Intraocular lens power calculations in the triple procedure.

When a triple procedure is planned, calculation of the intraocular lens becomes a problem. Postoperative corneal power bears no relation to preoperative power, and the axial length of the globe also changes. A prospective study of 24 keratoplasties revealed a close relationship between postoperative corneal power and donor corneal power. Changes in axial length were found to be too small to produce errors in calculation. The equation derived in this series to describe the relation between postoperative and donor corneal power is applicable only when certain trephine sizes are used and when the recepient cornea is not excessively scarred.