/ /

  • linkedin
  • Increase Font
  • Sharebar

    Centroid value, posterior cornea input adds game for toric calculators

    Advances reconsider surgically induced astigmatism: mean versus median versus centroid


    Centroid value

    Recently, surgeons have found that using a centroid value gives improved outcomes, Dr. Hill noted. A centroid value is the two-dimensional mean of SIA for a series of patients.

    Using data from a large physician database of more than 35,000 cases, Dr. Hill observed that for the typical temporal clear corneal incision, the calculated centroid value generally ranges from 0.08 D to 0.14 D.

    If a surgeon has not yet calculated a centroid value for a cataract surgery incision, he advised beginning with a centroid value of 0.12 D when using toric calculators. A centroid calculation can be carried out using a free tool (www.SIA-calculator.com).

    Dr. Hill also highlighted the currently available toric calculators in the United States, including the Bausch + Lomb Trulign, the Holladay IOL Consultant calculator, the Abbott Medical Optics calculator (Johnson & Johnson Vision Care), the updated Alcon calculator, and the Barrett toric calculator, available on the American Society of Cataract and Refractive Surgery website (www.ascrs.org/barrett-toric-calculator).

    “The Barrett toric calculator is currently the most advanced one we have,” Dr. Hill said. “[Dr.] Koch gave us the gift of the posterior cornea and [Dr.] Barrett made it practical for all of us.”


    Warren E. Hill, MD

    E: [email protected]

    This article was adapted from Dr. Hill’s presentation during Refractive Subspecialty Day at the 2016 meeting of the American Academy of Ophthalmology. Dr. Hill is a consultant for Alcon Laboratories.

    New Call-to-action


    You must be signed in to leave a comment. Registering is fast and free!

    All comments must follow the ModernMedicine Network community rules and terms of use, and will be moderated. ModernMedicine reserves the right to use the comments we receive, in whole or in part,in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.

    • No comments available


    View Results