What is laser refractive surgery?
The term laser means light amplified by stimulated emission of radiation, when this radiation is concentrated in a point the laser cuts. In ophthalmology we use a type of laser called excimer, which is an ultraviolet light with a strong energetic power. With this laser we try to correct refractive errors, myopia, astigmatism and hyperopia and we are even taking advanced steps in the treatment of presbyopia. In short, the aim of refractive surgery is the elimination of corrective lenses and contact lenses.
Which patients can undergo laser refractive surgery?
There are a number of factors that prevent us from performing refractive surgery. In women, pregnancy and lactation. And, in general, psychiatric problems, retinal alterations, corneal pathologies, fundus pathologies, progressive cataracts, progressive myopia and immunological diseases.
Two other very important factors are age and intensity of the defect. Regarding age, we can say that we correct these defects from the age of 19, if there is a stabilization of the defect in the glasses for at least two years. After the age of 40, it should be noted that, even if we correct the defect, the patient will have to wear glasses for near vision in the immediate future.
Talking about the intensity of the defects in myopia we correct from one to ten diopters correcting a little bit the corneal thickness, but I am more in favor of correcting up to eight because from eight there are other techniques for refractive defects such as intraocular lenses that give better results and less side effects. In hyperopia we correct up to five diopters as well as astigmatism.
After refractive surgery, when can normal activities be resumed?
It should be remembered that there are two different techniques for laser application. The laser that is applied directly on the cornea -PRK or refractive photokeratectomy- causes much greater postoperative discomfort, although with an adequate analgesic regimen it can be minimized, but recovery is also a little slower.
Then there is the laser when it is applied inside the cornea, in the corneal stroma, it is an operation that allows visual recovery in a matter of hours and the post-operative discomfort is much less, simple foreign body sensation or tearing that in four hours is solved. The patient can return to work the following day.
What risks or contraindications can we find when performing the surgery?
It is a process full of advantages: it does not require hospitalization, the anesthesia is topical and the results are very stable.
But there are risks inherent to any surgical intervention. Those related to the technique can be corrected by going to a surgeon with extensive experience and who performs a good exploration. One of the side effects that we have to take into account is dry eye due to tear deficiency, also the vision of colored halos that occur when treating medium-high myopia with light diffraction, as well as an alteration in contrast vision (white-black) that can make driving a little difficult.
The most important thing is that although it happens very rarely, sometimes we can fall short or overdo it, but this can be corrected after two months with a small touch-up.