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 note that during surgical treatment of ametropia, the refractive power of the retina changes, due to which the image rays are clearly focused in the macular area. 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. When this function is impaired, visual acuity decreases, which leads to a decrease in quality of life.
Astigmatism, myopia and hyperopia in all cases are accompanied by a decrease in visual acuity. Any refractive error leads to the fact that the focal point of the rays is located not in the plane of the retina, but in front or behind it. Therefore, such patients need correction of visual function using external optical devices (glasses or contact lenses). This necessity may cause some inconvenience and is sometimes unsafe.
Among the diseases accompanied by refractive error, myopia is the most common. According to statistics, a third of all inhabitants of the Earth suffer from myopia. This disease can be diagnosed at any age, but most often patients with myopia are diagnosed at the age of 8-16 years. In the future, the disease may stabilize or continue to progress. In any case, myopia affects the quality of life, causing discomfort to the patient, and therefore requires a lot of attention from specialists.
It should be noted that any visual impairment requires mandatory correction. Many people believe that when using glasses to correct vision, visual acuity decreases, but this is not true. On the contrary, if you do not use any correction method, your eyes may stop working, which will definitely lead to amblyopia over time. In this case, even with perfect vision correction, it will not be 100%
Why do you need laser vision correction?
Due to the fact that many people suffer from refractive errors (hyperopia, astigmatism, myopia), specialists are constantly developing new methods of effective treatment. One of the new highly effective methods for ametropia is laser restoration of visual function.
Despite the fact that both glasses and contact lenses are widespread, easy to use and cheap, every day several thousand people turn to specialists with a request to perform laser vision correction.
It is quite simple to explain why this happens. Firstly, even the most modern glasses bring some discomfort to the owner. With prolonged use, pressure occurs on the bridge of the nose and ears, sometimes accompanied by pain. It is also very inconvenient to wear glasses in winter, since with a sharp change in temperature in a warm room, the glasses immediately fog up. In addition, when engaging in active sports, glasses not only cause discomfort, but can be dangerous.
Glasses, like contact lenses, can be forgotten or lost, so prudent people always have an extra pair to replace them.
If you choose the right contact lenses, they will definitely cause 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. However, when using lenses, even the most modern ones, the concentration of oxygen in the corneal cells decreases. As a result, vessels from the underlying layers begin to grow into the cornea, and over time, dry eye syndrome may also develop. In most cases, irreversible changes in the eye occur 5-10 years after starting contact lens wear. Afterwards, patients often have to switch to glasses or look for another alternative.
Laser correction of refractive error helps the patient to give up contact lenses and glasses forever, so this treatment provides 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 18 years old cannot undergo laser correction, since the growth of the eyeball is not yet complete. For this category of patients, glasses and contact lenses represent 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 to the cornea. An ophthalmologist will help you do this if you visit him regularly and monitor the dynamics of visual changes.
Preoperative preparation for laser vision correction
To perform laser vision correction surgery, you must first conduct a comprehensive ophthalmological examination. During the diagnosis, the doctor separately evaluates the condition of the eyeball as a whole and all its structures. Many important parameters are also measured.
The main diagnostic methods include:
- Visometry, i. e. measurement of visual acuity;
- Pneumotonometry, necessary to determine the intraocular pressure value;
- Pachymetry, during which the thickness of the cornea is measured;
- Autorefractometry, in which the refraction of the eye is determined automatically;
- Ecobiometry necessary to measure the length of the eye;
- Perimetry, i. e. determination of the boundaries of the visual field;
- The Schrimer test is necessary to evaluate the amount of tear fluid produced;
- Computerized topographic analysis of the cornea, which is a modern method of clarifying the structure of the cornea;
- Examination of fundus structures after preliminary maximum mydriasis using medicinal drops.
After careful preoperative preparation and diagnosis, the doctor can speak with high certainty about the results that the patient can expect after laser correction. This also allows you to avoid the most common complications in the postoperative period.
How is laser vision correction performed?
During the operation, a minimally invasive effect on the substance of the cornea is performed, which leads to a change in the curvature of its surface.
After the doctor corrects the shape of the cornea using an excimer laser, the image rays converge at a point located strictly 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 lasts on average about 10-15 minutes. During the operation, local anesthesia is used, which is performed with special eye drops. This helps minimize pain, both during the procedure and after. Once the operation is completed, the patient is observed in the clinic for approximately an hour and a half. Then the patient is sent home, having previously given all the recommendations. It is important to note that laser vision correction surgery has practically no effect on the patient's pace of life, that is, restrictions in the postoperative period are minimal.
Already in the complete medical examination phase, the doctor will provide all the explanations regarding the characteristics of the preoperative and recovery period. To systematize this information, there are very convenient reminders in which the patient will find answers to all his questions.
Benefits of restoring vision with excimer laser
Vision correction using excimer laser is a very common procedure and required in all countries.
The advantages of the method include:
- Reliability of results;
- Painless;
- Speed of execution (no more than a quarter of an hour);
- Safety;
- Performing manipulations on an outpatient basis;
- Wide range of possibilities;
- Short recovery period;
- Predictable and predictable result with high accuracy;
- No cutting or sewing;
- Simplicity and accessibility;
- No further testing is necessary;
- 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, it is not always possible to perform laser correction of visual function. All contraindications to this operation can be divided into two large groups: temporary and permanent. Among the temporary contraindications, the most common are those pathologies of the eye (or of the organism as a whole) that are reversible. After these diseases have been treated, it is quite possible to carry out laser correction. Temporary contraindications include:
- Progressive myopia, since the refraction is not stable;
- Acute inflammatory changes, both in the eye itself and in other body systems;
- Pregnancy;
- Breastfeeding period;
- Changes in the fundus, including tears and dystrophic changes;
- Degenerative processes in corneal cells.
If there are constant contraindications, laser vision correction becomes impossible. These include:
- Thin cornea;
- Glaucoma;
- Subluxation of the lens;
- retinal detachment;
- Cataract;
- Decompensated diabetes mellitus;
- Previous surgical treatment for retinal detachment.
Interestingly, even if there are absolute contraindications for laser vision correction, it is possible to choose an effective alternative treatment method that will help restore vision.
The main differences between laser surgery and other techniques
Laser correction for refractive error includes several types. After reading the name, most patients do not understand the essence of the operation, since mainly abbreviations or established terms are used. A distinctive 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, since patients may think that the conventional LASIK technique is somehow inferior to it and is inferior. In foreign literature, a more correct term is used (custom LASIK). In translation, this operation should be called custom LASIK. This does not mean that traditional LASIK surgery has any disadvantages. Except that in some particular cases it is preferable to perform SuperLASIK, while in other situations one can limit oneself to a simple LASIK operation. That is why, when choosing a method of laser vision correction, it is necessary to use an individual approach, taking 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 step, in which the superficial corneal flap is cut with a microkeratome blade, in FemtoLASIK is performed using a femtosecond laser. This technique is quite new, so not enough experience has yet been accumulated to clearly determine its effectiveness and safety.
Some doctors believe that the femtosecond laser is much safer than the microkeratome, but other specialists do not agree with this statement and prefer mechanical flap formation.
Another new method of laser vision correction is the Smail operation. During this procedure only a femtosecond laser is used and the phase of formation of a superficial valve from the corneal tissue is absent. In this case, a refractive section immediately forms in the deep layers of the cornea. The latter is removed through a minimal incision (2-4 mm) in the superficial layers of the cornea using a special instrument. This incision is also performed 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 can not agree that a person needs eyes constantly, that is, 365 days a year. This is why it is so important to take care of them from an early age.