[Effects of myopic correction by replacement of spectacles, laser in situ keratomileusis, and phakic intraocular lens implantation on modulation transfer function and retinal magnification].

To compare the modulation transfer function and the retinal magnification after myopic correction by replacement of spectacles, laser in situ keratomileusis (LASIK), or phakic intraocular lens (phakic IOL) implantation.Using the ray tracing method, we measured the modulation transfer function and the retinal magnification after these myopic corrections in a Gullstrand eye model.The modulation transfer function (3-mm pupil, 100 cycles/mm) after phakic IOL implantation for the correction of low, moderate, and high myopia was 45%, 44%, and 44%, respectively. These same measurements after LASIK were 50%, 47%, and 46%, respectively, and the same measurements after spectacle correction were 41%, 32%, and 21%, respectively. The retinal magnification was least changed by the amount of myopic correction after phakic IOL implantation, more changed by LASIK, and most changed by spectacle correction. Specifically, the improvement in the retinal magnification after phakic IOL implantation, LASIK, and spectacle correction for the correction of high myopia was 1.00, 0.97, and 0.88 times, respectively.There were no significant differences in the modulation transfer function after phakic IOL implantation and LASIK. On the other hand, the modulation transfer function was significantly decreased after spectacle correction, especially when the amount of myopic correction was large. The retinal magnification was least affected by phakic IOL implantation, more affected by LASIK, and most affected by spectacle correction. Phakic IOL implantation and LASIK are considered to be optically excellent correction methods.