Evaluation of the efficacy of the Allegretto Wave and the Wavefront-optimized ablation profile in non-anterior astigmatisms

Purpose: To assess the efficacy of the Allegretto Wave and the wavefront-optimized ablation profile (WFO) in non-anterior astigmatism correction, in both LASIK and photorefractive keratectomy (PRK) treatments. Methods: Seventy-four refractive surgery candidates were recruited prospectively in a non-randomized trial. Only one eye from each candidate was randomly enrolled in the study. Of them, 40 eyes underwent LASIK treatment (LG group), while 34 eyes underwent PRK treatment (PG group). Preoperatively, the ocular residual astigmatism (ORA) was calculated for each eye, according to which each astigmatism fault was characterized as primarily anterior or non-anterior. Twenty LG eyes and 16 PG eyes presented primarily anterior astigmatism (LG-A and PG-A subgroups, respectively), while 20 LG eyes and 18 PG eyes demonstrated primarily non-anterior astigmatism (LG-NA and PG-NA subgroups, respectively). Postoperatively, vector analysis of astigmatism correction was conducted. The following indexes were calculated: (i) correction index (CI), (ii) difference vector (DV) and (iii) index of success (IOS). Results: Preoperatively, mean differences between manifest and topographic astigmatisms for the LG and the PG subgroups were significant (p:0.006 and p?