Intraocular Lenses: PDF OnlyDonzis Paul B. MD; Kastl, Peter R. MD PhD; Gordon, Robert A. MDCLAO Journal: April-May-June 1985 Buy Abstract new intraocular lens (IOL) power formula based on a percentage change concept is described. The formula is a modification of the SRK regression formula so that IOL power is varied proportionally to the percentage change in axial length. Our formula yielded the same results as the SRK formula in normal length adult eyes. In four cases of IOL implantation in pediatric patients, our percentage change formula better predicted postoperative refractive error than either the SRK or theoretical formulas. Further, in long myopic eyes our formula yielded the same results as a new regression formula designed only for use in long eyes. Although our data are limited, we believe this percentage change formula better predicts IOL power or expected postoperative refractive error over an expanded range of axial lengths. This formula may be especially useful in the treatment of pediatric cataracts when IOL use is considered. © 1985 The Contact Lens Association of Ophthalmologists, Inc.