We offer an analysis that shows that the approximations made for the ablation depth during practical refractive surgery, in which the square-root terms are replaced by the first two terms of the series expansion, can limit the visual function of the observer by reducing the modulation transfer function (MTF). To simulate the refractive-surgical operation, we considered two groups of myopic patients with different ametropia who were emmetropized with different ablation profiles. We made the MTF calculations by taking the spherical aberration into account. In addition, a fuller analysis showed that these approximations limit the possibility of considering surfaces that are aspherical for reshaping the anterior cornea to optimize the observer’s visual function.
© 2001 Optical Society of America
(070.2580) Fourier optics and signal processing : Paraxial wave optics
(080.1010) Geometric optics : Aberrations (global)
(110.4850) Imaging systems : Optical transfer functions
(170.4470) Medical optics and biotechnology : Ophthalmology
José Ramón Jiménez, Rosario González Anera, and Luis Jiménez del Barco, "Effects on Visual Function of Approximations of the Corneal-Ablation Profile During Refractive Surgery," Appl. Opt. 40, 2200-2205 (2001)