Laser vision correction. Consequences

27.10.2017

One of the most popular methods of improving vision today is the use of laser correction. The process occurs using an excimer laser. It is controlled via a computer, and the specialist selects the method of refractive surgery. This may be the least dangerous operation from the point of view of injury, LASIK or SUPERLASIK (LASIK/SUPERLASIK), or PRK (photorefractive keratectomy).

Advantages of laser vision correction procedure

When a doctor advises a patient to use this technique, many people naturally ask whether laser vision correction is dangerous.

Cautions

Like any other medical procedure, LZK has its certain disadvantages.

In some cases, laser vision correction is dangerous due to darkening of the cornea. If this happens, the person will have a blurred vision of surrounding objects, which can sometimes even cause double vision. Darkening of the cornea is characterized by a sharp deterioration in vision in dim light or in bright light.

Another possible side effect is getting the opposite of what you expected. For example, if myopia was treated with a laser method, farsightedness may occur and vice versa. The problem is that it will no longer be possible to correct vision using a laser again. In this case, more serious intervention will be required.

Sometimes surgery can cause a weakening of the cornea, which can lead to significant vision impairment. Then the success of laser correction in this case is reduced to zero, and the patient returns to wearing glasses or contacts.

Another danger of laser vision correction is pupil displacement. When the eye is exposed to a laser, the lens receives a very strong load, which can cause the pupil to move. Elimination of this defect requires a new complex operation, which does not guarantee a positive result.

Possible consequences of laser correction include conjunctivitis, problems with binocular vision, various inflammations, as well as fragility of the eyeballs. Sometimes the retina or sclera of the eye is damaged. These consequences require long-term treatment, which will include not only medication, but also surgery. If the eyeballs have become fragile after surgery, then any impact on them will cause vision deterioration.

To summarize, it is necessary to mention that laser vision correction using the LASIK or SUPERLASIK method (LASIK/SUPERLASIK) is a modern and high-tech medical procedure. In our medical center, before recommending this procedure, the ophthalmologist conducts a full ophthalmological examination, the results of which determine the need and indications for laser vision correction for each patient absolutely individually. The predicted result is assessed and discussed with the patient. And if there are contraindications to laser vision correction or the possibility of any complications in the future, our doctors recommend not to carry out this procedure.

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Any surgical intervention is associated with risks of complications, and laser vision correction is no exception. The incidence of side effects is less than one percent, but they are still worth checking out.

In general, there are a large number of myths and prejudices around laser vision correction that have nothing to do with reality. Patients often have unreasonable fears and fear of losing their vision.

The procedure is performed under local anesthesia and is virtually painless. High-quality drugs are used for anesthesia. Immediately after vision correction, you are allowed to read, write, and work on the computer.

What can we say about some people’s fear of going blind after manipulation? This is simply impossible! The very idea and manufacturability of laser surgery eliminates the possibility of vision impairment and, especially, blindness. The laser beam acts exclusively on the superficial tissues of the cornea. No punctures or deep cuts are made. In the entire history of laser surgery, there has not been a single case of a patient losing his sight.

Over the years, the visual improvements achieved through correction do not change. The exception is some ophthalmological diseases, which may require additional correction. The manipulation lasts about twenty minutes. There is no need for the patient to be hospitalized.

Surgical intervention eliminates blood loss and the need for stitches. Thanks to this, the duration of the rehabilitation period is significantly reduced. The procedure can be performed on both eyes simultaneously. The laser beam has a highly precise effect on tissue without affecting healthy areas of the cornea.

The automated system minimizes the human factor. The possibility of errors in laser operation is excluded. The procedure is prescribed to correct myopia, farsightedness and astigmatism. As a result, we get consistently good vision. Modern equipment has simplified the manipulation. Millions of people around the world have given up glasses and contact lenses and regained their vision. Along with unconditional advantages, there are also some negative aspects. What consequences can laser vision correction lead to?

Possible complications

Experts openly talk about the disadvantages of laser surgery. Unfortunately, it is not always possible to get rid of astigmatism and farsightedness. The same can be said about high myopia. Most often, the procedure turns out to be useless.

Sometimes there are inaccuracies in calculations and diagnostics, which can lead to insufficient correction. It is worth understanding that laser correction is a correction of an existing vision defect, but it cannot protect against possible dysfunctions. That is why in patients who had surgery at a young age, the risk of presbyopia (senile farsightedness) cannot be excluded. Moreover, due to an early operation, the pathology can occur unpredictably.

Laser vision correction can lead to the development of the following complications:

fluctuations in visual acuity;
dry eye syndrome;
photophobia;
redness, swelling, tearing;
increased intraocular pressure;
retinal damage;
spread of infection;
deterioration of twilight vision;
astigmatism;
appearance of light halos.

Dry eyes are caused by damage to the nerve endings involved in the functioning of the lacrimal glands during surgery. You may need to moisturize your vision for six months after the procedure.

Night vision may be impaired for several months. Longer-term vision disturbances occur in less than one percent of patients.

Another complication of laser surgery can be excessive or, conversely, insufficient correction. In the first case, this means a transition from minus to plus. Vision usually improves over time. To correct age-related farsightedness, insufficient correction is introduced deliberately. Since one organ of vision is operated for high-quality vision at a distance, and the second for near vision. Only in two percent of all cases is there a need for a repeat procedure.

Why does vision deteriorate after laser surgery? Normally, the effect occurs within a couple of days and does not regress. The restoration of visual function may pause for some time, and then resume again. But vision loss is extremely rare.

However, some patients experience a decrease in visual acuity several weeks after correction. Most often, patients themselves provoke the development of such events. For example, not all patients consciously follow the doctor’s recommendations and begin to engage in intense physical activity or overload their eyes. Such an irresponsible attitude towards one’s health can lead not only to slower regeneration, but also to regression. But the deterioration will stop as soon as the patient stops violating the regimen prescribed by the doctor.

Dry eye syndrome (DES)

Despite the fact that laser surgery minimally destroys the tissue of the eye apparatus, approximately every second patient experiences dry keratoconjunctivitis after correction. The patient feels the presence of a foreign body. It seems to him that the eyelid is sticking to the eyeball. Usually discomfort is accompanied by cutting, burning, pain, itching, and redness. Tearing does not bring any relief. During the day, visual acuity indicators change. There is a blurry vision of objects.

Dry eye syndrome is a common complication of laser eye surgery.

