What is Refractive Surgery?

7 Ocak 2022

With the help of our Refractive Surgery - Excimer Laser unit, we enable our patients to live fulfilling lives by eradicating their visual impairments. Our happiness is in every grinning eye.

Excimer laser treatment: what is it?

For more than 20 years, the excimer laser treatment has been used to successfully treat refractive errors. Excimer lasers, also referred to as Eye Draw, use Ar F gas to generate ultraviolet light with a wavelength of 193 nm. The treatment of myopia, hyperopia, or astigmatism is made possible by the laser beam created here, which removes the targeted tissue in the desired thickness and width. This results in a permanent change in the cornea layer, which is located at the outermost part of the eye. Femtolasik and Lasik Laset, PRK, and No-Touch Excimer are three different laser procedures.

What is LASIK? Whom Can It Be Used For?

The most popular method for treating focusing defects is LASIK. Patients who have been wearing the same pair of glasses for the past 12 months and are over the age of 18 are eligible for this procedure. The refractive error in the eye and the structure of the eye must be suitable for Lasik surgery. All candidate patients are subjected to a series of tests that demonstrate the characteristics of the corneal layer in addition to a thorough eye examination for this purpose.

Astigmatism, hyperopia, and myopia up to 12.0 degrees can all be treated with LASIK. Prior to having Lasik, contact lens use must stop. Patients who wear soft lenses should wait at least a week to stop wearing them, and those who wear hard lenses should wait at least three weeks.

Who Is Not a Candidate for LASIK?

  • Patients with corneal structural issues, particularly keratoconus, those whose corneal thickness is below a certain threshold, those who suffer from severe dry eye, diabetics and people with rheumatic diseases, pregnant and nursing women with eye conditions like cataracts, glaucoma, and infection.

The LASIK Procedure

In the LASIK procedure, the cornea layer, which is found at the very edge of the eye, is first numbed with 1-2 drops of anesthetic solution. The patient does not experience any pain as a result of the intervention. The lids are covered with a device called a speculum to stop the lids from moving on their own.

The Wavelight FS200 is then used to make a 0.12 mm incision in the corneal layer after creating a smooth surface inside the eye with the vacuum ring. The excimer laser procedure is then used to treat the underlying corneal tissue after the flap (cover) formed is removed. The flap is then positioned in the same location, and the procedure is finished.

Pain is not experienced during any of these procedures, which take an average of 5 minutes for both eyes. It is advised to rest the eyes as much as possible the same day as LASIK even though they are not closed.

On average, eye drops are applied for one week. It is not advised to put on eye makeup, go swimming, or rub one's eyes vigorously during this time.

Benefits of LASIK Surgery

The comfort that LASIK offers the patient is its most significant benefit. When performed on patients with healthy eyes, LASIK can successfully correct even high prescriptions. After treatment, the patient can have good vision in just a few hours, and healing happens very quickly.

Within 12 hours, at the latest, pain, watering, and stinging issues disappear, and one day after treatment, the patient is able to resume his regular activities and work. Following surgery, eye drops must be used for about a week.

What precisely is Femtolasik (Knifeless Lasik)?

Making a flap from the upper portion of the cornea is the most crucial step in the LASIK procedure. In recent years, flap creation has been accomplished using femtosecond laser technology. The depth, width, and shape of an incision can be customized using a femtosecond laser. The fastest and safest technology created for this purpose is the FS 200 Femtosecond laser.


  • Complications that could be seen in previously employed microkeratome systems have almost completely disappeared as a result of this device.
  • A femtosecond laser can produce unique flaps for a person's refractive error.
  • Results are better, particularly when treating astigmatism and hyperopia.
  • Femtosecond laser flaps better preserve the biomechanics of the cornea.
  • Since Lasik can lift flaps of the desired thickness, it can be used particularly on patients with corneal thickness that is on the fence.
  • After laser treatment, less aberration (light deviation) forms because the flap interface is smoother.
  • The risk of developing dry eye is lower with femtosecond flaps, especially in elderly patients.
  • Using femtosecond laser systems, corneal implants, keratoplasty (corneal transplant), and astigmatic keratotomy procedures can also be carried out in addition to creating flaps.


