Laser removal of dioptres by LASIK and PRK methods

The two most commonly used methods of laser diopter removal today are LASIK (laser in situ keratomileusis)and PRK (photorefractive keratectomy). Despite the fact that the patient’s recovery and return to normal life mode is much faster after LASIK, PRK has its advantages and is used in patients who are not considered suitable candidates for laser dioptre removal by the LASIK method. For this reason, the intervention itself is preceded by a detailed examination where, by taking maps of the cornea and observing its thickness and shape, as well as the quality of the tear film, the refractive surgeon decides on one of the mentioned methods.

In the LASIK method, the surface of the device is separated using a microkerat layer of the cornea by forming a flap or cover, one part of which remains attached to the cornea.  The PRK method implies the removal of the entire surface layer of the epithelium without forming a flap. After that, in both methods of laser dioptre removal, excimer laser laser beams remodel the exposed corneal tissue and thus remove the existing dioptre. After the action of the laser in the LASIK method, the flap immediately returns to its place and heals quickly, while in the PRK method, since the surface layer of the epithelium has been removed, it takes several days for it to regenerate and for new epithelial cells to cover the surface of the eye. The end result of laser dioptre removal is identical regardless of the method used to perform the intervention.

PRK method – advantages	PRK method – Disadvantages
Enables laser removal of dioptres even in people whose cornea thickness is insufficient to perform LASIK	Slower recovery than after the LASIK method of removing dioptres – it takes several days for the corneal epithelium to be renewed
Better option for patients with poor tear film quality	After LASIK the improvement in visual acuity is immediately visible, while with the PRK method it takes several days
There is no risk of complications related to the corneal flap as with the LASIK method of dioptre removal	There is a slightly higher risk of postoperative infection and inflammation with the PRK method of laser dioptre removal
The PRK method of laser dioptre removal carries a lower risk of pathological changes in thickness and shape corneas	A few days after PRK methods have more pronounced subjective complaints (swelling of the eyelids, tearing, feeling of discomfort), which disappear after the end of epithelization