During surgery, the tear film is damaged. But it is precisely this that protects the eyeball from drying out, infection and irritation. In addition, during the procedure, the outer part of the cornea is cut off, which destroys the nerve endings responsible for the production of tear fluid.

The risk of developing keratoconjunctivitis sicca increases in the following cases:

dry eyes before surgery;
myopia;
thyroid diseases;
hypovitaminosis;
menopause;
taking certain medications;
wearing contact lenses;
long stay in an air-conditioned room.

If risk factors are detected, tear replacement therapy is performed several weeks before surgery. An effective treatment for dry eye syndrome is artificial tear preparations.

You can also cope with excessive dryness by actively blinking. This promotes uniform distribution of tear fluid over the entire surface of the eyeball. In addition, experts recommend increasing the consumption of fats of plant and animal origin. Fish oil and flaxseed oil are of great benefit to the visual system.

The main focus in the treatment of dry eye syndrome is to stimulate tear production and improve film stability. In parallel with this, the primary causes of the pathological process and disturbing symptoms are eliminated.

The pharmaceutical market offers a wide selection of moisturizing drops. Such drugs differ in consistency, duration of therapeutic action and the presence of the active component. For patients leading an active lifestyle, disposable dropper tubes have been developed. They are not only convenient to use, but also ensure hygiene and prevent the development of an infectious process.

Preference is given to medications that gently moisturize the organs of vision and also effectively combat insufficient tear production. It is best to choose natural-based drugs that have a long-lasting therapeutic effect.

Keratoconus

Keratoconus is a disease in which the cornea is damaged. This is a progressive bilateral disease that can lead to visual impairment and even disability.

Complications may arise due to the following reasons:

undiagnosed keratoconus before laser correction;
presence of latent keratoconus;
violation of the surgical technique.

Clinical symptoms of this complication usually appear some time after the procedure. The patient's vision may deteriorate so much that he cannot even count the fingers on his hand. When looking at a light source, halos appear. Another manifestation of the disease is severe astigmatism, which cannot be corrected.

What to do if such a dangerous complication is discovered? Unfortunately, conservative therapy is ineffective in most cases. Experts manage to stabilize the condition with the help of cross-linking. The essence of this procedure is to expose the cornea to ultraviolet radiation. In severe cases, repeat refractive surgery or corneal transplantation is performed.

How to avoid side effects

Any medical procedure has a number of contraindications for use. There are also certain limitations to laser correction. If you ignore them, the risk of unwanted consequences increases dramatically. So, laser correction is contraindicated in the following cases:

patients under eighteen years of age and over forty-five years of age;
cataract;
glaucoma;
pregnancy;
lactation period;
keratoconus;
lens spasm;
diabetes;
AIDS;
rheumatoid arthritis;
inflammatory processes of the eye;
arthritis;
vascular pathologies;
presbyopia;
retinal detachment.

Relative contraindications include colds, which are accompanied by a runny nose and cough. In addition, after a preliminary examination, the ophthalmologist may discover individual limitations to the manipulation.

Deterioration of vision after laser correction during intense visual or physical activity in the first days of the postoperative period

Separately, I would like to highlight some of the absolute contraindications. Why is surgery prohibited for minor patients? The fact is that in childhood the tissues of the eyeball are still developing and forming. Because of this, visual acuity may fluctuate. Even when 100% vision is achieved, physiological processes in the body can affect the result.

As for the state of the immune system, the weakening of the body’s defenses in itself is not a limitation to the operation. However, disturbances in the functioning of the immune system can increase the risk of complications and lengthen the recovery period.

If we talk about such serious diseases as cataracts, glaucoma and retinal detachment, they require preliminary treatment. In the presence of such pathologies, it is difficult for a specialist to establish the features of visual impairment and correctly carry out correction.

For ophthalmological diseases of an inflammatory nature, a laser procedure can further intensify the course of the pathological process. The rehabilitation period in this case will last much longer.

If you have skin diseases, such as eczema, psoriasis or neurodermatitis, there is a high likelihood of keloid scars forming. As a reaction to the procedure, scarring processes can also occur on the tissues of the eye, and this can lead to complete blindness.

And of course, the procedure is not performed on patients with serious neurological or psychological conditions. Unexpected inappropriate behavior during surgery or the rehabilitation period can lead to self-injury.

Pregnant women and nursing mothers experience hormonal imbalances. This can negatively affect the healing process of the visual organ. It is also worth considering the fact that after surgery, patients are prescribed antibacterial agents to avoid complications. Antibacterial agents can affect the development of the fetus. And during the lactation period, because of this, the baby will have to be switched to artificial feeding.

A sharp drop in visual acuity over the course of a year is also a contraindication to manipulation. The fact is that decreased vision may be a manifestation of some hidden pathologies. Therefore, first of all, the patient must undergo a comprehensive examination and undergo drug treatment.

The consequences of laser correction will be minimized thanks to proper preparation and planning. The main element of preparatory measures is to conduct a comprehensive examination to determine the presence of contraindications. During diagnosis, the doctor determines the characteristics, which are subsequently used to configure the laser device.

ATTENTION! Most often, complications arise due to non-compliance with doctor’s recommendations and personal hygiene rules.

If there are any chronic pathologies, the patient should notify the ophthalmologist. Immediately before the procedure, it is prohibited to use any cosmetics, including creams and lotions.

In the first few days after the procedure, the patient may experience severe itching. You shouldn't be afraid of him. The appearance of this symptom indicates tissue healing. Under no circumstances should you rub your eye, as this may cause injury to the operated area.

There will be increased sensitivity to sunlight for several days after surgery, so it is best to bring sunglasses. Also, in the first days, doctors do not recommend driving a car.

Doctors do not recommend washing your face at all in the first days. Try not to get water, much less cosmetics, into your eyes. Visiting the bathhouse and sauna is prohibited. Moisture penetration can disrupt the tissue healing process.

If the patient’s professional activity is not associated with intense visual or physical activity, he can begin work the very next day. Laser vision correction is a cosmetic procedure, so sick leave is not issued in most cases.

LASIK surgery is the most widely advertised and widely performed vision correction for astigmatism and other diseases. Millions of surgeries are performed every year around 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 approximately 5% of cases. Serious consequences that significantly reduce visual acuity occur in less than 1% of cases. Most of them can only be eliminated through 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). It can also be used to correct myopia up to 15 diopters and farsightedness up to 4 diopters.

The surgeon uses a microkeratome tool to cut the top of the cornea. This is the so-called flap. One end remains attached to the cornea. The flap is turned to the side and access to the middle layer of the cornea is opened.

