Intraocular lens prediction accuracy after corneal refractive surgery using K values from 3 devices

Abstract

To compare results of intraocular lens (IOL) power calculation methods using different keratometry (K) values after myopic refractive surgery. Seoul St. Mary's Hospital, Seoul, South Korea. Evaluation of diagnostic test or technology. The IOL power of patients who had cataract surgery after refractive surgery was calculated using the SRK/T formula with true net power (TNP) and the equivalent K using the Pentacam Scheimpflug system. The simulated K, 2.0 mm zone of total mean power (TMP 2.0 mm) maps, and 4.0 mm zone of total optical power (TOP 4.0 mm) maps were calculated using the Orbscan II scanning-slit topographer and keratometer of the IOLMaster partial coherence interferometer (PCI). The IOL power was also calculated with the Haigis-L method with the corneal radius using the PCI system. The PCI axial length was used with all methods. The prediction error and absolute prediction error measured with the Haigis-L, TNP, TMP 2.0 mm, and TOP 4.0 mm were significantly lower than the equivalent K, simulated K, and PCI K (P<.05). The percentages of correct refraction predictions within ± 0.50 diopter (D), ± 1.00 D, and ± 2.00 D in the Haigis-L method were the highest (64.5%, 80.6%, and 100%, respectively) of all methods. The Haigis-L using corneal radius with the PCI measurement was the most predictable method for IOL calculation after corneal refractive laser surgery in patients without a clinical history. The TMP 2.0 mm in the scanning-slit topographer and the TNP in the Scheimpflug system may also be relatively predictable keratometric values for IOL calculation.