Irregular curvature of the cornea so when. This insidious keratoconus is the fight against corneal pathology

Keratoconus is a painful deviation of the eyes with a change in the structure of the cornea, which becomes thinner and curved under impact. intraocular pressure. Deformation changes the shape of the cornea to a cone. The refraction of rays passing through the conical cornea becomes incorrect, distorting images and violating visual acuity. The disease is called keratoconus, which means "conical cornea" in Greek.

Keratoconus is most often diagnosed in adolescents during puberty. Quite rarely, keratoconus occurs in children and people over thirty years of age. The disease is fixed in 3-4 people per 100 inhabitants. Not later than 20 years after its manifestation, the disease stops developing. However, in very advanced cases, corneal rupture and even loss of vision can occur.

AT international classification diseases ICD-10 keratoconus has a code H18.6.

Classification

Keratoconus can be unilateral, when only one eye is affected, or bilateral. Statistics show that about 95% of all cases of the disease occur in both eyes at once.

Due to appearance:

• Primary, caused by genetic factors;
• Secondary, resulting from adverse effects external environment, surgical operations on the organs of vision, the consequences of injuries.

According to the course of the disease:

• Acute;
• chronic;
• with variable flow.

Visual deviation from the norm in keratoconus is divided into 3 stages:

• Weak, with a value of up to 40 diopters. During this period, small morphological changes occur in the cornea of ​​the eye, signs of astigmatism appear;
• Average degree, no more than 55 diopters. Cracks in the Descemet's membrane of the cornea are formed, allowing moisture to pass from the anterior chamber. The top of the cone acquires a cloudy outline, and the patient practically ceases to see in the dark;
• Severe, with a diopter value of more than 55. Visually, the unnatural shape of the cornea is already noticeable, it can become completely cloudy. Vision deteriorates sharply, a person sees poorly even during the day. At high probability corneal rupture requires urgent surgery.

The level of corneal dystrophy can be:

• Moderate, with its thickness close to 0.5 mm;
• Medium, with a value of 0.4–0.5 mm;
• Over or close to breaking, with a thickness of less than 0.4 mm.

According to the degree of deformation of the cornea, the following forms are distinguished:

• Dot dome. The pathology has a diameter of about 5 mm and is located in the center of the cornea;
• Oval shape of the dome. The cornea is protruded up to 6 mm, its deformation is localized below the center and sags;
• spherical deformation. The cone is more than 6 mm, the disease covers up to 70% of the cornea.

Causes of Keratoconus

Oddly enough, doctors have not yet come to a consensus about what causes the occurrence of keratoconus. Among the most common theories of occurrence are:

• hereditary or genetic predisposition;
• Negative consequences after laser vision correction;
• Unfavorable ecology, influence of ultraviolet radiation;
• The consequence of improper selection of contact lenses that cause injury to the cornea;
• Eye injury as a result mechanical impact and even the habit of rubbing the eyes;
• Disturbances in the work of the endocrine system, dysfunction hormonal background, failures in the process of metabolism.

According to another theory, it is believed that the cause of keratoconus is the consequences of previous infectious diseases, since in most cases it is formed in children with weak immunity. Some researchers associate the occurrence of keratoconus with mental trauma, stress and nervous experiences.

Symptoms of keratoconus

Initially, the symptoms of keratoconus are similar to other eye diseases. A person complains of severe eye fatigue, double images while looking at light objects on a dark background, the appearance of flies before the eyes, and the presence of discomfort. If the pathology development process begins to progress rapidly, visual acuity will decrease, as happens with myopia or astigmatism. In the early stages, wearing glasses or contact lenses helps to overcome visual impairment, in the future, optical correction loses its effectiveness.

Vision in keratoconus decreases gradually. Due to the increase in the number of diopters, the patient often has to change glasses. However, this does not always guarantee a positive result. Pathology can sometimes progress so quickly that changing glasses does not have time to adjust vision. also cannot be of benefit due to abnormal corneal bulge. In this case, the patient should begin serious treatment of the organs of vision.

Usually, the stages of development of keratoconus continue for 10-15 years, sometimes it is delayed for a longer period of remission. Only in 5% of cases, the disease abruptly turns into an acute form, in which there is a rupture of the Descemet's membrane with leakage of intraocular fluid.

Diagnosis of keratoconus

The beginning of the detection of keratoconus of the eye is the moment the patient contacts an ophthalmologist with a complaint of visual impairment. After the interview, the doctor measures the visual acuity and refraction of the eyes. If the presence of myopia or hyperopia is not confirmed, the examination of the patient will be continued. Exist following methods diagnostics:

• Skiascopy. With the help of a special device (skiascope), a counter-movement of shadows specific to keratoconus, called the "scissors effect" is determined;
• Keratometry is the most common diagnostic method, which determines the curvature of the cornea;
• Refractometry. With the help of the technique, irregular astigmatism and myopia, which arose as a result of corneal deformities, are detected;
• Computed tomography of the eye or its ultrasound. These studies reveal changes in the tissues of the cornea, including scars on its surface.

In the later stages of the disease, its diagnosis is not difficult, since the pathology of the cornea is immediately visible without special devices. Only examinations will be required to determine the degree of damage to the eye tissue. When confirming the diagnosis, some additional examinations will be required from related specialists.

