Intraocular lens power calculation after previous myopic laser vision correction based on corneal power measured by Fourier-domain optical coherence tomography

Purpose: To use Fourier-domain optical coherence tomography (OCT) to measure corneal power and calculate intraocular lens (IOL) power in cataract surgeries after laser vision correction. Setting: Doheny Eye Institute, Los Angeles, California, and Cullen Eye Institute, Houston, Texas, USA. Design: Prospective comparative case series. Methods: Patients with previous myopic laser vision correction who had monofocal IOL implantation were enrolled. A Fourier-domain OCT system was used to measure corneal power and pachymetry. Axial length and anterior chamber depth were measured with partial coherence biometry. An OCT-based IOL formula was developed, and the mean absolution error (MAE) of postoperative refraction was compared with that for the Haigis-L formula. At Doheny, corneal power was also measured using the clinical history method, the contact lens overrefraction method, and slit-scanning tomography total optical power. Results: Sixteen eyes of 16 patients were enrolled at the 2 sites. Previous laser vision correction ranged from -9.81 to -0.88 diopter (D). The MAE was 0.50 D for OCT-based IOL calculation and 0.76 D for the Haigis-L formula (P=.14). In the 6 eyes enrolled at Doheny, the MAE of OCT-based IOL calculation was 0.60 D. In comparison, the contact lens overrefraction (MAE = 1.46 D, P<.05) and clinical history (MAE = 1.78 D, P<.05) methods were worse. Slit-scanning tomography gave an MAE of 1.28 D (P>.05). Conclusion: The predictive accuracy of OCT-based IOL power calculation was equal to or better than current standards in post-laser vision correction eyes. Financial Disclosures: Drs. Tang, Li, and Huang receive grant support from Optovue Inc., Fremont, California, USA. Dr. Huang received patent royalty, stock options, travel support, and speaker honorarium from Optovue, Inc., and receives patent royalty from the Massachusetts Institute of Technology related to optical coherence tomography technology licensed to Carl Zeiss Meditec, Inc. Dr. Wang received research support from Ziemer USA, Inc., Alton, Illinois, USA. Dr. Koch is a consultant to Alcon Surgical, Inc., Fort Worth, Texas, USA.