Prior to the use of wavefront technology in laser vision surgery, only two components of the optics of the eye could be readily measured: defocus (nearsightedness or farsightedness) and astigmatism. These are referred to as lower order optical aberrations. Although they are responsible for most of visual blurring, they are not the only causes.
Higher order optical aberrations such as coma, tre-foil and spherical aberration among others are other fairly common geometric abnormalities of the cornea that cause blurred or distorted vision. These abnormalities cannot be corrected with regular glasses.
Wavefront technology was developed for use in analyzing and improving the optics of telescopes and other mechanical optical devices. It has been used commonly in laser vision surgery since the early 2000’s. Wavefront works by shining a laser light onto the retina and then analyzing the reflected light beam. An array of lenslets measures the deviation of the reflected light from where it should be if it were perfectly focused. Using complex calculations (Fourier method), the optical abnormalities of the eye can be reconstructed.
More than a diagnostic tool, wavefront technology is applied to the laser treatment as well. Once calculated, the optical abnormalities of an eye can be removed by programming the laser to precisely treat the abnormal areas . This is what is referred to as “custom cornea” laser vision correction. We use the VISX Wavefront with Fourier upgrade device in our center. It captures reliable wavefront assessments and integrates seamlessly with the VISX Star S4 IR laser.