LASIK-Laser Eye Surgery

What is LASIK Surgery?

Laser Eye Surgery; Refractive surgery is the type of treatment applied to ensure that patients who wear glasses or contact lenses due to eye disorders can see clearly without glasses. LASIK is a surgery to correct eye impairments using laser beams. LASIK surgery is the most common and most reliable laser eye surgery method all over the world and in our country.

In order for a clear vision to be formed, the rays coming into our eyes must be properly refracted and focused on our retina. This focusing process is done by the cornea and lens in our eyes. In eyes with refractive errors, the light cannot be refracted correctly and a blurred vision occurs.

LASIK stands for laser assisted in situ keratomileusis. In LASIK surgery, an incision in the form of a valve called a flap is made on the outer layer of the eye, which we call the cornea.

This flap was made with blades called microkeratome in the past. Today, it is done without blades with femtosecond lasers (INTRALASE). Later, this cover is removed and laser beams are applied to the area under the flap of the cornea and the cornea is reshaped.

The flap is covered again and a rapid recovery is achieved. Thus, the correct refraction of the rays is ensured, the refractive error is corrected and clear vision is provided.

For which eye disorders is LASIK surgery applied?

The refractive errors that can be corrected with LASIK surgery are myopia, hyperopia, and astigmatism. These eye disorders are corrected with the help of glasses and contact lenses. When glasses or lenses are not worn, the patient sees blurry. In other words, the patient is dependent on glasses and lenses. With LASIK surgery, the need for glasses and contact lenses is eliminated.

• Myopia is the problem of nearsightedness. Incoming rays to the eye are focused in front of the retina and distant objects appear blurred. There is usually no problem with near distance. The corneas of these patients are shaped and straightened by LASIK surgery, allowing the light to focus on the retina.

1. In hyperopia, the objects in the far distance are seen clearly, while the objects in the near distance are blurred. While reading something, the letters get mixed up and the eyes get tired. Incoming rays to the eyes are focused behind the retina. With LASIK surgery, the cornea is erected and the rays are focused on the retina.
2. In astigmatism, the rays focus diffusely due to the structural deformity of the cornea. Both far and near objects appear blurry. With Lasik surgery, the shape of the cornea is corrected and the light is focused properly.

Who is suitable for LASIK surgery?

Some prerequisites are required in order to have LASIK surgery. These are:

• Being over 18 years old (preferably 21 years old). The progression of eye numbers stops at this age.
• The fact that the degree of eye disorder can be corrected with LASIK surgery.
  • Myopia up to 10 degrees
  • Hyperopia up to 4 degrees
  • Astigmatism up to 6 degrees are corrected with LASIK surgery.
• The fact that the numbers of glasses or contact lenses have not changed in the last 1 year.
• Adequate thickness of the corneal layer.
• Condition of normal eye surface map, which we call corneal topography.
• No other eye disease other than visual impairment.

If you have these pre-criteria, you can consider having LASIK surgery. Then, your ophthalmologist will perform detailed examinations and tests to evaluate whether your eye is fully suitable for surgery.

• Who is NOT suitable for LASIK surgery?
• Patients under the age of 18
• People with a change in eye number
• People with very high vision impairment degrees
• People with thin cornea
• People with severe xerophthalmia
• Pregnant and breastfeeding women
• Uncontrolled diabetes patients
• People with corneal disease called keratoconus
• People with eye diseases such as cataracts, glaucoma, retinal disorders other than visual impairments,

are not suitable for Lasik surgery.

How is suitability evaluated before LASIK surgery?

If you meet the prerequisites for LASIK surgery, your ophthalmologist will evaluate the suitability of your eye by performing detailed eye examinations and tests. If the patient wears contact lenses, they should stop using them 5 days before the examination.

• By determining the eye number, it will be determined that your eye number has not changed and your eye numbers are at a level that can be corrected with surgery.
• Determination of thin corneas with corneal thickness measurement is very important in preventing postoperative complications.
• Corneal surface map measurement, called corneal topography is performed both to determine the disorders that prevent surgery and to apply personalized laser treatments.
• Since night vision impairments may occur in people with very large pupils, the determination of the pupil diameter must be evaluated.
• It will also be evaluated whether there are other diseases that prevent you from having surgery, such as xerophthalmia, cataract, glaucoma, retinal diseases.
• Measurement of the eye’s detailed refraction map with an instrument called WAVEFRONT.

As a result of these evaluations, your ophthalmologist will talk to you about other alternative methods and will explain the advantages and disadvantages of LASIK surgery.

What questions should I ask when talking to my ophthalmologist about LASIK surgery?

Before having LASIK surgery, it is very important for you to learn and clarify the answers to the following questions in order to be happy after the surgery.

• Are my eye numbers suitable for LASIK surgery?

LASIK surgery can be applied for certain degrees of myopia, hyperopia and astigmatism disorders. In severely impaired eyes, adequate correction may not be achieved or the numbers may return.

