From PRK to FEMTOLASIK: the exhilarating journey of laser eye surgery
Laser techniques caused a real technological breakthrough in the late 80s of the 20th century. The incisional methods which consisted of making incisions in the corneal tissue to modify its optical power – such as radial keratotomy and keratomileusis without laser – became particularly obsolete thanks to the first generation technique, PRK (Photorefractive Keratectomy or ‘Photokeratectomy with refractive aiming’). The PRK allows in particular to sculpt the cornea of the eye with a precision of the order of a micron thanks to an excimer laser.
The steps of the PRK technique:
The epithelium or the most superficial layer of cells on the surface of the cornea is removed using alcohol, a laser, or a brush
The excimer laser changes the radius of curvature of the cornea.
A dressing lens is placed over the surface of the cornea to protect the eye and help it heal.
However, this method, which aims to correct myopia and astigmatism, has several disadvantages such as post-operative pain (72 hours), slow visual recovery, risks of infection and foggy vision, and the impossibility of operating both eyes on the same day.
In the 90s, the LASIK method (Laser Assisted in situ Keratomileusis or ‘Sculpture within the cornea assisted by laser’) was born. A second-generation technique, this involves using an automatic plane to create a cowl. The surgeon lifts the flap and acts on a deeper surface of the eye with an excimer laser. The hood is refitted afterwards.
This method does not cause post-operative pain, the risk of foggy vision is virtually absent, the operation of both eyes can be performed at the same time, and the recovery of vision takes place a few hours following the operation. However, the cover may be incomplete or irregular, and therefore unstable.
In 2008 appeared the femto-laser, allowing the development of LASIK in FEMTOLASIK. Instead of an automatic planer, a femtosecond laser is used to create a perfect cowl. The disadvantages due to cutting with the automatic plane are therefore avoided.
The steps of the LASIK and FEMTOLASIK techniques:
Cutting the flap or stromal flap: the outline of the flap is made with a mechanical blade microkeratome (LASIK) or with the femtosecond laser (FEMTOLASIK) to create the flap flap.
Corrective photoablation: using the excimer laser, the cornea is remodeled in its thickness within the corneal stroma.
Resting the flap on the reshaped corneal tissue.
This is a significant contribution to the safety, precision and quality of the results of the correction of myopia, astigmatism, hyperopia and presbyopia, even combined. However, of the 34 laser vision correction centers in Switzerland today, only 12 have opted for FEMTOLASIK, including MV Santé Vision.
From fiction to reality: the revolutionary SMILE
technique The most recent laser vision correction technique was introduced in 2014. A third-generation procedure, SMILE (Small Incision Lenticule Extraction) is minimally invasive, particularly painless and safe. The femtosecond laser from Zeiss notably enables exact correction and rapid visual recovery.
The SMILE can simultaneously treat myopia and astigmatism. This technique which avoids the cutting of a flap, modifies the curvature of the cornea; a lenticule is then created in the heart of the latter, then it is removed via a micro-incision. Healing is therefore immediate, and the resumption of normal life is done the next day, including non-aquatic sports, driving a car, work, make-up, and eye rubbing.
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