The Lasik OP
Overall, the shape of the cornea is changed during Lasik OP. In myopia (Myopia) becomes a flattening where farsightedness (Hyperopia) aimed at a division by the Lasik in order to correct the visual defect.
After anesthesia of the eye (topical Anesthesia), an eyelid retractor is inserted into the patient for an optimal overview of the eye, which presses the eyelids apart and in this way keeps the eye open.
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In order to also immobilize the eye during the Lasik OP, the patient must permanently fix a point, the so-called "eye tracker". The operation at Lasik then begins with a corneal incision, which runs parallel to the surface of the cornea. At the same time, the eye is stabilized with a suction ring. The instrument used for this in Lasik OP is called a microkeratome. The approx. 150 µm thin corneal part, a corneal lamella (Flap), is then folded up so that the underlying corneal tissue (Stroma) by means of a special laser - excimer laser
Procedure of the operation
During the cutting process of the Lasik OP, the applied suction causes the increased eye pressure and the resulting impression of the optic nerve (Optic nerve) short-term blindness of the patient. Finally, the flap and the space below (interface) thoroughly rinsed, the flap folded back and fixed to the rest of the cornea. Rinsing during Lasik surgery is important so that no foreign bodies (e.g. dust particles) remain under the flap. Sutures or the like to fix the corneal lamella are not necessary, as this "sticks" to the rest of the corneal tissue. This is achieved through capillary forces and the inward liquid suction.
Finally, after the Lasik operation, an antibiotic, a steroid ("cortisone") and, if necessary, a nonsteroidal anti-inflammatory drug (NSAID) are dripped into the operated eye and protected with a sturdy shell or protective goggles for a total of three days. The flap is checked both after an hour and after a day. Postoperatively, antibiotic treatment (antibiotic eye drops) is necessary for a week. Steroid drops should also be administered for this long. To improve the wetting of the eye, the patient should regularly drip their eyes for one to six months after the Lasik.
The result of the Lasik OP is a thinned cornea which, due to the changed shape or thickness, now has a different refractive power, so that the original refractive error is corrected.
An excimer laser is a special type of laser that is used in a Lasik operation. The word comes from the English terms "excited" and "dimer“And means something like“ dimer excitation ”, whereby the term“ dimer ”is used for a compound molecule made up of two parts. As gas lasers, which include excimer lasers, they produce the actual laser radiation in the form of pulses. This is to be understood as a form of radiation that is not continuous, but with short interruptions (intermittently) is sent out. This pulsed radiation is created on the basis of the excitation of gas molecules in an energetically higher state. When these excited gas particles decay, energy is generated which is emitted as laser beams by the Lasik. These rays also have a certain amount of energy (fluence).
The indications for performing a Lasik operation are diverse. This includes an inadequate Visual acuity despite the correction of the visual defect by a glasses or intolerance of contact lenses. This occurs, for example, with dry eyes as part of an underlying disease (so-called Sicca syndrome, "Sicca" = Latin for "dry"). Even if a laser operation has already been performed, but the result does not correspond to the desired result, the indication for a new Lasik operation is made. Another indication for a Lasik is the job-related necessity to do without glasses or lenses, as is the case, for example, with pilots or police officers. The last thing to be mentioned in this context is the patient's wish, which is considered an indication for performing a Lasik.