Customized spherical aberration in presbyopic LASIK with adaptive optics

E. Villegas, B. Leray, G. Perez, L. Hervella, F. Malecaze, P. Artal
Purpose: To evaluate the depth of focus achieved with a customized process to optimize Spherical Aberration (SA) in hyperopic/prebyopes LASIK patients with an Adaptive Optics instrument.
Methods: A group of 32 hyperopic/presbyopic patients were evaluated before and after LASIK surgery using an Adaptive Optics Vision Analyzer (AOnEye, Voptica SL, Murcia, Spain). This is a clinical instrument to perform visiual testing with full control of the optical aberrations induced in the patient’s eye non-invasively. It includes a wave-front sensor, a spatial light modulator to induce the desired aberration profile on the patient’s eye, and a micro-display to present visual stimuli. The customized process was performed in the non-dominant eyes of every patient to find out the optimal value of SA for acceptable far and near vision simultaneously. Different amounts of SA were presented to the eye sequentially and the Visual Acuity (VA) was evaluated. The criterion to select an optimal value of SA was: distance-VA higher than 0.50 (decimal) and near-VA higher than 0.60. In those cases that this criterion was not reached, the patient was not treated for inducing SA. After surgery, VA for far and near vision, and the deviation between the optimum and the induced values of SA were measured.
Results: A sub-group of 23 patients were selected for inducing the value of SA provided by the procedure. After surgery, those patients with a deviation lower than 0.075 microns (4.5 mm pupil size) between the target and induced amounts of SA showed average values of VA as 0.74±0.18 for distance vision and 0.78 ±0.07
for near vision respectively.
Conclusions: Hyperopic/presbyopes are good candidates for customized LASIK to induce SA for an extended depth of focus. This procedure is optimized when mediated with an adaptive optics instrument (AOnEye) to predict the right amount of SA to be induced.