[Importance of individualizing the formula for improving the accuracy of calculating emmetropia in intraocular lenses before cataract surgery].

The authors evaluated the individualized A-constants of 858 patients. These patients were divided into 12 groups according to the surgeon and the type of implanted IOL. The valuation of the results showed a marked discrepancy between the mean value of the individualized A-constant and the value recommended by the manufacturer. In this set of patients the individualization of the formula decreased the postoperative refractive error in some cases by 0.4 D for three-piece lenses and by 1.7 D for one-piece lenses.