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

The procedure is fully computer controlled, fast and painless. Once completed, the flap is returned to its place. In a few minutes it adheres firmly and no stitches 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. They can be called side effects. They are usually part of the normal post-operative recovery process.

As a rule, they are temporary and are observed for 6-12 months after surgery 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:

Deterioration of night vision. One of the consequences of LASIK may be deterioration of vision in low light conditions, such as dim light, rain, snow, fog. This deterioration may become permanent, and patients with dilated pupils are at greater risk of this effect.

Moderate pain, discomfort, and a feeling of a foreign object in the eye may be felt for several days after surgery.

Watery eyes usually occur within the first 72 hours after surgery.

The occurrence of dry eye syndrome is an eye irritation associated with drying of the corneal surface after LASIK. This symptom is temporary, often more severe in patients who have suffered from it before surgery, but in some cases it can become permanent. Requires regular moistening of the cornea with artificial tear drops.

Blurred or double images are most often observed within 72 hours after surgery, but can also occur in the late postoperative period.

Glare and increased sensitivity to bright light are most noticeable in the first 48 hours after correction, although increased sensitivity to light may persist for a long time. The eyes may become more sensitive to bright light than they were before surgery. Driving at night may be difficult.

Ingrowth of the epithelium under the corneal flap is usually noted in the first few weeks after correction and occurs as a result of a loose fit of the flap. In most cases, ingrowth of epithelial cells does not progress and does not cause discomfort or visual impairment for the patient.

In rare cases (1-2% of all LASIK procedures), epithelial ingrowth can progress and lead to flap elevation, which negatively affects vision. The complication is eliminated by performing an additional operation, during which overgrown epithelial cells are removed.

Ptosis or drooping of the upper eyelid is a rare complication after LASIK and usually goes away on its own within a few months after surgery.

It must be remembered that LASIK is an irreversible procedure that has its own contraindications. It involves changing the shape of the cornea of the eye, and after it is performed, it is impossible to return vision to its original state.

If the correction results in complications or dissatisfaction with the result, the patient's ability to improve vision is limited. In some cases, repeated laser correction or other operations will be required.

Complications of laser vision correction using LASIK technology. Analysis of 12,500 transactions

Refractive lamellar corneal surgery dates back to the late 1940s with the work of Dr. Jose I. Barraquer, who first recognized that the optical power of the eye could be altered by removing or adding corneal tissue1. The term "keratomileusis" comes from two Greek words "keras" - cornea and "smileusis" - to cut. The surgical technique itself, instruments and devices for these operations have undergone significant evolution since those years. From the manual technique of excision of part of the cornea to the use of freezing of the corneal disc with its subsequent treatment for myopic keratomileusis (MCM)2.

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 3,4,5. 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 V.V. Belyaev. and his schools6. Dr. Luis Ruiz proposed in situ keratomileusis, first using a manual keratome, and in the 1980s an automated microkeratome - Automated Lamellar Keratomileusis (ALK).

The first clinical results of ALK showed the advantages of this operation: simplicity, rapid restoration of vision, stability of results and effectiveness in the correction of high myopes. However, the disadvantages included the relatively high percentage of irregular astigmatism (2%) and the predictability of results within 2 diopters7. Trokel et al8 proposed photorefractive keratectomy in 1983 (25). However, it quickly became clear that with high degrees of myopia, the risk of central opacities, regression of the refractive effect of the operation significantly increases, and the predictability of results decreases. Pallikaris I. et al. 10, combining these two methods into one and using (according to the authors themselves) the idea of Pureskin N. (1966) 9, cutting out a corneal pocket on a pedicle, proposed an operation that they called LASIK - Laser in situ keratomileusis. In 1992 Buratto L. 11 and in 1994 Medvedev I.B. 12 published their variants of the surgical technique. Since 1997, LASIK has gained more and more attention, both from refractive surgeons and from patients themselves.

The number of operations performed each year already amounts to millions. However, with the increase in the number of operations and surgeons performing these operations, with the expansion of indications, the number of works devoted to complications increases. In this article, we wanted to analyze the structure and frequency of complications of LASIK surgery based on 12,500 operations performed in Excimer clinics in the cities of Moscow, St. Petersburg, Novosibirsk and Kiev for the period from July 1998 to March 2000. Regarding myopia and myopic astigmatism, there were 9600 operations (76.8%) were performed for hypermetropia, hypermetropic astigmatism and mixed astigmatism - 800 (6.4%), corrections of ammetropia in previously operated eyes (after Radial keratotomy, PRK, Through corneal transplantation, Thermokeratocoagulation, Keratomileusis, pseudophakia and some others) - 2100 (16.8%).

All operations under consideration were performed on a NIDEK EC 5000 excimer laser, optical zone - 5.5-6.5 mm, transition zone - 7.0-7.5 mm, and multi-zone ablation at high levels. Three types of microkeratomes were 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 LASIK operations (more than 90%) were performed simultaneously bilaterally. Topical anesthesia, postoperative treatment - local antibiotic, steroid for 4 - 7 days, artificial tear according to indications.

Refractive results correspond to world literature data and depend on the initial degree of myopia and astigmatism. George O. Warning III proposes to evaluate the results of refractive surgery according to four parameters: effectiveness, predictability, stability and safety 13. Efficiency refers to the ratio of postoperative uncorrected visual acuity to preoperative best-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 effectiveness 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 effectiveness is 0.7/0.6 = 1.17. Predictability is the ratio of the planned refraction to the received one.

Safety is the ratio of maximum visual acuity after surgery to this indicator before surgery, i.e. A safe operation is when before and after surgery the maximum visual acuity is 1.0 (1/1=1). If this coefficient decreases, then the risk of the operation increases. Stability determines the change in refractive outcome over time.

In our study, the largest group was patients with myopia and myopic astigmatism. Myopia from - 0.75 to - 18.0 D, average: - 7.71 D. Observation period from 3 months. up to 24 months 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), patients after 40 years were planned to have residual myopia. Predictability (* 1 D, from the planned refraction) - 92.7%. Average Astigmatism 0.5 D (from 0 to 3.5 D). Uncorrected visual acuity was 0.5 or higher in 89.6% of patients, 1.0 or higher in 78.9% of patients. Loss of 1 or more lines of maximum visual acuity - 9.79%. The results are presented in Table 1.

