Differences between real and predicted corneal shapes after aspherical corneal ablation.
We study the differences between real and expected corneal shapes, using an aspherical ablation algorithm with a known equation and avoiding the limitation imposed by most studies of refractive surgery in which the ablation equations are not known. We have calculated the theoretical corneal shape predicted by this algorithm, comparing this shape with the real corneal topography. The results indicate that the deviations that appear in the corneal shape are significant for visual performance and for the correction of eye aberrations. If we include in this analysis the effect of reflection losses and nonnormal incidence on the cornea, we can reduce corneal differences, but they will remain significant. These results confirm that it is essential to minimize corneal differences to achieve effective correction in refractive surgery.
Anera
Rosario G
RG
Departamento de Optica, Universidad de Granada, Spain. rganera@ugr.es
Villa
César
C
Jiménez
José R
JR
Gutiérrez
Ramón
R
del Barco
Luis Jiménez
LJ
D000465:Algorithms; D003198:Computer Simulation; D003315:Cornea / Q000503:physiopathology* / Q000601:surgery*; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D006801:Humans; D054018:Lasers, Excimer; D008954:Models, Biological; D018903:Photorefractive Keratectomy / Q000379:methods; D011300:Preoperative Care / Q000379:methods; D011379:Prognosis; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000175:diagnosis* / Q000503:physiopathology; D054140:Refractive Surgical Procedures; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome