Like other types of refractive surgery, the LASIK procedure reshapes the cornea to focus light that enters the eye properly into the retina; in this way, one obtains a clearer vision.

Different types of surgical corrections of vision are possible, such as:

  1. PRK (refractory photochlerectomy),
  2. LASEK (fotoablação corneana subepitelial)
  3. LASIK (“laser-assisted in situ keratomileusis”)

There is no difference: if the eyes are light, brown or black, they can all be operated on and the results are no different.

The ophthalmologist will determine if surgery is appropriate for the patient’s illness and what is the best technique.

 

What are the ideal candidates for LASIK eye surgery?

The best candidates for LASIK eye surgery are people with healthy eyes who have not had previous eye surgeries and try to correct:

  • Myopia,
  • Hypermethropy,
  • Astigmatism.

Patients should have stable vision for at least one year because if they tend to worsen over time, laser results may not be satisfactory.
The minimum age for surgery is between 18 and 20 years, but it would be better between 25 and 40.

People with certain diseases and those who take certain medicines can not perform the LASIK procedure.
Some people with thin corneas may be better suited for some refractive surgery procedures, such as PRK.

 


How much does LASIK eye surgery cost ?

The cost range is between 1500 and 2500 euros (in Brazil between 2500 and 4000 reais each eye).

 


Before LASIK surgery

The ophthalmologist performs a thorough examination to ensure that the patient’s eyes are healthy enough for surgery. He evaluates:

  • The doctor also evaluates:The shape and thickness of the cornea;
  • The size of the pupil;
  • Refractive defects (myopia, hypermetropia and astigmatism);
  • All other eye diseases.
  1. Eye lubrication and may recommend a precautionary treatment to reduce the risk of developing dry eyes after LASIK surgery.
  2. Typically, a corneal topography is performed to measure the curvature of the front surface of the eye and create a “map” of the cornea.
  3. The ophthalmologist should also evaluate the general medical history and any medications the patient is taking to determine if they are a suitable candidate for LASIK surgery .

It is necessary to stop wearing contact lenses for a period of time recommended by the doctor (usually about two weeks) before the LASIK examination and procedure, since the lenses can change the natural shape of the cornea.

 

How does LASIK surgery work?

LASIK surgery is performed while the patient is lying under a surgical device called the Excimer Laser.

  • The intervention is performed in a hospital-day.
  • First, the eye is anesthetized with a few drops of topical anesthetic.
  • An eyelid retractor (blepharostat) is placed between the eyelids to keep them open and prevent the patient from blinking.
  • suction ring is attached to keep the eye still.
    The patient may feel the pressure on the eyelid retainer and the finger-like suction ring pressed firmly on the eyelid.
    From the moment the suction ring is placed over the eye until it is removed, the vision is blurred or everything appears black.
  • When the cornea is flattened, the surgeon cuts and lifts a piece of horny tissue that is created using an automated microsurgery device (microkeratome) or a laser.
  • This flap of corneal tissue is lifted and folded back.
  • Then the Laser Excimer is centered over the eye that must be operated.
  • The surgeon makes sure that the laser is positioned correctly.
  • The patient looks at a special millimeter light called fixation or target light, while Excimer Laser models the tissue of the cornea.
  • Then the surgeon puts in place the corneal tissue that he had folded and smoothed the edges.

The corneal flap adheres to the underlying cornea within two to five minutes and no stitches are required.

 


How long does the surgery last?

LASIK surgery lasts for a few minutes, but recovery times range from a few days to several weeks.

 

After LASIK Surgery

The doctor tells the patient to sit down a little and usually after a few minutes he can go home.

Convalescence
The patient should have someone take him home after the procedure and then relax.

  • No dressing or post-intervention lenses are required.
  • The surgeon gives an eye drop to help the eye heal and relieve dryness .
  • It is possible to feel a  temporary burning or to have an itchy sensation in the eyes immediately after the operation.
  • It is normal to have  a blurred vision immediately after the operation; however, the next morning the sharpness of the image should improve.
  • Vision should stabilize and continue to improve for a few days, although in rare cases it may take several weeks or longer.
  • For most people, vision improves immediately.
    The patient may be able to work the next day, but many doctors advise a few days of rest.
  • In addition, it is recommended to abstain from intense physical activity for at least two or three weeks because there is a risk of traumatizing the eye, thereby affecting the results.
  • Usually, it is necessary to return to the ophthalmologist or LASIK surgeon the day after surgery. At the initial checkup, the doctor checks to make sure the patient can drive without glasses or contact lenses.
  • As with any other surgery, it is always necessary to respect the doctor’s instructions and take the prescribed medications.
  • It is important not to rub the eyes because there is a small chance of reopening the corneal tissue.

 

Risks of laser surgery and side effects

Development of a new visual defect

  • Hypocorrection. If the laser removes very little tissue from the eye, one does not get clear vision as expected.
    Failure to correct it is the most common complication for myopic people.
    Other refractive surgery may be needed.
  • Hypercorrection. It is possible that the laser also removes too much tissue from the eye; usually caused by human error.
    Overcorrection may be more difficult to recover compared to hypocorrection.

Scar  – a corneal scar can form that causes blurred vision and to correct it, the patient may need a new laser surgery.

Corneal
thinning Ectasia is a corneal deformity caused by excessive thinning after surgery. It can cause serious eye problems and invasive surgeries may be necessary.

Astigmatism . 
Astigmatism can be caused by the removal of irregularly shaped tissue.

Stains, aberrations or double vision. After surgery, you may notice some difficulty with night vision.
It can be noticed:

  • Obfuscating,
  • Halos around the lights,
  • Diplopia (double vision).

Sometimes these problems can be treated with eye drops containing a type of cortisone , but it is possible to consider a second surgery.
Even when you get a good visual result, measured with the test under standard conditions, vision in the penumbra (such as twilight or in the event of fog) may be reduced after surgery.

Dry eye. The LASIK procedure causes a temporary decrease in lacrimation .
In the first six months after surgery, you may feel unusually dry eyes.
Dry eyes can reduce the quality of vision.
The ophthalmologist can advise the use of eye drops during this period.
If you have a severe dry eye , you can opt for another surgery to insert special tampons into the tear canal to prevent tears from draining from the surface of the eyes.

Problems with the corneal tissue flap. By folding or removing the flap of corneal tissue from the front of the eye during surgery, complications may occur, including:

  • Infection,
  • Tears in excess,
  • Swollen eyes .
  • The outermost layer of the cornea (epithelium) may grow abnormally under the flap of corneal tissue during the healing process.

Some diseases can increase the risks associated with LASIK surgery or make the results less predictable.
These disorders include:

  • Autoimmune diseases, such as rheumatoid arthritis ,
  • Immune deficiency caused by immunosuppressive drugs or HIV ,
  • Eye disorders: cataracts, malformations of the eye, very thin cornea, persistent eye dryness,  keratoconus .
  • Pregnancy,
  • Unstable vision,
  • Diabetes.

For some people, presbyopia may worsen with age.
LASIK surgery may not be advisable in the case of:

  • Good enough vision,
  • Severe myopia.

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