Possible consequences of laser vision correction. What is the danger of laser vision correction

The negative consequences of laser vision correction (we are primarily interested in complications) are extremely rare. However, problems sometimes happen, and they are different for each ophthalmic disease. Therefore, it is important to understand their specifics.

Nowadays, millions of people are dissatisfied with the imperfection of their vision, some have myopia, others have farsightedness, and sometimes even astigmatism. To correct all these imperfections, just wearing glasses or lenses is not enough, so many people turn to laser correction for help, often without thinking about the consequences.

First, let's take a closer look at those common eye diseases that may require laser vision correction.

Myopia

This pathology (scientifically myopia) occurs when the eyeball is deformed - it is stretched. In this case, the focus shifts from the retina towards the lens, and the person sees objects as blurry.

The difference in the location of the focus and the structure of the eye in normal vision, nearsightedness and farsightedness

farsightedness

Farsightedness or hypermetropia appears due to a decrease in the eyeball, while the focus of objects close to the person is formed behind the retina, as a result of which the person sees these objects indistinctly.

Astigmatism

This disease is more complex than myopia or hypermetropia, and can be observed in both the first and second cases. It occurs when the cornea of ​​​​the eye, sometimes the lens, is irregularly shaped. In normal people, the cornea and lens of the correct spherical shape, and with astigmatism, their shape is broken. At the same time, when a person looks at objects, the focus is either behind the retina or in front of it, as a result of which he sees some lines clearly and others not, and the image is blurry.

eyes with normal vision and with astigmatism

What is laser vision correction

Most often, doctors advise correcting these pathologies with the help of glasses and lenses, but there are alternative ways to deal with them, among which laser correction is not the last. At the moment, this is the most effective and popular way to treat these ailments.
In 1949, Colombian doctor José Barraquer discovered a way to correct vision with a laser. And in 1985, the first operation with an excimer laser was already performed. In simple words, laser correction is an operative intervention, the purpose of which is to change the cornea of ​​​​the eye. Today there are two main methods of laser correction - PRK and Lasik, and several advanced methods based on the Lasik system. Now let's take a closer look at each of these methods.

Photorefractive keratectomy (PRK)

PRK is the very first operation using a laser. With this method, there is a direct effect on the upper layer of the cornea. Using a laser, a specialist removes the surface layer of the cornea, then with a cold ultraviolet beam, he corrects it to the desired size, calculated using a computer, so that the focus of the image is on the retina. So with myopia, the cornea is made flatter, with farsightedness, more convex, with astigmatism, the cornea is corrected to the shape of a regular sphere. Restoration of the upper epithelial layer after the operation occurs in three to four days, this occurs with little discomfort for the eye. After three to four weeks, vision is restored.

Advantages of the technique:

• non-contact impact;
• painlessness;
• short duration of the operation;
• stability in predicting results;
• high quality of vision is achieved;
• low likelihood of complications;
• the possibility of carrying out with a thin cornea.

Disadvantages of the technique:

• duration of recovery;
• discomfort in the eye during recovery;
• temporary deterioration in the transparency of the surface of the cornea (haze);
• the impossibility of simultaneous correction in both eyes.

Lasik

The LASIK operation is carried out as follows: the surface layer of the cornea (corneal flap) is separated with an instrument or a special solution, and after correction it is put back on the method. Within a couple of hours after the operation, the epithelial layer is completely restored. And vision returns after seven, and sometimes even after four days.

The Lasik method is subdivided into several more methods: the Lasik method itself, Super Lasik, Femto Lasik and Femto Super Lasik.

These techniques differ from each other in the way in which the corneal epithelium is separated at the first stage of the operation, as well as in the use of more advanced computerized equipment, which allows minimizing complications after the operation.

Classic Lasik

During this operation, a "cold" ultraviolet beam of an excimer laser is used, with the help of which the optical power of the cornea is changed. Thanks to this change, it is possible to achieve a complete focus of the light rays on the retina, which is necessary for the return of sharp vision. So, for patients with myopia, the Lasik technique allows you to correct the steep shape of the cornea, making it fairly flat. And for patients with farsightedness, on the contrary, it corrects the shape of the cornea to a steeper one.

Advantages of the technique:

• fast recovery;
• preservation of the epithelial layer of the cornea;
• painlessness;
• no complications during the recovery period;
• the ability to operate on both eyes at the same time.

Disadvantages of the technique:

• high risk of intraoperative complications (bleeding);
• discomfort in the eye after surgery (pass quickly);
• inability to use with a thin cornea;
• in the absence of a strong connection of the corneal layer with the cornea, optical distortions may occur;
• the risk of dry eye syndrome (recovered after a year);
• the need to instill the medicine in the eyes for 10-14 days.

Super Lasik

The Super Lasik technique allows a more individual approach to each case with the help of high-tech diagnostic equipment - the Wave Scan wave analyzer system. Using this equipment, a specialist can find out the dimensions of all components of the visual apparatus and accurately record all deviations of the visual system of the operated person.

Advantages of the technique:

• achieving high results up to 100%;
• fast recovery;
• the possibility of correcting the shortcomings obtained during earlier operations.

Disadvantages of the technique:

• complications due to mechanical impact on the cornea;
• the possibility of dry eye syndrome;
• sometimes the depth of impact on the cornea is greater than with conventional Lasik.

Femto Lasik

The Femto Lasik technique eliminates the use of mechanical instruments to obtain a corneal flap, as in the Lasik technique. The specialist sets the necessary parameters, and the computer system, which includes a high-precision femtosecond laser, separates the horn-shaped flap of a given thickness. Then everything happens the same as with the Lasik operation.

Advantages of the technique:

• the possibility of surgery with a thin cornea;
• high stability of results;
• fast recovery.

Disadvantages of the technique:

• more time to work with the corneal flap and, as a result, the lengthening of the whole process;
• the need for strict fixation of the eye, which can affect the eyeball;
• the cost is twice as high as the conventional Lasik surgery.

Femto Super Lasik

The Femto Super Lasik technique includes the use of a Wave Scan analyzer and a femtosecond laser. This makes it possible to obtain a corneal flap in a non-contact way and take into account all the individual characteristics of the eye of a particular person being operated on at the moment.

Advantages of the technique:

• fast operation;
• individual approach for each specific patient;
• achievement of high results;
• fast recovery;
• lack of mechanical impact;
• the possibility of surgery with a thin cornea.

Disadvantages of the technique:

• high price.

Complications after laser vision correction

Although laser correction is a completely painless and outpatient operation and the risk of possible adverse effects is minimized, it is still an operation and a patient who wants to use it for vision correction needs to be aware of the possible complications. Here are some of the effects of laser vision correction:

1. complications due to poor-quality equipment or an unqualified specialist;
2. violations that may appear in the postoperative period;
3. inflammation after surgery;
4. swelling, redness, discomfort in the eye;
5. unsatisfactory result of the operation (eye disease was not completely cured, etc.);
6. long-term consequences (the possibility of the return of the disease a few years after the operation);
7. the possibility of visual impairment;
8. chance of corneal clouding.