Treatment of keratoconus

Treatment of keratoconus of the eye with drugs, unfortunately, is not yet possible. Taufon and others similar preparations designed to nourish the eye tissue and relieve burning and dryness in visual organs. Therefore, such medicines can only be part of complex therapy when choosing a particular method of treatment.

At initial stages keratoconus apply conservative methods treatment. More severe forms of keratoconus require surgical intervention. They also use traditional medicine.

Vision correction with glasses is prescribed first. While their use brings a therapeutic effect, the use of contact lenses is not allowed. The reason is quite clear: the lenses are capable of causing microtrauma to the surface of the eye.

Only when the corneal taper situation changes the refraction of the image does the spectacle fitting stop. This optical device is being replaced by lenses, the selection of which takes place individually, taking into account the stage of the disease and the capabilities of the body:

• Soft lenses do not scratch the cornea, but their use can correct vision only with a slight protrusion. Practice shows that such lenses are not very suitable for keratoconus: taking the form of the cornea, they do not create a tear film, which is why the refractive power of the eye does not improve;
• Rigid lenses are made personally, so they have a great therapeutic effect. Retaining their shape, they are able to eliminate corneal curvature. A tear film can already form between these lenses and the eye. The disadvantage of lenses is to create uncomfortable sensations when worn on a damaged cornea;
• Hybrid lenses consist of a hard center and a soft rim, combining utility and comfort. Recommended for those who wear hard lenses causes great inconvenience.

The development of medicine has made it possible to develop several options for surgical correction, but only a doctor should make a choice in favor of a particular operation. by the most modern method it is considered the introduction of colorless rings into the cornea tissue (implantation of intrastromal rings), which will bring its shape closer to the natural one. Nevertheless, the operation is not able to stop the course of the disease.

The operation of the eye is modern and safe method treatment and has a short recovery period.

Also popular is the operation, in which donor tissue is placed in place of the damaged one. It is recommended for severe corneal deformation as a result of other methods of treatment, but carries the risk of such dangerous complications as glaucoma and rejection of the transplanted tissue. Finally, in the most advanced cases, a corneal transplant is used. This operation is the only way to stop the course of the disease. The most qualified clinic for the treatment of keratoconus is in Moscow.

Folk methods should be resorted to early stages disease in order to slow down the progression of pathology. It is possible to use traditional medicine during the rehabilitation period, but it must be understood that it is impossible to correct the cornea in such ways. But compresses prepared on the basis of chamomile flowers help to remove eye itching, relieve excessive stress from a sore spot.

Keratoconus and the army

"Do they take to the army with keratoconus?" - the question is very important and has a great social aspect, since, as mentioned earlier, keratoconus is a disease of the young, and its first signs may appear shortly before the call. It should immediately be noted that with such a disease they are not taken into the army. Moreover, if there is a suspicion of keratoconus of the eye, then the young man receives a deferment from conscription for six months. After a specified period of time, the diagnosis must either be confirmed or refuted.

In this situation, it must be clearly understood that any military registration and enlistment office has its own medical commission, which assesses the health of the conscript, and only she has the right to decide whether the patient is fit for military service or not. Ordinary ophthalmologists cannot make such decisions for a commission.

Prevention of keratoconus

To minimize the occurrence of keratoconus, young people first of all need regular visits to the ophthalmologist and the implementation of all his recommendations. Upon detection inflammatory processes in the organs of vision, prompt measures should be taken to eliminate them.

While reading, working at a computer, while watching TV, it is necessary to control the load on the eyes. To prevent undue stress, adequate lighting should be provided in the work area or activities that require concentration and attention to the eyes.

Should not be neglected protective equipment under circumstances that can harm the eyes: dusty air, cold wind, bright light.

Proper nutrition and lifestyle bad habits will benefit the whole body and the eyes in particular. It is important to take prompt measures when allergic processes appear and observe eye hygiene by washing them with decoctions of healing plants.

The term keratoconus comes from two Greek words: "kerato", meaning "cornea" in translation, and "konos" - "cone". Keratoconus is a degenerative eye disease in which the cornea structural changes becomes thinner and takes a conical shape in contrast to the normal spherical one. This pathology usually occurs in adolescence, but sometimes also occurs in children and young people under 30 years of age. The change in the shape of the cornea occurs slowly, usually over several years. However, there are also cases of more rapid progression of keratoconus.

The earliest references to keratoconus belong to the German physician B. Mohort (dating back to 1748) and Taylor (1766), but for the first time the disease was described in detail and isolated from the group of other corneal ectasias by the British D. Nottingham in 1854. At that time, the treatment of keratoconus was reduced to cauterization of the cone-shaped part of the cornea with silver nitrate and the application of a tight bandage in combination with the instillation of drugs that cause miosis.

In 1888, the French ophthalmologist Eugène Kalt began work on a glass sheath designed to flatten the steep conical apex of the cornea and thereby correct its shape. This is the first known use of contact lenses to correct keratoconus.

