Unfortunately, there is no causal treatment for myopia. Therefore, the defective person has no choice but to put on glasses or to struggle with contact lenses. In addition, there are also surgical procedures with a special laser (excimer laser), which are now scientifically recognized and established. However, these treatments are not suitable for everyone and are not without risk. They require an experienced corneal or eye surgeon and should only be performed in clinics that have routine with this treatment. Furthermore, it should be remembered that surgical treatment of myopia is not a health insurance benefit and must be borne by the patient.
Photorefractive keratectomy (PRK).
In “photorefractive keratectomy,” a laser beam is used to remove tissue from the cornea. For myopia, the central cornea is selectively flattened, with the result that incident light is refracted more weakly after treatment. This procedure is used only for moderate myopia (up to a maximum of -6 diopters). In 90 percent of those operated on, the defective vision can be reduced as a result (to a value between +1 and -1 diopter). The best results are achieved with low myopia. The operation, which is performed on an outpatient basis, takes only a few minutes. The eye is anesthetized with drops beforehand. The doctor uses an instrument to remove the top covering layer of the cornea – the epithelium. Then the laser removes the predicted amount of cornea on a diameter of 6 to 7 millimeters. The procedure is not very stressful for the patient, as it is painless and – thanks to the laser – also contact-free.
After the eye surgery
Immediately after the procedure, visual acuity is reduced. In addition – when the effect of the eye drops wears off – pain occurs, which already subsides after 2-3 days. The refractive power of the eye may still fluctuate in the first months after the treatment. Increased sensitivity to light and glare and slight corneal opacities may last a little longer (about half a year). In addition, over- or under-correction may occur as a result of treatment, requiring a second procedure or the continued wearing of visual aids. PRK has been used since 1986 and was classified in 1995 by both the German Ophthalmological Society and the Professional Association of Ophthalmologists as a scientifically recognized procedure for the correction of myopia up to approximately -6 diopters and astigmatism (pathological change in corneal curvature) up to approximately 3 diopters.
For severe myopia: “laser in situ keratomileusis” (Lasik).
For more severe nearsightedness, another laser method comes into question, the so-called “laser in situ keratomileusis” (Lasik). In this method, a thin flap of the cornea is first almost cut off and folded back. Now, the laser is used to remove tissue inside the cornea. Then the flap is folded back again and after a few minutes the cornea has sucked the adjacent flap back in. Finally, eye drops are administered and a bandage or a bandage lens is applied This method has proven particularly successful for myopia in the range of minus 4 to minus 10 diopters. Here, the success rate is between 70 and 90 percent, depending on the initial value of the refractive error. In most clinics, the surgery is performed on two consecutive days or both eyes are operated on in one session.
Also for farsightedness
Farsightedness can be corrected by Lasik up to +3 diopters, with some limitations even up to +5 diopters. In this procedure, corneal tissue in the periphery of the cornea is removed by laser. The central, and thus optically effective, cornea is thereby divided in such a way that a “plus lens” is created. LASIK has been used since 1990 and was classified in 1999 by both the German Ophthalmological Society and the Professional Association of Ophthalmologists as a scientifically recognized procedure for the correction of myopia up to approximately -10 diopters and astigmatism up to approximately 3 diopters.
Risks and side effects
The advantage of LASIK over PRK is that the surface of the cornea is not destroyed. Therefore, scarring is much less than after PRK and there is no pain after surgery. The risk of seeing worse after LASIK surgery than before is very low. The complication rate for LASIK is less than 1%.However, as with any medical procedure, a residual risk can never be completely eliminated:
- In twilight or darkness, glare and the perception of halos and double contours may occur. This may limit driving ability during nighttime driving. However, these changes usually occur only in myopia above -5 diopters and in hyperopia.
- In rare cases, rubbing of the eye may cause displacement of the corneal flap, which requires a new operation.
- Rarely, ingrowth of the superficial corneal layer under the corneal flap may occur during the first few weeks. Also in this case, another operation may be necessary.
- In very rare cases, too much weakening of the cornea can lead to a protrusion (keratectasia).
- Very rarely, there is a deterioration of vision or infection with scarring.
