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Clinical outcomes of laser in situ keratomileusis using combined topography and refractive wavefront treatments for myopic astigmatism

Noel Alpins, FRANZCO, FRCOphth, FACS, George Stamatelatos, BScOptom

PURPOSE: To evaluate outcomes of laser in situ keratomileusis (LASIK) guided by wavefront alone versus wavefront plus topographic data.
SETTING: NewVision Clinics, Cheltenham, Australia.
METHODS: Twenty-one eyes (14 patients) were distributed into 2 groups in a prospective doublemasked study. One group was treated by wavefront parameters alone (WF, n Z 11), and the other, by wavefront combined with topography values (WF&VP, n Z 10) using vector planning. All treatments were performed using Visx Star S4 CustomVue software. In the WF&VP group, the treatment profile was calculated using simulated keratometry readings from the Humphrey Atlas topography and 2nd-order Zernike coefficients defocus 4 and astigmatism 3 and 5 from the WaveScan wavefront display of the entire eye.
RESULTS: Mean corneal astigmatism preoperatively was 1.07 diopters (D) G 0.54 (SD) in the WF group and 1.50 G 0.87 D in the WF&VP group. At 6 months, it was 0.67 G 0.57 D (39% reduction) and 0.83 G 0.55 D (44% reduction), respectively. The WF&VP group had a greater reduction in horizontal coma. The mean gain in low-contrast visual acuity under mesopic conditions was 0.06 in the WF group and 0.11 in the WF&VP group and the mean gain in high-contrast visual acuity, 0.02 and 0.05, respectively. Two patients reported a change in the preferred eye postoperatively to the eye treated using vector planning. No result demonstrated statistical significance.
CONCLUSION: The WF&VP group had greater reduction in corneal astigmatism and better visual outcomes under mesopic conditions than the WF group and equivalent higher-order aberrations.
J Cataract Refract Surg 2008; 34:1250–1259 Q 2008 ASCRS and ESCRS