What is refractive error?
The visual functions of our eyes are roughly analogous to the function of acquiring the image of a camera. The rays coming from the external environment pass through the refractive surfaces such as the outermost transparent layer of the eye, the cornea and the lens, and focus on the yellow spot in the eye's web layer which is responsible for the vision. The visual disturbances that occur due to the focusing of the external rays in a place different from the yellow point are called “refractive errors”.
What are the types of refraction defects?
Fracture defects can be divided into 3 groups:
Myopia, defined as the inability to see clearly, occurs when the rays coming into the eye focus on the front of the web, not on the web. It is most often caused by the fact that the anteroposterior axis of the eye is longer than normal. It is a structural disorder and genetic transmission is common. It usually starts at school age and increases with age.
In general, relatives can not see well. It occurs as a result of the rays coming into the eye focusing behind, not on the web layer. In contrast to myopia, the anteroposterior axis of the eye is shorter than normal in hyperopia. The most common causes of hypermetropia are structural and hereditary causes. Untreated hypermetropia increases the risk of lazy eye in children. Therefore, it is recommended that children have an eye examination prior to school age. Apart from hypermetropia, visual impairment is called “presbyopia kaynaklanan due to the decrease in the focusing feature of the eye lens over the age of 40. Presbyopia is not an eye disease but a natural part of the aging process.
The light of the cornea is caused by the fact that the refractive power is different in different meridians. Astigmatism is an eye disease that causes blurred vision at any distance. It may occur as a result of diseases, infections and traumas that may cause changes in the corneal layer.
How are refractive defects treated?
Surgical treatment of refractive defects can be divided into two main groups:
Excimer Laser Operation
The laser, which is actually a light source, is obtained by strengthening, directing and increasing the intensity of one of the wavelengths that make up the light with the help of special systems. Excimer laser is a light source that is obtained in this way and is located in the invisible ultraviolet wavelength. Since this laser system is used for the treatment of refractive errors requiring the use of glasses or lenses, the operation is also called “excimer laser.. Excimer laser operation in the world
It has helped more than 50 million people get rid of glasses and lenses.
In Excimer laser operation, modern laser technology is used, all stages are customized. Excimer laser operation; remodels the corneal layer of the eye and treats refractive errors. Because the structure and disorders of each eye are different from each other, a different method is used for each person and even for each eye. Individual differences in the eye structure of everyone have brought to the agenda personalized treatment.
The stages of excimer laser operation are:
a. Determination of personal opinion profile
The structural and functional characteristics of the guest's eye are determined by special tests. The special system used makes a three-dimensional map of the visual defect and then personal treatment is planned through the digital information received from this map. In laser treatment, a digital locking system is used between the device and the eye as it is very important that the device fires at the intended point of the eye.
b. Creation of a flap in the cornea
In the corneal layer of the eye, a layer is created without the use of a surgical knife and this layer is removed. It serves to form the diameter, thickness, grip and regularity of the layer as planned.
c. Customized laser operation
The corneal layer of the eye is reshaped and refractive defects are treated by personal excimer laser operation.
D. Closure of the cornea layer
After applying a personal excimer laser operation, the layer formed in the cornea is closed and the operation is finished.
Intraocular Lens Operation
In patients with high number myopia, hypermetropia, astigmatism or excimer laser operation due to the characteristics of the cornea; Intraocular lens operation provides sharp vision without using glasses or lenses. Intraocular lenses, such as eyeglasses or contact lenses, allow the image to fall clearly on the yellow dot in the eye, eliminating refraction defects.
In intraocular lens operation, all stages are individual. In this operation; Intraocular lenses are placed on the lens (lens) of the person's own eye in the spaces called the anterior or posterior chamber, or the lens (lens) in the person's own eye is removed and the appropriate intraocular lens is placed in the same place. Since the structure and disorders of each eye are different from each other, intraocular lens operation uses a different method for each person, and even for each eye, that is, a personalized operation is planned.
The lens to be placed in the eye is chosen according to the refractive error of the person (myopia, hyperopia, astigmatism). In this sense, people with multiple refraction defects, multifocal lenses aimed at removing all of these refractive defects at the same time.
The lenses used in intraocular lenses can be classified into three groups:
Monofocal intraocular lens: Treats only one of the refractive errors.
Bifocal (bifocal) intraocular lens: Bifocal lenses, near and far. Although it provides both near and far sight-free, the middle distance (40 cm - 2 meters) cannot be seen clearly.
Multifocal (multi-focus) intraocular lens: The most preferred of these types of so-called “smart lenses trif are trifocal lenses. Trifocal lenses allow the person to see far, close and intermediate distance (40 cm - 2 meters) without glasses.
The stages of intraocular lens operation are as follows:
a. Removing one's own lens
A surgical incision of less than 3 mm is used to reach the lens of the person's eye and remove the lens while maintaining its integrity. The lens is then liquefied and absorbed by a device emitting ultrasound waves.
b. Intraocular lens placement
A new artificial lens with a foldable feature is replaced with the lens of one's own eye. The lens is normalized by body temperature after being inserted into the eye through a previously used 3mm surgical incision.