Intraocular lens power calculation: a challenging case.

PURPOSE: To highlight different methods in calculating intraocular lens (IOL) power in the case of undetectable keratometric (K) readings. CASE REPORT: A 54-year-old woman was referred to us for cataract surgery in her left eye. The slit lamp examination revealed the presence of corneal scars that did not allow us to take reliable K readings. To calculate them, the following regression formula was used: K= Rx-42.613/-0.0424*AL. The IOL power calculation was performed aiming at a postoperative error = -0.5 diopters. One month after surgery, the uncorrected visual acuity was 20/100 and the best spectacles corrected visual acuity was 20/25 with +1.0 -4 × 180 (-1.0 diopter spherical equivalent). CONCLUSIONS: This seems to be a reliable method to calculate the IOL power when K readings are undetectable, but to make a definitive statement, prospective studies are needed.