Symptoms

The first signs of keratoconus are often the need for frequent shift glasses and blurred vision, not corrected by them. classic symptom this disease is the occurrence of multiple imaginary images, known as monocular polyopia. This effect is most noticeable when viewing high-contrast visual patterns, such as a bright dot on a dark background. Instead of seeing a single dot, the eye with keratoconus sees a chaotic picture of many of its images.

The reasons

Despite extensive research, the etiology of keratoconus remains unknown. Presumably, this disease has several causes. Among them: genetic predisposition, stress, corneal injury, cellular factors and influence environment. All of them can serve as an impetus for the development of keratoconus.

Classification of keratoconus

According to the magnitude of the curvature of the cornea, the following types of keratoconus are distinguished:
- light (less than 45 diopters)
- medium (from 45 to 52 diopters)
- developed (from 52 to 62 diopters)
- heavy (more than 62 diopters)
Based on the differences in the shape of the cone morphological classification:
- mastoid - has a small size (up to 5 mm) and is located closer to the center of the cornea
- oval - 5-6 mm in size, usually displaced downward from the center
- spherical - dimensions exceed 6 mm, in pathological process more than 75% of the cornea is involved.

The advanced stage of keratoconus can sometimes progress to corneal dropsy, also called "acute keratoconus", when fluid enters the stroma through breaks in the Descemet's membrane, which leads to its edema and, it is possible, to secondary severe scarring of the cornea.

Diagnosis of keratoconus

With the technical improvement of medical equipment used for topographic mapping and measurement of the cornea, it has become much easier for ophthalmologists to diagnose keratoconus and choose more effective methods treatment.

Keratoconus is often difficult to detect on early stages, as vision suffers still slightly. One of the early warning signs for an ophthalmologist is the difficulty of achieving maximum visual acuity in a patient even with ideal spectacle correction.

Other clinical manifestations that help confirm the presence of keratoconus are: thinning of the corneal stroma, deposits of iron oxide (hemosiderin) in the basal layer of the epithelium (Fleischer's ring) and tears in the Bowman's membrane. All of them can be identified by examination with a slit lamp. In addition, the presence of keratoconus is determined using instruments such as a retinoscope and a keratometer. They make it possible to detect signs irregular shape cornea.

Ultrasound and other pachymetry methods are certainly useful in confirming the diagnosis of keratoconus, as they are used to measure the extent of corneal thinning in patients with suspected keratoconus. The equipment of some manufacturers, in particular, Bausch & Lomb and Orbscan, combines the capabilities of various methods for conducting these examinations in order to more accurately establish the diagnosis.

Treatment of keratoconus

Not currently known medical preparations leading to regression or prevention of the development of keratoconus, but patients have the opportunity to slow the progression of the disease by refraining from rubbing the eyes. In cases where glasses or soft contact lenses are no longer effective, conservative (hard contact lenses) and surgical methods of treatment are used, including penetrating and layered keratoplasty, implantation of intrastromal corneal rings, epikeratophakia, asymmetric radial keratotomy, and corneal collagen crosslinking.

Contact lenses for keratoconus

Refractive error
with keratoconus

Keratoconus correction
contact lens

In the early stages of keratoconus, the distortion of visual images is corrected with glasses that correct the slight myopia and astigmatism that are caused by the disease. In the advanced stage, contact lenses are the first choice for vision correction. In most cases, the mode of wearing them is permanent. There is no single lens design that is ideal for every type and stage of keratoconus. Required individual approach to each patient in order to make a carefully considered decision on the use of those or other contact lenses that achieve the best combination of visual acuity, comfort and corneal condition.

Soft contact lenses
The possibility of using soft contact lenses is limited due to the fact that such a lens, covering the wrong surface of the cornea, takes its shape. At the same time, a space filled with lacrimal fluid is not created between them, which, in turn, does not contribute to an increase in the efficiency of the refractive surface of the cornea in comparison with the initial one in keratoconus.

Rigid gas permeable contact lenses
Rigid gas permeable contact lenses are the main method of vision correction in keratoconus. They correct the irregular shape of the cornea and, together with the tear film that fills the space between the contact lens and the outer surface of the cornea, function as a new refractive surface in the eye. The term "rigid" defines the type of lens, while "gas permeable" describes the properties of its material. There are many different types of hard contact lenses.

"Double layer" lenses
Combination "two-layer" lenses can be used in difficult cases, for example - with individual intolerance to rigid gas-permeable contact lenses, severe central corneal opacities in keratoconus, thinning of the apex or recurrent epithelial erosion. This system consists of a rigid lens mounted on upper surface soft. Its goal is to maintain visual acuity by using a single lens that combines the benefits of two types of lenses.

Hybrid lens system
Contact lenses Softperm (Ciba Vision) belong to a hybrid lens system and are rigid gas permeable lenses with a soft hydrophilic edge. They are usually used in cases of individual intolerance to hard lenses. Softperm lenses have many advantages. They provide more comfort than rigid ones. gas permeable lenses, better centering on the eye and acceptable visual acuity. But these lenses are generally used only in exceptional cases due to the risk of induced corneal edema and neovascularization.

