Laser Treatment For Nearsightedness (myopia)

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Laser Treatment For Nearsightedness (myopia)
Laser Treatment For Nearsightedness (myopia)

Video: Laser Treatment For Nearsightedness (myopia)

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Video: Laser Eye Surgery (LASIK) 2023, January
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Laser treatment for myopia

In addition to correcting visual acuity with glasses or contact lenses, laser correction of the cornea can be carried out in the case of myopia (nearsightedness). The cornea is the foremost part of the eye where light rays arrive, which are then focused on the retina by the pupil and lens. In myopia, the eye is too long and / or the curvature of the cornea is too steep. As a result, the focal point (point at which rays of light meet) lies in front of the retina and the image for distant objects is out of focus.

The curvature of the cornea can be flattened with so-called excimer or femtosecond lasers. In this way, the focal point reaches the retina exactly again and the image of distant objects becomes sharp again.

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  • What laser surgical treatment methods are there?
  • LASIK and Femto-LASIK
  • SMILE (small incision lenticule extraction)
  • Surface treatments
  • How do excimer lasers and femtosecond lasers work?
  • How do you prepare for the procedure?
  • How does the procedure work?
  • When is laser treatment not possible?
  • What complications can arise?
  • Results of comparative clinical studies
  • Whom can I ask?
  • How are the costs going to be covered?

What laser surgical treatment methods are there?

The following laser surgical treatment methods are available:

Surface treatments using excimer lasers

  • PRK (photorefractive keratectomy), trans PRK (transepithelial PRK)
  • LASEK (laser epithelial keratomileusis)
  • Epi-LASIK (epithelial LASIK)

Lamellar excimer laser surgery

  • LASIK (laser in situ keratomileusis)
  • Femto-LASIK (LASIK with femtosecond laser)

Refractive lenticle extraction with the femtosecond laser

SMILE (small incision lenticule extraction)

Note By combining it with special diagnostic devices (wavefront, topography), the corneal surface can be measured precisely. This enables highly precise treatments to be carried out, which lead to even more precise results.

LASIK and Femto-LASIK

With LASIK, a corneal flap is formed using a microkeratome (plane) and pushed to the side, with Femto-LASIK this is formed using a femtosecond laser.

The cornea is then removed with an excimer laser and the flap is then returned to its original position. The complaints after the procedure (e.g. pain) are usually minor, the visual rehabilitation (resolution of complaints and achievement of the desired visual acuity) is quick.

Note Suitable up to -8 diopters (limit range -10 diopters).

SMILE (small incision lenticule extraction)

With this method, corneal tissue is cut out lens-shaped using a femtosecond laser with two laser cuts. This so-called lenticule is then removed through a small incision on the edge of the cornea.

Even after SMILE, it is possible to achieve very good visual acuity in the first few days after the procedure. The visual rehabilitation usually takes a little longer than with LASIK or Femto-LASIK.

Note Suitable for -3 to -8 dioptres (limit range -10 dioptres).

Surface treatments

LASEK

In LASEK, the top layer of the cornea is loosened with alcohol, then pushed to the side and returned to its original position after the laser treatment.

PRK (photorefractive keratectomy) and trans PRK

During this procedure, the upper corneal layer is removed mechanically or by means of a laser (trans PRK).

Epi-LASIK

With a fine, plane-like device, a particularly thin corneal flap can be formed during Epi-LASIK. It is therefore one of the surface treatments.

For all surface treatments, the cornea is also treated with an excimer laser. The epithelium grows back over the treatment area over the next three to four days. Pain can occur during this time. Visual performance is already better immediately after the procedure, but it takes longer than with LASIK or Femto-LASIK and SMILE until the final visual acuity is achieved.

Note Suitable up to -6 dioptres (limit range -8 dioptres); with additional astigmatism correction (up to 5 dioptres) the sum of the dioptres of both ametropia must not be above this limit.

How do excimer lasers and femtosecond lasers work?

The excimer laser is a cold light laser. The wavelength of the laser beams is in the ultraviolet (UV) range, so the excimer laser cannot cause any heat damage.

The laser beams of the femtosecond laser have a wavelength in the infrared range. With this laser, the cornea can be ablated particularly quickly - in a few 100 femtoseconds (10-15 seconds) - and finely at a predetermined depth.

For the treatment of myopia, the laser device is individually programmed and corneal tissue is ablated under computer control. Up to 20 percent of the corneal thickness and corneal tissue with a maximum diameter of seven millimeters can be removed. With modern devices, a laser eye tracking system detects eye movements during the treatment by the device and the laser treatment is corrected accordingly. In this way, incorrect removal of corneal tissue by inadvertent eye movements can be avoided.

How do you prepare for the procedure?

Before laser eye surgery, a detailed examination will be carried out by the ophthalmologist who will perform the procedure. Besides the

  • Measurement of the eye,
  • Assessment of the cornea or the fundus and
  • to determine the maximum pupil size, in particular the
  • The extent of myopia should be carefully examined.

Note: For this examination, soft contact lenses must not be worn for at least one and hard contact lenses at least two weeks beforehand.

How does the procedure work?