Table 1. Results of LASIK surgery in patients with myopia and myopic astigmatism with a follow-up period of 3 months. or more (out of 9600 cases, it was possible to trace the results in 9400, i.e. in 97.9%)

Complications after laser vision correction using LASIK

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Chronic diseases: not specified

Hello! Please tell me what complications can occur after laser vision correction using the LASIK method?

They say that the consequences can be not only immediately after the operation, but also long-term, several years later. Which?

Tags: laser vision correction, CVS, laser correction, lasik vision correction, lasik method, lasik, corneal erosion, diffuse lamellar kerati, rubbing the eye after correction, eye erosion after surgery, rubbing the eye after lasik

Possible complications after laser vision correction

Keratoconus is a protrusion of the cornea in the form of a cone, formed as a result of thinning of the cornea and intraocular pressure.

Iatrogenic keratectasia develops gradually. Over time, corneal tissue softens and weakens, vision deteriorates, and the cornea becomes deformed. In severe cases, a donor cornea transplant is performed.

Insufficient vision correction (hypocorrection). In the case of residual myopia, when a person reaches the age of 40-45 years, this deficiency is corrected by developing presbyopia. If, as a result of the operation, the resulting quality of vision does not satisfy the patient, repeated correction is possible using the same method or using additional techniques. More often, hypocorrection occurs in people with a high degree of myopia or farsightedness.

Overcorrection is excessively enhanced vision. The phenomenon is quite rare and often goes away on its own in about a month. Sometimes wearing weak glasses is required. But with significant values of hypercorrection, additional laser exposure is required.

Induced astigmatism sometimes appears in patients after LASIK surgery and is eliminated by laser treatment.

“Dry eye” syndrome - dryness in the eyes, a feeling of the presence of a foreign body in the eye, sticking of the eyelid to the eyeball. The tear does not properly wet the sclera and flows out of the eye. “Yugo eye syndrome” is the most common complication after LASIK. It usually goes away 1-2 weeks after surgery, thanks to special drops. If the symptoms do not go away for a long time, it is possible to eliminate this defect by closing the tear ducts with plugs so that the tears linger in the eye and wash it well.

Hayes occurs mainly after the PRK procedure. Clouding of the cornea is the result of a reaction of healing cells. They produce a secret. which affects the transparency of the cornea. Drops are used to eliminate the defect. sometimes laser intervention.

Corneal erosions can form due to accidental scratches during surgery. If postoperative procedures are carried out correctly, they heal quickly.

Deterioration of night vision occurs more often in patients with too wide pupils. Bright sudden flashes of light, the appearance of halos around objects, and illumination of objects of vision occur when the pupil dilates to an area larger than the laser exposure area. They interfere with driving a car at night. These phenomena can be smoothed out by wearing glasses with small diopters and instilling drops that narrow the pupils.

Complications during the formation and restoration of the valve may arise due to the fault of the surgeon. The valve may turn out thin, uneven, short, or cut off to the end (this happens extremely rarely). If folds form on the flap, it is possible to reorient the flap immediately after surgery or subsequent laser resurfacing. Unfortunately, people who have undergone surgery remain forever in the danger zone of trauma. Under extreme mechanical stress, flap detachment is possible. If the flap disappears completely, it cannot be reattached. Therefore, it is necessary to strictly observe the rules of postoperative behavior.

Epithelial ingrowth. Sometimes fusion of epithelial cells from the surface layer of the cornea with the cells located under the flap occurs. When the phenomenon is pronounced, such cells are removed surgically.

"Sahara syndrome" or diffuse lamellar keratitis. When foreign microparticles get under the valve, inflammation occurs there. The image before your eyes becomes blurry. Corticosteroid drops are prescribed for treatment. If such a complication is quickly identified, the doctor washes the operated surface after lifting the valve.

Regression. When correcting large degrees of myopia and hypermetropia, it is possible to quickly return the patient's vision to the level that he had before the operation. If the cornea maintains its proper thickness, a repeat correction procedure is performed.

It is too early to draw final conclusions about the positive and negative aspects of laser vision correction. It will be possible to talk about the stability of the results when all the statistics on the condition of people operated on 30-40 years ago are processed. Laser technologies are constantly being improved, making it possible to eliminate some of the defects of previous level operations. And it is the patient, not the doctor, who should decide on laser vision correction. The doctor only needs to correctly convey information about the types and methods of correction and its consequences.

It often happens that the patient is not satisfied with the results of the correction. Expecting to receive 100% vision and not receiving it, a person falls into a depressed state and needs the help of a psychologist. A person's eye changes with age, and by the age of 40-45 he develops presbyopia and has to wear glasses for reading and near work.

This is interesting

In the USA, laser vision correction can be done not only in ophthalmology clinics. Small points equipped for carrying out operations are located near beauty salons or in large shopping and entertainment complexes. Anyone can undergo a diagnostic examination, based on the results of which the doctor will perform vision correction.

For the treatment of hypermetropia (farsightedness) up to +0.75 to +2.5 D and astigmatism up to 1.0 D, the LTK (laser thermal keratoplasty) method has been developed. The advantages of this method of vision correction are that during the operation no surgical intervention is performed in the eye tissue. The patient undergoes a preoperative examination, and before the operation anesthetic drops are instilled into him.

Using a special pulsed holmium laser of infrared radiation, tissue is annealed on the periphery of the cornea at 8 points with a diameter of 6 mm, the burned tissue shrinks. Then this procedure is repeated at the next 8 points with a diameter of 7 mm. Collagen fibers of the corneal tissue in places of thermal influence are compressed, and the central

Due to tension, the part becomes more convex, and the focus shifts forward to the retina. The greater the power of the supplied laser beam, the more intense the compression of the peripheral part of the cornea and the stronger the degree of refraction. The computer built into the laser, based on the data from a preliminary examination of the patient’s eye, automatically calculates the parameters of the operation. The laser only lasts about 3 seconds. The person does not experience any unpleasant sensations, except for a slight tingling sensation. The eyelid expander is not immediately removed from the eye so that the collagen has time to shrink well. Afterwards the operation is repeated on the second eye. Then a soft lens is placed on the eye for 1-2 days, antibiotics and anti-inflammatory drops are instilled for 7 days.

Immediately after the operation, the patient develops photophobia and a feeling of sand in the eye. These phenomena quickly disappear.

Restorative processes begin in the eye and the refractive effect gradually smoothes out. Therefore, the operation is performed with a “reserve”, leaving the patient with a weak degree of myopia up to -2.5 D. After approximately 3 months, the process of returning vision ends, and the person returns to normal vision. Over the course of 2 years, vision does not change, but the effect of the operation lasts for 3-5 years.