The main disadvantages of Softperm lenses are frequent breakdowns, the development of giant papillary conjunctivitis and peripheral corneal neovascularization. It should be noted that this type of lens was originally intended to treat not keratoconus, but the cornea. normal form. But due to the fact that these lenses provide wearing comfort soft lenses and visual acuity, as in hard ones, they began to be used by patients with keratoconus, who inevitably exceeded the recommended periods of wearing them, which eventually led to complications.

Scleral lenses
These are large-diameter lenses that rest on the white outer shell of the eye, called the sclera, while completely covering the cornea. Their size may seem intimidating, but there are many benefits to wearing them. Due to the size, scleral lenses do not fall out of the eye, and dust and dirt particles cannot get under them during wearing. These lenses are very comfortable to wear, as their edges are hidden under the edges of the upper and lower eyelids, making them invisible.

Crosslinking

Crosslinking is new method stop the progression of keratoconus. The full name is: "corneal collagen crosslinking with riboflavin (abbreviated as C3R/CCL/CXL)". This is a procedure that stiffens the cornea, allowing it to resist further deformation.

With keratoconus, the cornea weakens, becomes thinner, its shape becomes more convex, with the development of irregular astigmatism. Crosslinking enhances the bonds between collagen microfibrils in the cornea and between and within the molecules that form these microfibrils. This is achieved by using the non-toxic substance riboflavin (vitamin B2), which acts as a photosensitizer. Dosed ultraviolet irradiation in the long-wave range (UV-A) causes the formation free radicals inside the cornea and, as a result, chemical cross-links ("cross-links").

In practice, the crosslinking procedure is simple and gentle for the patient. Local anesthetic drops are instilled into the eye before removal of the corneal epithelium in the central part. Riboflavin solution is used to saturate the stroma for 30 minutes before ultraviolet irradiation, which is also carried out for 30 minutes using a precisely calibrated instrument, such as a UV-X system. Postoperative care is almost the same as after excimer laser photorefractive keratotomy and includes wearing a therapeutic contact lens, as well as local treatment over the next 3 days to increase comfort and accelerate epithelization.

An increase in the number of bonds between collagen fibrils in the cornea gives it a rigidity similar to that observed during natural aging. The biomechanical strength of the human cornea can be increased by 2-3 times. This increased rigidity is thought to be responsible for slowing down or stopping corneal ectasia.

The crosslinking technique using a riboflavin solution combined with long-wave ultraviolet exposure was developed in Germany in 1993, and the first operation using this technique was carried out in 1998. It has steadily gained momentum since the results of clinical trials became available, which are ongoing at several centers around the world, and the FDA recently approved a study on crosslinking.

Published data unequivocally show no progression of keratoconus over a 3-5 year period after the procedure. For example, in the Dresden study, 60 eyes after crosslinking for 5 years did not observe further development process, and more than half of them showed some flattening of the cornea by up to 2.87 diopters. A slight improvement in visual acuity was also revealed: with optimal correction — by 1.4 lines.

Potential candidates for crosslinking are those who have progression of keratoconus or other keratoectasia (transparent marginal corneal degeneration, iatrogenic cases). For surgery, the thickness of the cornea must be at least 400 microns to protect the endothelium from potentially toxic ultraviolet (UV-A) radiation at an index of 8 after removal of the epithelium. This parameter is measured prior to treatment: if the cornea is too thin, a hypertonic riboflavin solution may be applied to induce sufficient swelling to safely carry out the procedure. During the use of this method, no dangerous side effects were identified.

It is important to understand that collagen cross-linking is not a panacea for the treatment of keratoconus, but rather aims to stop the progression of this disease. After the procedure, patients will continue to wear glasses or contact lenses, although the prescription may need to be changed. The main goal of crosslinking is to stop the progression of keratoconus and thus prevent further deterioration of vision and the need for corneal transplantation.

Radial keratotomy in the treatment of keratoconus

This type of surgical intervention is not generally accepted, and reliable data on its safety and effectiveness are currently available. The opinions of ophthalmologists, as well as the available research results on this issue, are contradictory. Those few who perform it speak of the effectiveness of the technique: it combines not only stabilizing properties in relation to the progression of keratoconus, but also refractive, correcting ametropia and improving visual acuity. Unfortunately, it is not possible to conduct adequate studies for various reasons, therefore it is necessary to consider this technique experimental.

The following are options for performing keratotomy for keratoconus.

Asymmetric radial keratotomy
The “mini” technique of asymmetric radial keratotomy (ARK) is sometimes identified with its predecessor, radial keratotomy, which is not entirely true. This is a special surgical procedure, in which micro-incisions are made on the cornea in such a way as to smooth out or enhance the irregularity of the shape of the cornea.

The technique began many years ago, and the person who had the greatest influence on its development was the outstanding Russian ophthalmologist Svyatoslav Fedorov, the father of modern radial keratotomy.

Professor Massimo Lombardi, who studied with Fedorov for a long time, developed the technique and adapted it specifically for the treatment of keratoconus. After many years of testing and technical improvements, an asymmetric "mini" surgical technique was developed. The "Fedorov" radial keratotomy had to be adapted to deal with the variability in the shape of the cornea in each case and the unevenness of its thickness, characteristic of keratoconus. For this reason, the incisions were shortened and limited to the central optical zone.

