Understanding Vision

Surgery in lieu of glasses?

Enjoy excellent vision again without glasses – this is what laser surgery promises. But beware: The procedure does have inherent risks

12 March 2022
  • Surgery in lieu of glasses?

Many people who suffer from visual impairments get very excited when they hear commercials hailing laser eye surgery as totally risk free. For patients whose vision is so poor that they can only perceive their environment with a visual aid, this does indeed sound very tempting. However, there is an important fact anyone considering eye surgery should remember – such an operation is always performed on healthy tissue. There are definitive risks and patients could sustain permanent damages.

It sounds so easy: The laser procedure only lasts 30 seconds; it is supposedly completely painless and on the very same day the eye should see sharply again. For 20 years now, doctors have been engraving the optical refractive power of the visual aid into the cornea using the explosive pulse of laser beams. If all goes well, the patient will not need spectacles any longer. That is in a perfect world – however, laser surgery is not completely risk free.

There are fundamental concerns patients planning to have laser eye surgery should consider:

  • It is not for people under 21 years of age because the eye’s growth is not yet complete;
  • It is not for ametropia that has recently changed by more than 20%;
  • It cannot be used on lachrymal disturbances of the corneal surface due to insufficient tear film;
  • It also cannot be used on patients with eye diseases such as virus-related corneal inflammations; nor on
  • Patients with cataracts, because the condition requires traditional surgery first. The cloudy eye lens must be replaced by an artificial lens. The decisive advantage: Distance spectacles are usually no longer needed after the operation;
  • It is not for pregnant women, because the ametropia can be unstable during those nine months;
  • Do not have the surgery if you suffer from general illnesses such as such as rheumatism, wound healing impairments, metabolic diseases, monophthalmia;
  • It should not be used on very severe cases of ametropia (more than -6.00 dpt or more than +4.00 dpt)

Complications that can occur as a result of laser surgery

When you listen to the grandiose promises made by eye laser clinics, you would never even think that a laser eye procedure can result in numerous complications. In fact, a disruptive sensitivity to glare and a declining mesopic vision can be consequences of the procedure. Light objects can appear extremely glaring, and rays can emanate from light spots like fireworks.

Also possible is the haze effect, in which coronas appear around light sources primarily at night. Or “ghosting,” in which a ghost image appears next to a sharply perceived image like a shadow that is slightly shifted. Many times the damage caused to the eye is irreparable.

Around 40 percent of the people who have undergone laser surgery also suffer from temporarily or permanently dry eyes. Another thing to keep in mind: The more severe the myopia, the more of the cornea the laser has to evaporate. The long-term consequences of this procedure, which results in a much thinner cornea, cannot be foreseen at present.

A life without spectacles?

No question: Laser methods have considerably improved over the past 20 years. Even so, the hope to be able to live without glasses is not always fulfilled. Refractive eye surgery cannot achieve accurate correction with zero dioptres, which is indeed possible with spectacles.

Another improvement that can only be achieved by spectacles or contact lenses is the ability to flexibly adapt to changing conditions. Patients should keep in mind that spectacles for presbyopia are possible as of the age of 40 to 45. People who suffer from this impairment and have undergone laser surgery will still need reading glasses.

Moreover, ametropia is not a stable factor. It can change and does in three percent of all cases over a period of several years. There is an increased risk, particularly among patients who were severely ametropic, of the impairment worsening again three years after the laser procedure. Furthermore, hormonal disorders and connective tissue diseases can make a person myopic again.

How laser surgery works

Multiple laser surgery methods are now available. Lasik surgery is the one most patients know about and it is the most widespread. The procedure itself is performed in three steps:

  1. Cut
    A thin sheath (flap, approx. 0.14 mm thick) is cut from the upper corneal layer to around 90% with an automatic micro plane.
  2. Laser
    The flap is folded like a book cover. The laser beam evaporates the corneal tissue in the optical zone for myopia, on the outer edge for hyperopia.
  3. Protect
    Finally, the flap is folded back into its original position like a natural bandage. The flap adheres there, but will not permanently grow together again.

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