Prediction of pseudophakic anterior chamber depth with the newer IOL calculation formulas

Five methods for predicting pseudophakic anterior chamber depth (ACD) by five previously described intraocular lens power calculation formulas (Binkhorst II, Lepper and Trier, Holladay et al., Sanders-Retzlaff-Kraff (SRK/T), Olsen et al.) were evaluated in a series of 640 patients with a posterior chamber lens implant. Significant differences in formula performance were found in unusually short and long eyes. High errors were found in long eyes with the Lepper and Trier formula, the Holladay formula, and the SRK/T method. The highest accuracy was found with the Binkhorst formula and our previously described linear regression formula which expresses the pseudophakic ACD as a function of the average pseudophakic ACD for a given lens style, the preoperative ACD, and the axial length. The use of the preoperative ACD in combination with the axial length for the prediction of the pseudophakic ACD can therefore be expected to improve the accuracy of IOL power calculation.