The procedure is individual for each patient and requires a careful assessment of the indications for it and a preoperative examination. The cornea is carefully scanned and mapped in detail. After perimetry and other examinations, it is calculated where, to what depth, what length, at what angle, etc. every cut will be made. This outpatient procedure is performed under local anesthesia and lasts 1-3 minutes on one eye.

The experience of the surgeon plays a very important role in performing this manipulation, since it takes many years to learn how to use this method for the treatment of keratoconus. For this reason, ARC is not widespread. According to the author, the fact that the treatment of a patient with keratoconus is selected taking into account a specific, individual in each case, corneal profile, makes it possible to obtain optimal results from this surgical intervention.

Optical diamond surgery
The technique of optical diamond surgery developed by academician Artsybashev, according to the author, makes it possible to maintain the stability of the results even 20 years after the operation. It not only stops the progression of keratoconus, but also improves visual acuity. The incisions made by this method in keratoconus due to the redistribution of intraocular pressure exerted on the corneal tissue lead to a change in its irregular shape and, as a result, to partial or full recovery functions. After surgery, in most cases, the cornea is completely restored, visual acuity increases. This method used to preserve the patient's own cornea and prevent acute keratoconus requiring corneal transplantation or keratoplasty.

The operation is performed on an outpatient basis, under local anesthesia and lasts 2-3 minutes. Patients are discharged from the hospital on the first day after surgery. Its results are felt the very next day. Patients are under medical supervision, control examinations are carried out one, three, six months, one and two years after the intervention. Also developed postoperative treatment, which provides conditions for better scarring of micro-incisions, thanks to which the basis for strengthening the cornea is created. Since 1983, Dr. Artsybashev has performed more than 1,000 surgeries for stages I-IV of keratoconus, and more than 30,000 refractive surgeries to improve the optical function of a healthy cornea. Each operation was planned taking into account the exact individual shape of the cornea, so a thorough preoperative examination is necessary.

In the end, I would like to remind you once again that all the described variants of keratomy are not included in any protocol for the treatment of keratoconus and cannot be recommended for use along with the generally accepted ones. Methods require full-fledged research, the results of which may lead to a decision on their introduction into global practice or total ban for these interventions in ophthalmology.

Intrastromal corneal rings

The newest surgical method correction of irregular astigmatism in keratoconus, an alternative to corneal transplantation is the implantation of intracorneal ring segments (keraring).

Two types of intrastromal rings are currently available: Intacs, which have a hexagonal section and are placed at a greater distance from the center than the second type, Ferrara Rings, which are shaped triangular prism. Rings can be implanted deep into the middle of the corneal substance (stroma). The operation is quick and painless, outpatient settings using anesthetic drops. In this case, a specially designed vacuum layered dissector is used, which creates an arcuate pocket for rings, or, according to latest technology, femtosecond laser. The exact mechanism of action of the rings is not known, but it is believed that they exert an outward buoyancy against the curvature of the cornea, flattening the apex of the cone and restoring it to a more natural shape. Previous studies also assign a large role in this process to the thickening of the overlying epithelium adjacent to the segments, which gives a significant leveling effect.

Ferrara Rings intrastromal corneal rings differ from Intacs in that they have a smaller radius of curvature (in the former it is fixed and is 2.5 mm, in the latter it can vary from 2.5 to 3.5 mm), and also in that, despite to a smaller size, the chance of glare after installation is less due to the prismatic shape. Any light beam that hits the ring is reflected in the opposite direction in such a way that it does not enter the field of view. Since Ferrara Rings are smaller and closer to the center of the cornea, they provide a stronger effect and can correct myopia up to -12.0 D, i.e., more than can be corrected with Intacs rings. The appearance of glare was noted in some patients with a large pupil diameter. In such cases, installing Intacs is recommended.

As a rule, the results of treatment in most patients are positive, as evidenced by a significant decrease in the degree of astigmatism after surgery, accompanied by an increase in visual acuity both with and without optimal spectacle correction. So far, the groups of patients studied for the most part remain small, however, the achievement of favorable outcomes within 24-36 months of follow-up is noted. The best results were obtained on eyes with light and middle form keratoconus.

Perforation of the anterior chamber during surgery, lack of expected results, infection, aseptic keratitis, postoperative extrusion (pushing out) of the ring are among the possible complications. Removing problematic segments can be easily done. This allows the cornea to return to its original preoperative state. Studies have shown that in about 10 percent of cases, it becomes necessary to remove the rings, either due to the complications listed above, or due to lack of effect. But this does not exclude the possibility of subsequent implementation of layered or penetrating keratoplasty.

Corneal transplant

Corneal transplantation, or keratoplasty, is a surgical intervention to remove damaged corneal tissue and replace it with a healthy one taken from the eye of a suitable donor. It can improve vision and relieve pain in an injured or diseased eye.

Keratoplasty is usually indicated in cases where the cornea has become severely deformed after treatment with other methods, or when it is damaged due to illness, infection, or injury.

Corneal transplantation involves the removal of a part (layered keratoplasty) or all layers (penetrating keratoplasty) of cloudy or deformed tissue and its replacement with a graft taken from a deceased donor.

