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 corrective products (glasses or contact lenses).
It is important to note that during the surgical treatment of ametropia, the refractive power of the retina changes, as a result of which the rays from the image are clearly focused on the macular area. At the same time, vision becomes significantly better.
Why does the vision decrease?
Refraction refers to the optical power of the entire eye. Refraction is usually expressed in diopters. When this function is damaged, the visual acuity decreases, which leads to a decrease in the quality of life.
Astigmatism, myopia and farsightedness 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 not located in the plane of the retina, but in front or behind it. Therefore, such patients require correction of visual function using external optical devices (glasses or contact lenses). This need can cause some discomfort and is sometimes insecure.
Among the diseases associated with refractive error, myopia is the most common. According to statistics, one 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 great attention from specialists.
It should be noted that any visual impairment requires mandatory correction. Many people believe that when they use glasses to correct their 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 certainly 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 (farsightedness, astigmatism, myopia), specialists are constantly developing new methods of effective treatment. One of the new methods that is very effective for ametropia is laser restoration of visual function.
Despite the fact that both glasses and contact lenses are widespread, easy to use and affordable, 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. First, even the most modern glasses bring some worries to their owner. During prolonged wear, pressure occurs on the bridge of the nose and ears, which is sometimes accompanied by pain. It is also very inconvenient to wear glasses in winter, as with a sharp temperature change in a warm room, the glasses immediately fog up. In addition, when engaged 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, do not put pressure on the bridge of the nose and are comfortable for active activities. However, when using any lens, even the most modern ones, the concentration of oxygen in the cells of the cornea decreases. As a result, vessels from the underlying layers begin to grow in the cornea, and dry eye syndrome may also develop over time. Mostly, irreversible changes in the eyes occur 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 for 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 18 cannot undergo laser correction, as their eye growth is not yet complete. For this category of patients, glasses and contact lenses are the only possible way to improve visual acuity. In this case, it is important to wear the lens correctly so as not to cause irreversible changes in the cornea. An ophthalmologist will help you do 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, you must first undergo a comprehensive ophthalmic examination. During the diagnosis, the doctor separately assesses the condition of the eye socket and all its structures. Many important parameters are also measured.
The main diagnostic methods include:
- Visometry, that is, the measurement of visual acuity;
- Pneumotonometry, 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 determined automatically;
- Echobiometry necessary to measure the length of the eye;
- Perimetry, i. e. defining the boundaries of the field of vision;
- The Schrimer test is needed to assess the amount of tear fluid produced;
- Topographic computer analysis of the cornea, which is a modern method for clarifying the structure of the cornea;
- Examination of the fundus structures after maximum prior mydriasis using medicinal drops.
After careful preparation and diagnosis before surgery, the doctor can speak with high certainty about what results 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 is performed on the substance of the cornea, which leads to a change in the curvature of its surface.
After the doctor has corrected the shape of the cornea using an excimer laser, the rays from the image converge to 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 itself takes about 10-15 minutes on average. During the operation, local anesthesia is used, which is performed with special eye drops. This allows you to minimize pain, both during and after the procedure. After the operation, the patient is observed in the clinic for about 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, limitations in the post-operative period are minimal.
Already at the stage of a complete medical examination, the doctor will give all the explanations regarding the features of the pre-operative 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 excimer laser vision restoration
Vision correction using an excimer laser is a very common procedure that is required in all countries.
The advantages of the method include:
- Reliability of results;
- Without pain;
- Execution speed (not more than a quarter of an hour);
- Security;
- 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 additional tests are needed;
- 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 for 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 the body as a whole) that are reversible. After these diseases are cured, it is quite possible to perform 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;
- Lactation period;
- Fundus changes, including ruptures and dystrophic changes;
- Degenerative processes in corneal cells.
If there are persistent contraindications, laser vision correction becomes impossible. These include:
- Thin cornea;
- Glaucoma;
- Lens subluxation;
- Retinal detachment;
- Cataract;
- Decompensated diabetes mellitus;
- Previous surgical treatment for retinal detachment.
Interestingly, even if there are absolute contraindications for laser vision correction, you can choose an effective alternative method of treatment 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, as abbreviations or established terms are mainly used. A distinguishing feature of REIC and LASIK operations from SuperLASIK is the second stage of the operation, when a femtosecond laser is included in the process.
The term SuperLASIK, used in practice, is not entirely correct, as patients may think that the conventional LASIK technique is somewhat inferior to it and is inferior. In foreign literature, a more accurate term is used (LASIK to order). In translation, this operation should be called personalized LASIK. This is not to say that traditional LASIK surgery has disadvantages. It's just that in some special cases it is preferable to perform SuperLASIK, while in other situations you can limit yourself to a simple LASIK operation. That is why, when choosing a method of laser vision correction, an individual approach should be used, which takes into account the data of the pre-operative examination.
An important difference between FemtoLASIK and traditional laser correction is that the operation is completely non-contact. The first stage, in which the superficial flap of the cornea 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.
A number of doctors believe that the femtosecond laser is much safer than a microkeratome, but other specialists disagree with this statement and prefer the mechanical formation of the flap.
Another new method of laser vision correction is the Smail operation. During this procedure, only a femtosecond laser is used and the phase of forming a surface valve from corneal tissue is missing. In this case, a refractive section is immediately formed 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 cut is also done 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 disagree that a person needs eyes constantly, that is, 365 days a year. That is why it is so important to take care of them starting from an early age.