[The accuracy of optical power calculations of intraocular lenses in cataract surgery]

The author selected 12 groups of patients (858 patients altogether). The operation was carried out by the same surgeon and the same type of IOL was implanted in each group. An individual A-constant was calculated for each patient. Using individualized A-constant for each group a postoperative refractive error was calculated for each patient. Following formulas were used for the calculation: SRK, SRK II, Holladay formula (A-constant), Holladay formula (surgeon factor) and SRK/T. No substantial difference between the results of formulas SRK, SRK II, Holladay formula (surgeon factor) and SRK/T was found. The postoperative refractive error +/- 1.0 D was found in the interval 65.6% - 67.8% for all these formulas. Holladay formula (A-constant) yielded the postoperative refractive error +/- 1.0 D in 62.2% of cases.