The correction of myopia is carried out on an outpatient basis. The laser surgical treatment usually only takes a few minutes. Due to the pre-treatment with the local anesthetic, the procedure is painless.

After the procedure, the eye surgeon prescribes antibiotic and anti-inflammatory eye drops; for surface treatments, bandage contact lenses must be worn for a few days. Eye rubbing should be avoided, initially there is still a low sensitivity to light. After the procedure, regular check-ups are carried out by the ophthalmologist.

When is laser treatment not possible?

Laser treatment to correct myopia is only possible from the age of 18, because the eye has not yet completed growth by this age.

Laser treatment cannot be performed in the following cases:

  • chronically progressive corneal diseases,
  • Keratoconus (caution is advised in relatives with keratoconus cases due to family history)
  • very thin cornea,
  • Cataract (cataract),
  • Glaucoma (glaucoma) with pronounced visual field defects,
  • advanced macular degeneration,
  • Eye infections,
  • rapidly changing ametropia as well
  • during pregnancy and breastfeeding and possibly after eye injuries.

Note Even with particularly wide pupils, laser surgery correction of myopia is not recommended. This could increase the occurrence of stray lights or halos (halos) at night.

When should the decision to undergo laser surgery be made particularly carefully?

  • Severe myopia can lead to reduced quality of vision (poor contrast). Other methods (implantation of an additional lens or refractive lens exchange) may be more suitable here.
  • In the case of presbyopia, only distant vision can be improved. Glasses are still required for reading.
  • The risk of vision deterioration following an eye injury may be increased after eye laser surgery. Individuals involved in risky sports or occupations in this regard should take this into account when making a decision.
  • The risk of complications is increased with:

    • Autoimmune diseases (e.g. rheumatoid arthritis),
    • dry eyes or
    • taking drugs that affect the immune system (e.g. HIV drugs, immunosuppressants) or visual acuity (e.g. certain drugs for high blood pressure).

What complications can arise?

Overall, complications after refractive laser surgery have become rare. This is due to the careful selection of patients and better technology.

Frequent complaints such as deterioration in vision at dusk and at night, scattered lights, shadows and halos (halos) usually recede after a few weeks. Inflammations that require treatment or wound healing disorders that can result in scarring of the cornea rarely occur.

With LASIK or Femto-LASIK and SMILE, nerves in the cornea that play an important role in the production of tear fluid are severed. Therefore, dry eyes occur particularly with these methods (usually temporarily) and must be treated with tear substitutes in the first few weeks.

Corneal opacity (haze) can lead to permanent glare sensitivity during surface treatments.

Very rarely, incision errors can occur or too little or too much corneal tissue can be removed. Wrinkles or shifting of the upper corneal layer can also occur. This can result in permanent ametropia, which can, however, be treated with eye surgery. The occurrence of postoperative keratectasia (irregular corneal curvature) can be reduced by careful patient selection.

Also very rarely it can happen with SMILE that not all of the corneal tissue cut by the laser can be removed through the small hole. This can cause irregularities in the corneal surface that reduce vision.

If the visual acuity is not satisfactory after the treatment, a correction can be made or glasses or contact lenses can be adjusted again.

Note The risk of complications generally decreases the more advanced the technique used is. The competence of the eye surgeon with regard to patient selection and mastery of the technology used also influences the complication rate.

Results of comparative clinical studies

With correct patient selection, the treatment results of the available techniques are very similar. The results of Femto-LASIK are best predictable.

The most precise results could be determined in small comparative studies in the first year after the procedure with techniques in which the corneal surface is precisely measured before the laser treatment. With these so-called individually adapted ablation profiles it can be precisely calculated how much corneal tissue should be removed in different areas. Clinical studies are currently still investigating whether the superiority of these techniques can be proven over a longer period of time. There are currently contradicting study results in this regard. These techniques cannot be used with SMILE.

After surface treatment, pain occurs more frequently than with LASIK or Femto-LASIK and SMILE. In addition, these treatments can take some time to achieve ultimate vision. Visual disturbances (e.g. blurred or veiled vision or double vision) can also occur more frequently with these interventions than with LASIK or Femto-LASIK and SMILE.

Dry eyes occur mainly with LASIK, Femto-LASIK and SMILE and resolve most quickly with SMILE.

People at high risk of eye injury may be more likely to benefit from surface treatment.

Whom can I ask?

The attending ophthalmologist can provide you with information on laser eye centers in your area.

How are the costs going to be covered?

The main association's health insurances cover the costs of refractive surgery for:

  • myopia greater than six diopters and

    • a proven medically justified contact lens intolerance due to e.g. corneal scars after keratitis (corneal inflammation) or a corneal ulcer (corneal ulcer) or
    • documented multiple attempts to adapt various types of contact lenses, both soft and dimensionally stable contact lenses
  • or if there is a difference in the ametropia in both eyes of at least three diopters and a combined contact lens intolerance.

With certain health insurance providers, you may have to pay a deductible (treatment contribution) (e.g. BVAEB, SVS, SVS, BVAEB).

For more information about the respective provisions, please contact your health insurance provider, which you can find on the website of your social insurance, for example.

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