Dr. Edvard Zirm in 1905 in the territory of the present Czech Republic performed the first successful transplant human cornea, and the graft remained viable throughout the patient's later life. Since that time, a number of new techniques for this operation have been developed. The most common method of corneal transplantation is penetrating keratoplasty.

Keratoplasty (Penetrating Keratoplasty or Corneal Transplant)
Penetrating keratoplasty (see photo) includes complete removal cornea (all 5 layers) and its replacement with a donor one, which is sewn into place so that the distance between adjacent sutures is 20 microns (40% of the thickness of a human hair!).

The stitches are usually removed after one year. It may take the same amount of time to restore vision to a satisfactory level. Often, patients who have undergone penetrating keratoplasty need to wear glasses or contact lenses to correct their vision. The graft survival after this operation is on average 15 years.

Deep anterior laminar keratoplasty (DALK)
Such a surgical intervention is performed in cases where the endothelium lining the cornea from the inside is healthy, and the stroma is pathologically changed. The operation allows you to remove the affected stroma and preserve healthy underlying tissues of the deep layers. The pathologically altered anterior part of the cornea is removed and replaced with a new donor one, which is fixed with small sutures. The graft lies on top of the patient's own tissues lining the cornea from the inside. Since the inner layers of the graft do not move, the risk of rejection is lower, and the prognosis for long-term graft survival is better. However, the patient after deep anterior layered keratoplasty will have a longer recovery period, in addition, the same quality of vision is not always achieved as with penetrating keratoplasty.

Risks in corneal transplantation

Corneal rejection
Rejection is the process by which the patient's immune system recognizes the donor cornea as foreign and mounts an immune response against it. Such cases are very common and occur in every fifth patient who has undergone transplantation. Most rejections are suppressed effective treatment, the graft takes root and continues to function. The key to a successful outcome is early treatment. At the first onset of rejection symptoms, patients should emergency consult a specialist. Symptoms to look out for include:
photophobia, or photophobia hypersensitivity to bright light)
irritation or pain;
redness;
decreased or blurred vision.
Treatment consists of instillation of steroid eye drops and, sometimes, orally or parenteral administration drugs in this group.

Infection
The surface of the graft may become infected if the sutures holding it in place have loosened or broken. In cases where the infection cannot be controlled, it can lead to death of the transplanted tissue or loss of the eye.

Glaucoma
This is an increase in intraocular pressure that damages the optic nerve at the back of the eye. Steroid medications used after corneal transplantation can cause glaucoma in some patients.

Retinal disinsertion
It is observed in approximately 1% of patients after penetrating keratoplasty. Can be treated with subsequent surgery.

Keratoconus- a term made up of two Greek words: "kerato" and "konos", which are translated from Greek like "cornea" and "cone". Actually, the name reflects the essence of the disease in the best possible way: with keratoconus, the cornea of ​​the eye, due to degenerative changes, becomes thinner, and instead of normal spherical shape takes the form of a cone.

Usually, similar problem occurs in adolescents, but sometimes keratoconus can be found in very young children, and even in persons of thirty years of age. Usually, the transformation of a spherical cornea into a cone occurs rather slowly, several years. True, sometimes there are cases and the rapid development of the disease.

The first mention of the disease dates back to the 18th century (B. Mohort, Taylor), but it was described in detail a century later, when the British ophthalmologist D. Nottingham in 1854 singled it out from the group of other corneal ectasias. The treatment of keratoconus in those days was carried out by cauterizing the cornea with a solution of silver nitrate, after which a tight bandage was applied to the eye and drops were prescribed that caused miosis.

A little later, the Frenchman Eugene Kalt began to work on the manufacture of a special glass shell, which, when put on the eye, would flatten the conical top of the cornea and correct its shape. This experiment is considered the first mention of the treatment of keratoconus with contact lenses.

Symptoms of keratoconus

The initial sign of keratoconus, as a rule, is blurred vision, which is not corrected even with frequent changes of glasses. The identification sign of this disease is the occurrence of multiple phantom images, called monocular polyopia. A similar effect is especially often manifested with visible objects of high contrast, for example, when looking at dark dots on a light background. In this case, instead of a single point, a person with keratoconus observes a picture with many chaotic images of it.

Causes of Keratoconus

Serious research conducted in the field of keratoconus has not yet been able to establish the exact cause of the disease. Several factors are believed to contribute to the onset of keratoconus, such as: genetic predisposition, corneal injury, decreased gland function internal secretion, viral infections (hepatitis B), stress, allergies, adverse effects of the external environment. Each of them can serve as a trigger for the development of the disease.

Video about the causes and symptoms of keratoconus

Classification of keratoconus

Today in ophthalmology there are at least five different classifications of the disease, but the classification according to M. Amsler is most often used. It is based on the features of the biomicroscopy of the picture of the cornea with ophthalmometric changes. According to her, there are 4 stages of the course of the disease:

1. Stage one: visual acuity 0.1-0.5, with the possibility of correction with cylindrical glasses, corneal curvature - over 7.2 mm.
2. Stage two: visual acuity up to 0.1-0.4, there is the possibility of correction with cylindrical glasses, thinning of the cornea and slight ectasia are not excluded, the curvature of the cornea is 7.19-7.1 mm.
3. Stage three: visual acuity is 0.02-0.12, there is the possibility of correction with extremely difficult to tolerate rigid lenses, the radius of curvature of the cornea is 7.09-7.0 mm, protrusion of the cornea and its thinning are noticeable, opacities in the Bowman's membrane.
4. Stage four: terminal with opacities of the corneal stroma, damage to the Descemet's membrane. Corneal curvature - no more than 6.9 mm, visual acuity is not corrected, amounting to 0.01-0.02.