Consider some of the consequences of complications in more detail.

Complications due to poor-quality equipment or an unqualified specialist

Sometimes, due to some technical reasons or due to the insufficient level of qualification of the doctor, some complications are possible during the operation itself. For example, indicators for the operation may be incorrectly selected, vacuum loss may occur, a corneal flap may be cut incorrectly. All these reasons can lead to clouding of the cornea, the appearance of irregular astigmatism, double vision. Such complications account for approximately 27% of all operations.

Disorders that appear in the postoperative period

Complications during this period include inflammation and swelling of the eye, retinal rejection, hemorrhage, discomfort in the eyes. The reason for such complications is the individuality of each organism, its ability to quickly recover after surgery. These complications account for approximately 2%. To get rid of them, you will have to be treated for a long time or undergo a second operation, and sometimes this does not help to fully recover.

Unsatisfactory result of the operation

Sometimes the operation does not fully justify itself and we do not get the desired result. For example, after laser correction, residual myopia may occur. In this case, a second operation is needed in one to two months. If it turned out to be a plus from a minus, or vice versa, a second operation is also needed, but after two to three months.

Long-term consequences

Sometimes there are so-called long-term consequences that occur after three or more years after the operation. Unfortunately, in a large number of cases, the correction does not completely get rid of the disease, and in the future it may return. Experts have not determined why these complications occur, because of the operation itself or because of the characteristics of the human body, or perhaps because of its lifestyle. But even after a second operation, luck is not guaranteed.

Contraindications for laser correction

Laser vision correction can not be performed:

1. pregnant women;
2. during breastfeeding;
3. patients under the age of 18;
4. people with diabetes (and in general with diseases that can cause poor healing);
5. with impaired immunity;
6. in eye diseases such as: thinning of the cornea (keratoconus disease), retinal detachment, cataracts, glaucoma.

Limitations and necessary actions of the patient after laser correction

To avoid complications after surgery, you must strictly follow the doctor's advice:

1. during the rehabilitation period, try to sleep on your back;
2. do not use cosmetics on the face, especially for the eyes;
3. limit washing of the face and head for 3-4 days after the operation;
4. spend less time watching TV, computer, reading;
5. do not visit public water bodies;
6. wear dark glasses in bright sunlight;
7. do not drink alcohol for one week after the operation;
8. do not drive vehicles at night;
9. do not rub your eyes;
10. try to exclude physical activity;
11. strictly on time and the required number of times to apply eye drops prescribed by a specialist;
12. at the appointed time to undergo examinations with a doctor.

Most often, the cause of complications after laser vision correction (LKZ) lies in the personal reaction of the body to surgery.

Complications can lead to visual impairment: the occurrence of astigmatism, retinal rejection, monocular double vision, corneal clouding, epithelial ingrowth, conjunctivitis.

The benefits of laser vision correction

It should be noted that with the help of LKZ You can immediately comprehensively correct several problems with vision. If for some reason a person cannot wear glasses or lenses (for example, due to a profession), then laser correction will be the only way out.

In addition to improving vision, there are the following advantages:

• Method safety.
• No need for postoperative hospital treatment.
• There is no need to use general anesthesia.

Reference. Refractive lamellar corneal surgery was discovered in 1940 thanks to the work of Dr. Joseph I. barraquer. The first laser vision correction surgery was performed in a Berlin clinic in 1985 and has since been successfully practiced all over the world.

What is dangerous LKZ: possible harm from the operation

Contraindications:

• constantly progressive myopia;
• inflammatory processes in the body, affecting the eyes;

• dystrophic changes in the retina;
• diabetes;
• glaucoma;
• cataract;
• nervoses especially during an exacerbation.

If all contraindications are taken into account, then the risks are minimal. According to medical statistics, complications occur only at 25%. To avoid harm to health, laser correction should be carried out strictly according to the indications and according to the recommendation of a qualified specialist, taking into account the patient's health status and personal contraindications.

Complications after laser vision correction: how terrible they are

Some complications may occur after laser vision correction.

Postoperative clouding or erosion of the cornea

Clouding of the cornea caused by decaying cells. They produce a secretion that directly affects the transparency of the cornea. Drops are used to solve the problem, in extreme cases, laser intervention is recommended. Corneal erosions of varying degrees may appear with scratches and microtraumas during the correction. With proper postoperative care, the eyes heal on their own.

Photo 1. Clouding of the cornea after laser surgery. Small white spots appear on the eye area.

Traumatic injury to the corneal flap

Poor quality flap cut: thin, small, short, uneven, cut of the leg - is quite rare. For highly skilled surgeons, the risks are 1% . If, due to damage, further correction is not possible, the flap is returned to its place without interfering with the middle layers of the cornea. The next operation is allowed no earlier than six months later.

Pupil displacement

Corectopia - violation of the natural position of the pupil, at which it shifts to the side or changes shape. Caused by a strong load on the lens. Corectopia may or may not affect visual acuity. If vision is rapidly deteriorating, causing amblyopia, then surgery is necessary.

Photo 2. Corectopia after laser vision correction. The pupil has shifted from the center of the cornea of ​​the eye.

You will also be interested in:

Risks of damage to the retina or sclera of the eye

A fairly common complication, this can also include fragility of the eyeball. It is eliminated medically or surgically, depending on the state of the visual organs.

Postoperative keratoconus

Corneal deformity in the form of a cone, which occurs due to the thinning of the cornea and intraocular pressure, i.e. complex deterioration in the medium term. Develops gradually. The cornea softens and weakens, vision becomes worse, and deformation occurs. Keratoconus may require a donor cornea transplant.

Photo 3. Human eye with keratoconus. When the disease occurs, the cornea takes on a conical shape.

Hypocorrection and hypercorrection

Hypocorrection is insufficient correction of vision. With this complication, a repeated correction is prescribed, but with the use of additional techniques. People with farsightedness and nearsightedness are especially susceptible to this deterioration. Hypercorrection - exaggerated (over) improved vision.

This is a common occurrence and usually resolves on its own. within a few months. In some cases, the doctor prescribes weak glasses. For other values ​​of the problem, repeated laser intervention may be required.

Dry eye syndrome

Unpleasant dryness in the eyes, a feeling of the presence of a foreign body, a feeling of a “stuck” eyelid. In DES, the tear does not wet the sclera enough. It is considered one of the most common complications.

Passes about after 10-14 days after correction. Ophthalmologists recommend the use of special drops. If dry eye does not go away on its own, minor surgery to close the tear ducts to keep the tear in the eye is possible.

Danger of postoperative impairment of night vision

Occurs when the patient has dilated pupils. This complication is characterized by sudden bright flashes of light, the appearance of "halos" around objects (halo effect), and illumination of objects of vision. It can be of a permanent nature, and also significantly interfere with driving a car in the evening and at night, fog, snow, and rain additionally affect. The way out will be glasses with small diopters, and special drops, the action of which is aimed at narrowing the pupils.