Currently, vision correction using the LTK method is also recommended for presbyopia (age-related vision deterioration). People aged 40-45 years often experience the appearance of farsightedness, when small objects and printed fonts become difficult to distinguish. This happens due to the fact that the steel frame loses its elasticity over the years. The muscles that support it also weaken.

To reduce vision regression based on the LTK method, a technique with a longer-lasting effect of thermal keratoplasty has been developed: diode thermokeratoplasty (DTC). In DTC, a constant diode laser is used, in which the energy of the beam supplied by the laser remains constant, and annealing points can be applied arbitrarily. Thus, it is possible to regulate the depth and location of coagulants, which affects the duration of healing of the corneal tissue and, accordingly, the duration of action of DTC. Also, with a large degree of hypermetropia, a combination of LASIK and DTK methods is performed. The disadvantage of DTC is the possibility of astigmatism and slight pain on the first day of surgery.

Complications after LASIK

and her safety

As we know, LASIK surgery may seem scary at first, but in fact, Opti LASIK ® laser vision correction is fast, safe, and almost immediately afterward, you will finally have the vision you've always dreamed of!

Safety of LASIK eye surgery

Corrective laser surgery is considered one of the most common procedures of choice today. Those who passed it are very happy about it. Results of a survey of patients who underwent LASIK surgery. showed that a whopping 97 percent of them (that's impressive!) said they would recommend the procedure to their friends.

Based on the results of controlled clinical trials conducted in the United States to evaluate the safety and effectiveness of the operation, FDA FDA: Abbreviation for Food and Drug Administration, a federal agency within the U.S. Department of Health and Human Services that is responsible for determining the safety and effectiveness of drugs and medical products. approved LASIK for use in 1999, and since then, LASIK has become the most widely accepted form of laser vision correction today, benefiting approximately 400,000 Americans each year. 1 In 93 percent of cases, patients' vision after LASIK is at least 20/20 or better. The impressive thing is that this operation takes only a few minutes and is almost painless.

Of course, as with any other surgical procedure, there are some safety considerations and complications that you may encounter. Take a quick look at the potential complications of LASIK before making any decisions.

Complications after LASIK

Laser technology and surgeons' skills have advanced significantly over the past 20 years since LASIK was first approved by the FDA in 1999, but no one can accurately predict how an eye will heal after surgery. As with any surgical procedure, there are risks associated with LASIK. In addition to the short-term side effects that some patients experience after surgery (see After LASIK Eye Surgery), some people may experience conditions that last longer due to differences in the healing process between individuals.

Listed below are some LASIK complications that you should discuss with your surgeon if they occur after surgery.

The need to use reading glasses. Some people may need to use reading glasses after LASIK surgery, especially if they were nearsighted to read without glasses before surgery. They are more likely to suffer from presbyopia - Presbyopia: A condition in which the eye loses its natural ability to focus correctly. Presbyopia is a natural result of aging and leads to blurry near vision. If presbyopia is diagnosed, glasses or corrective contact lenses must be used to maintain quality near vision distances. physiological condition that comes with age.

Decreased vision. Sometimes, indeed, some patients after LASIK note a deterioration in vision relative to previously optimally corrected vision. In other words, after laser surgery you may not see as well as you could with glasses or contact lenses before surgery.

Decreased vision in low light conditions. After LASIK surgery, some patients may not see well in low light, such as at night or in foggy, cloudy weather. These patients often experience halos. Halos: A visual effect - a circular haze or haze that may appear around a headlight or illuminated objects. or annoying glare around bright light sources, such as street lamps.

Severe dry eye syndrome. In some cases, LASIK surgery can result in insufficient tear production to keep the eyes moist. Mild dry eye is a side effect that usually goes away within about a week, but in some patients the symptom persists permanently. When determining whether laser vision correction is right for you, let your doctor know if you have been bothered by dry eye syndrome, have problems with contact lenses, are in menopause, or are taking birth control pills.

Need for additional interventions. Some patients may need enhancement procedures to further correct their vision after LASIK surgery. Rarely, patients' vision changes, and sometimes this can be attributed to an individual healing process that requires an additional procedure (re-treatment). In some cases, people's vision has decreased slightly and has been corrected by slightly increasing the power of the prescribed glasses, but this does not happen often.

Eye infections. As with any surgical procedure, there is always a small risk of infection. However, the laser beam itself does not transmit infection. After surgery, your doctor will likely prescribe prescription eye drops to protect against post-surgery infection. If you use the drops as recommended, the risk of infection is very low.

The FDA does not monitor the conditions of each surgery and does not inspect doctors' offices. However, the government requires surgeons to be licensed through state and local agencies and regulates medical products and equipment, requiring clinical studies that prove the safety and effectiveness of each laser.

To read the supporting material on choosing the right doctor. continue to the next section.

Comments on the review

Andrey June 6, 2012 Anything is possible! I know for sure that a lawsuit is now being prepared against AILAZ, due to the negligence of doctors.

Oksana Sergeevna Averyanova, AILAZ center September 14, 2012 I called and did not specifically find out the name of the patient - the “victim”, or the circumstances of the case. The answer was supposedly from a “representative” of the “affected person.” There have been no calls to our clinic from the court.

Laser vision correction

Messages: 2072 Registered: Sat Mar 26, 2005 04:40 From: Barnaul

My husband recently did this. Seems happy

The postoperative period is three days, the second is the most difficult, because the eyes are watery and hurt, there is increased irritability to light and everything bright, but even that is not scary. There are fewer unpleasant sensations during Lasik surgery, when the epithelial layer is incised and then put back in place (rather than burned out and then a new one grows), but they explained to us that with Lasik there is a greater risk that something will go wrong.

As I understand it, there are no special guarantees that vision will not begin to deteriorate again, this is a minus. On the other hand, for those who do not tolerate lenses well, this is still a solution, even if only for a few years.

I think I will also have surgery on myself, but only after I give birth for the second time, although they say that surgery is not a contraindication for natural childbirth, it’s still scary after giving birth; I personally had red eyes, you never know.

I am collecting reviews about laser vision correction.

If it’s not difficult, I ask those who have undergone laser vision correction to unsubscribe here!

If possible, indicate the degree of myopia (astigmatism, farsightedness), the method of laser correction and when it happened, the sensations during the operation, etc. You can indicate the clinic - what if this helps someone?

The most important thing is the result.

