What exactly is the PRK technique?
The PRK Technique (Photo Refractive Keratectomy – Photorefractive Keratectomy) is based on the ablation of superficial layers of the cornea so as to change the curvature (shape) and focus the light rays correctly on the retina. It is one of the first techniques used in the field of refractive surgery and is characterized, to date, very safe. The procedure takes only a few minutes for each eye. Initially, local anesthetic drops are instilled and with a special tool refractive surgeon easily removes the surface film, in a central region of the cornea (epithelium). Then the excimer laser is acting on the corneal surface correcting refractive the errors (refractive errors).
After the tissue burn at the end of surgery, the surgeon places a therapeutic contact lens (at zero degrees). This lens has the ability to assist in healing of the membrane (regenerated epithelium) in the next four or five days. This operation is completely painless. But postoperatively, the patient is facing some inconveniences. However special eyedrops are given that help recovery.
When to use?
The photorefractive keratectomy (PRK) is used when the thickness of the cornea, according to the topography and pachymetry is not enough to allow the creation of a corneal flap (corneal flap – in the LASIK technique). It is also selected in cases of various epithelial abnormalities or scars.
What are the technical advantages of PRK?
- the epithelium can “forgiving” imperfections
- deflections are avoided
- more tissue that contributes to the industrial corneal stability
- more tissue in the case of re-operation
- reduced dry eye case
- absence of intraoperative / postoperative complications related to the creation of the flap
- application in difficult anatomy orbit
What exactly happens in the TransPRK Technique?
The feature that makes the TransPRK technique distinct is that the removal of the epithelium is performed by special software of the excimer laser with high accuracy (and not a special surgical instrument), creating an epithelial profile thinner in the center than in the periphery. The method is called no touch laser or no touch PRK because, virtually, absolutely no surgical instrument is in contact with the eye of the refractive patient.
All you need for refractive correction is the contact of the surgeon with the foot pedal (footswitch) of the excimer laser.