FEMTO-LASIK AT FOCUS TOP-MEDICINE 2018 EUROEYES

LASIK (laser in situ keratomileusis) has been a scientifically recognized and established procedure for the correction of ametropia for many years and is therefore one of the worldwide preferred surgical methods of many eye specialists.This classical LASIK method has been developed decisively in recent years: to Femto-LASIK.In order to correct a defective vision with LASIK or Femto-LASIK, a small round corneal cut must first be prepared. The preparation of this corneal cut, also known as flap, is carried out with a micro-knife in classical LASIK. In Femto-LASIK, a femtosecond laser prepares the flap completely without the use of mechanical cutting instruments.

Femto-LASIK is a precise procedure for creating the corneal flap. Therefore, when choosing a clinic, you should always make sure that a femtosecond laser is used for eye laser treatment with one flap.

The femtosecond laser is an infrared laser that can treat tissue very precisely with significantly less heat created than other laser treatments a big advantage in laser eye surgery. Femtosecond lasers work with ultra-short light impulses that need only a billionth of a second to create a spot as tiny as 1/100mm. To illustrate the extremely short pulse time: In one second, light travels 7.5 times around the earth, however, in one femtosecond, it only travels one half of the thickness of a hair!

A specially developed laser system, the femtosecond laser VisuMax from Carl Zeiss, is used for ReLEx treatment. This system has already proven itself in Femto-LASIK procedures due to its sophisticated technology, precision and reliability. Through appropriate further development, it now makes it possible for the first time to prepare a lenticular tissue within the intact cornea with millimetre precision, so that larger incisions and a flap can be dispensed with. In this way, the surrounding corneal tissue is spared as much as possible and the visual defect can be corrected in a targeted manner. A particular advantage of the femtosecond technology, in addition to its high precision, is that it is highly reproducible and can be accurately predicted even when high corrections are involved.

In order to prevent the cornea from being unnecessarily compressed, a contact lens is used which is adapted to the individual corneal anatomy and allows a precisely fitting treatment. This also prevents short-term vision loss, which can be caused by excessive intraocular pressure.

In addition to state-of-the-art laser technology, a functionally sophisticated and ergonomically shaped patient couch has also been developed for ReLEx treatments, which provides maximum comfort and a relaxed position during the procedure. During the operation, the patients position is continuously monitored and can be automatically adjusted if necessary.

Contrary to traditional lasers, the energy of the laser beam from a femtosecond laser does not affect the tissue on the corneal surface, but reaches a specific predetermined depth inside the cornea. Very high energy levels can thereby be achieved through intense focusing of the laser beam. The point of focus of the laser beam allows material to be divided at the molecular level (photo-disruption), gently separating the tissue. The surrounding corneal tissue remains undisturbed without damage. The femtosecond laser scans the cornea starting at one edge and works its way towards the other side. The laser beam produces a layer of tiny bubbles in exactly the desired location depth of the cornea. This enables the corneal flap to be opened and lifted to the side like in traditional LASIK. The final treatment with the excimer laser is then identical to traditional LASIK.

Schematic Representation:

The Laser energy is focused at a precisely predetermined depth of the corneal tissue.

A micro bubble consisting of gas and water is generated (diameter: 5 12 m). The bubble expands and separates the surrounding corneal layers.

The photo-disruption results in a mixture of carbon dioxide (CO2) and water. The epithelial pumping action makes sure the latter is absorbed. What remains, is the separated corneal tissue.

The photo-disruption results in a mixture of carbon dioxide (CO2) and water. The epithelial pumping action makes sure the latter is absorbed. What remains, is the separated corneal tissue.

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FEMTO-LASIK AT FOCUS TOP-MEDICINE 2018 EUROEYES