Lasik MD
Your Guide to LASIK Eye Surgery
Lasers 101
Wavefront Optimized Treatments
Wavefront-optimized treatments contain both conventional and custom features and are only available on the Wavelight Allegretto laser. Wavefront-optimized treatments are not the same as the wavefront-guided treatments just described. The logic behind wavefront-optimized treatments requires a detailed explanation.
Because several opposing factors are in play, higher order aberrations are still increased with custom laser treatments. On the beneficial side, the patient's existing higher order aberrations are measured with the wavefront analyzer and treated by the laser. However, on the detrimental side, new higher order aberrations are induced by the laser treatment itself and, when LASIK or IntraLASIK is performed, by creation of the corneal flap. Therefore, most patients end up with a small net increase in higher order aberrations.
With conventional treatments, the higher order aberrations are increased even more because the preexisting higher order aberrations are not measured or treated.
Wavefront-optimized treatments can be thought of as a product of reverse engineering. A large number of conventionally treated patients were studied, and it was found that most of the increase in higher order aberrations was due to spherical aberration. Therefore, instead of measuring and treating an individual's unique aberration pattern, wavefront-optimized treatments aim to keep higher order aberrations down by simply adding in additional treatment for spherical aberration.
Proponents of wavefront-optimized treatments point to data that shows patients with normal levels of preoperative higher order aberrations end up with the same amount of postoperative higher order aberrations, regardless of whether a wavefront-optimized or wavefront-guided approach is used. Detractors point out that the additional spherical aberration treatment is based on population averages, and because some eyes deviate significantly from the average, it is better to use a wavefront analyzer to measure and treat each individual's exact aberrations.