This article is from the Monthly Science et Avenir – La Recherche n° 903, dated May 2022.
Every year in France, 150,000 myops opt for so-called refractive surgery techniques. All are based on the use of lasers to sculpt the cornea to the nearest micrometer. This transparent anterior portion covering the eye in front of the iris and pupil plays the role of transmitting light to the lens and retina. And it is on its curvature that surgeons intervene, modifying it more or less in depth, in the center and in the periphery.
more maneuverable laser
“A cornea measures 550 micrometers and our interference range is a maximum of 20% separation, or about zero to 100 micrometers. “, specifies PR Alexandre Denauer, eye surgeon at CHU in Reims. Appeared in the 1990s, the leading technology is the excimer laser, followed by LASIK (laser-assisted in-situ keratomileusis). (Read S and A. n° 706, n° 828), But for ten years, with more manageable lasers, LASIK has been losing ground to other more recent approaches: “Smile (Small Incision Lenticule Extraction) and more Recent Trans PKR (Transepithelial Refractive Photokeratectomy), 100% laser only, no eye contact with no equipment “, explains the expert. This variety of techniques makes it possible to adapt to conditions: LASIK or PKR for low myopia (from -0.25 to -2.5 diopters), LASIK or SMILE for average, or in most cases trans PKR.
a complete preoperative evaluation
But not all myopes are operable, the National Agency for the Safety of Medicines and Health Products (ANSM) warns. Because even if the technique is effective (less than 1% reoperation, few complications), it is necessary to wait until the age of about 25 years, the mean age of stabilization of myopia as well as respecting contraindications, eg a corneal very It’s good. It is therefore of importance to contact an experienced surgeon who will conduct a complete preoperative assessment with precise examination of the cornea, corneal topography, making it possible to assess its thickness, its regularity, etc.
Also, for severe myopia (beyond -8 diopters), no laser but a possible alternative: the use of flexible or rigid implants placed in front of the lens, which may or may not last depending on the patient’s age. These gestures are rarer, more risky than laser techniques, which account for less than 5% of surgical procedures. In any case, this surgery is not reimbursed and costs around EUR 1500 per eye. “It remains to improve the outlook for myops over 40 and to be able to function on both far and near vision “, concluded the surgeon.
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