Multifocality changes after LASIK

PurposeTo analyze the differences in induced multifocality after LASIK surgery in myopic and hyperopic patients using conventional and aberration-free profiles.SettingAugenlaserzentrum, Recklinghausen, Germany.MethodsWe retrospectively evaluated four consecutive groups of 280 eyes treated by the ESIRIS laser platform: Group A myopic with conventional treatment (70 eyes), group B myopic with aspheric treatment (70 eyes), group C hyperopic eyes treated with conventional LASIK (70 eyes) and group D hyperopic eyes treated with aspheric profile (70 eyes). We used in all the cases the ESIRIS SCHWIND Laser Platform and the Carriazo Pendular Microkeratome. The Optikon Keratron Topographer obtained the measurement of change in corneal refractive power of the anterior surface at 3, 5, and 7mm meridionally and in the form of corneal wavefront analysis.ResultsWe compared the preoperative multifocality with the created multifocality measured in diopters (D) per achieved diopter of defocus correction after LASIK treatment. The created multifocality was in the myopic group A +0.12D per achieved diopter of defocus correction, in group B +0.08D per achieved diopter of defocus correction, in the hyperopic group C −0.51D per achieved diopter of defocus correction and in group D −0.14D per achieved diopter of defocus correction.ConclusionsAnalyzing the slope of the anterior corneal surface and the corneal wavefront the local refractive changes after LASIK can be characterized in the form of positive (relative central myopization) and negative multifocality (relative peripheral myopization). Less multifocality is created with the aberration-free pattern than with the classic pattern