Vision restoration techniques

help yourself

Laser correction. Consequences.

This page collects information one way or another related to the consequences of laser vision correction. Information different from what can be found in tempting 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 clinics mentioned, if not specified, are located in Minsk.

e-mail correspondence, 2006:

Good afternoon!

Katerina

Thank you! :)

What was the name of the operation (lasik or another)?
- I read that before and after the operation there are some instructions - such as not wearing lenses, etc. - did you follow all of them?
- are there any negative aspects of this operation (except for the fact that everything came back over time)?
- haven’t you tried to restore it with exercises?

I don’t remember the name, I was 17 years old, somehow I didn’t remember it :)
Of course, there were instructions, of course, she followed them. There are also a lot of vitamins and procedures.
Apart from the fact that it didn’t work out, there are no other negative aspects, the operation was painless and there were no unpleasant sensations afterwards
I haven’t tried it, I take herbal supplements with blueberries - it helps much better;))

Katerina

e-mail correspondence, 2006:

communication at a 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. 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), Yanis Pallikaris (director of the eye clinic, Greece, inventor of the LASIK method), Maria Tassinho ( professor at the University of Antwern, Belgium), and others, more than 30 possible complications were noted that accompany the most popular laser surgeries today, the LASIK method. In these reports, there was 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 the possible loss of quality of vision, which cannot be further corrected by sphero-cylindrical optics.

The observations of ophthalmologists in Russia are fully consistent with world data. Thus, in the report of Russian scientists K.B. Pershin and N.F. Pashinov “Complications of LASIK: analysis of 12,500 operations”, made at the conference “Modern Medical Technologies” in Moscow, it is argued 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 Kiev, over the period from July 1998 to March 2000, it was discovered 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 NIDEK TC 5000 excimer laser systems. At the same time, in 12,8% In some cases, repeated operations were required to correct these defects.

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

Surgical complications. They are associated, first of all, 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 share 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 opacification. It seems that 0.15% is quite a bit, but imagine that it was you who ended up among these several dozen unfortunate people. What exactly is your cornea clouded, and in the very center of the eye, which is functionally the most important. You see this perfectly in the morning and poorly in the evening, and this is exactly what you see in the twilight, or, conversely, in bright low beams, due to reflection from possible small scars, flashes, rings of light, double vision appear in the eye, and besides, all this happens, when you drive a car. So is it worth the risk? Maybe it would be 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 subjective patient dissatisfaction with the result of the operation. These conditions (inflammation, swelling, conjunctivitis, epithelial ingrowth, “sand in the eye” syndrome, hemorrhages, retinal detachment, binocular vision disturbances 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 individual characteristics of postoperative healing. The frequency of such complications, which includes corneal opacity, according to various sources, averages 2% of the number of operations. All of these painful conditions require long-term treatment with the use of expensive medications, and often additional operations on an already weakened cornea. Moreover, not all of these events always lead to success and full recovery.

Complications associated with ablation. This, the largest group of complications during 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 detected immediately after surgery. In this case, you will need additional surgery in 1-2 months. If, on the contrary, they “overdid it” and turned a “minus” into a “plus” 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 successive operations one after another is far from unlimited.

Long-term consequences of laser vision correction. This is the most subtle and completely unexplored problem. In the same time, It is the long-term consequences of laser vision correction operations that can pose the greatest danger to humans. The fact is that laser correction does not cure myopia, farsightedness and astigmatism as such, 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 reasons in the human body. The operation only corrects and changes the shape of the eye so that the image falls on the retina, i.e. does not affect the causes of the disease, but fights only its consequences. The reasons why the shape of the eye changed in the wrong direction are: remain and continue to act with no less force. It is already known that the corrective effect of laser surgery weakens over time, although accurate long-term statistics of this weakening have not yet been obtained. Those. actually A hard contact lens, laser-cut from our living eye tissue, gradually becomes weaker. And the person returns to glasses again. Moreover, this is the best case scenario for him. More sad developments are also possible. It is known that over the years a person acquires additional diseases, the hormonal levels in his body change - all this can cause clouding and other serious problems with the cornea of the eye weakened by surgery. Or God forbid you get into some kind of trouble and get hit in the eye - the weakened shell can rupture and the consequences will be the most disastrous. The same can happen if you hit the ball poorly in some exciting game like volleyball, or if you lifted a bag of potatoes that was too heavy, or even just steamed in the sauna. Problems are guaranteed for you. In one of the Saturday issues of Komsomolskaya Pravda, an anecdote was published: “Laser vision correction. Inexpensive. The package includes a wand and a guide dog.” Truly, there is only a grain of joke in every joke.

And finally, the last thing. There are entire groups of the population 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, up to 25 years. The child grows, and the shape of his eye naturally also changes, which makes any artificial correction of this shape unreasonable until 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.

Complications of LASIK: analysis of 12,500 operations

Pashinova N.F., Pershin K.B.

Refractive lamellar corneal surgery began in the late 1940s with the work of Dr. Jose I. Barraquer, who was the first to recognize that the optical power of the eye could be altered by removing or adding corneal tissue. The term “keratomileusis” comes from two Greek words “keras” - cornea and “smileusis” - to cut. The surgical technique itself, instruments and devices for these operations have undergone significant evolution since those years - from the manual technique of excision of part of the cornea to the use of freezing the corneal disc with its subsequent treatment for myopic keratomileusis (MCM). 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 V.V. Belyaev. and his schools. Dr. Luis Ruiz proposed in situ keratomileusis, first using a manual keratome and, in the 1980s, an automated microkeratome—automated lamellar keratomileusis (ALK).

The first clinical results of ALK showed the advantages of this operation: simplicity, rapid restoration of vision, stability of results and effectiveness in the correction of high degrees of myopia. Disadvantages are the relatively high percentage of irregular astigmatism (2%) and the predictability of results within 2 diopters. Trokel et al in 1983 also proposed photorefractive keratectomy (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 significantly increases, and the predictability of results decreases. 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 pedicle (Pureskin N., 1966), 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 surgical technique.

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

Materials and methods

In this article, we wanted to analyze the structure and frequency of complications of LASIK surgery based on 12,500 operations performed in Excimer clinics in the cities of Moscow, St. Petersburg, Novosibirsk and Kiev for the period from July 1998 to March 2000. Regarding myopia and 9600 operations (76.8%) were performed for myopic astigmatism; regarding hypermetropia, hypermetropic astigmatism and mixed astigmatism - 800 (6.4%); corrections of ammetropia in previously operated eyes (after radial keratotomy, PRK, end-to-end corneal transplantation, thermokeratocoagulation, keratomileusis, pseudophakia and some others) - 2100 (16.8%).

