Hyperopia and hyperopic astigmatism correction with the SCHWIND ESIRIS: 1-year results

surgery has opened up the possibility to change the corneal curvature to compensate for refractive errors of the eye. In the case of small spot hyperopic laser in situ keratomileusis (H–LASIK), excimer laser systems produce a steepness of the cornea by ablating mainly at the periphery of the cornea. Hyperopic laser in situ keratomileusis (H-LASIK) treatments induce aberrations1. Other studies2,3 attempted to determine the changes in corneal asphericity after H-LASIK, and found a extreme corneal prolateness, indicating large amounts of induced negative spherical aberrations. This is predominantly caused by the loss of efficiency4-7 at the periphery and the biomechanics of the cornea, and has been described previously by other authors8,9. Later studies on hyperopic treatments with excimer lasers also suggested an increase in negative spherical aberration10,11. By comparison of the intended and achieved topographical changes after H-LASIK surgery, de Ortueta et al.12 obtained information as to whether the corneal power was changed as calculated, thus providing help in optimizing the ablation profiles (either in terms of nomogram adjustments or more sophisticated optimization algorithms like multifocal algorithms). Additionally, actual underor overcorrection can be differentiated from underor overcorrection due to wrong intended correction in this way. A study by O’Brart et al.13 analyzing hyperopic LASEK using a Munnerlyn based classical profile and a