The term Refractive Surgery comprehend all the techniques to correct refractive errors (myopia, hyperopia, astigmatism) acting on the cornea.
Usually, these defects are simply corrected with glasses or contact lenses.
But sometimes the patient doesn’t benefit from these aids, for example in the case of a very strong defect, or when there are big differences between one eye and the other, or even for job necessities (ex. aviation) or just to not depend on glasses in daily activities.
The operation is definitive and you could recover a 10/10 vision. In the most serious cases could remain a slight defect, but it could be corrected with a second minor operation.
The technique involves the removal of part of the corneal tissue according to certain profiles depending on the defect that has to be corrected. The challenge for the physician is to obtain a new lamellar epithelium that is smooth and polished, with a gradual transition to the untreated surrounding tissue, to facilitate a rapid and fast re-epithelialization.
Between the most common techniques we found:
– PRK (PhotoRefractive Keratectomy): it utilizes laser pulses to remold the ocular surface. It doesn’t burn tissues, but it vaporizes them breaking the molecular bonds.
– Lasik (Laser-Assisted In Situ Keratomileusis): there is an early uplifting (not the removal) of a thin layer of the corneal tissue (flap). Afterward, the excimer laser is used to remove part of the tissue. The flap is repositioned over the cornea without stitches and assumes the new curvature.
Following these operations, the corneal tissue needs a period of healing, because it is a living tissue and reacts to these harmful events. Often the physician uses a protective contact lens, that will be removed after the following examination, once it has reformed the epithelium.