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

Three types of microkeratomes were 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 LASIK operations (more than 90%) were performed simultaneously bilaterally. Topical anesthesia, postoperative treatment - local antibiotic, steroid for 4–7 days, artificial tear according to indications.

Refractive results correspond to world literature data and depend on the initial degree of myopia and astigmatism. George O. Warning III proposes that the results of refractive surgery be assessed according to four parameters: effectiveness, predictability, stability and safety. Under efficiency refers to the ratio of postoperative uncorrected visual acuity to preoperative best-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 effectiveness 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 effectiveness is 0.7/0.6 = 1.17. Predictability- this is the ratio of the planned refraction to the received one. Safety- the ratio of maximum visual acuity after surgery to this indicator before surgery, i.e. A safe operation is when before and after surgery the maximum visual acuity is 1.0 (1/1=1). 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 was patients with myopia and myopic astigmatism. Myopia from –0.75 to –18.0 D, average: –7.71 D. Observation period from 3 months. up to 24 months 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), patients after 40 years were planned to have residual myopia. Predictability (±1 D, from the planned refraction) - 92.7%. Average astigmatism 0.5 D (from 0 to 3.5 D). Uncorrected visual acuity was 0.5 or higher in 89.6% of patients, 1.0 or higher 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 include surgical, postoperative and late postoperative complications.

Surgical complications

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

Vacuum loss or insufficiency during cutting 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 operations, scars and cysts of the conjunctiva and some other reasons can lead to the fact that the altered conjunctiva obstructs the vacuum hole of the ring and the device shows the presence of 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 keratome head can depressurize the eye system - the vacuum ring.

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

Very steep or flat cornea, as well as in some microkeratome models, incorrectly selected sizes of rings and stops 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 complications associated with the flap:

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%.

Epithelial defects - 1.43%. Total surgical complications - 1.27% of the total number of operations, because usually they were combined (thin section, uneven, split with an epithelial defect). Complications that worsen functions 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 opacification.

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

If a complication does occur, it is necessary to develop a clear algorithm of actions in each specific case and strictly adhere to it, regardless of the circumstances (a nonresident patient, financial or any other problems). In our opinion, this algorithm may be as follows: it is necessary to recognize the complication in time, under no circumstances do ablation (except for “free cap”), carefully straighten the flap or what is left, prevent epithelial ingrowth as much as possible, treat the patient until maximum acuity returns vision, repeat cutting should be carried out no earlier than 3 months. taking into account the reasons that led to the first complication, and, if possible, with a different diameter and a different depth.

In the case of a complete cut of the flap, ablation is performed, the flap is placed according to the marks, about 5 minutes. dried, its stability is checked. As a rule, no additional fixation is required, and this does not affect the final result. It should be noted that the proportion of surgical complications decreases 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 subjective patient dissatisfaction with the result of the operation. They can be schematically divided into complications associated

with flap: displacement, swelling, inflammation;
with interface: epithelial ingrowth, debris and inclusions, central islands, Sands of the Sahara syndrome (SOS) and/or 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 keratopathies (glandular secretions, oil or other material from the keratome, debris, etc.), progression of cataracts, progression of macular degeneration, keratoectasia (induced keratoconus). And as a separate group, we can distinguish the subjective discrepancy between the results of the operation and the patient’s expectations.

Complications associated with the flap

Displacement of the superficial flap occurred in 0.04% of cases, which required its reposition, usually seamless, but sometimes it is necessary to use a contact lens or sutures. Flap swelling 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-related complications

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

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

Central islets in topographic studies they are relatively rare (0.04%). The etiology of this phenomenon is not completely clear. One explanation may be that the vacuum ring, increasing IOP more than 65 mm Hg. Art., changes the “pressure of corneal edema,” which leads to its dehydration. After the vacuum is removed, hydration occurs. The central cornea swells more rapidly and more than the periphery, which can lead to interface folds and flap formation.

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 a period of 1 to 3 months. after operation.

SOS or nonspecific diffuse intralamellar keratitis (DLK), first described by Smith & Maloney in 1998, according to several 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 of the flap. We encountered this complication 8 times (stage 2–3), which amounted to 0.07% of all cases. This 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 completely clear. Some authors explain this by trophic changes, others by a toxic-allergic reaction of the cornea to the secretions of Bowman's glands or to microscopic particles of metal and microkeratome oil. In our opinion, the most successful concept was proposed by V.V. Kurenkov. with co-authors and called “Syndrome of disadaptation 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 surface flap placed on it.

We, like most authors, adhere to active tactics in the treatment of DLK. It is more reasonable to carry out an examination after surgery on the second day. If the development of DLK is suspected, steroids should 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 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 were cases of herpetic stromal keratitis, 2 were chlamydial and 3 were bacterial with an unknown pathogen.

Complications associated with ablation

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

All of these patients underwent reoperations using masking agents or 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. Irregular astigmatism developed with decentrations, flap and interface problems. 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 through corneal scar with a microkeratome leads to changes in biomechanical properties and parameters, which unpredictably affects the shape of the cornea and its refraction.

In a 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 technique, the incidence of this complication in these patients does not exceed that in patients with normal myopia. The essence of the technique is that the first step is to cut the surface flap with a microkeratome without ablation, after which the flap is placed in place. Based on the topographic picture, they wait until the corneal refraction stabilizes (usually 2–4 weeks), after which the flap is raised and ablated according to the new topographic data.

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

Some data on operative 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 both the methodology as a whole, so training of each individual surgeon. 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 associated with the correction itself. More often they are associated with a severe initial condition 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.

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 of the left eye. Sectoral filling. One month after surgery Vis OD = 1.0; Vis OS = 0.6 s/k 0.8.
Patient K., 43 years old. Myopia 9.5 D. PPLK 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, additional correction was performed (without a new cut). Vis OU = 0.9 - 1.0. After 4 months after the first operation, retinal detachment OS. A cerclage with radial filling was performed. Vis OS = 0.6 n/k. After 6 months Vis OD = 0.9 sph - 0.75 = 1.0; Vis OS = 0.2 - 0.3 n/k.
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.
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.
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/k 0.5.

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

Macular hemorrhage also occurred 1 time (0.01%). The patient is 74 years old with pseudophakia (EEK+IOL more than 4 years ago), myopia and myopic astigmatism. LASIK was performed with good refractive and visual effect. 14 days after surgery, vision decreased sharply due to macular hemorrhage.

