[The value of preoperative calculation of intraocular lenses]

In 82 cataract patients the power of the pseudophakos to be implanted was determined. Axial length and anterior chamber depth were measured by ultrasound. The results of keratometry and the echographic data were used for lens power calculation. For the accuracy of prediction the estimated post-operative anterior chamber depth is of importance. Using R. D. Binkhorst's formula in a series of 32 four-loop iris clip lenses a mean of +0.16 D and a standard deviation of 0.81 D were obtained. In a group of 50 Kelman Quadraflex anterior chamber lenses the mean was +0.17 D and the standard deviation 0.66 D. No error greater than +/- 2.0 D was observed.