Expanded Range CustomCornea Algorithms for Myopia and Astigmatism: One-month Results

Abstract

To evaluate the early clinical results achieved with an algorithm adjusted for an expanded range of correction in wavefront-guided customized ablation with the LADARVision4000 (Alcon Laboratories Inc, Fort Worth, Tex). Fifty-five consecutive eyes from 31 patients underwent wavefront-guided, customablation laser in situ keratomileusis (LASIK) (Hansatome and BD 4000 microkeratomes, LADARWave aberrometer, LADARVision4000 laser system). These were normal myopic and astigmatic eyes that had never been operated on. The spherical equivalent refractive error was +0.30 to -8.13 diopters (D) (mean -4.26 +/- 2.14 D) and the astigmatism ranged from 0 to -3.75 D (mean -0.97 +/- 0.96 D). eyes were treated according to the CustomCornea protocol using the commercial LADARVision4000 platform. Patients were followed for at least 2 months and standard visual measurements were taken and recorded at 1 day and 1, 3, and 6 months after treatment. The results of treatment were assessed using the following parameters: uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA); manifest spherical equivalent refractive error; wavefront measurement of high order aberrations; and subjective reports of visual symptoms by patients. One month after LASIK, the mean manifest spherical equivalent refractive error was -0.18 +/- 0.41 D. Seventy-eight percent and 96% of eyes had manifest spherical equivalent refractive error within +/-0.50 D and +/-1.00 D of attempted correction, respectively, with 78% of eyes with 20/20 or better UCVA. Eyes with 20/16 and 20/12.5 BSCVA were 89% and 36%, respectively (55% and 7% preoperatively). The mean high order aberrations root-mean-square was 0.34 +/- 0.10 microm preoperatively and 0.35 +/- 0.09 microm postoperatively (6.0-mm pupil size). High order aberrations were either reduced, unchanged, or increased by <10% in 58% of eyes. Subjectively, patients reported no visual symptoms and had no complaints regarding the quality of their vision. The new optimized algorithm for higher refractive errors appears to be effective in improving BSCVA, and a minority of patients demonstrated an increase in the magnitude of high order aberrations when compared to preoperative aberrometry. A slight spherical equivalent refraction undercorrection will be addressed with future nomogram adjustments.