It is eye surgery that permanently changes the shape of the cornea (the clear covering at the front of the eye). This is done to improve vision and reduce the person’s need to wear glasses or contact lenses.
For clear vision, the cornea and lens of the eye must bend (refract) light rays properly. This allows images to focus on the retina. Otherwise, the images will be blurry.
This blurry vision is called “refractive error.” It is caused by a mismatch between the shape of the cornea (curvature) and the length of the eye.
LASIK uses an excimer laser (an ultraviolet laser) to remove a thin layer of corneal tissue. This reshapes the cornea so that light rays are clearly focused on the retina. LASIK makes the cornea thinner.
LASIK surgery is an outpatient surgical procedure. It takes 10 to 15 minutes for each eye.
The only anesthetic used is an eye drop that numbs the surface of the eye. The procedure is done while you are awake, but you will be given medicine to help you relax. LASIK surgery can be performed on one or both eyes in the same session.
To perform the procedure, a flap of corneal tissue is created. This flap is then detached so that the excimer laser can reshape the underlying corneal tissue. A hinge on the flap prevents the flap from completely separating from the cornea.
The first time LASIK surgery was performed, a special automated knife (a microkeratome) was used to cut the flap. Now a more common and safe method is to use a different type of laser (femtosecond) to create the corneal flap.
The amount of tissue to be removed with the excimer laser is calculated in advance. The surgeon will calculate this amount based on several factors including:
- Your prescription glasses or contact lenses
- A wavefront test, which measures how light travels through your eye
- The shape of the surface of the cornea
Once the reformation is done, the surgeon replaces the flap and secures it. No sutures are needed. The cornea will naturally hold the flap in place.
Why the procedure is performed
LASIK surgery is most often performed on people who wear conventional or contact lenses for nearsightedness. It is sometimes used to correct farsightedness and can also correct astigmatism.
The US Food and Drug Administration (FDA) and the American Academy of Ophthalmology have developed guidelines for determining candidates for LASIK surgery:
- You must be at least 18 years old (21 in some cases, depending on the laser used). This is because the vision of people under the age of 18 can continue to change. The young child with one highly myopic eye and one normal eye is a rare exception. The use of LASIK to correct the highly myopic eye can prevent amblyopia (lazy eye).
- Your eyes must be healthy and your prescription stable. If you are nearsighted, you should postpone LASIK surgery until your condition has stabilized. Nearsightedness can continue to increase in some people until age 25 to late 30.
- Your prescription must be within the range that allows LASIK correction
- You must be in good general health. LASIK may not be recommended for people with diabetes, rheumatoid arthritis, lupus, glaucoma, herpetic eye infections, or cataracts. You should discuss this with your surgeon.
Other recommendations:
- Weigh the risks and benefits. If you are happy wearing glasses or contact lenses, you may not want to have this surgery.
- Make sure you have realistic expectations of the surgery.
For people with presbyopia , LASIK surgery cannot correct vision so that one eye can see both far and near. However, LASIK surgery can be done so that one eye sees far and the other sees near. This is called “monovision.” If you can adjust to this correction, it may eliminate or reduce the need for reading glasses.
In some cases, it is only necessary to operate on one eye. If your doctor thinks you qualify, ask about the pros and cons.
Risks
You should not have this procedure done if you are pregnant or nursing, as these conditions affect vision measurement values.
You should not have this procedure if you are taking certain prescription medications, such as Accutane, Cordarone, Imitrex, or predisone by mouth.
Risks may include:
- corneal infection
- Corneal scarring or permanent problems with the shape of the cornea, making it impossible to wear contact lenses
- Decreased contrast sensitivity, even with 20/20 vision, objects may appear blurry or gray
- dry eyes
- glare or halos
- light sensitivity
- Problems driving at night
- Red or pink patches on the white of the eye (broken blood vessels, usually temporary)
- Decreased or permanent loss of vision
- Itch
Before the procedure
A complete eye exam will be done before surgery to make sure your eyes are healthy. Other tests will be done to measure the curvature of the cornea, the size of the pupils in light and dark, the refractive error of the eyes, and the thickness of the cornea (to make sure you have enough corneal tissue left after surgery). ).
You will sign an authorization before the procedure. This confirms that you are aware of the risks, benefits, alternative options, and potential complications of the procedure.
After the procedure
After surgery:
- You may have burning, itching, or a feeling that something is in your eye. This sensation does not last more than 6 hours in most cases.
- A shield or patch will be placed over the eye to protect the flap. It will also help prevent rubbing or pressure on the eye until the eye has had enough time to heal (usually overnight).
- It is very important NOT to rub the eye after LASIK surgery, so that the flap does not become dislodged or move. For the first 6 hours, keep your eye closed as much as possible.
- The doctor may prescribe mild pain medication and a sedative.
- Vision is usually blurry or cloudy on the day of surgery, but will improve the next day.
Call your eye doctor right away if you have severe pain or if any of your symptoms worsen before your scheduled follow-up appointment (24-48 hours after surgery).
At the first visit after surgery, the eye shield will be removed and the doctor will examine your eye and test your vision. You will be given eye drops to help prevent infection and inflammation.
Do not drive until your vision has improved enough to drive safely. Other things to avoid include:
- Swimming
- Bathtubs and whirlpools
- contact sports
- Use of lotions, creams, and eye makeup for 2 to 4 weeks after surgery
The health care provider will give you specific instructions.
Expectations (forecast)
In most people, vision will stabilize within a few days after surgery, but for some people it can take up to 3 to 6 months.
A small number of people may need another surgery because vision is over or under corrected. Although a second surgery may improve distance vision, it may not relieve other symptoms such as glare, halos, or trouble driving at night. These are common complaints after LASIK surgery, especially when using an older method. These problems should disappear by 6 months after surgery in most cases. However, a small number of people may continue to have problems with glare. Even after a second surgery, few people may still need to wear contact lenses or glasses.
Frequent Questions
Is laser refractive surgery always 100% laser?
No. The patient must be well informed about the surgical procedure. In some centers, despite being called the Lasik technique, they still use a blade in the first part of the surgery. At Vizovis we have completely abandoned the use of the blade and have replaced it with a femtosecond laser.
Is femtosecond laser refractive surgery a painful procedure?
During the intervention you can feel a sensation of touch, pressure, but not pain. In the immediate postoperative period, during the first 5 or 6 hours, a sensation of grit, stinging, tearing, and photophobia may appear. The normal thing is that the next day there is practically no discomfort.
In femtosecond laser surgery, are both eyes operated at the same time?
Yes. The patient will also find it more comfortable if the surgery is bilateral.
Is FemtoLasik surgery a forever treatment?
The effect of the femtosecond laser is permanent, but in a small percentage of patients, over time, myopia may increase again because the eye becomes longer. It is also important for this not to happen that the ophthalmologist assures the patient that her graduation is stable. However, it can be corrected again with a touch-up.
After femtosecond laser surgery, what care should I take?
It is vitally important to avoid rubbing the eyes. You must use the eye drops as prescribed. It is convenient to use glasses as a protective measure in situations with risk of trauma or inclusion of particles.
