• Refractive Mgmt/Intervention

    This prospective, randomized study found that wavefront-guided and -optimized LASIK using the Alcon WaveLight Allegretto Eye-Q 400-Hz excimer laser platform provided similar results in myopic patients, although the guided approach showed small advantages in visual acuity, predictability and higher-order aberrations (HOAs).

    The study’s authors write that multiple studies have compared wavefront-guided with wavefront-optimized platforms in LASIK surgery. The majority of these studies suggest advantages of wavefront-guided platforms over optimized platforms, but some have suggested no significant benefits of wavefront-guided LASIK over wavefront-optimized. However, many of these investigations have been limited by small sample sizes, which are confounded by differences in wound healing and corneal biomechanical factors between patients.

    They randomized one eye of each of 36 participants with myopia with or without astigmatism to wavefront-guided or wavefront-optimized LASIK with the WaveLight Allegretto Eye-Q 400-Hz excimer laser platform (Alcon, Inc.). LASIK flaps were created using the 150-kHz IntraLase iFS (Abbott Medical Optics). The fellow eye received the alternative procedure.

    There were no statistically significant differences between the groups at postoperative months one and three in mean UDVA and CDVA (all P  ≥  0.05). However, there was a trend favoring better CDVA in the wavefront-guided group compared with the -optimized group that was statistically significant at six months but did not reach statistical significance at 12 months (P = 0.04 and 0.11, respectively). There was also a trend favoring better UDVA in the wavefront-guided group that approached but did not reach statistical significance at 12 months (P = 0.05).

    There were no statistically significant differences in mean CDVA between the groups at <5 percent and <25 percent contrast sensitivity conditions at all postoperative time intervals (all P  >  0.05); however, there was a trend approaching statistical significance at 12 months that favored slightly better <5 percent contrast sensitivity in the wavefront-guided group.

    At postoperative month one, the wavefront-guided group's mean sphere was 0.17 D less negative than the wavefront-optimized group's sphere (P = 0.01). This trend continued through month 12, when the difference was 0.15 D (P = 0.01).

    Similar to the differences observed in sphere between the groups, the wavefront-guided group's mean spherical equivalent was less negative, or closer to emmetropia, than the wavefront-optimized group's spherical equivalent. This statistically significant trend was observed at postoperative months one, six and 12.

    There were no statistically significant differences in coma and higher-order root mean square (RMS) error between the groups postoperatively (all P > 0.05), but there was a statistically insignificant trend favoring lower higher-order RMS error in the wavefront-guided group at months 3 and 12 (both P = 0.06). Also, the wavefront-guided group had reduced trefoil compared with the wavefront-optimized group at all postoperative time intervals.

    There were no statistically significant differences in subjective parameters between the groups at postoperative month 12. However, participants more frequently preferred their wavefront-guided eye (33.3 percent) to their wavefront-optimized eye (18.2 percent).

    The authors conclude that both approaches provide similar results in myopic patients, but the guided approach may yield small but statistically significant gains in visual acuity, predictability and certain HOAs compared with wavefront-optimized.