Diffuse lamellar keratitis

It's called differently Sands of the Sahara Syndrome. When extraneous foreign microparticles (under the valve) enter the eye, inflammation begins there. The image changes from sharp to blurry.

Ingrown epithelium

Fusion of epithelial cells with the surface layer of the cornea, with cells under the flap. Usually happens in the first few weeks after the correction. The problem is concentrated in the loose fit of the corneal flap. Rarely progresses. Correction is carried out by surgical intervention. Required 1-2% of patients.

Is it possible to go blind after surgery?

Laser vision correction is considered a very reliable operation, after which any complications are rarely observed.

In the entire history of the existence of LKZ was not diagnosed no loss of vision after this procedure. The main thing is to observe all postoperative restrictions, and then the result will be guaranteed for many years.

Restrictions

Before the procedure the patient must undergo certain training. This is a complete examination to identify contraindications, an eye test immediately before the LKZ and the use of anesthetic drops after the procedure.

The LASIK operation is the most widely advertised and mass-performed vision correction for astigmatism and other diseases. Millions of surgeries are performed annually all over the world.

Much has been said about its benefits, but the possible complications are not often covered. After LASIK, complications of one kind or another of varying severity are observed in about 5% of cases. Serious consequences that significantly reduce visual acuity occur in less than 1% of cases. Most of them can only be eliminated with additional treatment or surgery.

The operation is performed using an excimer laser. It allows you to correct astigmatism up to 3 diopters (myopic, hyperopic or mixed). Also, it can be used to correct myopia up to 15 diopters and hyperopia up to 4 diopters.

The surgeon uses a microkeratome instrument to incise the top of the cornea. This is the so-called flap. At one end it remains attached to the cornea. The flap is turned to the side and access to the middle layer of the cornea is opened.

Then the laser evaporates a microscopic part of the tissue of this layer. This is how a new, more regular shape of the cornea is formed so that the light rays are focused exactly on the retina. This improves the patient's vision.

The procedure is fully computer controlled, quick and painless. At the end, the flap is returned to its place. In a few minutes, it adheres firmly and no sutures are required.

Consequences of LASIK

The most common (about 5% of cases) are the consequences of LASIK, which complicate or lengthen the recovery period, but do not significantly affect vision. You can call them side effects. They are usually part of the normal postoperative recovery process.

As a rule, they are temporary and are observed within 6-12 months after the operation, while the corneal flap is healing. However, in some cases, they can become a permanent occurrence and create some discomfort.

Side effects that do not cause a decrease in visual acuity include:

vision restoration techniques

help yourself

laser correction. Effects.

This page collects information, one way or another related to the consequences of laser vision correction. Information that is different from what can be found in inviting advertising. The goal is for you to have more or less objective information about the possible consequences of laser vision correction, so that you think about the risks.

Note: all the mentioned clinics, if there is no clarification, are located in Minsk.

e-mail correspondence, 2006:

Good afternoon!

Katerina

Thanks! :)

What was the name of the operation (lasik or other)?
- I read that before and after the operation there are some prescriptions - such as not wearing lenses, etc. - did you follow them all?
- Are there any negative aspects of this operation (except that everything returned with time)?
Have you tried recovery exercises?

I don’t remember the name, I was 17 years old, somehow I didn’t remember :)
Of course, the instructions were, of course, carried out. There are a lot of vitamins and procedures.
In addition to the fact that it didn’t work out, there are no other negative points, the operation is painless and then there were no unpleasant sensations
I haven’t tried it, I drink herbal supplements with blueberries - it helps much better;))

Katerina

e-mail correspondence, 2006:

communication at the corporate forum, 2003:

And here are reviews and comments about laser vision correction from the Dialogues section of the forum.

Here's another article. Unfortunately, the source is unknown, found on one of the Internet forums.

The main disadvantages of laser vision correction

There are many of them in laser vision correction, so many that even the founding fathers of this method no longer recommend it for widespread use. So, for example, in the reports at the conference on refractive surgery in 2000, such founders of the method as Theo Sailer (director of the eye clinic of the University of Zurich, Switzerland), Janis Pallikaris (director of the eye clinic, Greece, inventor of the LASIK method), Maria Tassinho ( Professor at the University of Antwernen, Belgium) and others have identified more than 30 possible complications associated with the most popular LASIK laser surgery today. In these reports, there was a clear concern not only about possible surgical and postoperative complications, which at the very least, to one degree or another, can be eliminated, but also about a possible loss of vision quality, which cannot be further corrected by spherical cylindrical optics.

Observations of ophthalmologists in Russia are fully consistent with world data. So, in the report of Russian scientists K.B. Pershina and N.F. Pashinova "LASIK complications: analysis of 12500 operations", made at the conference "Modern Medical Technologies" in Moscow, it is stated that when analyzing the structure and frequency of complications of laser vision correction operations based on 12,500 operations performed in Excimer clinics in the cities of Moscow, St. Petersburg, Novosibirsk and Kyiv, over the period from July 1998 to March 2000, it was found that complications, deviations from the normal course and side effects of LASIK are noted in 18,61% cases! These operations were performed by leading Russian surgeons with significant experience and professional skills using modern excimer laser systems NIDEK TC 5000. At the same time, in 12,8% cases, repeated operations were required to eliminate these defects.

We list only the main types of complications in laser vision correction:

Operational complications. They are associated primarily with the technical support of the operation and the skill of the surgeon: loss of vacuum or its insufficiency, incorrectly selected parameters of vacuum rings and stoppers, thin section, split section, and much more. The proportion of such surgical complications according to the article cited above is 27% of the total number of operations. At the same time, complications that worsen visual function and affect long-term results are 0.15%, which can be expressed in a decrease in maximum visual acuity, monocular double vision, induced astigmatism and irregular astigmatism, as well as corneal clouding. It seems that 0.15% is quite a bit, but imagine that it was you who got into these few dozens of unfortunate people. That it is your cornea that has become cloudy, and in the very center of the eye, which is functionally the most important. You see this perfectly in the morning and badly in the evening, and it is precisely in your twilight, or, conversely, in bright passing light, due to reflection from possible small scars, flashes, light rings, doubling appear in the eye, and besides, all this happens, when you are driving. So is it worth the risk? Maybe it's better to just wear glasses, which, by the way, are very easy to remove, as opposed to irreversible surgical interventions on the cornea?

Postoperative complications. In modern refractive surgery, this group of complications includes a large number of conditions: from inflammatory reactions to the subjective dissatisfaction of the patient with the result of the operation. These conditions (inflammation, edema, conjunctivitis, epithelial ingrowth, "sand in the eye" syndrome, hemorrhages, retinal detachment, binocular vision disorders, and much more) occur in the next few days after surgery and do not depend on the skill of the surgeon and the laser technology used, but associated with the individual characteristics of postoperative healing. The frequency of such complications, which include clouding of the cornea, according to various sources, averages 2% of the number of operations. All of these painful conditions require long-term treatment with expensive drugs, and often additional operations on an already weakened cornea. Moreover, not always all these activities lead to success and complete recovery.

