Arquivos Brasileiros de Oftalmologia
Print version ISSN 0004-2749
CARVALHO, Luis Alberto Vieira de. Computational simulation of customized photorefractive surgery and precision of correction related to different order aberrations. Arq. Bras. Oftalmol. [online]. 2007, vol.70, n.6, pp. 917-923. ISSN 0004-2749. http://dx.doi.org/10.1590/S0004-27492007000600006.
PURPOSE: To develop and implement an algorithm for simulation of photorefractive surgery. It is well known that many flying-spot lasers in the market have limitations in correcting higher order aberrations, but there is little quantitative information about errors related to aberration complexity. METHODS: By applying known surfaces described by Zernike polynomials of different orders it was possible to simulate several target surfaces that may well resemble in vivo cases of refractive surgery candidates. An algorithm that uses the mathematical concept of convolution was implemented and several simulated surfaces were tested, ranging from low order aberrations (sphere-cylinder) to 10th order aberrations, (high orders of coma, spherical aberration, trefoil, etc). RESULTS: the results show that the laser profile and diameter are critical factors when considering the correction of higher order aberrations. CONCLUSIONS: Not all aberrations of the same high order induce the same amount of error - spherical aberrations are shown to be far more difficult to correct than higher order aberrations related to angular frequency.
Keywords : Refractive errors [surgery]; Computer simulation; Refraction, ocular; Calibration; Algorithms; Surgery, computer-assisted.