The procedure is performed under topical anesthesia with the application of special drops. This is when the surgeon performs the corneal cut with specialized equipment called a microkeratome, creating a flap that is lifted, and then begins the predetermined laser treatment for each patient. The disability is only 24 to 48 hours.

Another alternative is not to create a corneal flap, but to perform the treatment by applying the laser directly to the cornea, without making any cuts.

This technique is called Trans-PRK. It has the advantage that it is technically simpler for both the surgeon and the patient, and it can be used on corneas that are thinner. On the other hand, Trans-PRK requires more recovery time, and vision is blurred for about 10 days.  

To be a candidate for refractive surgery, the patient must be at least 18 years old, have refractive stability of the defect for at least 1 year, undergo an examination called corneal topography which must be normal, and have reasonable post-operative expectations.

The great advantage of using lasers to correct visual defects is its maximum precision. Surgery with Excimer Laser can be of two types:

Lasik: In addition to the Excimer Laser, an automated scalpel (microkeratome) is used to lift a layer of the cornea of approximately 130 microns so that the laser can be applied within the inner thickness of the cornea.

Surface ablation: the first superficial layer of the cornea is scraped and the laser is applied directly to the surface.

It is reserved for cases where the cornea is very thin and does not allow cutting with the microkeratome. What the laser does is literally evaporate corneal tissue and, in this way, remodels the shape of the cornea, making it flatter in cases of myopia and more curved in cases of farsightedness.

In the hands of an excellent surgeon, with the most advanced technology, adequate experience and compliance with all requirements, it is highly safe. However, like any other surgery, it has inherent risks. These include: infection, inflammation and corneal scarring among others. Fortunately, the probability of them occurring is very low, but if they do occur, they can leave visual consequences.

The best candidate for this procedure is anyone who is unhappy with their glasses or contact lenses and wants to stop depending on them. Some of the requirements necessary to be a good candidate for laser surgery are:

• Older than 18 years-old.
• The refractive error must be stable.
• The eye must not have any disease that prevents it. Therefore, the absence of glaucoma, Keratoconus and other eye diseases must be confirmed.
• The corneal thickness must be adequate (greater than 500 microns). In order to determine these characteristics, it is essential to perform specialized tests such as corneal topography and Pachymetry.
• When refractive errors are greater than approximately 8 diopters and 5 diopters of hyperopia or astigmatism, it is very difficult to achieve adequate correction with laser surgery and the recommended option is to perform surgery to place a permanent intraocular lens.

Additionally, in patients over 50 years of age, this type of excimer laser surgery is generally not ideal and another type of slightly more complex operation may be required, which is called phacoemulsification plus intraocular lens implantation for refractive purposes.

Local anesthesia is used for the intervention, therefore the patient remains awake during the treatment, but, as their eyes are anesthetized, there is no pain and, in general, only minimal discomfort.

The correction made by the laser for distance vision is long-term. When patients exceed 50 or 60 years of age, they have the normal risk of presenting another disease that affects vision: Cataract. In a low percentage of cases (less than 5%), progression or regression of the defects may occur, but, in general, at levels well below the initial defect.

Regarding near vision (reading and other near vision activities), it is very important to understand that, due to the appearance of presbyopia, any patient who has surgery on both eyes for distance vision will require the use of reading glasses after 40 years of age.

The first thing you should do is attend a specialized optometry and ophthalmology consultation. Detailed examinations are performed to determine if you are a good candidate for laser surgery and to rule out any disease that may prevent the intervention.

If you are a good candidate, the ophthalmologist gives you the indications and recommendations that you must take into account before the procedure to guarantee its quality.

Finally, your surgery is scheduled for the nearest date or for the day that you consider most convenient.

If you wear soft contact lenses, you should stop using them before performing the pre-surgery exams: one week if they are soft and two weeks if they are rigid.

Basic Care

• The patient may notice some additional tiredness or difficulty focusing, sometimes feeling dizzy. All this is normal during the initial period.
• During the first three months it is essential not to rub your eyes and avoid any possibility of hitting them (do not play contact sports).
• Physical effort in itself does not imply any problem, the patient can practice aerobics, lift weights, etc.; a few days after surgery.
• It is recommended to avoid entering swimming pools, the sea or Turkish baths for 3 weeks (due to the risk of contamination) and not to wear eye makeup for two weeks.
• Whenever you ride a motorcycle or bicycle, it is essential to use appropriate protective glasses to avoid the possibility of foreign bodies entering the eye.
• It is advisable to protect yourself from the sun with dark glasses.
• It is very important to apply all the drops according to the indications.