Purpose: To demonstrate an analytical method to compare the actual and intended refraction after cataract surgery that allows incorporation of refractive surgical effects.
Setting: Corneal and External Eye Disease Service, Royal Liverpool University Hospital, Liverpool, United Kingdom.
Methods: The actual postoperative refraction was compared to the intended postoperative refraction before and after removal of surgically induced changes in keratometry; that is, the keratometric surgical effect. Application of hypothesis testing is demonstrated using a standardized method of analyzing refractive data; that is, refractive data transformed into the refractive power matrix with calculation of the mean and variance-covariance of the data.
Results: The method of analysis demonstrated how surgically induced changes in refractive components can be incorporated into hypothesis testing when comparing intended and actual postoperative refractions.
Conclusion: Application of the standardized method of analyzing refractive data allows a more accurate evaluation of methods or formulas used to calculate intraocular lens power in cataract surgery.