Complications associated with ablation. This, the largest group of complications in laser vision correction, is due to the fact that often the refractive result from the operation is not what was expected. The most likely undercorrection is residual myopia. It is revealed immediately after the operation. In this case, you will need additional surgery in 1-2 months. If, on the contrary, they “overdid it” and made “plus” out of “minus” or vice versa, then a second correction is carried out after 2-3 months. Again, it is not necessary that the second operation will be more successful than the first. And the ability of the eye to perceive the following one after one operation is far from unlimited.

Long-term effects of laser vision correction. This is the most subtle and not fully explored problem. In the same time, it is the long-term consequences of laser vision correction operations that can pose the greatest danger to a person. The fact is that laser correction of myopia, farsightedness and astigmatism as such does not cure, because. These are systemic diseases of the entire organ of vision with damage to the retina, sclera and structures of the anterior part of the eye, caused by certain biological and genetic causes in the human body. The operation only corrects, changes the shape of the eye in such a way that the image falls on the retina, i.e. does not affect the causes of the disease, but fights only with its consequences. The reasons why the shape of the eye changed in the wrong direction, remain and continue to operate with no less power. It is already known that the corrective effect of laser surgery weakens over time, although the exact long-term statistics of this weakening has not yet been obtained. Those. actually The rigid contact lens “carved” by a laser from our living tissue of the eye gradually becomes weak. And the man again returns to the glasses. Moreover, this is the best case for him. More unfortunate developments are also possible. It is known that a person acquires additional diseases over the years, the hormonal background changes in his body - all this can cause clouding and other serious problems with a weakened cornea operation. Or God forbid you get into some trouble and "get in the eye" - a weakened shell can break and the consequences will be the most deplorable. The same thing can happen if you didn't take the ball too well in some exciting game like volleyball, or if you lifted a sack of potatoes that were too heavy, or even just steamed in the sauna. You are guaranteed problems. In one of the Saturday issues of Komsomolskaya Pravda an anecdote-announcement was printed: “Laser vision correction. Inexpensive. The set of services includes a wand and a guide dog. Truly, in every joke there is only a fraction of a joke.

And finally, the last one. There are entire population groups for whom laser vision correction in any form is generally contraindicated. First of all, these are children under the age of at least 18 years, and according to some literary data, even up to 25 years. The child grows, and the shape of his eye naturally changes as well, which makes it unreasonable to make any artificial correction of this shape before natural growth stops. Secondly, after 35-40 years, most people develop farsightedness. This is not a disease - it is a variant of the age norm. In this situation, laser vision correction done in youth ceases to fulfill its positive purpose and the person returns to glasses again.

Complications of LASIK: analysis of 12500 operations

Pashinova N.F., Pershin K.B.

Refractive lamellar corneal surgery began in the late 1940s with the work of Dr. José I. Barraquer, who was the first to recognize that the refractive power of the eye could be altered by removing or adding corneal tissue. The term "keratomileusis" originated from two Greek words "keras" - cornea and "smileusis" - to cut. The surgical technique itself, instruments and devices for these operations have undergone a significant evolution since those years - from the manual technique of excising a part of the cornea to the use of freezing the corneal disc with its subsequent treatment in myopic keratomileusis (MKM) . Then the transition to techniques that do not require tissue freezing, and, therefore, reduce the risk of opacities and the formation of irregular astigmatism, providing a faster and more comfortable recovery period for the patient. A huge contribution to the development of lamellar keratoplasty, understanding of its histological, physiological, optical and other mechanisms was made by the work of Professor Belyaev V.V. and his schools. Dr. Luis Ruiz proposed in situ keratomileusis, first using a manual keratome, and in the 1980s with an automated microkeratome – automated lamellar keratomileusis (ALK).

The first clinical results of ALK showed the advantages of this operation: simplicity, rapid recovery of vision, stability of results and efficiency in the correction of high degrees of myopia. The disadvantages are a relatively high percentage of irregular astigmatism (2%) and the predictability of results within 2 diopters. Trokel et al. also proposed photorefractive keratectomy in 1983 (25). However, it soon became clear that with high degrees of myopia, the risk of central opacities, regression of the refractive effect of the operation and the predictability of the results are significantly increased. Pallikaris I. et al., combining these two techniques into one and using (according to the authors themselves) the idea of ​​cutting out a corneal pocket on a leg (Pureskin N., 1966), they proposed an operation that they called LASIK - Laser in situ keratomileusis. In 1992 Buratto L. and in 1994 Medvedev I.B. published their versions of the operation technique.

Since 1997, LASIK has been gaining more and more attention from both refractive surgeons and patients. The number of operations performed per year is already in the millions. However, with an increase in the number of operations and surgeons performing these operations, with the expansion of indications, the number of works devoted to complications also grows.

Materials and methods

In this article, we wanted to analyze the structure and frequency of complications of LASIK surgery on the basis of 12,500 operations performed at the Excimer clinics in Moscow, St. Petersburg, Novosibirsk and Kyiv during the period from July 1998 to March 2000. myopic astigmatism was performed 9600 operations (76.8%); about hypermetropia, hyperopic astigmatism and mixed astigmatism - 800 (6.4%); ammetropia corrections in previously operated eyes (after radial keratotomy, PRK, penetrating corneal transplantation, thermokeratocoagulation, keratomileusis, pseudophakia and some others) - 2100 (16.8%).

All the operations under consideration were performed using a NIDEK EC 5000 excimer laser, the optical zone was 5.5–6.5 mm, the transition zone was 7.0–7.5 mm, and multizone ablation was performed at high degrees.

Three types of microkeratoms have been used:

1) Moria LSK-Evolution 2 - keratome head 130/150 microns, vacuum rings from -1 to +2, manual horizontal cut (72% of all operations), mechanical rotational cut (23.6%).

2) Hansatom Baush&Lomb - 500 operations (4%).

3) Nidek MK 2000 - 50 operations (0.4%).

As a rule, all operations (more than 90%) LASIK were performed simultaneously bilaterally. Topical anesthesia, postoperative treatment - topical antibiotic, steroid for 4-7 days, artificial tear according to indications.

The refractive results correspond to the world literature data and depend on the initial degree of myopia and astigmatism. George O. Warning III proposes to evaluate the results of refractive operations in four parameters: efficiency, predictability, stability and safety. Under efficiency refers to the ratio of postoperative uncorrected visual acuity to preoperative maximally corrected visual acuity. For example, if postoperative visual acuity without correction is 0.9, and before surgery with maximum correction the patient saw 1.2, then the efficiency is 0.9/1.2 = 0.75. And vice versa, if before the operation the maximum vision was 0.6, and after the operation the patient sees 0.7, then the efficiency is 0.7/0.6 ​​= 1.17. Predictability is the ratio of the planned refraction to the received. Safety- the ratio of the maximum visual acuity after surgery to this indicator before surgery, i.e. a safe operation is when the maximum visual acuity is 1.0 (1/1=1) before and after surgery. If this coefficient decreases, then the risk of the operation increases. Stability determines the change in the refractive result over time.

