Friday, January 17, 2020

Eye laser: finally a look?

Seeing clearly without glasses or contact lenses - for many people with defective vision, this is a dream. Laser surgery could fulfill this wish.



It foggy on cold winter days. In summer, when you sweat, it slips off your nose - when doing sports anyway: Even when glasses sharpen your vision, it can be quite annoying. Those who switch to contact lenses struggle with other problems, such as dry eyes or inflammation. Over 20 million people in Germany are short- sighted or far-sightedrelying on a visual aid. But more and more of them want to do without it and are ready to lie down on the operating table. "Around 150,000 people have their eyes lasered in Germany every year," says Professor Michael Knorz, ophthalmologist and head of the FreeVis Lasik Center at the University Clinic in Mannheim. In 1993 he introduced the Lasik method in Germany. Back then, fine knives were used for the intervention. Today, laser beams alone do the fine cuts on the eye. "This has made the procedures more precise and less risky," says Knorz.




We now have a number of eye laser centers. The eye correction business is booming. On radio, on buses or in newspapers, providers use slogans such as "Never again glasses" to promote the new quality of life after the operation. The procedure does not take longer than half an hour. A short time later, the patients should be able to see clearly.

But does the method do what it promises? Many doctors are still arguing about their benefits after more than twenty years. In the American PROWL study from 2016, newly operated patients were interviewed about the side effects of the procedure. To ensure that they were not influenced, the treating physicians had neither access nor access to the questionnaires. The investigation showed that the majority of the patients were very satisfied with the result after the operation. However, a third of the respondents complained of dry eyes , a foreign body sensation in the eye or poor vision at night.

Poor vision after lasering



Many German experts are also critical of the intervention. A common argument is that surgery is not essential, you can wear glasses. "A product is sold for which there is no medical need," says Dr. Andreas Berke from the secondary school for optics in Cologne. Often the ametropia is not completely eliminated even after an intervention. Many patients cannot manage without glasses even with lasered eyes. And at the latest with the onset of presbyopia between the ages of 40 and 50, vision deteriorates again and reading glasses are required. The intervention does not fulfill the dream of lifelong freedom from glasses. Dry eyes are very common after the operation. If a high level of ametropia (from approx. -6 diopters) is corrected, the side effect that one can see poorly in the dark or at dusk can be massive: "Sometimes it is even so strong that the patient can no longer drive a car at night" , says Berke.

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Knorz knows these side effects: "It is not uncommon in the first few weeks after the procedure, but these symptoms usually go away on their own after half a year." It is important to follow the doctor's instructions exactly after the procedure, to put the drops in the eye and to carry out the follow-up checks. "In the weeks after the operation, the visual acuity may fluctuate temporarily for hours or days," says Knorz. "The eye usually takes some time to get used to the new circumstances."

Two methods for a clear view


The most common in Germany is the so-called Lasik method. The abbreviation Lasik stands for laser in situ keratomileusis. A femtosecond laser cuts a semicircle into the cornea. The surgeon then opens the corneal lid: a second laser grinds the cornea underneath somewhat. A few thousandths of a millimeter removed is enough to change the refractive power and correct the ametropia. Finally, the lid is put back on the eye.

Since 2011, a further developed, gentler procedure has been used: With the surgical technique called ReLEx Smile (refractive lenticule extraction), the laser beams underneath the cover skin detach tissue from the top corneal layer, which is then removed by a tiny incision.



Only the attending doctor can determine which method is more suitable. Various preliminary examinations provide information about this. Knorz emphasizes how important these examinations are: "Because not all ametropia can be remedied by laser surgery." Problems after an operation could arise especially when patients come under the laser whose eyes are actually not suitable for the procedure. Thorough preliminary examinations, in which, in addition to the thickness of the cornea, the nature of the cornea and the diameter of the pupil are determined, doctors can determine whether the eye is suitable for an operation. The number of diopters also plays a role: "With standard procedures, ametropia can be up to about minus eight in the case of myopia , in one Farsightedness can be corrected up to approximately plus three, "says Knorz.

Find the right doctor


In order to support patients in the choice of doctor, the Refractive Surgery Commission has defined quality criteria at the Association of Ophthalmologists. Patients can find all information about the procedure and a list of certified doctors on the website of the professional association of ophthalmologists in Germany ( Augeninfo.de/krc ). They have committed to perform operations according to the current recommendations of the professional association for ophthalmologists and the German Ophthalmological Society and to undergo regular training.

A thorough preliminary examination, an experienced doctor and even the most modern technology cannot guarantee that you will not have to wear glasses for a lifetime. But they are the prerequisite for the treatment to be safe and successful.