TransPRK is a "no-touch" surface treatment. In PKR (photorefractive keratectomy) the laser ablates the surface of the cornea after mechanically lifting the epithelium (brush or spatula), the epithelium being the protective membrane of the cornea. For TransPRK, it is the no-touch excimer laser that performs this ablation prior to the refractive treatment, that is to say the vision correction treatment.
The operation is conducted under local anaesthetic with the use of eye drops a few minutes before the operation, which will numb the cornea. The patient is seated in a surgical chair that ensures perfect positioning beneath the laser. The use of a spreader maintains the eye in the open position without pain or risk.
The laser treatment lasts for around ten seconds. By removing a few microns from the surface of the cornea, it re-contours it and can correct the visual defect.
At the end of the operation healing drops are placed on the eye and analgesics are also prescribed.
Advantages: Its main advantage is safety.
Disadvantages: The disadvantages lie in the painful phenomenon that can subside for a few days. In some cases, a haze can arise that can delay visual recovery. This haze is most often minimum, but in rare cases it can be fairly intense and can affect the vision for several months before recovery thanks to medicinal treatments.
FemtoLASIK is an ALL LASER technique requiring 2 different lasers: the first, a femtosecond laser performs a cornea cap and the second the excimer laser is used for the visual correction.
In this method, the laser that corrects the vision is applied in the thickness of the cornea (not on the surface) after laser cutting a flap of corneal tissue, placed back at the end of the operation.
The operation is conducted under local anaesthetic with the use of anaesthetic eye drops a few minutes before the operation. The operation is conducted in an operating theatre with additional hygiene conditions required for cutting the cornea.
A suction ring is placed on the eye so as to keep it immobile during the operation. The femtosecond laser cuts by photodisruption, a painless and accurate action. When the cutting is complete, the surgeon uses a surgical spatula to lift the cornea cap cut in this manner. The corrective laser procedure can then begin, and it is strictly identical to that of surface PKR.
At the end of the operation, the surgeon replaces the cornea cap without any sutures and natural healing plays its role in 2 to 3 minutes. A protective shell can be placed on the treated eye as the corneal flap/cornea connection nonetheless remains fragile for a few weeks.
Advantages: Visual recovery is rapid with a few hours being enough in most cases
Disadvantages: A longer surgical operation, specific complications to laser cutting subsist, even if they are greatly reduced in comparison with mechanical cutting.
PresbyMAX™ is a non-invasive treatment for presbyopia using the same lasers as for the treatment of myopia. The presbyopia treatment can be associated or not with the treatment of another visual pathology (myopia, hyperopia, astigmatism).
In contrast with traditional laser treatment (PRK or femtoLASIK), several areas of vision are operated on the eye, in a similar way to the principle of contact lenses or multifocal intraocular lenses.
For near vision, the central part of the cornea is sculpted, and for far vision the outer edge, with the transition zone providing intermediate vision. Both eyes contribute equally in providing visual acuity at all distances (in contrast with Monovision, which improves distance vision for the dominant eye).
Patients with the greatest levels of satisfaction are those with presbyopia, followed by people with strong astigmatism, strong myopia, emmetropia (who have good sight without glasses) and weak myopia.
Excimer and femtosecond lasers are class IIb medical devices (as per European classification).
These are regulated health products that carry EC marking pursuant to this regulation.
They are exclusively for use by doctors.