Due to the guidelines of the Commission of Refractive Surgery Germany LASIK is suitable for the elimination of:
The first step in the LASIK-OP is the preparation of a thin flap of 120 up to 140 microns with an oscillating blade made of steel in form of a microkeratome.
Then, the flap will be deflected and the genuine corneal ablation will be performed using an excimer laser.
Afterwards, the flap is repositioned properly
The flap acts like a contact lens and diminishes the irritation of the treated corneal surface (so-called “deep treatment”, please compare to „surface treatment/LASEK/PRK“).
Thus, postoperative pain is less common and the time needed for visual recovery compared to LASEK/PRK therefore is reduced up to 4 or 5 days.
During the plano-scan LASIK procedure the corneal tissue is evenly abladed by the laser beam. Thus, it is often also called “standard-LASIK”.
Using the asheric profil means to ablade the corneal tissue in an “egg-shaped” way using a “flying spot” laser beam, similar to an american football. Therefore, a better contrast sensitivity (i.e. night-vision) is reached postoperatively.
A special mathematical algorhythm is used in the tissue-saving profile in order to save as much corneal tissue as possible during the laser ablation time in case of “borderline cases” with regard to the initial corneal thickness when the “standard LASIK” procedure is no longer possible.
In case of the application of the wavefront guided LASIK procedure, which is often also called “individualized” or personalized treatment” LASIK, the eyes are measured preoperatively using a wavefront pattern scanner. Thus, rays of light placed in a special set of array are led into the eye and are deflected by certain structures in it. The degree of this deflection by the reflected rays of light are measured, leading to the so-called “aberrations”. These aberrations e.g. in form of halos around light sources can subjectively be very annoying.
By using the wavefront guided LASIK procedure these phenonema can be eliminated and therefore result in an optimum of visual acuity as well in daylight as in night-vision.
The Femto-Lasik procedure differs from the standard LASIK procedure in that manner, that a femtosecond laser is used for the preparation of the flap, which uses ultrashort laser impulses to cut through the corneal tissue in a depth of free choice.
This procedure offers the advantage of fewer flap-cut-complications in comparison to the use of a mechanical microkeratome. Further more, clinical studies have proven the better adhesion of the flap in case of performing a Femto-LASIK instead of using a microkeratome.
Due to the guidelines of the Commission of Refractive Surgery Germany LASEK/PRK is suitable for the elimination of:
shortsightedness up to -6 diopters
astigmatism up to -5 diopters
LASEK/PRK are unappropriate procedures for eliminating farsightedness!
When performing the LASEK/PRK procedure only the upper 50 microns of the corneal surface are soaked using an alcoholic solution and are wiped off with a spatula.
Then, the genuine corneal ablation will be performed using an excimer laser (so-called “surface treatment”, please compare to “deep treatment/LASIK“). Due to the superficial defect caused by this procedure the application of a protective contact lens on the cornea postoperatively is unevitable in order to minimize resulting pain.
The contact lens should be kept on the cornea for about 4 up to 5 days for the corneal epithelium to heal beneath.
The time period for postoperative visual recovery is about 2½ up to 3 weeks time.
In young adults the eyes are still allrounders. They are able to focus flexibly on everything in the near and the far distance as the intraocular lenses are bended adequately to alter the lens power in order to provide us with excellent visual acuity. This process is called accomodation. In most cases, beginning in the mid-fourties, this ability tends to fail. At that time presbyopia starts. I.e. the eye does not focus properly any longer on things in the near distance – therefore reading glasses are needed.
Based upon the LASIK procedure, which has been well established within the last decades, both eyes are treated in a single session using a special ablation profile for the correction of the underlying presbyopia. Thus, an alteration of the central corneal power is achieved. This is done simultaneously while correcting the ametropia for the far distance. Hence, things in the near distance return to become more distinct again as the focal point is projected right on the retina. But also in the intermediate distance, e.g. while using a computer or recognizing traffic signs the SUPRACOR™ procedure is able to improve the visual acuity. 96 percent of the treated patients are able to read the newspaper or use their computers without wearing glasses.
The most suitable patients for the SUPRACOR™ procedure are hyperopics (+1.0 to +3.0 diopters for the far distance), who are older than 50 years and who are already wearing reading glasses for a couple of years.
The INTRACOR™ procedure is suitable for the elimination of early stages of presbyopia. Five concentric rings are cut into the corneal stroma (middle layer of the cornea) of the non-dominant eye by a femtosecondlaser without even opening the cornea itself. The treament only lasts about 18 seconds. Short time afterwards everything in the near distance can be seen more distinct again. The non-treated dominant eye is still capable to view properly in the far distance. Thus, this is called monovision. Therefore the INTRACOR™ procedure is not suitable for activities, which depend on stereoscopic or higher contrast perception. The INTRACOR™ procedure should be preferrably performed in patients who do not need glasses for the far distance and whose correction of the underlying presbyopia is less than +1.0 diopter.