Evaluation of the efficacy of the Allegretto Wave and the Wavefront-optimized ablation profile in non-anterior astigmatisms.
OBJECTIVE
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<0.001, respectively), while postoperatively, aforementioned differences were non-significant (p:0.18 and p:0.09, respectively). Regarding vector analysis in the LG group, mean CI, IOS and DV were 1.39±1.26, 0.37±1.06 and 0.30±0.51, respectively. Differences in CI, IOS and DV between LG-A and LG-NA subgroups were non-significant. Regarding vector analysis in the PG group, mean CI, IOS and DV were 1.22±0.33, 0.47±0.46 and 0.27±0.25, respectively. Differences in CI, IOS and DV between PG-A and PG-NA subgroups were non-significant.


CONCLUSIONS
Our results suggest that the Allegretto Wave and WFO profile seem to be equally effective in both anterior and non-anterior astigmatism correction, regardless of treatment type.
Department of Ophthalmology, University Hospital of Alexandroupolis, Alexandroupolis, Greece. labiris@usa.net
Georgios
G
Labiris
Zisis
Z
Gatzioufas
Athanassios
A
Giarmoukakis
Haris
H
Sideroudi
Vassilios
V
Kozobolis
D000328:Adult; D001251:Astigmatism / Q000601:surgery*; D019781:Corneal Topography; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D018903:Photorefractive Keratectomy; D011446:Prospective Studies; D016896:Treatment Outcome