Clinical Results of a Corneal Radius Correcting Factor in Calculating Intraocular Lens Power After Corneal Refractive Surgery

PURPOSE: To describe the clinical results of a corneal radius correcting factor (CRCF), which is based on the axial length and independent of knowledge from the previous surgical procedure, in calculating intraocular lens (IOL) power in eyes that developed cataract after corneal refractive surgery. METHODS: Intraocular I lens power for 62 eyes that previously underwent corneal refractive-surgery was calculated with the SWT and SRK 11 formulas using an axial length-related CRCF, and the expected refractive errors were compared-with the actual postoperative refractive errors. RESULTS: Using the CRCF, the refractive outcomes ranged between -3.25 and +1.00 diopters (D) (mean -0.41 +/- 0.75 D), with 37 (60%) eyes within +/- 0.50 D and 53 (85%) eyes within +/- 1.00 D of the intended refraction. Using the raw data, without the correcting factor, the refractive outcomes would have ranged between -2.00 and +5.00 D (mean +2.17 +/- 1.45 D) with 7 (11%) eyes within +/- 0.50 D and 15 (24%) eyes within +/- 1.00 D of the intended refraction. CONCLUSIONS: Pending further validation through a the CRCF combined with larger prospective evaluation, the SRK/T formula is recommended in eyes with an axial length up to 30 mm and the average IOL power calculated with the SRK/T and SRK 11 formulas When the axial length is >30 mm. [J Refract Surg. 2009;25:599-603] doi:10.3928/1081597X-20090610-05