Abstract
Purpose:
To compare efficacy of wavefront-optimized LASIK and PRK in patients with baseline cylinder of 2.00 or greater.
Methods:
In this retrospective study, 34 eyes of 24 consecutive patients with a baseline cylinder of 2.00 or greater who underwent wavefront-optimized LASIK or PRK with Alcon Wavelight Allegretto® Eye-Q 400 excimer laser were analyzed. All eyes were targeted for emmetropic vision.
Results:
Six months after LASIK, 10/23 eyes were lost to follow up. Of the remaining, 9/13 had uncorrected distance visual acuity (UDVA) of 20/40 or better and 5/13 had 20/25 or better. 2 eyes gained one or more lines of best-corrected distance visual acuity (CDVA). No eyes lost any lines of CDVA. Mean preop spherical equivalent decreased from -4.52+/-2.43 diopters (range -8.0 to 2.5) to -0.84+/-0.53 (-1.75 to 0). Mean cylinder decreased from 3.61+/-0.99 diopters (2.00 to 5.25) to 0.37+/-0.32 (0 to 1.0). Wavefront analyses revealed an increase in higher order aberrations from preop RMS error of 0.33 +/- 0.12 (0.13 to 0.54) to 0.40 +/- 0.16 (0.14 to 0.67). Coma increased from 0.17 +/- 0.11 (0.04 to 0.44) to 0.23 +/- 0.12 (0.05 to 0.42). Trefoil decreased from 0.16 +/-0.08 (0.03 to 0.29) to 0.11 +/- 0.07 (0.01 to 0.23). Spherical aberration decreased from 0.13 +/- 0.13 (-0.13 to 0.41) to 0.11 +/- 0.22 (-0.18 to 0.58).<br /> <br /> Six months after PRK, no eyes were lost to follow up. 10/11 eyes achieved 20/40 UDVA or better and 8/11 achieved 20/25 or better. 4 eyes gained one or more lines of CDVA. 2 eyes lost one line of CDVA. Mean preop spherical equivalent decreased from -2.96+/-4.00 diopters (range -9.75 to 3.63) to -0.09+/-0.51 (-0.88 to 0.75). Mean cylinder decreased from 3.53+/-0.87 diopters (2.00 to 5.25) to 0.68 +/-0.40 (0 to 1.25). Wavefront analyses revealed an increase in higher order aberrations from preop RMS error of 0.31 +/- 0.09 (0.12 to 0.43) to 0.47 +/- 0.15 (0.28 to 0.70). Coma increased from 0.15 +/- 0.07 (0.03 to 0.33) to 0.23 +/- 0.13 (0.09 to 0.48). Trefoil increased from 0.17+/-0.08 (0.03 to 0.33) to 0.24 +/- 0.12 (0.10 to 0.43). Spherical aberration decreased from 0.08 +/- 0.10 (-0.07 to 0.30) to 0.02+/- 0.19 (-0.32 to 0.30).
Conclusions:
Both LASIK and PRK are effective in eyes with high baseline cylinder. There is a trend towards increased higher order aberrations post-LASIK or PRK surgery.