ASSOC.PROF.
AYŞE ÇİÇEK , MD

Excimer Laser is a technology used in the treatment of vision disorders such as myopia, hyperopia, and astigmatism. In the past, to correct these disorders, precise incisions were made on the cornea, the transparent front part of the eye, using delicate blades. The term "corneal reshaping" is used for this method. Nowadays, the procedure to correct vision numbers is performed with excimer lasers, and no incisions are made on the cornea. Therefore, it is more accurate to use the term "excimer laser" instead of "corneal reshaping" for the procedure to get rid of vision numbers.

​

Excimer lasers have been used for the treatment of vision disorders since 1988. It is the treatment method with the highest patient satisfaction. During the procedure, the refractive power of the cornea is modified with micron precision. The refractive power is reduced in myopia, increased in hyperopia, and equalized across the entire corneal surface in astigmatism. These procedures are performed very quickly, typically lasting 5-6 seconds.

​

Who is eligible for Excimer Laser eye surgery (corneal reshaping)?

​

Individuals who want to undergo Excimer Laser must meet three criteria:

• Be 18 years of age or older.

• Have stable vision numbers, meaning that the vision disorder does not increase by more than 0.5 diopters within one year.

• Have suitable eye structure.

 

Apart from these criteria, it is not recommended to perform Excimer Laser on individuals with diabetes, connective tissue disorders, rheumatism, or pregnant or breastfeeding women.

​

It should be noted that one of the fundamental principles of medicine is the rule that "There is no disease, only patients." Each patient is unique and should be evaluated individually. Therefore, it is not correct to say that everyone who meets these criteria can undergo laser or that those who do not meet the criteria cannot undergo laser.

​

What are the methods of Excimer Laser eye surgery (corneal reshaping)?

​

There are two different Excimer Laser eye surgery methods: PRK (Photorefractive Keratectomy) and Femto-LASIK (Laser in-situ Keratomileusis). There is no superior method or a comparison between the two methods as each has its advantages and disadvantages. When the appropriate method is selected for the suitable patient, there is no difference in the results. Neither procedure causes pain or discomfort during the surgery.

​

PRK:

 

In this method, the superficial layer of the cornea is first removed surgically using a surgical instrument or alcohol. Then, the excimer laser procedure is performed to reduce the vision numbers. Afterward, a contact lens is placed. The superficial layer of the cornea regenerates naturally within approximately 3 days, and the contact lens is removed at the end of this period. The laser procedure takes about 3 minutes for one eye. A follow-up examination is typically scheduled between the 3rd and 5th day after the laser procedure.

​

Advantages of PRK:

• It can be applied to thin corneas.

• Dryness is milder and shorter in duration.

• Lower probability of corneal steepening in the long term.

• Lower cost due to the use of a single laser system.

 

Disadvantages of PRK:

• Burning, watering, and light sensitivity that can last for two days.

• Longer time for complete visual recovery compared to LASIK.

• Possibility of corneal haze in higher vision numbers.

​

Femto-LASIK:

​

In Femto-LASIK, approximately a 100-micron thick layer (flap) is first lifted from the corneal surface. In the past, tissue removal was done with a blade, but now it is performed with a computer-controlled Femtosecond laser tailored to the individual. The use of Femtosecond laser has significantly reduced the side effects associated with LASIK. After the tissue is removed, the Excimer laser is applied to reduce the vision numbers, and the lifted flap is repositioned. The procedure takes about 7 minutes for one eye. A follow-up examination is typically scheduled on the first day after the laser procedure.

 

Advantages of Femto-LASIK:

• Except for a burning sensation that may last approximately 2 hours after the laser procedure, no discomfort is felt.

• Clear vision is achieved on the next day, and the person can resume daily activities.

• It can be applied to higher vision numbers since there is no possibility of corneal haze.

 

Disadvantages of Femto-LASIK:

• The cornea needs to have a certain thickness.

• There is a higher possibility of developing dryness.

• It has a higher cost due to the use of two laser systems.

 

How is the preparation process for Excimer Laser eye surgery (corneal reshaping) carried out?

​

The most important criterion for Excimer Laser surgery is determining the appropriate patient and the suitable method. Therefore, Excimer Laser should always be performed by an experienced ophthalmologist specialized in lasers and cornea. Before the laser procedure, a detailed discussion should be held with the patient, and a comprehensive eye examination should be conducted. Many topics such as the reason for wanting laser, post-laser procedure expectations, occupation, hobbies, sports activities, existing medical conditions, and medications used should be discussed during the examination stage.

 

During the initial examination, vision numbers are determined, eye pressure is measured, a squint examination and microscopic examination are performed. In the following stage, corneal structure is checked with a topography film to assess its suitability for laser treatment. If the corneal structure is suitable for the laser procedure, drop-based measurements and a retinal examination are conducted. Drop-based measurements are mandatory for every patient undergoing laser.

​

What should the patient pay attention to before Excimer Laser surgery?

​

• Stop using contact lenses at least 2 days before the laser examination and procedure.

• Do not use perfume, deodorant, or apply eye and facial makeup on the day of the laser procedure.

• Arrive for the laser procedure with a companion.

• After the laser procedure, you should not drive immediately. It is advisable to have someone accompany you who can drive.

• There are no restrictions on eating before the laser procedure.

• It would be good to have your sunglasses with you.

 

What is the post-operative process for Excimer Laser?

​

After PRK, the patient may experience burning, watering, and light sensitivity for approximately 2 days. Therefore, rest is required. The person can return to their daily activities from the 3rd day onwards. Additionally, there may be a slight hazy vision that does not significantly affect daily life but can be felt for about 1 month after PRK. The contact lens placed during the laser procedure is removed at the 5th-day follow-up. The patient uses artificial tears for about 1.5 months. The follow-up examinations continue for a certain period.

​

After Femto-LASIK, the patient may experience a burning sensation for approximately 2 hours. On the next day, the person can see clearly and resume daily activities. It is not recommended to swim in the sea or pool for 4 weeks. The patient uses artificial tears for about 1.