The outermost layer of the eye is where the LASIK procedure is performed. As a result, it is impossible to harm the eye's internal structures. Additionally, complications like infections, allergies, and insufficient grade correction may appear after the procedure and during the removal of the corneal flap.

These issues are directly related to the LASIK surgeon performing the procedure and the caliber of the laser system used. Before getting lasik, one should inquire about the Excimer laser's quality, particularly its FDA certification.

The Alcon ALLEGRETTO WAVE® Eye-Q Excimer Laser system used in our hospital has a speed of 400 Hz and is one of the fastest laser systems in the world. It can treat 1 diopter eye deficiency in less than 2 seconds. The laser treatment is carried out in a very safe manner thanks to the 400 Hz eye tracker system.

Lasik Extra

In the Lasik extra system, crosslinking and Lasik are both used. In circumstances where LASIK surgery may be risky, such as thin corneas, high myopia, or a family history of ectasia, it is done to strengthen the cornea. In high hyperopia cases, there is also a chance of regression (some recovery of corrected refractive error).

According to studies, Lasik Extra increases the success rate in cases of severe hyperopia. In the Lasik extra procedure, the stromal bed is treated with a special riboflavin solution for 1 minute after a Lasik flap has been created and the Excimer laser has been used. The flap is then positioned, the cornea is exposed to high dose UV for 1.25 minutes, and the procedure is finished.

Accelerated Cross-Linking Avedro

In the typical crosslinking procedure, the cornea's outermost epithelial layer is removed, the eye is treated with riboflavin B2 for 30 minutes, and then the eye is exposed to UV light for another 30 minutes. By speeding up the customary Crosslinking procedure, which takes more than an hour in total, Avedro improves patient comfort.

The total process time can be shortened to 14 minutes with the help of this system, which employs a high energy and regular light profile. Additionally, crosslinking can be applied to patients whose corneal thickness is too thick for the standard procedure by leaving the epithelial layer in place using specific riboflavin solutions. (Transepithelial Crosslinking)

What Do Focusing Defects Mean?

The eye functions somewhat like a camera. The cornea (the eye's outermost transparent layer), the lens, and the macula region, which is responsible for sharp vision in the retina, are the refractive surfaces that allow light from the environment to enter the eye. Refractive error is the focussing of rays in a different location.

The three types of refractive errors—myopia, hyperopia, and astigmatism—can be studied separately. In addition to these, presbyopia is the term used to describe the decline in near vision brought on by the eye lens's loss of its ability to focus close up after age 40. This problem is not an eye disease, but rather an unavoidable aspect of aging.


Myopia, also known as farsightedness, is caused by the eye's lens focusing light rays in front of the retina. It most frequently occurs when the eye's anterior-posterior axis is longer than usual.

It is a structural characteristic that frequently transmits genetically. It typically begins when a child enters school and grows over time. Myopia can also develop as a result of cataract development in older age due to the lens's altered refraction.

Short-sightedness in general is called hypermetropia. The rays that enter the eye focus behind the retina, causing it to happen. The eye structure is smaller than usual, in contrast to myopia.

The most frequent causes of hyperopia are structural and hereditary characteristics. Children who have untreated hyperopia are more likely to develop lazy eyes. This justifies the requirement that all preschoolers receive an eye exam.


Because the cornea's refractive power varies along different meridians, astigmatism is the result. The eye condition known as astigmatism impairs vision at all distances.

It may be structural or result from trauma, degenerative diseases, infections, or other conditions that can alter the corneal layer.


The procedure known as lasik, which involves removing the corneal flap, is used as a standard treatment for refractive errors when using an excimer laser.

However, not every patient's corneal structure will be suitable for this treatment. Treatments that are superficial should be chosen in these circumstances. The recovery time is one of these procedures' biggest drawbacks, even though it has long-term results that are comparable to lasik when carried out using the right technique.


It is the initial technique used in excimer laser therapy. After mechanically removing the epithelium from the cornea's transparent outermost layer, an excimer laser treatment is administered.

