Chemin de Beau-Rivage 18
1006 Lausanne
With a clear view ahead, you can overcome any challenge - take care of your vision!
Book your free laser consultation today and discover how you can start a new chapter in your life without visual aids.
The PRK technique (medical term: photorefractive keratectomy) is the oldest method of laser eye surgery. This technique removes a thin layer of cells from the surface of the eye, allowing the laser to model the underlying cornea. It offers an alternative for people who have a lower corneal thickness and are therefore ineligible for laser eye surgery using the Femto-LASIK procedure.
In the course of the PRK method, only a very thin cell layer of the cornea (= the epithelium) is wetted with a weak alcohol solution and then pushed to the side with a spatula, and is ultimately completely removed and not reused.
The surgeon has two options for removing the epithelium:
As soon as the eye is exposed, the cornea is shaped using a laser to enable light rays entering the eye to be precisely focused on the retina. Finally, a protective lens is placed onto the eye, which remains there until the epithelium grows back – usually within a few days. The full recovery of vision usually occurs after about one month, but it may take longer in some cases.
The PRK technique is often considered equivalent to the LASIK procedure, but the two methods differ slightly in the first step: while the epithelium is completely removed and not reused as part of the PKR technique, the tissue is returned to its original position after surgery in the case of LASIK surgery. However, both methods follow the same surgical procedure.
As with all ophthalmological topics, the PRK technique first involves a discussion with the ophthalmologist treating the patient, which explores suitable solutions for your visual impairment and explains the advantages and disadvantages of the different laser eye treatment methods.
After performing some tests, the ophthalmologist is able to tell patients whether their refractive error can be corrected using the PRK procedure. Of course, the PRK treatment method that best suits the individual needs of the patient will then be selected in consultation with the ophthalmologist.
The PRK procedure is fundamentally suitable for many people, as it can be performed even with thin corneal tissue.
Exclusion criteria for laser eye correction using the PRK technique are
Ophthalmic surgeons advise their patients not to wear hard contact lenses for at least four weeks before the operation or soft contact lenses for at least two weeks before the operation (contact lenses may affect the diagnostic tests carried out before the operation).
Laser eye correction using PRK procedures takes an average of 10 to 15 minutes and is performed on an outpatient basis using anaesthetic eye drops (local anaesthesia).
Chemin de Beau-Rivage 18
1006 Lausanne
Faubourg de l`Hôpital 81
200 Neuenburg
It is important that patients observe the following after the operation:
Follow-up appointments with an ophthalmologist usually take place one day and seven days, one month and thee months after the operation. A further check-up appointment is then scheduled one month after the procedure.
The TransPRK procedure – the further development of the PRK technique – is much gentler, since the eye does not come into contact with mechanical instruments. Instead, the uppermost layer of the cornea (i.e. the layer of the cornea that is not suitable for laser eye surgery) is removed minimally and without contact, thanks to state-of-the-art laser technology, which makes this technique many times more precise.
As it takes 10 to 15 minutes per eye to perform PRK technique, it is advisable to perform the procedure on both eyes on the same day, as this means less strain on the patient.
As an anaesthetic in the form of eye drops is applied to the eye for the procedure, which makes the corneal surface numb, the patient feels nothing for the entire duration of the procedure. After surgery, patients often describe a 'sandy sensation' in their eyes, although this sensation subsides after a few days.
The major advantage of the PRK technique is that it removes the uppermost layer of the cornea and avoids the creation of a flap, as is the case with the Femto-LASIK process. The method can also be used if the corneal layer is thin: the PRK procedure is an alternative procedure for patients for whom the Femto-LASIK procedure is not an option due to having a thin cornea.
The biggest disadvantage of the PRK technique is its safety profile, because the conventional PRK method has the following disadvantages compared with other laser eye procedures:
The cornea may become cloudy after the operation. Unclear vision or scarring is also one of the major postoperative risks associated with PRK treatment. The milky cloudiness of the cornea can be treated with eye drops and usually does not become a permanent condition.
It is also possible that the eyes will feel hard, uncomfortable and even itchy after the operation. This is due to the fact that it takes around five days for a new cell layer to grow back. As soon as this has happened, the ophthalmologist can remove the protective contact lens.