Use of the Pentacam True Net Corneal Power for Intraocular Lens Calculation in Eyes After Refractive Corneal Surgery

Purpose: To assess the accuracy and validity of true net corneal power of the Pentacam system to provide a keratometry reading for calculating intraocular lens (IOL) power in postoperative refractive surgery eyes. Methods: Refraction, an automated keratometry reading, and true net corneal power were measured for 30 eyes that required cataract surgery and had previously undergone refractive surgery. Target refraction values calculated with the SRK/T formula using true net corneal power were compared with postoperative manifest refraction values. Results: Using true net corneal power, the mean deviation from the desired postoperative cataract refractive outcome was 0.47±0.56 diopters (D); the actual refraction was within ±0.50 D of the intended refraction for 70% of eyes (21/30) and within ±1.00 D for 93% of eyes (28/30). Conclusions: The true net corneal power can be used as a keratometry reading for eyes with previous refractive surgery requiring cataract surgery. [ J Refract Surg . 2009;25:285–289.]