Refractive surgery in Paris
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REFRACTIVE SURGERY: DEFINITION
The first refractive surgeries were performed in the 1970s in Russia using radial keratotomy. The first PRK procedures were carried out in 1983, followed by the first LASIK and Phakic IOL implants in the 1990s.
There are two main categories of techniques:
- Subtractive techniques, which involve >the cornea and are based on removing a layer of corneal tissue with a LASER (PRK, LASIK, SMILE, etc.).
- Additive techniques, which involve placing an intraocular lens (Phakic lens implant, clear lens extraction surgery).
Each year, 200,000 patients undergo laser refractive surgery in France, making it the second most common eye surgery after cataract surgery. The most widely used techniques are PRK and LASIK. For patients deemed suitable after a preoperative assessment, these are safe and well-controlled procedures.
Numerous studies have evaluated the satisfaction and success rates of refractive surgery. The satisfaction rate is excellent, at 95% in the general population, and also 95% in a study of patients who themselves are ophthalmic surgeons specializing in refractive surgery.
TYPES OF REFRACTIVE SURGERY
Corneal anatomy
The cornea is the most anterior part of the eyeball, in direct contact with the external environment. It is a transparent, avascular tissue. Its anterior surface is covered by the tear film, while the posterior surface is bathed in aqueous humor.
PRK
Photorefractive keratectomy (PRK) corrects visual defects using an excimer laser applied to Bowman’s layer and the anterior corneal stroma after removing the superficial corneal layer (the epithelium, about 50 microns thick).
LASIK
All-laser LASIK is the most commonly used technique in refractive surgery. It is a reference procedure with long-term data, allowing correction of myopia, astigmatism, hyperopia, and presbyopia. Currently, about two-thirds of laser refractive surgeries are performed using LASIK.
Trans PRK
Trans-epithelial PRK is a recent technique derived from PRK. It offers the same safety and efficacy benefits but with faster visual recovery and less initial discomfort. The corneal epithelium is directly photoablated with the excimer laser. This is a completely contactless and therefore totally painless procedure.
PRESBYLASIK
Various surgical solutions exist to address both sphero-cylindrical ametropia (myopia, hyperopia, astigmatism) and presbyopia simultaneously.
PHAKIC LENS IMPLANT
This is the reference technique for high ametropia (severe myopia or hyperopia) and for patients whose corneas are unsuitable for laser treatment. It involves placing an ICL V5 intraocular lens (from Staar Surgical) in a straightforward, controlled surgical procedure.
PRELEX
PRELEX stands for “presbyopic lens exchange.” Approved by the FDA in 1997 at the initiative of two American ophthalmologists, this technique consists of extracting a clear lens and implanting a multifocal intraocular lens.
Frequently asked questions
I cannot see well at distance or near, so I use progressive lenses. Is it possible to have surgery that will last over time?
It is indeed possible to treat presbyopia surgically to free you from progressive lenses. Your eligibility will be determined during the preoperative assessment with your surgeon.
What is the preferred technique for correcting high myopia
High myopia, defined as greater than -6 diopters, can be corrected in several ways (LASIK, PRK, Phakic lens implants, etc.). The choice of technique will be determined by your preoperative examination. PRK can indeed correct high myopia. However, in both LASIK and PRK, myopia is corrected with the excimer laser, which reshapes the cornea by performing a photoablation of the central corneal stroma. The higher the myopia, the more stroma must be removed, increasing the risk of “haze” (corneal scarring opacity after PRK). There is no consensus on the maximum amount of stroma that can be ablated with PRK, but it is generally accepted that beyond 100 microns of ablation (corresponding to about 6 to 8 diopters of myopia), the risk of haze must be considered. In such cases, your surgeon may prefer LASIK, which does not carry a risk of haze.
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This page was written by Dr. Camille Rambaud, an ophthalmologist based in Paris and a specialist in refractive surgery.
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