Purchase this article with an account.
Emily Waisbren, Li Wang, Maolong Tang, Douglas Koch; Intraocular lens power prediction in eyes with prior radial keratotomy using Fourier-domain optical coherence tomography. Invest. Ophthalmol. Vis. Sci. 2013;54(15):1834.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To evaluate the accuracy of intraocular lens (IOL) power calculation using Fourier-domain optical coherence tomography (OCT) in eyes with prior radial keratotomy (RK), and compare to methods using the ASCRS calculator.
Records of patients with prior RK for myopic correction who underwent primary cataract extraction with IOL implantation were analyzed. We included only patients with postoperative best-corrected vision of 20/25 or better. Patients with inadequate follow-up of less than 3 weeks were excluded from the study. Preoperatively, a Fourier-domain OCT system was used to measure anterior, posterior, and net corneal power and pachymetry. Axial length and anterior chamber depth were measured using partial coherence interferometry. Using these variables and the postoperative refractive error, we developed an OCT-based formula for calculating IOL power. The IOL power was also calculated using the ASCRS online calculator. We then determined the IOL power prediction error, or the difference between the predicted IOL power and the implanted IOL power, with and without the use of OCT, and compared this value to the prediction errors obtained when using a variety of variables from different devices.
Seventeen eyes of 12 patients with previous RK who underwent primary cataract surgery and IOL implantation from January 2008 through October 2012 at one institution were included in the study. The IOL power prediction error of the OCT formula was 0.29 ± 2.44D. For the ASCRS calculator, the prediction errors of multiple variables were predicted and compared to the OCT-based error. The results were: 0.04 ±2.68D, p=0.39 (EffRP), 0.18±2.78D, p=0.45 (IOL Master), 1.41± 1.40D, p=0.15 (Atlas 1-5mm zones), -1.89± 6.19D, p=0.11 (Atlas rings 1-4mm), -2.76± 2.72D, p=0.0001, (Galilei 1-3mm rings), -1.92± 2.91D, p=0.01 (Galilei 1-4mm rings), and -2.60±2.84D, p=0.0001 (Galilei 1-5mm zones).
The OCT-based IOL power calculation is a promising option for calculating IOL power in post-RK eyes.
This PDF is available to Subscribers Only