In addition, it is customary to distinguish:

• Anterior keratoconus(true). Him chronic course with pathological processes occurring in the Bowman's membrane. Its difference is the occurrence of almost transparent ectasia.
• Acute keratoconus(hydrops) - dropsy of the cornea. The condition is accompanied by damage to the Descemet's membrane, when intraocular moisture, due to a change in the barrier function, enters the layers of the cornea, causing clouding and edema of the stroma.
• Posterior keratoconus- an anomaly due to the underdevelopment of the mesoderm. It is distinguished by a centrally formed thinning, sometimes in the form of a saucer. The cornea is almost flat, optically weak. The condition is stable for a long time.

Diagnosis of keratoconus

The development and improvement of special ophthalmic equipment for measuring the cornea and topographic mapping has greatly facilitated the diagnosis of keratoconus, which also had a positive effect on the choice of treatment methods.

Very often, the disease is almost impossible to detect at the earliest stages of its occurrence, since visual functions are almost unchanged. Most early sign keratoconus that does not go unnoticed experienced professionals, - the difficulty in achieving the patient's maximum visual acuity, even in the case of perfectly matched glasses.

Among other symptoms confirming the presence of the disease, one can distinguish: thinning of the corneal stroma, deposits in the basal layer of the corneal epithelium of hemosiderin (Fleischer's ring), as well as perforation of the Bowman's membrane. These signs are easily identified during examination using a slit lamp. In the diagnosis of keratoconus, special devices are also used: a retinoscope, a keratometer. With their help, signs of an abnormal shape of the cornea are revealed.

In particular, the ultrasound method and the pachymetry method are certainly useful, which are very important for confirming the diagnosis, because they can be used to identify the degree of thinning of the cornea in people with suspected keratoconus. The devices from Bausch & Lomb and Orbscan are especially suitable for this, which combine the possibilities of different methods of diagnostic examinations, which facilitates the detection of the disease.

Our ophthalmological clinic offers its patients all the most effective and proven methods of treating keratoconus used in the world of ophthalmology. Turning to the "Clinic of Dr. Shilova" you can be sure of the professionalism of doctors and 100% German technology for your vision!

Treatment of keratoconus

Today, medicine is not yet able to offer patients with keratoconus convincingly effective medicines capable of preventing or curing the disease. However, it is possible to slow down its progress if you simply do not rub the sore eye.

If the correction with glasses or soft contact lenses is ineffective, the patient may be offered conservative treatment of keratoconus with hard contact lenses or surgical treatment of the disease. Keratoconus surgery is particularly diverse and includes the following methods: penetrating and layered keratoplasty, implantation of intrastromal rings, asymmetric radial keratotomy, epikeratophakia, collagen crosslinking of the cornea.

Keratoconus and contact lenses

Distortion of visible objects in the early stages of the disease can be corrected by glasses for a small degree of myopia and astigmatism caused by keratoconus. With the development of the disease, the unconditional choice of vision correction is the constant wearing of contact lenses. The selection of lenses is strictly individual, because there is no single design that is ideal for all types and stages of keratoconus.

Soft contact lenses . The use of such lenses is limited, because when covering the abnormal surface of the cornea, they take its shape. In this case, there is no space filled with tear fluid between the lens and the cornea, which reduces the effectiveness of the refractive corneal surface.

Gas permeable rigid contact lenses. This is the main method of vision correction in this disease. They contribute to the correction of the abnormal shape of the cornea. Besides, hard lenses in conjunction with the lacrimal fluid in the space between the lens and the corneal surface, become a new refractive surface of the eye.

Double Layer Lenses . Consisting of two layers, combined lenses are used in particularly difficult cases: with intolerance to hard lenses, thinning of the apex of the cornea, epithelial erosion, central corneal opacities. Such an optical system includes a rigid lens and a soft lens adjacent to the surface of the eye.

Radial keratotomy

Radial keratotomy is one of the surgical techniques for the treatment of myopia, developed by the outstanding Soviet ophthalmologist S. Fedorov . To get rid of keratoconus, one of its modifications is used - asymmetric radial keratotomy (ARK). This is a specific surgical procedure where micro incisions are made in the cornea to smooth out or enhance irregularities in its shape. However, this operation is not widely used due to high risk complications and unstable results.

Crosslinking

Corneal collagen crosslinking (C3R/CCL/CXL) has become a new method to stop the development of keratoconus. This procedure helps to increase the rigidity of the cornea, enabling it to further resist deformation.

Keratoconus weakens and thins the cornea, and irregular astigmatism develops. When crosslinking, non-toxic riboflavin (B2) is used, which plays the role of a photosensitizer and dosed exposure to UV rays, which causes free radicals to appear inside the tissue. The effect is to strengthen the bonds of collagen microfibrils of the corneal tissue, which contributes to an increase in its rigidity.

