Vision correction, which refractive surgery deals with, corrects optical defects and various imperfections of the visual organ. The main disorders that most people face are myopia (myopia), hyperopia (hypermetropia) and astigmatism. Depending on the localization of the disorder and the specifics of the defect (anomalies of the structure of the eye, nuances related to the optical strength or length of the eye), the methods of solving visual imperfections will depend.
More about violations of the optics of the eye
Three main types of violations of the optics of the eye have already been named. They directly affect the quality of vision and the sharpness of perception of the “picture”:
- Myopia (light rays are refracted incorrectly, stronger than necessary and the focus is located directly in front of the retina);
- Farsightedness (refraction of rays is too weak, so focusing occurs behind the retina of the eye);
- Astigmatism (total defocusing occurs when the focus can be located both behind and in front of the retina of the eyes, greatly impairing visual abilities).
How to correct vision
Modern ophthalmology has a wide range of various operations, minimally invasive, laser treatment techniques, as well as correction of myopia or hyperopia through lenses and other similar devices. All types of vision correction can be divided into four global categories:
- Contact lenses are a popular and very convenient way to solve vision problems without surgery. Using these devices, it is possible to completely get rid of the defect. There are a lot of different types that differ from each other in different parameters. However, wearing lenses is not always acceptable for patients (due to individual intolerance or due to professional activity, for example);
- Glasses are the oldest, but reliable method to improve the quality of your vision. No matter how high-quality such attributes are, wearing accessories is always associated with a number of inconveniences, therefore, if possible, most patients try to resort to radical methods of correction;
- Microsurgical laser operations inside the eye itself. Specialists resort to surgical interventions in the event that visual disturbances are presented to an extremely high degree;
- Microsurgical operations on the cornea. This variant of refraction is considered the most high-tech and high-quality, allowing a person to regain excellent vision.
All about laser correction
Considering modern methods of treatment in ophthalmology, first of all, it is necessary to consider the features of laser vision correction. Laser exposure can be used in patients from 18 to 55 years of age.
Usually laser surgery allows you to solve such visual defects:
- Manifestations of myopia from -1.0 to -15.1 diopters;
- Farsightedness up to +1.0 to 6.0 diopters;
- With astigmatism from ± 0.5 to ± 5.0 diopters.
The laser treatment method combines many technologies, practices and special surgical algorithms. One of the most popular procedures for vision correction is considered to be “Lasik”. Let’s study the technology in more detail.
Lasik (Laser-Assisted in SItu Keratomileusis) is a popular laser vision correction procedure that allows to cope with visual refractive errors (myopia, hypermetropia, astigmatic deviations). The operation, like most manipulations performed with a laser, does not require any preparatory measures. The doctor performs work in an outpatient clinic.
Laser surgery is performed under local anesthesia. The patient does not experience any discomfort or pain. The mucous membrane of the eyes is treated with anesthetic drops. This is enough for manipulation.
The recovery period is the shortest. A day after the manipulation, the patient can live a full life without using glasses and lenses.
How is the process going
The operation of laser vision correction is quite fast. After anesthesia, the patient should focus his vision on a special luminous point generated by the display of an ophthalmic device.
The doctor uses a microkeratome to form a miniature flap on the corneal mucosa. It is bent away, opening access to deeper structures of the eyes. With the help of a laser, the moisture of the cornea evaporates, a new shell is immediately formed. Usually, the laser type of intervention does not require suturing: there is enough collagen in the human body to heal the damaged cornea quickly and correctly.
At the end of the operation, the flap is returned to its place, and the mucosa is thoroughly washed with special antiseptic solutions. If the patient’s second eye also needs a vision correction procedure, the operation is performed immediately.
Despite the fact that Lasik is considered the most delicate and high-tech operation that allows for high-quality vision correction, even here it is not without postoperative complications. This is due to the fact that the structure of the eye tissues is very delicate. In addition, the stronger the symptoms of the disease and the more deformed the tissues were, the higher the risk of side effects.
Most often, after Lasik laser vision correction surgery, the following problems may occur:
- Diplopia (double vision);
- Reduced visual contrast;
- The appearance of white circles in the dark;
- Postoperative astigmatism;
- Dry eye syndrome;
- Sensitivity to light.
Most deviations from the norm disappear by themselves after a couple of days (less often after a few weeks) after surgery. However, there are also problems that can be solved only with the support of an ophthalmologist. The laser correction procedure can lead to infectious complications, sharp fluctuations in visual acuity, the appearance of posterior thyroid detachment on the eye.
There are a number of obstacles that do not allow temporarily performing laser vision correction operations, or they force you to abandon such a profitable technique altogether. The list of basic limitations includes the following pathological conditions and physical features:
- Corneal hypotrophy;
- Pronounced keratotonus;
- Myopia of unknown origin, prone to rapid progression;
- Herpetic lesion of corneal tissues;
- Autoimmune diseases;
- Serious destructive changes in the bottom of the eye;
- Retinal pathology;
- Scars of the optical part of the cornea.
PRK is the first technique of laser correction, which was patented back in the 1980s. Despite the total dominance of the Lasik operation, there are situations when vision correction is possible only through the PRK technique. We are talking about those situations when a number of pathological conditions do not allow laser intervention in the LASIK format. For example, corneal hypotrophy or pathologically wide pupils.
Features of surgical intervention
PRK loses to Lasik with a relatively long recovery period. Patients after surgery on the surface of the cornea experience pronounced discomfort for 2-4 days, which gradually disappears by itself.
During the operation, the doctor works directly with the cornea itself. Previously, the epithelial ball is removed from the surface, then the laser beam vaporizes the necessary tissue fragments. Such laser correction leaves a wider wound surface. This explains the appearance of pain syndrome and general discomfort. As soon as the regeneration processes are over, and the epithelium is restored again, all negative manifestations will disappear.
Keratoplasty is another popular procedure performed in modern ophthalmology. Operations are carried out if necessary to restore the previous shape, and with it the functional potential of the corneal web. The doctor eliminates congenital and acquired defects, the consequences of injuries and transferred infectious processes.
The parts of the cornea that are suitable for a particular patient are removed from the donor and the transplant procedure is performed. The duration of the operation is from 30 to 50 minutes. Correction is performed using a microscope with a scalpel. A fragment of the corneal web is cut off, donor tissues are placed in its place and sewn according to a certain technique. There is also a laser technique carried out in a similar way, only with the help of a laser.
Stitches are not removed for more than six months. Such vision correction requires the patient to wear lenses for some time. Their task is to protect the operating canvas from infections and contamination. At the same time, after the operation, the patient undertakes to use antibacterial eye drops for a long time.
Crosslinking is a high–tech vision correction aimed at strengthening the ligaments in the cornea. Most of these operations are performed under local anesthesia. Correction is carried out with a special ophthalmic apparatus: a part of the corneal web is cut off, a special vitamin composition is instilled to saturate the structures, irradiated. This will significantly increase the density of the corneal layer.
Such a correction, like the previous options, also requires the wearing of postoperative lenses. After 2-3 days, the patient can go home. It is necessary to be observed by an ophthalmologist for 6 months (minimum).
In addition, there are many other ways to restore vision. It is enough to visit the ophthalmologist’s office, pass the necessary tests, and the specialist will be able to prescribe the treatment format that is most acceptable in each case. Vision correction is performed by means of high-tech devices that minimize the risk of postoperative complications.