CALCULATING INTRAOCULAR-LENS POWER IN EYES WITH KERATOCONUS USING VIDEOKERATOGRAPHY

A patient with keratoconus had cataract extraction and intraocular len s (IOL) implantation in both eyes. The IOL power was determined using keratometric values (K-values) measured by standard keratometry in the right eye and videokeratography in the left eye. The ideal IOL power and the K-value that would have led to the ideal IOL power were determ ined from the postoperative refraction at 6 weeks. The ideal K-value w as compared with the K-values derived from videokeratography and stand ard keratometry. Refraction at 6 weeks postoperatively was 5.60 and 1. 00 diopter more myopic than the aim in the right and left eye, respect ively. The mean power in ring 3 in videokeratography of the left eye w as the same as the ideal K-value calculated using the Holladay formula . Determining IOL powers with videokeratography-derived K-values might be more accurate than standard keratometry in patients with keratocon us.