Measuring the power of an in situ intraocular lens with the keratometer.

A method to measure the power of an intraocular lens (IOL) in situ using an extended range keratometer and a depth measuring apparatus is described. With this method, the IOL power was measured in ten patients with an anterior chamber IOL and in ten patients with a posterior chamber IOL and compared with the labeled power. The total mean error (measured power minus labeled power) was found to be 0.01 diopters (D) with a standard deviation of 0.22 D. The largest error was 0.40 D.