During the procedure, there is no discomfort or pain experienced.

The patient's eye is fitted with a contact lens, and recovery takes 2-3 days. It works well, especially when dealing with low numbers.

The drawbacks include a painful recovery period and a significant risk of regression (some increase in the number of glasses) and haze (turbidity), particularly when treating large numbers.


In contrast to PRK, this treatment method releases the epithelial layer with a diluted alcohol solution, then places it back in place after laser treatment.

After wearing bandage contact lenses for about 4-5 days, healing is complete.

Compared to PRK, the epithelial layer that is left behind serves as a barrier, minimizing post-operative discomfort as well as the chance of haze and regression.

Phakic Lens
It is a preferred method for people between the ages of 20 and 45 who have corneal structure or degree of refraction defect issues that preclude Excimer laser treatment.

The anterior or posterior chamber can accommodate one of three types of phakic lenses:

  • Angle supported
  • Iris flick
  • Settled in sulcus

For these lenses to be able to be fitted, it is necessary for personal characteristics such as the number of endothelium and the depth of the anterior chamber to be suitable.

Exchange of Refractive Lenses

It is a technique used to treat myopia, hyperopia, astigmatism, and presbyopia in people over 45 who have difficulty focusing up close due to aging.

With the recent developments in toric (correcting astigmatism) and multifocal (providing both near and far vision) lenses, we are able to offer services to our patients.

Refractive Surgery Frequently Asked Questions
Does pain occur during and after laser treatment?

Eye drops with anesthetic properties are used during laser treatments. During the procedure, there is no pain. Since the procedure only takes a few minutes—5 minutes on average—per eye, it is completed before the majority of our patients are aware of what is happening. The post-lasik treatment discomfort (stinging, burning, watering, and blurred vision) lasts for about 5 to 6 hours. In other words, patients are able to carry out their daily tasks with ease when they awaken the following day.

What needs to be taken into account before laser treatment?

Patients who wear hard contact lenses should stop wearing them three weeks prior to the event, while those who wear soft contacts should wait one week. On the day of surgery, it is advised to wear loose-fitting clothing, refrain from wearing makeup, and even avoid using perfume.

Is laser treatment safe?

Since about 20 years ago, excimer laser therapy has been used all over the world. We did not experience any significant issues during this process that would have required stopping this course of treatment. If the right patient is chosen and the right course of treatment is taken, the results, particularly with the aid of the recently developed examination devices, are very satisfactory.

Following laser treatment, you should do the following:

Our patients are given 2 eye drops containing antibiotics and steroids immediately following the treatment, and they are instructed to use them hourly. The drug dosages are lowered after a day, and these drops are taken for a week. For a week, avoid swimming in the sea or pool, and avoid rubbing your eyes.

Does laser eye surgery avert future cataract operations?

To determine the number of intraocular lenses to be inserted, a measurement called biometry is carried out prior to the cataract surgery. The cornea's refractive index is a parameter in biometrics. Intraocular lens calculations were challenging for a while because excimer laser treatment permanently altered the corneal curvature. With the new formulas created in the last two to three years, this issue has been solved.

What distinguishes femtolasic lasik from conventional lasik?

The most crucial step in excimer laser treatment, flap removal, is carried out using a femtosecond laser technique. In addition, it can be applied to corneal implants and kerotoplasty (corneal transplant) procedures. With infrared pulses delivered in one quadrillionth of a second, this laser technology—winner of the Nobel Prize in physics—creates a very smooth incision in the cornea. This system creates flaps without the complications that are seen in conventional keratomas, making it a safer procedure. Using a femtosecond laser for refractive surgery reportedly produces better visual outcomes than using a regular keratoma, according to several publications.

Can the number return after receiving laser treatment?

The corrected number cannot be recovered in its entirety. However, it's possible that 5 out of 100 patients will still need glasses. In this situation, the same area can be used to produce laser once more.


You can get in touch with our hospital to discuss any number of eye health-related issues, receive thorough information about your specific eye issues, and discover the course of treatment.

Geri Bildirim