Progression of cataracts We noted in 5 patients (0.04%), of which in two cases phacoemulsification with IOL implantation was performed. It should be noted that in all these cases, cataracts were identified during the 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 surgical parameters are not observed (residual postoperative corneal depth of at least 250 microns and total corneal thickness after surgery of 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. In this case, 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) it was not detected initial keratoconus. In the third case (myopia with SE = - 12.0 D), 250 microns of intact cornea are left, the microkeratome head is 130 microns thick.

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

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

We did not identify complications associated with diseases of Bowman's membrane, autoimmune and systemic diseases.

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 irregular astigmatism, and, consequently, a decrease in visual acuity. Complications affecting the visual result in the long-term postoperative period, after reoperations (total reoperations - 12.8%), were 0.67%.

A separate group consists of patients in whom, according to the surgeon, everything is excellent, which is 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 patient’s expectations 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 legislative framework that currently determines the relationship between clinic - doctor - patient makes this problem very urgent.

Conclusion

The rate 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 have their own specific features.
The presence of different keratomes and lasers expands the surgeon's capabilities in atypical cases.
The presence of various vacuum rings and microkeratome heads of different cutting depths allows you to optimize the parameters of each specific operation.
The “Low Vac” mode of the microkeratome ensures reliable centering of ablation, speeds up the procedure and reduces the risk of complications.
Stepwise vacuum removal reduces corneal hydration, which increases the stability of the laser and reduces the effect of absorption of liquid and debris under the flap.
Standardization of surgical technique, methods of dealing with complications and postoperative management can significantly improve results. It should be noted that Not only the work of the surgeon, but also the entire clinic team, including diagnostics, operating nurses and engineering staff, is subject to optimization. Only in this case can you achieve consistently good results, and failures in any of the links will not entail serious clinical consequences.
A thorough and detailed discussion with the patient of indications and contraindications for a specific refractive surgery; the patient’s understanding of how and what they are going to do with him; awareness that the patient himself also accepts risks associated with complications independent of the surgeon and equipment; identification by the doctor of the patient’s unreasonable expectations 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

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Here is a small excerpt from Svetlana Troitskaya’s book “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-vision".

Lately there has been more and more talk about laser surgeries. Sometimes they are presented as the only solution for people with poor vision. However, even after laser surgery you cannot count on 100% vision. In addition, for laser surgery, as in general for any serious surgical intervention, there are contraindications. For example, surgery cannot be performed on those under 18 years of age. You should not go under the laser if you have progressive myopia, eye diseases, pregnancy, or infectious diseases. After the operation, you must follow certain doctor's instructions and be under his supervision for at least 3 months.

And the cost of the operation is considerable, since it consists of many components. This includes computer diagnostics, consultations, and the operation itself. It comes out to approximately 2-3 thousand dollars. So think carefully, dear reader, before you take this step.

And if you’ve almost made up your mind, think about this. Doesn't it bother you that most ophthalmologists still wear glasses?

Food for thought.

Below you can see photographs of the richest people on our planet in 2007, all of them are billionaires. They understand perfectly well what risk is. They have the opportunity to pay for the most highly qualified doctors. Question: why are they still wearing glasses?

After laser vision correction, the patient does not experience any significant pain, but for 2-3 hours after the operation he may be very bothered by:

Tearing
Stinging in the eyes
Feeling "sand"
Photophobia

Bright light may aggravate these complaints, so you should bring sunglasses with you to the clinic. It is advisable to wash the frame well with soap in advance.

After laser vision correction, the patient may experience pain in the eyes, a feeling of blockage, and watery eyes. After 3 hours these phenomena disappear

During the first hour after surgery, your vision without glasses will improve, but there will still be fog and blurriness. In just a few hours, these complaints will subside, and just a feeling of discomfort will remain.

You should definitely have a follow-up examination at a slit lamp to ensure that the corneal flaps are properly seated. In extremely rare cases, if the patient accidentally roughly rubs the eyes, a slight displacement of them may occur, which requires the supervision of a doctor.

1-2 hours after the correction, you should undergo a control examination using a microscope and be allowed to go home until the next day of examination.

After the doctor's examination, you can go home. We do not recommend that you drive yourself after the correction, as post-operative discomfort symptoms will not allow you to drive safely. Take a taxi or ask your loved ones to take you. Public transport is not contraindicated, but one must be wary of eye infections and colds.

It is better to leave the clinic by taxi or ask your loved ones to take you home. Driving is prohibited immediately after surgery.

In some clinics that take a particularly responsible approach to the prevention of complications, patients are given special occluders for the eyes - transparent protective screens with ventilation holes that eliminate the possibility of mechanical pressure on the eye, so as not to damage the cornea during sleep or accidental touch.

Consequences of laser vision correction

Many patients are afraid of the undesirable consequences of laser vision correction. Yes, they exist, but their percentage is so small that with proper selection of patients and exclusion of contraindications, it does not exceed 0.02-0.05%. Deterioration of vision after laser vision correction can be due to several reasons:

Firstly, this is the progression of myopia. If the patient is young and his eye continues to grow in length, then the corrected myopia may partially return.

This issue is always discussed with the patient during the preoperative examination. If myopia returns, then it is possible to discuss with your doctor a repeat operation.

With careful preoperative diagnosis, undesirable consequences of laser vision correction occur in 0.02-0.05% of cases.

Secondly, the reason for dissatisfaction with the result may be incomplete correction. Those. the patient has a residual 0.5 - 0.75 diopters of myopia, farsightedness or astigmatism. In this case, as a rule, additional correction is proposed to achieve the desired result, but not earlier than after 2-3 months. Experience shows that such cases of additional correction are infrequent: 1 eye per 100-200 operations, or even less often.

Thirdly, the cause of some changes in vision in the long-term period after vision correction may be mild cloud-like opacities. These phenomena are extremely rare. A carefully collected anamnesis allows you to identify patients at risk and almost completely eliminate these problems.

Fluctuations in hormonal levels during pregnancy can adversely affect the healing of corneal tissue.

It is precisely because of the occurrence of corneal opacities that ophthalmologists recommend not planning childbirth or pregnancy after laser vision correction for at least six months. This is due to the unfavorable effect of hormonal fluctuations on the healing processes of corneal tissue.

Complications after laser vision correction can occur if the operation itself deviates from the planned plan. Most of these problems improve over time or with active treatment.