In our study, the largest group is patients with myopia and myopic astigmatism. Myopia from -0.75 to -18.0 D, average: -7.71 D. Follow-up period from 3 months. up to 24 months The maximum visual acuity before surgery was more than 0.5 in 97.3%. Astigmatism from -0.5 to -6.0 D, average -2.2 D. Average postoperative refraction -0.87 D (from -3.5 to +2.0), residual myopia was planned for patients after 40 years of age. Predictability (±1 D, from the planned refraction) - 92.7%. Average astigmatism 0.5 D (from 0 to 3.5 D). Uncorrected visual acuity of 0.5 and above in 89.6% of patients, 1.0 and above in 78.9% of patients. Loss of 1 or more lines of maximum visual acuity - 9.79%. The results are presented in table 1.

Complications can be divided into operational, postoperative and complications of the late postoperative period.

Operational complications

As a rule, surgical complications are associated with the technical support of the operation: loss of vacuum or its insufficiency during the cut, blade defects, incorrectly selected parameters of vacuum rings and stoppers.

Vacuum loss or insufficiency during the cut can be for several reasons:

• insufficient exposure, i.e. the cut itself started very quickly and the vacuum did not have time to reach the required parameters
• chemosis of the conjunctiva, filtration cushions after antiglaucomatous surgeries, scars and cysts of the conjunctiva and some other reasons can lead to the fact that the altered conjunctiva obturates the vacuum hole of the ring and the device shows that there is sufficient pressure for the operation, but it does not correspond to the true pressure of the eye at this moment
• compression and displacement of the eye tissues during the passage of the keratoma head can depressurize the eye system - the vacuum ring.

Blade defects - there may be a factory defect, as well as damage to the blade during assembly of the microkeratome.

Very steep or flat corneas, and in some models of microkeratoms, incorrectly selected sizes of rings and restraints can lead to a significant discrepancy between the expected and obtained sizes of the flap and the corneal bed.

The above reasons can lead to flap-related complications:

• thin flap - 0.1%
• uneven flap (step) - 0.1%
• button-hole (flap with a round defect in the center) - 0.04%
• full cut (free cap) - 0.3%
• incomplete cut - 0.56%
• split cut - 0.02%.

Defects in the epithelium - 1.43%. Total surgical complications - 1.27% of the total number of operations, because usually they were combined (thin section, uneven, split with an epithelium defect). Complications that impair function and affect long-term results - 0.15%, which can be expressed in a decrease in maximum visual acuity, monocular double vision, induced astigmatism or irregular astigmatism, corneal clouding.

In order to exclude the possibility of surgical complications as much as possible, the following rules must be observed: careful and careful selection of patients according to the parameters of the preoperative examination; correct choice of rings and stopper; use disposable blades only 1 time; control of the edge of the blade after assembly of the microkeratome; control the vacuum before the cut; wet the surface of the cornea during the cut, especially in aged patients.

If, nevertheless, a complication has occurred, it is necessary to develop a clear algorithm of actions in each specific case and strictly adhere to it, regardless of the attendant circumstances (non-resident patient, financial or any other problems). In our opinion, this algorithm can be as follows: it is necessary to recognize the complication in time, under no circumstances do ablation (the “free cap” exception), carefully straighten the flap or what is left, prevent epithelium ingrowth as much as possible, treat the patient until the maximum severity returns vision, re-section should be carried out no earlier than 3 months. taking into account the reasons that led to the first complication, and, if possible, a different diameter and a different depth.

In the case of a complete cut of the flap, ablation is performed, the flap is placed along the marks, about 5 minutes. dried, its stability is checked. As a rule, its additional fixation is not required, and this does not affect the final result. It should be noted that the proportion of surgical complications decreases by 10 times after the first 200-300 operations.

Postoperative complications

In modern refractive surgery, this group of complications includes a large number of conditions: from inflammatory reactions to the subjective dissatisfaction of the patient with the result of the operation. Schematically, they can be divided into complications associated

• with flap: displacement, swelling, inflammation;
• with interface: epithelial ingrowth, debris and inclusions, central islets, Sands of the Sahara syndrome (SOS) and/or Nonspecific diffuse intralamellar keratitis (DLK), inflammation;
• with ablation: Hypo/hypercorrection, decentration, irregular astigmatism;
• with other eye diseases: retinal detachment, macular edema, macular hemorrhage, Bowman's membrane diseases, autoimmune diseases, toxic keratopathy (glandular discharge, oil or other material from a keratoma, debris, etc.), cataract progression, progression of macular degeneration, keratoectasia (induced keratoconus). And as a separate group, one can single out the subjective discrepancy between the results of the operation and the patient's expectations.

Flap related complications

Displacement of the superficial flap occurred in 0.04% of cases, which required its reposition, usually sutureless, but sometimes it is necessary to use a contact lens or suturing. Flap edema occurred in 0.03% of cases and required conservative treatment. Inflammations were more common (0.23%) in the form of herpetic keratoconjunctivitis (8 cases), bacterial keratoconjunctivitis (6 cases) and fungal keratoconjunctivitis (2 cases).

Interface Complications

Ingrown epithelium, affecting visual functions and requiring surgical intervention, was rare - 0.07% of cases.

Debris and inclusions (“garbage” under the flap) biomicroscopically, it can almost always be detected, but there was not a single case that this affected the functional result.

central islets in topographic examination are relatively rare (0.04%). The etiology of this phenomenon is not completely clear. One explanation may be that the vacuum ring, by raising IOP over 65 mm Hg. Art., changes the “corneal edema pressure”, which leads to its dehydration. After the vacuum is removed, hydration sets in. The central cornea swells faster and more than the periphery, which can lead to interface folds and flaps.

The interface, like a pump, draws in water and debris during and after surgery until the epithelial barrier is restored. In these cases, there is decrease in both maximum possible and uncorrected vision. As a rule, they gradually disappear within 1 to 3 months. after operation.

SOS or nonspecific diffuse intralamellar keratitis (DLK), first described by Smith & Maloney in 1998, according to a number of authors, occurs with a frequency of 1 in 500 to 1 in 5000 operations. Develops 2-5 days after surgery. There are four stages of DLK (Eric J. Linebarger 1999): stage 1 - whitish inclusions in the interface along the periphery, which do not reduce vision; Stage 2 - point inclusions throughout the interface, including the center, which do not reduce vision or reduce it by 1–2 lines; stage 3 - point inclusions in the center begin to merge into conglomerates and a significant decrease in vision occurs; Stage 4 - melting the flap. We encountered this complication 8 times (stages 2–3), which accounted for 0.07% of all cases. Such a small percentage is explained by the fact that only cases requiring additional conservative or surgical intervention were taken into account. The causes of DLK are not fully understood. Some authors explain this by trophic changes, others - by a toxic-allergic reaction of the cornea to the secrets of Bowman's glands or to microscopic particles of metal and microkeratome oil. In our opinion, the most successful concept was proposed by Kurenkov V.V. with co-authors and named "Disadaptation Syndrome of the Superficial Corneal Flap" . They consider the formation of striae and folds of the superficial flap after LASIK as the initial stage in the development of DLK. The authors see the reason for this in the incongruence of the ablated surface of the corneal stroma and the superficial flap laid on it.

