Refractive Surgery

What does refractive error mean?

When we look at an image, the rays reflected from the objects come into the eye. The light rays coming into the eye are first refracted by the transparent tissue called the cornea in the front of the eye, and then by the lens in the eye, and focus on the retina layer on which the light-sensing cells are located. If the rays coming into the eye are not focused on the retina, a blurred image occurs and this is called refractive error.

What are the types of refractive errors?

For the sake of simplicity, we can divide refractive errors into two main groups: myopia and hyperopia. In myopia, the rays focus in front of the retina, while in hyperopia they focus behind the retina. Apart from myopia and hyperopia, there is another group of refractive errors called astigmatism. Astigmatism is the inability of the image to focus on a single point. Light rays from the horizontal and vertical axes are focused at different points.

How to treat refractive errors?

Glasses or contact lenses are generally used in the treatment of refractive errors. The beginning of research on the surgical treatment of refractive errors dates back to the 1930s. Especially with the introduction of laser technology in the 1980s and the developments in the field of computers and software in the 2000s, refractive surgeries have become repeatable, reliable and predictable applications.

Are refractive error treatments with laser reliable?

There are still hesitations among the public in the treatment of refractive errors with laser. A big reason for this is due to misinformation. We have long-term results of more than 35 years of surgeries performed with laser systems that have become almost perfect technologically. Considering these results, it is scientifically inferred that the safety, reliability and predictability of such surgeries are above the ninety-five percent level in appropriate patients and when appropriate methods are applied.

What types of refractive surgery options are there?

Depending on the type and size of the refractive error and the personal eye structure, different surgical procedures can be applied. These surgical procedures are:

              1. LASIK: A cap-shaped tissue is lifted from the front of the cornea with specially made instruments or with the help of a femtosecond laser. After laser is applied to the underlying corneal tissue, the lifted cap tissue placed in place.

                2. LASEK: Before the laser is applied, the top epithelial layer of the cornea is carefully peeled off. Laser is applied to the underlying corneal tissue. The epithelial layer is then placed in place.

                3. No-touch laser: During this procedure, the surgeon does not interfere with the eye at any stage, and all procedures are performed by the laser device in a computer-controlled manner. After the epithelial layer of the cornea is shaved with laser, laser is applied to the underlying corneal tissue. A contact lens is placed at the end of the procedure. Three days later, this contact lens is removed.

                4. PRK: After the epithelial layer of the cornea is removed, laser is applied to the underlying corneal tissue and a contact lens is placed at the end of the procedure. Three days later, this contact lens is removed.

                5. SMILE: The tissues cut from the inner layers of the cornea are removed with a laser through a small gap without removing the corneal upper layer completely.

                6. Refractive lens replacement: In cases where the refractive error is beyond the limits of the laser, or the corneal tissues are not sufficient for laser operation, the lens in the eye is removed and replaced with an artificial intraocular lens, similar to cataract surgery.