surgery in eyes that have undergone prior kerato-refractive surgery.
authors.affiliation: Albert Einstein College of Medicine, Montefiore Medical Center, Department of Ophthalmology and Visual Sciences, Bronx, NY, USA.
authors.forename: Gowtham
authors.initials: G
authors.lastname: Jonna
authors.forename: Prabjot
authors.initials: P
authors.lastname: Channa
mesh_terms: D001699:Biometry / Q000379:methods*; D002387:Cataract Extraction; D003315:Cornea / Q000601:surgery; D006801:Humans; D007910:Lenses, Intraocular; D009216:Myopia / Q000601:surgery; D055095:Optics and Photonics; D011182:Postoperative Care; D054140:Refractive Surgical Procedures