We, like most authors, adhere to active tactics in the treatment of DLK. Inspection after the operation is more reasonable to carry out on the second day. In case of suspicion of the development of DLK, steroids must be administered locally in drops and subconjunctival injections for 1-2 days. In the absence of positive dynamics or an increase in clinical manifestations, it is necessary to lift the superficial flap and thoroughly rinse both the stromal bed itself and the inner surface of the superficial flap with dexamethasone solution. In foreign literature, there are references to the successful use of cytostatics (methotrexate) in such cases.

Inflammation was not common, in 0.1% of cases (10 eyes). Of these, 5 cases of herpetic stromal keratitis, 2 - chlamydial and 3 bacterial with an unknown pathogen.

Complications associated with ablation

The third, largest group of complications is directly related to ablation. Hypocorrection and regression (less refractive effect of the operation or its decrease from the planned one by more than 0.5 D) noted in 16% of cases. Of these, reoperations required 12.4%. Hypercorrection (greater effect of the operation by 0.75 D and above) met much less often - 0.2%, of which reoperations - 0.07%. Decentrations affecting function in the form of monocular diplopia, glare, halos, decreased vision in the dark or in bright light - 0,1%.

All patients underwent reoperations in these patients using camouflage substances or with displaced ablation. The CAP method using the VISX excimer laser greatly facilitates such interventions.

Induced astigmatism (more than 0.5 D) and irregular astigmatism was in 0.35% of cases, of which 0.18% required reoperations. Incorrect astigmatism developed with decentrations, problems with the flap and interface. Analyzing this type of complications, we noticed that their number is much higher in patients with existing corneal scars (traumatic scars, conditions after penetrating corneal transplants and radial keratotomy, pseudophakia after EEC, etc.). Apparently, the intersection of a penetrating corneal scar with a microkeratome leads to a change in biomechanical properties and parameters, which unpredictably affects the shape of the cornea and its refraction.

In the group of patients who underwent LASIK after penetrating corneal transplantation for keratoconus, significant induced astigmatism was detected in more than 50% of cases. After we switched to the two-stage LASIK method, the frequency of this complication in these patients does not exceed that in patients with normal myopia. The essence of the technique lies in the fact that the first step is to cut the superficial flap with a microkeratome without ablation, after which the flap is placed in place. According to the topographic picture, the stabilization of the refraction of the cornea is waited (usually 2-4 weeks), after which the flap is lifted and ablated according to new topographic data.

Total the total number of reoperations (raise of the flap or a new cut for additional correction or for flushing the interface) was 12,8% .

Some data on operational and postoperative complications in comparison with the analysis of complications after LASIK conducted by the European and American Societies of Refractive and Cataract Surgeons are presented in Table. 2. A large percentage of surgical complications in 1998 is associated with mastering as a technique in general, and individual surgeon training. According to leading refractive surgeons, the percentage of surgical complications decreases by an order of magnitude after the first 200-300 operations.

Complications associated with other eye diseases

Fortunately, the vast majority of complications associated with other eye diseases cannot be directly related to the correction itself. More often they are associated with a severe initial state of the myopic eye.

Retinal disinsertion- in 5 eyes, which amounted to 0.05% of the group of patients with myopia and 0.04% of all operations. In all cases, detachment occurred no earlier than 4-6 months after surgery. All patients had previously undergone prophylactic peripheral laser coagulation (PPLC) of the retina.

1. Patient L., 19 years old, LASIK for high myopia (-8.0 D). PPLC in 14 days. Vis OU = 1.0 after correction. After 8 months retinal detachment in the left eye. Sectoral filling. One month after the operation, Vis OD = 1.0; Vis OS = 0.6 s/k 0.8.
2. Patient K., 43 years old. Myopia 9.5 D. PPLC OU 7 years ago. LASIK OU with planned residual myopia -1.5 D. On day 10 Vis OU = 0.7-0.8 sph - 1.0 = 1.0. After 2 months Vis OD = 0.6 sph - 1.25 = 1.0; Vis OS = 0.3 sph - 2.25 = 1.0. At the request of the patient, an additional correction was performed (without a new cut). Vis OU = 0.9 - 1.0. After 4 months after the first operation retinal detachment OS. Produced circling with radial sealing. Vis OS = 0.6 n/a. After 6 months Vis OD = 0.9 sph - 0.75 = 1.0; Vis OS = 0.2 - 0.3 n/a.
3. Patient D., 47 years old. Myopia - 7.0 D. PPLC OU 10 years ago. After LASIK Vis OU = 0.6 sph - 1.0 = 0.8 (maximum possible). Retinal detachment OD after 8 months. after correction. The operation for detachment at the request of the patient was carried out in another clinic.
4. Patient P., 46 years old. Myopia OU - 10.0 D. PPLC 14 days before correction. OD injury 1.5 years after LASIK. Operated at the place of residence.
5. Patient N., 34 years old. LASIK for high myopia (OD - 7.0 D, OS - 9.0 D). PPLC 1 month before surgery. Vis OU = 0.6 s/k 0.9. 6 months after surgery retinal detachment OS. Sectoral filling. Vis OS = 0.3 c/c 0.5.

Macular edema was in one eye (0.01%) in a patient with complicated axial myopia of a very high degree. Patient L., 28 years old. Myopia of a very high degree (SE = - 22.0 D). Vis OU with corr. = 0.4. LASIK on one eye with multizone ablation (6 zones). The next day SE = + 0.75 D. Vis = 0.05 n/c. Macular edema in the fundus. 2 weeks later, after a course of conservative therapy, Vis = 0.3.

macular hemorrhage also met 1 time (0.01%). A 74-year-old patient with pseudophakia (EEC+IOL more than 4 years ago), myopia and myopic astigmatism. LASIK was performed with good refractive and visual effect. 14 days after the operation, the vision decreased sharply due to macular hemorrhage.

Cataract progression we noted in 5 patients (0.04%), of which phacoemulsification with IOL implantation was performed in two cases. It should be noted that in all these cases, cataract was detected at the stage of preoperative examination and patients were warned in advance about the possibility of its progression.

