First Author: R.Date UNITED STATES
Co Author(s): K. Miller
Purpose:
To validate the Diehl/Miller equation for achieving emmetropia in post-LASIK cataract surgery patients, and to present a more refined equation and associated nomogram. Diehl/Miller relates the manifest refractive spherical equivalent (MRSE) change induced by LASIK to an adjusted target post-operative refractive error (RE) to be used in IOL power calculations.
Setting:
: Jules Stein Eye Institute, University of California, Los Angeles, United States
Methods:
Pre-operative and post-operative refractive and cataract surgery data were collected from medical charts of post-LASIK patients who underwent cataract surgery by Dr. Kevin M. Miller between July 2007 and June 2011. IOL power data and post-operative refractive information were used to calculate a “true” target refractive error (REtrue, the refractive error that should have been targeted to achieve emmetropia) for each patient, which was then compared to that calculated from Diehl/Miller. Regression analysis of the combined data from the Diehl/Miller study and Date/Miller study was used to develop a refined equation (Date/Miller equation).
Results:
Twenty-three eyes from 18 patients were evaluated. The target RE calculated from Diehl/Miller differed from REtrue by an absolute mean of 0.481 +/- 0.376 D. A regression of the combined data from the Date/Miller study and the Diehl/Miller study yielded a 2nd-order polynomial equation (Date/Miller equation): Target RE = -0.0198(MRSE change)^2 + 0.170(MRSE change) – 0.0079. Using Date/Miller, the calculated target RE fell within +/- 0.50 D of REtrue for 49% of patients and within +/- 1.00 D for 93% of patients.
Conclusions:
This study is the first validation that Diehl/Miller accurately predicts target RE for achieving emmetropia in post-LASIK cataract surgery patients. The refined Date/Miller equation and associated nomogram can be utilized by cataract surgeons to avoid post-operative refractive errors in such patients.
Financial Disclosure:
None.
Financial Disclosure:
No
