Abstract
Purpose: :
To measure the impact on postoperative quality of vision of two different approaches to correcting higher-order aberrations (HOA) in laser vision correction (LVC).
Methods: :
Charts for 211 eyes undergoing laser vision correction were retrospectively reviewed. All flaps were made with an IntraLase femtosecond laser. Approximately half the eyes (102) received Wavelight wavefront-optimized treatments (WFO), while the other half (109) received Visx CustomVue wavefront-guided treatments (WFG) with iris registration. The treatment range was similar between groups. HOAs over 4.00-mm and 6.00-mm zones, including separate measures of spherical aberration, coma, and trefoil, were analyzed pre- and post-operatively in all eyes in both groups. UCVA & BSCVA were measured at high (98%) and low (5%) contrast and cross-analyzed by the modulation transfer function (MTF), a measure of optical image quality.
Results: :
Mean total HOA increased in the WFO group from 0.29 preop to 0.42 ± 0.27 postop, and decreased in the WFG group, from 0.29 preop to 0.27 ± 0.15 postop. HOAs were the same or better in 59% and worse in 41% of eyes in the WFO group. In the WFG group, HOAs were the same or better in 88% and worse in only 12% of eyes. The areas under the 4.0-mm and 6.0- mm MTF were significantly different at 0.67 ± 0.14 and 0.25 ± 0.07 for WFG and 0.58 ± 0.14 and 0.21 ± 0.06 for WFO (p < 0.001). Lower total HOA and higher MTF correlated with better high- and low-contrast acuity.
Conclusions: :
WFG procedures are much less likely than WFO procedures to worsen higher-order aberration. The areas under the 4.00-and 6.00-mm MTF were significantly better in the WFG group, demonstrating that WFG LASIK with a femtosecond laser flap produces better quality of vision than wavefront-optimized LASIK.
Keywords: refractive surgery: comparative studies • refractive surgery: LASIK • refractive surgery: optical quality