Keratoectasia after LASIK (induced keratoconus), according to the literature, is quite rare if the parameters of the operation are not observed (residual postoperative corneal depth of at least 250 microns and total thickness of the cornea after surgery is at least 400 microns) or if keratoconus is not detected during preoperative examination. Only in the article Amoils S.P. et al., 2000 reported 13 cases of iatrogenic keratoconus in patients with myopia from -3.0 to -7.0 diopters, with normal corneal thickness, no evidence of initial keratoconus before surgery and normal parameters of the operation. At the same time, keratoconus developed 1 week - 27 months after LASIK.

We have identified induced keratoconus in two patients in 3 eyes (0.02%), one of which underwent penetrating keratoplasty. In two cases (one patient) was not detected initial keratoconus. In the third case (myopia with SE = -12.0 D), 250 microns of intact cornea was left, the head of the microkeratome was 130 microns thick.

Toxic epitheliopathy in the late postoperative period(0.04%), as a rule, require conservative treatment and do not ultimately affect the outcome of the operation.

One patient (0.01%) 2 years after LASIK had dry form of macular degeneration, which currently does not reduce visual acuity.

Complications associated with diseases of the Bowman's membrane, autoimmune and systemic diseases, we have not identified.

Total if we sum up all the complications encountered, deviations from the normal course and side effects of LASIK, we get 18,61% . Quite often they are combined in one patient. For example, an uneven cut of a microkeratome with an epithelial defect during surgery can lead to epithelial ingrowth in the postoperative period, which, in turn, can lead to the occurrence of induced or abnormal astigmatism, and, consequently, a decrease in visual acuity. Complications affecting the visual result in the late postoperative period, after reoperations (total reoperations - 12.8%), was 0.67%.

A separate group consists of patients in whom, according to the surgeon, everything is fine, which is also confirmed by clinical data, but they subjectively dissatisfied with the result. This discrepancy between the result of the operation performed by the ophthalmic surgeon and the expectations of the patient leads to the most intractable problems between them. The prevalence and relative accessibility of refractive surgery against the backdrop of weak insurance medicine and significant gaps in the legal framework that determines the relationship between the clinic - the doctor - the patient at the present time, makes this problem very relevant.

Conclusion

1. The proportion of complications depends more on the experience of the surgeon and the clinic as a whole than on the type of microkeratome and laser. However, it should be noted that each microkeratome and excimer laser has its own specific features.
2. The presence of different keratomas and lasers expands the possibilities of the surgeon in atypical cases.
3. The presence of various vacuum rings and microkeratome heads of different cut depths allows you to optimize the parameters of each specific operation.
4. The "Low Vac" mode (low vacuum) of the microkeratome provides reliable centralization of ablation, speeds up the procedure and reduces the risk of complications.
5. Gradual vacuum release reduces corneal hydration, which increases the stability of the laser, reduces the effect of fluid absorption and debris under the flap.
6. Standardization of the surgical technique, methods of dealing with complications and postoperative management can significantly improve the results. It should be noted that optimization is subject not only to the work of the surgeon, but also to the entire team of the clinic, including diagnostics, operating nurses and engineering staff. Only in this case can consistently good results be achieved., and failures in any of the links will not entail serious clinical consequences.
7. Thorough and detailed discussion with the patient of indications and contraindications for a specific refractive surgery; understanding by the patient how and what they are going to do with him; understanding that the patient also takes risks associated with complications independent of the surgeon and equipment; identification by the doctor of unreasonable expectations of the patient from the result of the operation - all this will eliminate conflicts between the patient and the doctor, and, consequently, improve the quality of refractive surgery in general.

Literature

1. Barraquer JI. Queratoplastia Refractiva. Estudio Inform. 1949; 10:2-21.
2. Barraquer JI. Results of myopic keratomileuses. J. Refract. Surg.1987; 3:98-101.
3. Barraquer JI. Keratomileuses. Int. Surg. 1967; 48:103-117.
4. Swinger CA, Barker BA. Prospective evaluation of myopic keratomileuses. Ophthalmology. 1984; 91:785-792.
5. Nordan LT. Keratomileuses. Int. Ophthalmol. Clin. 1991; 31:7-12.
6. Belyaev V.S. Operations on the cornea and sclera. Moscow: Medicine, 1984, 144 p.
7. Slade SG, Updegraff SA. Complications of automated lamellar keratectomy. Arch. Ophthalmol. 1995; 113(9): 1092-1093.
8. Trokel S, Srinivasan R, Braren B. Excimer laser surgery of the cornea. Am. J. Ophthalmol. 1983; 94-125.
9. Pureskin N.P. Weakening of eye refraction by partial stromectomy of the cornea in the experiment. Vestn. Ophthalmol. 1967; 8:1-7.
10. Pallikaris I, Papatzanaki M, Stathi EZ, Frenschock O, Georgiadis A. Laser in situ keratomileuses. Laser Surg. Med. 1990; 10:463-468.
11. Buratto L, Ferrari M, Rama P. Excimer laser intrastromal keratomileuses. Am. J. Ophthalmol. 1992; 113:291-295.
12. Medvedev I.B. Advanced technology of myopic keratomileusis with high myopia. Diss. Cand. Honey. Nauk - Moscow, 1994, 147 p.
13. George O. Waring III. Standard graphs for reporting refractive surgery. J. Refractive Surg. 2000; 16:459-466.
14. Kurenkov V.V., Sheludchenko V.M., Kurenkova N.V. Classification, causes and clinical manifestations of complications of laser specialized keratomileusis in the correction of myopia and hypermetropia. Vestn. Ophthalm. 1999; 5:33-35.
15. Amoils SP, Deist MB, Gous P, Amoils PM. Iatrogenic keratectasia after laser in situ keratomileuses for less than -4.0 to -7.0 diopters of myopia. J of Cataract & Refractive Surg. 2000; 26:967-978.

Here is a small fragment of the book by Svetlana Troitskaya “Get rid of killer glasses forever!” .

And here is what Igor Afonin writes about laser correction in his book “Take off your glasses in 10 lessons. Book of Insight".

Recently, more and more talk about laser surgery. Sometimes they are presented as the only way out for people with poor eyesight. However, even after laser surgery, one cannot count on one hundred percent vision. In addition, for laser surgery, as in general for any serious surgical intervention, there are contraindications. For example, you can not do the operation to those who are under 18 years old. You can not lie down under the laser if you have progressive myopia, eye diseases, pregnancy, infectious diseases. After the operation, it is necessary to follow certain prescriptions of the doctor, to be under his supervision for at least 3 months.

And the cost of the operation is considerable, as it consists of many components. Here and computer diagnostics, and consultations, and the operation itself. Approximately 2-3 thousand dollars comes out. So think carefully, dear reader, before you take this step.

And if you have almost made up your mind, think about this. Does it bother you that most ophthalmologists still wear glasses?

Information for reflection.

Below you can see photos of the richest people on our planet in 2007, they are all billionaires. They understand what risk is. They have the ability to pay for the most highly qualified doctors. Q: Why are they still wearing glasses?

At the service of such billionaires as Bill Gates, Paul Allen, Karl Albrecht, James Clark, the world's best specialists in the field of laser vision correction. However, having the opportunity to pay for the most expensive operations, they wear glasses and do not rush to the laser. The question arises: "Why?".

