The physical principles of this method were first used in astronomy. Over ten years ago, the optics of the well-known Hubble space telescope were improved using wavefront measurement and suitable correction of aberrations.
Because similar anomalies in the bending of light within the eye negatively influence on visual acuity and quality of vision, this technology was soon also applied to the field of refractive vision correction laser surgery. In the eye, measurements of optical irregularities are performed by sending short impulses into a dense net of arranged laser rays. Whenever a special device is used to direct these rays towards the fundus of the eye, they travel through the entire eye, reflect from the fundus and re-emerge. At the spot they re-emerge, a special device is again used to measure and analyse the change in their wavelengths. On the basis of this change, it is possible to use complex computer analyses to calculate all of the irregularities in the bending of light within the eye. These irregularities are called optical aberrations and are the cause of poor visual acuity, worse visual contrast and unwanted phenomena such as glowing and glare.
Optical aberrations of a lower degree that are the consequence of an incorrect curvature of the cornea and length of the eyeball are better known as nearsightedness, farsightedness and astigmatism. These aberrations can already be discovered in standard examinations and by measuring dioptre. In 15 to 20 percent of individuals who don't see well, optical aberrations of a higher degree are also present. These include chromatic, coma and spherical aberrations. In spite of successful standard laser refractive vision correction, these aberrations can still diminish the quality of vision, particularly in poorly lit conditions.
Wavefront analysis of the eye uncovers these more complex optical irregularities of the cornea. These irregularities are taken into consideration in calculating a sample of laser cornea smoothing during Wavefront guided laser correction. The laser surgery itself is completely individualized and adapted to all the peculiarities of your cornea. Using Wavefront laser surgery, we can in addition to correcting nearsightedness, farsightedness and astigmatism, also correct all optical aberrations of a higher degree - which can significantly improve quality of vision. This method of laser correction can be used with LASIK/SBK and LASEK surgery techniques. The expression CUSTOM LASIK/LASEK is also frequently used for this method of laser refractive vision correction.
The LASEK method, which we use to correct refractive error in nearsightedness, farsightedness and astigmatism, is used in patients who have a very thin cornea. This applies to approximately 5 percent of our patients. The essential advantage of surface smoothing techniques is that they are technically less demanding, while the disadvantage is that the restoration of visual acuity is slower after surgery.
Refractive vision correction with intraocular lens implantation is similarly as successful and reliable as laser surgical procedures but is due to its somewhat more limited indications not as widely used or as well known. This procedure of refractive vision correction is performed by implanting an artificial lens into the eye and is also successful in refractive vision correction in patients with a high dioptre as well as in patients whose cornea is too thin to be suitable for laser surgery.
Age-related farsightedness can successfully be treated with the insertion of a special, multifocal lens that enables good near and far visual acuity. The best results of this type of surgery are achieved in patients in which age-related farsightedness appears alongside an already present refractive error, regardless of whether this is nearsightedness or farsightedness.