Laser vision correction. A patient and team of surgeons in the operating room during ophthalmic surgery. Eyelid speculum. Lasik treatment. Patient under sterile cover

Refractive surgery: what is it for, how is it performed and what to do?

By Cristiano Antonino On Oct 27, 2022

Refractive surgery is a technique that uses excimer lasers to reshape the surface of the cornea in order to correct or significantly reduce refractive vision defects (myopia, hypermetropia or astigmatism)

It is an eye surgery with permanent effects that can be performed on a large sample of patients (about 6-7 patients in every 10 are eligible).

Refractive defects, in fact, are pathologies that have a significant impact on a person’s life: those who are affected by myopia, hypermetropia or astigmatism necessarily need to use corrective lenses, be they prescription glasses or contact lenses, and refractive surgery can be a valuable ally in getting back to looking at the world.

What is refractive surgery? Excimer laser: how does it work?

The excimer laser is a state-of-the-art instrument that allows the cornea to be reshaped by removing microscopic parts of tissue with the utmost precision.

The software enables advanced tracking so as to compensate for all those involuntary movements that may be made by the eye during treatment, even though the patient is keeping his or her gaze still.

In this way, the action on the cornea is constantly compensated and the procedure can be carried out with extreme speed.

One fear of many patients, in fact, relates specifically to the consequences that an involuntary movement of the head or eyes might have, but one can rest assured: the excimer laser’s eye tracker is extremely sensitive and can follow eye movements by monitoring them a thousand times per second.

In addition to this, there is an optical coherence tomography (OCT) system that can record extremely high resolution images of the cornea and measure its thickness from the beginning to the end of treatment.

Excimer laser refractive surgery allows for a non-invasive procedure that can be performed on an outpatient basis, with topical anaesthesia administered with eye drops and no sedation.

The procedure lasts only a few minutes and at the discretion of the specialist both eyes can be treated at the same time.

What are the advantages of refractive surgery?

As shown in the study ‘Advanced Surface Ablation With a New Software for the Reduction of Ablation Irregularities’ published in the Journal of Refractive Surgery, patients had better vision without glasses after the operation than they had with glasses before refractive surgery.

The correction of the refractive defect after excimer laser surgery is permanent, i.e. it remains stable.

By stable, however, we do not mean that there may be no changes in vision over the following years: changes that do not depend directly on the surgery but on the normal passage of time.

Furthermore, already during the preliminary examination there are certain factors that can lead to a greater or lesser success of the operation and which will be explained to the patient before the surgery is scheduled.

Factors that can lead to a disappointing result include an out-of-ordinary tissue response, unsuitability of the patient, or errors in treatment and problems in the functioning of the instrumentation.

However, the problem can often be resolved with an additional session.

When to choose refractive surgery?

Approximately 60-70% of patients with refractive defects can undergo excimer laser surgery, while the remaining patients may be unsuitable following follow-up examinations by the ophthalmologist at the check-up.

The specialist uses state-of-the-art instrumentation in the diagnostic phase, which allows all aspects of the patient’s eye health to be assessed and the surgery to be defined with extreme precision.

Refractive surgery: age and type of eyesight defect

To undergo refractive surgery, it is necessary to be at least 18 years old and the stability of the refractive defect must have been ascertained for at least one year since the last ophthalmic check-up: thus the defect, whether myopia, hypermetropia or astigmatism, must not have worsened in that time.

As a rule, this kind of disorder stabilises after the age of 20, in the case of hypermetropia, and a few years later in the case of myopia.

To whom is surgery not recommended?

Refractive surgery is not recommended for pregnant patients, as drugs are administered during the operation and convalescence period that may not be suitable.

Another effect of pregnancy for which it is not recommended to proceed with excimer laser is the physiological biomechanical weakening of the cornea, which may compromise the outcome of the treatment.

What should be done after refractive surgery?

As we have said, it is possible, at the specialist’s discretion, for surgery to be performed on both eyes at the same time but, depending on the differences assessed during the examination, also for the operation time between one eye and the other to be different.

It is possible, in this case, that the specialist prescribes changes to the glasses: it should be emphasised that one should never take a personal initiative and always follow medical instructions (on the possible use of a specific eye drops or other medicines).

Can one do sport after the operation?

Excimer laser surgery is non-invasive and the patient’s recovery is very quick, so those who do physical activity will be able to resume it within a short time.

The eyesight, however, needs an adequate amount of time to adapt, so sports performance may not be optimal initially.

Is it possible to go swimming or to the beach after refractive surgery?

In the first period after surgery, particularly irritating situations for the eye, such as Turkish baths and saunas, are to be avoided, and appropriate precautions must be taken when going to the swimming pool or the sea.

Goggles or a mask in this case are essential, as is the use of sunglasses if one is exposed to sunny days.