Excimer laser surgery changes the geometry of the cornea. As a result of such an operation, the human optical system becomes more perfect, and the patient no longer needs to use optical correction products (glasses or contact lenses).
It is important to remember that during the surgical treatment of ametropia, the refractive power of the retina changes, as a result of which the rays from the image clearly focus on the macular zone. At the same time, vision improves significantly.
Why does vision decrease?
Refraction refers to the optical power of the entire eye. Refraction is usually expressed in diopters. If this function is damaged, the visual acuity decreases, which leads to a deterioration in the quality of life.
In all cases, astigmatism, nearsightedness and farsightedness are associated with a decrease in visual acuity. Any refractive error leads to the fact that the focal point of the rays is not in the plane of the retina, but in front or behind it. Therefore, in such patients, it is necessary to correct the visual function with external optical devices (glasses or contact lenses). This demand can cause some inconvenience and is sometimes unsafe.
Among the diseases associated with refractive error, myopia is the most common. According to statistics, one third of the world's population suffers from myopia. This disease can be diagnosed at any age, but myopic patients are most often diagnosed between the ages of 8 and 16. In the future, the disease may stabilize or progress. In any case, myopia affects the quality of life, causing discomfort to the patient, and therefore requires increased attention from specialists.
It should be noted that all visual impairments require mandatory correction. Many people think that visual acuity decreases when using corrective glasses, but this is not true. On the contrary, if you do not use any correction method, your eyes may stop working, which will certainly lead to the development of amblyopia over time. In this case, even with perfect vision correction, it will not be 100%
Why is laser vision correction necessary?
Given that many people suffer from refractive errors (farsightedness, astigmatism, nearsightedness), specialists are constantly developing new, effective treatment methods. One of the new methods that is highly effective in the treatment of ametropia is laser vision restoration.
Despite the fact that both glasses and contact lenses are common, easy to use and affordable, thousands of people turn to specialists every day for laser vision correction.
It is very easy to explain why this happens. First of all, even the most modern glasses cause discomfort to their owner. Long-term wear creates pressure in the bridge of the nose and ears, which sometimes causes pain. It is also very inconvenient to wear glasses in winter, as the sharp temperature change in a warm room causes the glasses to fog up immediately. In addition, during active sports, glasses not only cause discomfort, but can also be dangerous.
Glasses, like contact lenses, can be forgotten or lost, so prudent people always have an extra pair of glasses to spare.
By choosing the right contact lenses, you will undoubtedly experience less discomfort. For example, the lenses do not fog up, do not put pressure on the bridge of the nose, and are comfortable for active activities. When using any lens, even the most modern ones, the oxygen concentration of the corneal cells decreases. As a result, blood vessels from the underlying layers begin to grow into the cornea, and dry eye syndrome may develop over time. Most often, irreversible changes appear in the eye 5-10 years after starting to use contact lenses. After that, patients often have to switch to glasses or look for another alternative.
Laser correction of the refractive error helps the patient to give up contact lenses and glasses forever, so this treatment ensures a high standard of living.
It is important to know that not all patients are suitable for laser treatment of ametropia. For example, children under the age of 18 cannot undergo laser correction, as the growth of the eyeball is not yet complete. In this group of patients, glasses and contact lenses are the only possible way to improve visual acuity. In this case, it is important to wear the lenses correctly so as not to cause irreversible changes in the cornea. The ophthalmologist will help with this if you visit him regularly and monitor the dynamics of vision changes.
Preoperative preparation for laser vision correction
To perform laser vision correction surgery, a comprehensive eye examination must first be performed. During the diagnosis, the doctor evaluates the condition of the eyeball and all its structures individually. Many important parameters are also measured.
The main diagnostic methods are:
- Visometry, i. e. measurement of visual acuity;
- Pneumotonometry, which is necessary to determine the value of intraocular pressure;
- Pachymetry, during which the thickness of the cornea is measured;
- Autorefractometry, in which the refraction of the eye is automatically determined;
- Echobiometry to measure eye length;
- Perimetry, i. e. determining the boundaries of the field of vision;
- The Schrimer test is necessary to assess the amount of tear fluid produced;
- Computer topographical analysis of the cornea, which is a modern method for clarifying the structure of the cornea;
- Examination of fundus structures after preliminary maximum mydriasis with medicated drops.
After careful preoperative preparation and diagnosis, the doctor can talk with great confidence about what results the patient can expect after laser correction. This also makes it possible to avoid the most common complications in the postoperative period.
