To compare the visual outcomes of wavefront-optimized (WFO) and topography-guided customized ablation (T-CAT) for compound myopic astigmatism.

This double blind, prospective clinical trial study comprised 50 virgin eyes (26 patients) with compound myopic astigmatism.Myopia was considered between 1 to 8 diopters and astigmatism was considered between 1 to 3 diopters. Patient's eyes were randomly divided into two groups: wavefront optimized and topography-guided. All surgeries were done with Allegretto WaveLight® EX500 laser eximer. Visual acuity, refractive error, corneal aberrations, ocular high order aberrations and corneal asphericity were measured before and 6 months after surgery. The results were compared between the two groups.

At postoperative 6 months, the mean logMAR uncorrected distance visual acuity was similar in the WFO (0 ± 0.03) and T-CAT (0.01 ± 0.03) groups (P=0.804). Safety, efficacy, and predictability of refractive and visual outcomes were similar. Mean spherical equivalent refraction was -4.27 ± 1.68D and -4.27 ± 1.55 D (P=0.938) to -0.05 ± 0.12D and -0.03 ± 0.08D (P=0.496) in wavefront optimized and topography-guided groups after surgery. Less stromal tissue was ablated in the wavefront optimized group than in the topography-guided group (P = 0.536). There was no significant difference between the 3rd and 4th grade corneal aberrations between the two groups before and after the surgery (P>0.05). Six months after surgery, corneal coma aberration was decreased in both groups but this decreased was lower in the WFO group. Corneal and ocular spherical aberration was increased in both groups (P < 0.05). This increase was lower in the T-CAT group. Ocular higher order aberrations at a 6.0 mm pupil diameter increased from 0.36 ± 0.15 ?m and 0.36 ± 0.11 ?m (P=0.612) to 0.49 ± 0.15?m and 0.49 ± 0.15 ?m (P=0.786) in the WFO and T-CAT groups, respectively. Corneal asphericity increased in two group (P<0.001).

The results of topography-guided and wavefront optimized treatments with Allegretto eximer laser were similar in correction of compound myopic astigmatism, but TCAT induced fewer spherical aberration.