Principles of Wavefront Imaging
What is the word “wavefront” actually mean?
Light falling on the cornea [the front surface of the eye] has a smooth curvature- referred to as a “wavefront”. As this smooth wavefront shape courses through the various optics of the eye, ocular aberrations [imperfections] are induced. It results in an irregular wavefront curvature reaching the retinal surface, which degrades the retinal image quality. An aberration-free eye would result in a smooth wavefront image on the retinal surface. Wavefront-guided customized LASIK, also referred to as “customized ablation” or custom LASIK performs corrections based on individual wavefront measurements.
Current refractive procedures such as traditional or standard LASIK correct lower order aberrations such as spherical and cylindrical numbers alone. However, higher order aberrations affect the quality of vision and may not significantly affect the vision as read on the chart. It is these subtle deviations from the ideal optical system, which can be corrected by wavefront procedures, and thereby improve image quality.
In simple words, to achieve a better result with laser eye treatment, if the data is entered in the wavefront laser using wavefront analysis, there is a possibility that one may be able to achieve better quality 6/6 or 6/5 vision (a line better than 6/6). Many LASIK centers use the term Custom LASIK. Ideally it stands for customized wavefront LASIK or laser eye treatment. However, many centres do not have a wavefront analyser, hence not possible to capture data in the wavefront format and mislead LASIK candidates to believe that they receive a custom LASIK treatment, when in fact doing a standard LASIK treatment, albeit on a wavefront laser.
Hence, most important to do one’s homework, understand the terminologies and then seek LASIK.