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 the surgical treatment of ametropia, the refractive power of the retina changes, as a result of which the image rays are clearly focused 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. When this function is affected, visual acuity decreases, leading to a decreased quality of life.
Astigmatism, myopia and hyperopia in all cases are accompanied by a decrease in visual acuity. Any refractive error leads to the focal point of the rays not being in the plane of the retina, but in front or behind it. Therefore, these patients require correction of visual function using external optical devices (glasses or contact lenses). This necessity can 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 between the ages of 8 and 16. 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 using glasses to correct vision decreases visual acuity, but this is not true. On the contrary, if you do not use any correction method, your eyes may stop working, which will surely 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?
Because many people suffer from refractive errors (farsightedness, astigmatism, myopia), specialists are constantly developing new effective treatment methods. 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 come to specialists for laser vision correction.
It's pretty easy to explain why this happens. Firstly, even the most modern glasses cause their owner some discomfort. During prolonged use, 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, since with a sudden change in temperature in a warm room, the glasses immediately fog up. In addition, when playing active sports, glasses not only cause discomfort, but can also be dangerous.
Glasses, like contact lenses, can be forgotten or lost, so wise people always have an extra pair to replace them.
If you choose the right contact lenses, they will undoubtedly cause you 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 wearing lenses, even the most modern ones, the oxygen concentration in the corneal cells decreases. As a result, vessels in the underlying layers begin to grow towards the cornea and over time dry eye syndrome may also develop. Mostly irreversible changes to the eye occur between 5 and 10 years after starting to wear contact lenses. After this, patients often have to switch to glasses or look for another alternative.
Laser correction of refractive error helps the patient to abandon 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 of age cannot undergo laser correction, since the growth of their eyeball 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 use the contact lenses correctly to avoid causing irreversible changes to 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, a complete ophthalmological examination must first be performed. During diagnosis, the doctor evaluates the condition of the eyeball as a whole and all its structures separately. Many important parameters are also measured.
The main diagnostic methods include:
- Visometry, that is, 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 eye's refraction is determined automatically;
- Ecobiometrics needed to measure eye length;
- Perimetry, that is, determining the limits of the field of vision;
- The Schrimer test is necessary to evaluate the amount of tear fluid produced;
- Computer topographic analysis of the cornea, which is a modern method of clarifying the structure of the cornea;
- Examination of the structures of the fundus after preliminary maximum mydriasis using medicated drops.
After careful preoperative preparation and diagnosis, the doctor can speak with great certainty about the results that the patient can expect after laser correction. This also allows us 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 causes a change in the curvature of its surface.
After the doctor corrects the shape of the cornea with 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.
Laser vision correction surgery takes 10 to 15 minutes on average. 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. Once the operation is completed, the patient is observed in the clinic for approximately one and a half hours. 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 rhythm of life, that is, restrictions in the postoperative period are minimal.
Already at the stage of a complete medical examination, the doctor will give all explanations about the features of the preoperative and recovery period. To systematize this information, there are very convenient reminders in which the patient will find answers to all of their questions.
Benefits of excimer laser vision restoration
Vision correction using an excimer laser is a very common procedure that is in demand in all countries.
The advantages of the method include:
- Reliability of results;
- Painless;
- Speed of execution (no more than a quarter of an hour);
- Security;
- Carrying out manipulations on an outpatient basis;
- Wide range of possibilities;
- Short recovery period;
- Predictable and predictable result with high precision;
- No cuts or seams;
- Simplicity and accessibility;
- No additional testing is 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. Once these diseases are cured, it is very possible to perform laser correction. Temporary contraindications include:
- Progressive myopia, since the refraction is not stable;
- Acute inflammatory changes, both in the eye and in other body systems;
- Pregnancy;
- Breastfeeding period;
- Fundus changes, including breaks and dystrophic changes;
- Degenerative processes in corneal cells.
If there are constant contraindications, laser vision correction becomes impossible. These include:
- thin cornea;
- Glaucoma;
- Lens subluxation;
- Retinal detachment;
- Cataract;
- Decompensated diabetes mellitus;
- Previous surgical treatment of retinal detachment.
Interestingly, even if there are absolute contraindications to laser vision correction, an effective alternative treatment method can be chosen that helps 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, 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, as patients may think that the conventional LASIK technique is somehow inferior and it is inferior. A more correct term (custom LASIK) is used in foreign literature. Translated, this operation should be called custom LASIK. This does not mean that traditional LASIK surgery has disadvantages. Only in some special cases it is preferable to perform SuperLASIK, while in other situations you can limit yourself to a simple LASIK operation. Therefore, when choosing a method of laser vision correction, an individual approach should be used that takes into account the data of the preoperative examination.
An important difference between FemtoLASIK and traditional laser correction is that the operation is performed completely contactless. The first stage, 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 sufficient experience has not yet been accumulated to clearly determine its effectiveness and safety.
Several doctors believe that the femtosecond laser is much safer than the microkeratome, but other specialists disagree 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 there is no stage of forming a superficial valve from the corneal tissue. 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 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 can disagree with the fact that a person needs eyes constantly, that is, 365 days a year. That is why it is so important to take care of them from an early age.