How is laser vision correction performed?
During the operation, a minimally invasive effect is exerted on the material of the cornea, which leads to a change in the curvature of the surface.
After the doctor has corrected the shape of the cornea with an excimer laser, the rays from the image converge at a point that is strictly located in the plane of the retina. All methods used in modern medicine are very safe, accurate and provide high visual acuity.
The laser vision correction operation itself takes an average of 10-15 minutes. During the operation, local anesthesia is used, which is carried out with special eye drops. This allows you to minimize pain both during and after the procedure. After the surgery is completed, the patient is monitored in the clinic for about an hour and a half. Then the patient is sent home after giving all the recommendations in advance. It is important to note that laser vision correction surgery has practically no effect on the patient's rhythm of life, that is, the restrictions in the postoperative period are minimal.
The doctor gives all the explanations about the features of the pre-surgery and recovery period already at the stage of the complete medical examination. To organize this information, there are very convenient reminders in which the patient will find answers to all his questions.
Advantages of excimer laser vision restoration
Vision correction with an excimer laser is a very common procedure that is in demand in all countries.
The advantages of this method are as follows:
- Reliability of results;
- Painless;
- speed of execution (up to a quarter of an hour);
- Security;
- Performing manipulations on an outpatient basis;
- A wide range of possibilities;
- Short recovery period;
- Predictable and predictable results with high accuracy;
- There are no cuts or seams;
- Simplicity and accessibility;
- No further tests are required;
- High efficiency that lasts a lifetime.
It should be noted that despite the wide possibilities of laser vision correction, this operation does not guarantee the absence of various eye pathologies in the future.
Contraindications for laser vision restoration
Unfortunately, laser correction of visual function is not always possible. All contraindications to this operation can be divided into two large groups: temporary and permanent. Among the temporary contraindications, the most common are reversible pathologies of the eye (or the body as a whole). After these diseases are cured, laser correction is completely possible. Temporary contraindications are:
- Progressive myopia, as the refraction is not stable;
- Acute inflammatory changes both in the eye and in other systems of the body;
- Pregnancy;
- Lactation period;
- Changes in the fundus, including tears and dystrophic changes;
- Degenerative processes in the cells of the cornea.
If there are permanent contraindications, laser vision correction becomes impossible. These are:
- Thin cornea;
- Glaucoma;
- Lens subluxation;
- Retinal detachment;
- Gray cataract;
- Decompensated diabetes mellitus;
- Previous surgical treatment due to retinal detachment.
Interestingly, even if there are absolute contraindications to laser vision correction, you can choose an effective alternative treatment method that will help restore vision.
The main differences between laser surgery and other techniques
Laser correction of refractive error includes several types. After reading the name, most patients do not understand the essence of the operation, as they mainly use abbreviations or common terms. The distinguishing feature of SuperLASIK REIC and LASIK operations is the second stage of the operation, when a femtosecond laser is involved in the process.
The term SuperLASIK used in practice is not entirely correct, as patients may think that the traditional LASIK technique is somewhat inferior and worse. In foreign literature, a more precise term is used (individual LASIK). In translation, this operation should be called personalized LASIK. This is not to say that traditional LASIK surgery has disadvantages. Only in certain cases is it advisable to perform SuperLASIK, while in other cases it may be limited to a simple LASIK operation. That is why, when choosing the method of laser vision correction, an individual approach must be used, which takes into account the data of the preoperative examination.
An important difference between FemtoLASIK and traditional laser correction is that the operation is completely non-contact. The first stage, in which the surface flap of the cornea is cut with a microkeratome blade, is performed in FemtoLASIK with a femtosecond laser. This technique is quite new, so not enough experience has yet been accumulated to clearly define its effectiveness and safety.
Many doctors believe that the femtosecond laser is much safer than the microkeratome, but other specialists disagree and prefer the mechanical design of the flap.
Another new method of laser vision correction is the Smail operation. The procedure uses only a femtosecond laser, and the section of corneal tissue that forms the surface valve is missing. In this case, a fracture section is immediately formed in the deep layers of the cornea. The latter is removed through a minimal (2-4 mm) incision in the surface layers of the cornea with a special instrument. This incision is also made with a femtosecond laser.
It is very important to understand that vision and eyes are one of the most important tools for human interaction with the outside world. Few people agree that a person needs eyes all the time, i. e. 365 days a year. That is why it is so important to take care of them from an early age.