Laser corrections

For some, laser correction is the only chance to see the world with all its charms and colors, for others - to forget about the hated glasses and lenses. However, the article is not about those happy owners who got 100% vision back after correction by an ophthalmologist. We will talk about certain complications that may occur within six months or several years after the operation.

Let's start with the fact that no one knows the exact number of types of excimer laser vision correction. Today, LASIK is mainly used, the rest (PRK, LASIK, REIK, FAREC, LASEK, ELISK, Epi-LASIK, MAGEK) are only its varieties or modifications. Surgeons do not hide the complications of laser correction, however, they do not advertise them, trying to justify the promises of advertising with their professionalism. Because the answer to the silence was the rampant growth of rumors about the dangers of LASIK. What are only forums on the Internet about laser correction. Reviews are written by those who directly went through the procedure, as well as those whose relatives, friends, neighbors or acquaintances went through this procedure. After reading them, it becomes not only scary, but very scary. After reading sad stories, many forever give up the idea of ​​ever making an attempt to restore vision with the help of excimer laser correction.

Zhdanov V.G., professor of the International Slavic Academy and the Siberian Humanitarian and Ecological Institute, candidate of physical and mathematical sciences in the specialty "Optics", gave his assessment in the lecture "Operations on the eyes". Vladimir Zhdanov, known for his lectures on restoring vision in a natural way using the Shichko-Bates method, noted that by burning the upper layer of the cornea with a laser using a given computer program, as a result, the patient receives glasses from the eyes. “But if ordinary glasses can be removed, contact lenses too, then these artificially created glasses cannot be removed,” says an expert in the field of optical instruments. And people walk in them. A man was operated on with a laser, he opens his eyes, he sees everything, but his eye is sore. The eyes are sick. The eyes are protruding. Muscles don't work. And his eye continues to lengthen more and more, the performance of muscles decreases. He sees, but the eye is sick. And as a result, after two or three or four years, he is again forced to go either to them, to burn out further, or to put on glasses, to return to this initial state again. Therefore, these are very dangerous things and, I conjure you ... you, your relatives, loved ones not to use the services of all innovations in the field of health and, especially, vision.

What do you think about this?

The health insurance system, which came to us from the West, forces the doctor to inform the patient about the possible complications of a surgical operation against his signature. It turns out that the doctor is not so much fighting for the health and life of the patient with all available methods as he is following the algorithm prescribed to him in this case by insurance companies. He is trying to protect himself and the insurance company from the patient's legal claims. There are a lot of stories about how, as a result of severe complications after the procedure, the patient is left alone with his misfortune. A few reviews, each of which is a tragedy:

“Our friends took their 20-year-old daughter to Moscow,” we read on the forum, she was just tired of wearing glasses. In a well-known clinic, a laser vision correction procedure was performed. The girl is completely blind. Parents tried to sue, but nothing came of it. No money, no vision.

“My mother had a similar operation four years ago. Everything is fine. And a friend was there too - good reviews. A neighbor also underwent laser surgery, unfortunately, her retina was burned. She underwent two more procedures to restore her vision, but after three months she was completely blind. The whole horror of the situation is that before the start of the operation, a receipt was given that in the event of an unsuccessful outcome, there would be no claims on her part to the clinic.

And here is another review on the forum: “Since the healing process depends on 1000 factors, no one will give you a guarantee of 100% recovery, and believe me, they will not undertake repeated laser correction. This is done only once and there will be no second chance to correct it. The ophthalmologist gave me advice: if there is no progressive deterioration of vision, the disease does not interfere with life, then the operation should not be done yet. My friend wanted to make himself a correction, but he was warned in the clinic that then heavy physical activity would be prohibited for the rest of his life.

LASIK procedure

Despite the massive advertising in the press and on television, declaring the LASIK procedure, doctors do not hide the fact that the procedure is irreversible. Certain negative effects occur even when clinically significant complications are not detected. The percentage of severe complications that significantly reduce the quality of life of patients is very small, however, one should focus primarily on the individual characteristics of the body. The higher the degree of myopia and hyperopia in a patient before surgery, the greater the risk of various visual side effects, such as double vision, the appearance of luminous circles or halos around objects, mainly at night, reduced visual contrast, etc.

In addition to these visual effects, the following complications are possible after LASIK surgery:

• Inconsistent correction and fluctuations in visual acuity.
• Excessive or insufficient degree of correction of visual acuity, iatrogenic postoperative astigmatism.
• Keratoconus or iatrogenic keratoectasia (thinning of the cornea with a subsequent change in its surface in the form of a protruding cone, leading to a significant decrease in visual acuity). The average risk of developing keratoectasia is 3 years after surgery.
• The appearance of keratoconjunctivitis: inflammation of the conjunctiva with involvement in the process of the cornea of ​​​​the eye of varying degrees of prevalence and depth of the process.
• Photophobia or increased sensitivity to light.
• Development of degenerative processes: destruction of the vitreous body - clouding of the fibers of the vitreous body of the eye, observed by a person in the form of threads, "coils of wool", dotted, granular, powdery, nodular or needle-shaped inclusions that float after the movement of the eyes in one direction or the other .
• Complications associated with the corneal flap: accumulation of fluid under the flap, folds of the corneal flap, thinning of the flap with the development of erosion or a small hole, displacement of the laser treatment area, ingrowth of the corneal epithelium under the flap, diffuse lamellar keratitis.

Complications of LASIK that can significantly and irreversibly reduce vision

Serious traumatic injuries after LASIK are extremely rare. However, in the world ophthalmic scientific literature there are descriptions of the loss of the corneal flap due to trauma. Of course, a patient who has lost a corneal flap needs emergency hospitalization. Such an extensive wound of the cornea heals for a long time and painfully. Further treatment consists in implanting an artificial lens instead of the natural lens in the patient.

Complications that do not affect the final result of the correction: damage to the epithelium of the cornea with an eyelid expander. temporary ptosis (some drooping of the eyelid); toxic effect on the epithelium of the dye or staining of the sub-flap space after marking; debris (remains of tissue evaporated by the laser under the flap, invisible to the patient and dissolving over time); ingrowth of the epithelium under the flap (not causing visual impairment and discomfort); damage to the epithelial layer during the formation of the flap; marginal or partial keratomalacia (resorption) of the flap; dry eye syndrome (mild form).

Complications requiring repeated intervention for their elimination: keratitis improper flap placement; decentration of the optical zone of laser ablation; undercorrection; hypercorrection; tucking the edge of the flap; flap displacement; ingrowth of the epithelium under the flap (causing decreased vision and discomfort); debris (if located in the center of the optical zone and affects visual acuity).

Complications in which other methods of treatment are used: poor-quality flap cut (incomplete, thin, torn, small, with striae, full flap cut); traumatic damage to the flap (tearing or tearing of the flap); dry eye syndrome (chronic form).