• Is my age suitable for LASIK surgery?

Before the age of 20, eye numbers may change. Additionally, farsightedness occurs after the age of 40. While deciding on LASIK surgery, these situations should be evaluated and the patient should be informed.

• What kind of side effects can occur after LASIK surgery?
• Will my eye numbers come back?
• Will I use glasses again in the future?

How is the LASIK surgery and the post-operative process?

During LASIK surgery, your eye is anesthetized with drops. After cleaning your eye area, your eye is covered with a transparent cover. Then the process starts. After the flap is prepared, a laser beam is applied to the eye.

At this stage, you are asked to constantly follow the lights above. The eye is washed and the flap is closed. Drops are put in your eye and the surgery is terminated. All these procedures are applied to each eye separately and take about 5 minutes each.

On the first day after the surgery, your eye is covered with a transparent protective cover. You should use this protective cover while sleeping for several days. It is normal to have feelings such as burning and itching in your eyes for the first few days.

On the 1st day of the laser procedure,  you will see blurry. Over time, this blurred vision will pass. You will be given eye drops to use after the surgery.

Your first check will be done the next day. You should definitely not scratch your eyes. Water should not come into contact with your eyes for 3 days. You should stay away from activities such as sea, pool, sauna for 1 month after laser.

• Is blurred vision normal after LASIK surgery?

Blurred vision is completely normal on the first day after LASIK surgery. Your vision will be close to normal the next day. After a few days, the vision will become clearer. Blurred vision may take up to 1 week in surgeries such as LASEK and PRK.

• What is INTRALASE (FEMTOSECOND LASER)?

In the first step of LASIK surgery, a valve-shaped incision is made in the cornea. This is called flap. Flap preparation was done with very sensitive blades called microkeratome in the past. Today, as a result of the development of a very sensitive laser technology called Femtosecond, flap preparation is now done with this special laser nonsurgically. In this way, side effects due to microkeratome do not occur. Post-operative recovery is faster and more comfortable. This increases the chance of success of the surgery and the comfort during the recovery period. With Intralase, flaps of desired thickness can be prepared. In this way, LASIK can be applied safely by preparing thin flaps in people with thin cornea.  Another advantage of INTRALASE is that it causes less xerophthalmia.

• What is iLASİK?

If corneal flap preparation is done with a femtosecond laser, it is called intralase. Wavefront, on the other hand, is a special measurement made by sending a ray to the eye and evaluating the rays returning from the retina.

Just like fingerprints, wavefront measurement is unique to each person. LASIK surgery performed by combining these two technologies (ie INTRALASE laser and WAVEFRONT measurement technology) is called iLASIK surgery. In iLASIK, all treatment is planned and applied specifically to the eye structure and findings of the person.

9) What is SMILE LASER/RELEX?

With femtosecond laser technology, a thin lenticule (disc-shaped tissue) is created inside the cornea. This disc-shaped tissue is then removed through a very small opening. As a result, the cornea flattens and its refraction decreases.

So myopia is cured. There is no need to prepare a flap in this method. Thanks to the closed surgical technique, there is no need to make an incision. In this way, the biomechanics of the cornea do not deteriorate. It can be applied to thin corneas. It is preferred in myopia or astigmatism with high degrees.

• What are the alternative treatment methods for eyes that are not suitable for LASIK surgery?

Apart from LASIK surgery, there are different surgical methods that can be applied in the treatment of visual impairments. Some of these methods are reshaping the cornea with laser, while others are placing intraocular lenses inside the eye.

1. In the PRK technique, the outermost epithelial layer of the cornea is scraped and peeled. Visual impairment is corrected by shaping the cornea with a laser. The epithelium is allowed to heal on its own. Since the flap is not removed from the cornea, it is preferred in thin corneas and in special cases where scarring is not desired. However, the recovery process is more difficult than LASIK. That’s why LASIK is more preferred today.
2. LASEK/Epilasik: In this method, the outermost surface of the cornea, called the epithelium, peels off smoothly instead of mechanically scraped. After the cornea is shaped with laser, this epithelial layer is attached back into place. It recovers faster and easier than PRK. It is preferred in thin corneas.

• Phakic Intraocular Lenses: It is one of the preferred methods for eyes that are not suitable for LASIK surgery or for vision impairments with very high degrees. In this surgery, the eye’s own lens is not interfered with. An artificial lens is placed in front of or behind the pupil. Thanks to this lens, the vision impairment is corrected by focusing the rays on the retina.

1. Refractive (Transparent) Lens replacement: It is the process of replacing the patient’s natural lens with an artificial lens to correct the refractive error. As in cataract surgery, a clear vision can be achieved at all distances by attaching a trifocal (smart) lens. It is preferred for eyes that are not suitable for LASIK surgery or for vision impairments with very high degrees. Additionally, patients with mild cataracts may prefer this surgery to get rid of glasses without waiting for the cataract to progress.