Purpose: To compare the effects on contrast sensitivity of wave front-guided (WFG) versus standard LASIK.
Design: Prospective, nonrandomized, comparative clinical study.
Participants: Twenty-four eyes of 13 consecutive patients (mean age, 25.2+/-8.4 years; spherical equivalent, -0.5 to -4.25 diopters [D]) treated with WFG LASIK (WaveLight-Allegretto scanning-spot laser and wave front analyzer) and 22 eyes of 12 consecutive patients (mean age, 28.4+/-9.1 years; spherical equivalent, -0.75 to -4.5 D) treated with standard LASIK (WaveLight-Allegretto scanning-spot laser).
Methods: Best-corrected contrast sensitivity was measured before and 1 month after surgery in both the WFG LASIK group and the standard LASIK group. A sine-wave contrast sensitivity test (functional acuity contrast test) was used to measure contrast sensitivity at 5 spatial frequencies (1.5, 3, 6, 12, and 18 cycles/degree). We compared the LASIK-induced changes in contrast sensitivity in each groups at each spatial frequency.
Main outcome measure: The effect on contrast sensitivity of WFG LASIK versus standard LASIK.
Results: Uncorrected visual acuity of 20/20 or better was achieved by 72% of eyes treated with WFG LASIK and by 70% of the eyes treated with standard LASIK. One month after LASIK, 88% of the contrast sensitivity measurements improved in the WFG LASIK group, whereas in the standard LASIK group, only 40% of the contrast sensitivity measurements improved. The contrast sensitivity improvement was significantly larger in the WFG LASIK group at all spatial frequencies (P<0.05). The WFG LASIK patients had a negative correlation between the changes in contrast sensitivity and the preoperative refractive error.
Conclusions: The ability of WFG LASIK to correct optical aberrations results in significantly improved contrast sensitivity compared with standard LASIK 1 month after surgery.