LASIK is a type of refractive surgery performed using a laser that allows the patient to stop wearing glasses, since the correction of refractive errors is performed safely and effectively.

Nowadays, there is a set of surgical techniques that allow the correction of the different types of ametropias (myopia, hypermetropia e astigmatism), making glasses independent.

LASIK, using the Excimer laser, is nowadays the technique of choice to eliminate existing refractive errors since it is a less invasive, quick and painless surgery. However, apart from the laser (LASIK or PRK) refractive surgery can also be performed by implanting intraocular phakic or pseudophakic lenses.

You should have an ophthalmology consultation and respective complementary examinations so that the ophthalmologist can advise you on the most suitable procedure for your case.

To be a candidate for refractive surgery, you need:

• Be over 18 years of age;
• Refractive stability, i.e. it is necessary that the grading has remained stable in the last year;
• Absence of ocular pathologies, apart from refractive error, which condition the results of the surgery;
• Absence of systemic pathologies;
• Perform complementary diagnostic tests in order to determine the most suitable surgical technique for each case.

As pathologies associated with any of these types of surgery, we find the refractive errorsmore precisely, the myopia, a hypermetropia and astigmatism.

Refractive surgery is performed in an outpatient clinic, with the aid of topical anaesthesia. 

With both LASIK and PRK, it is common for both eyes to be operated on the same day, whereas with phakic IOL implantation, it is advisable to perform each eye on a different day, since it is an intraocular surgery.

These surgical procedures are painless and of short duration, usually taking around 20 to 30 minutes, plus the patient preparation time, which is longer with IOL implantation.

LASIK is considered to be a very safe surgery, where the results obtained are largely positive. For this reason, the risks associated with the various surgical techniques and procedures are very low, although they do sometimes exist. Most of the time, in order to resolve the situation and bring the vision back to an ideal level, it may be necessary to administer corticoids through eye drops. 

One of the main risks to be taken into consideration and present in any refractive surgery is the possibility of the existence of a residual dioptric value, that is, the person's refractive error may not be totally corrected. In most cases, this residual value is not significant and may not even have any influence on daily vision. In rarer situations, where the visual acuity obtained is not satisfactory, it may be necessary to perform a new surgery to correct the residual graduation, if the patient still has the necessary conditions for such. 

Among the less common risks, corneal lesions associated with surgery can sometimes result, such as scarring, which can impair vision and make daily activities difficult. In the more specific case of IOL implantation, the risks are the same as those associated with intraocular surgery. 

To avoid any risk of infection after surgery, it is very important to apply all the therapy recommended and prescribed by the ophthalmologist.

After refractive surgery, it is recommended that you completely follow all the information and recommendations made by the surgeon. Anti inflammatory and antibiotic medication may be prescribed to reduce both discomfort and the risk of infection. Recovery is fast, however it is expected that in the first hours the patient may experience cloudy vision and dry eye.

It is not recommended to perform extreme physical or visual efforts in the first days after the surgery. During the recovery, it is possible that in environments with more luminosity there is an increased discomfort, and the use of sunglasses with UV protection is recommended. 

The recovery process, from the moment the surgery is performed until the vision is stabilised and completely clear, differs according to the surgical technique used. With LASIK and PRK, visual recovery can take a few weeks or even a few months (between 1 to 3), and there is some variation in the quality of vision. With PRK, recovery depends on the complete regeneration of the corneal epithelium, so it may take longer and be more painful than with LASIK.

 With IOL implantation, recovery is expected to be rapid, and by the next day you may have reached full visual acuity. 

Throughout this period, it is necessary to monitor the healing process, respecting the dates of the post-surgical appointments.

Prof. Dr. Tiago Ferreira

Dr Samuel Alves