Accuracy of ultrasound intraocular lens calculation.

A review of the literature was made to evaluate the prediction accuracy of intraocular lens calculations. A uniform standard formula (percentage +/- 1.0 diopter/percentage +/- 2.0 D/range of error) for reporting accuracy was used to evaluate the accuracy of reports in the literature, as well as the accuracy of an ultrasound unit (Kretz 7100 MA), the HOffer formula, use of a standard 3.5-mm anterior chamber depth, and addition of a retinal thickness factor to the measured ultrasound axial length. The appropriateness of technicians performing this procedure also was evaluated. Results of previous studies show that the use of another ultrasound unit (Sonometrics DBR) and Binkhorst's formula is the least clinically accurate method.