Crosslinking is a gentle and fairly simple procedure. It is performed under local drip anesthesia. During the operation, a layer of epithelium is removed in the central part of the cornea. Before this, a solution of riboflavin is used to saturate the stroma, after which UV irradiation is performed. Irradiation is performed with a calibrated instrument for approximately thirty minutes. Postoperative period almost does not differ from that after PRK. The patient wears a protective lens and receives local drip treatment for at least three days, for the speedy epithelialization of the surgical wound.

In our clinic, you can get advice and undergo treatment from world-class cornea specialists, Professor Tatyana Yuryevna Shilova and the leading ophthalmologist of Germany - Doctor of Medicine, Professor Walter Secundo. By affordable prices and right in Moscow!

Intrastromal corneal rings

The method of implantation inside the cornea of ​​segments of special rings (keraring) has become the latest surgically correction of astigmatism caused by irregular keratoconus. The operation is a complete alternative to corneal transplantation.

Today, 2 types of intracorneal rings are used: Intacs, with a hexagonal section, and Ferrara Rings, with a triangular prism shape. Typically, the rings are implanted deep into the corneal stroma. Such operations are performed quickly and without pain, under local anesthesia, on an outpatient basis.

For the procedure, a vacuum layered dissector or a femtosecond laser is used, with the help of which a special pocket for the rings is created. It is assumed that the action of such rings is to create a buoyant pressure that flattens the top of the cone, making its shape more natural. Also, a large role in achieving a leveling effect belongs to the thickening of the overlying epithelium adjacent to the segments.

Corneal kering rings - Ferrara Rings and Intacs have many differences. So in the first case, the rings have a smaller radius of curvature and when they are installed, the likelihood of aberrations is less likely, which is explained by their prismatic shape. Ferrara Rings are smaller and this allows them to be placed closer to the corneal center for greater effect. With their help, it is possible to correct myopia up to -12.0D, and this result is much better than that of the Intacs rings. However, patients with large pupils may experience glare when receiving Ferrara Rings. In this case, Intacs implantation is indicated.

The results of treatment with intrastromal rings are usually positive, with a significant reduction in the degree of astigmatism and improvement in visual acuity. Particularly good results are achieved with mild and medium degrees keratoconus.

Possible complications of the procedure include anterior chamber perforations, infection, aseptic keratitis, and postoperative ring extrusion. If necessary, the rings are easily removed, after which the cornea returns to its original state.

Corneal transplant

Corneal transplant surgery is called keratoplasty. When it is performed, the damaged corneal tissue of the patient is replaced by a healthy donor. This greatly improves vision and relieves pain in the affected eye. Keratoplasty is indicated for severe corneal deformity due to disease, infection, trauma, or inadequate prior treatment.

The operation may consist of removing part of the clouded corneal tissue (layered keratoplasty) or all layers completely (penetrating keratoplasty) and replacing it with a suitable graft. In keratoconus, corneal transplantation is required in 10-20% of cases.

The success of keratoplasty, after which the patient gains good vision, is at least 90%, which is very high rate. Recovery of vision after keratoplasty is not immediate. It often takes several weeks or months, in very rare cases The process can take up to a year.

Most frequent risks operations are:

• transplant rejection. The process occurs due to the attack of the patient's immune system on a foreign element. Such cases are not at all uncommon and occur in every fifth person who has undergone a cornea transplant procedure. In most cases, after timely treatment, rejection can be avoided. The transplant takes root and functions successfully. As a treatment, drugs of the steroid group are prescribed in drops, tablets, sometimes in injections.
• Transplant infection. The situation occurs when the sutures that hold the flap in place are loosened or torn and is extremely serious. If the infection does not respond to treatment, the transplanted graft may die, in the worst case, loss of the eye is possible.

• Glaucoma. Application steroid drugs after transplantation, can cause a persistent increase in IOP, which gradually damages the optic nerve.

• Retinal disinsertion. After penetrating keratoplasty, this condition is observed only in 1% of cases. Well treated surgically.

Our clinic has developed a unique author's method for the treatment of end-stage keratoconus, which allows not only to preserve your own cornea and stop the disease, but also significantly improve your vision - sign up for a consultation with Professor Tatyana Yuryevna Shilova today!

197 02/13/2019 5 min.

Keratoconus refers to those diseases that are accompanied by deformations of the components eyeball, which leads to loss of vision or even the eyeball. As a rule, such changes are rarely amenable to conservative treatment and require surgical intervention. Therefore, it is especially important at the very first symptoms of the disease to register with an ophthalmologist and monitor the course and results of therapy.

Disease Definition

Keratoconus is a disease of the cornea of ​​the eye, accompanied by its deformation. During the course and progression of the disease, it does not become inflamed, but becomes thinner and takes the form of a cone. AT severe forms and as a result, the patient is able to lose the former quality of vision. This phenomenon is associated with increased pressure of moisture inside the eye, which affects all layers of the shell.

At risk are people between the ages of twenty and forty. Complete loss of vision () due only to the progression of keratoconus, as a rule, does not occur. In addition, the disease proceeds slowly and is often accompanied by remissions. It can be in acute and chronic form.

The disease can be inherited, therefore, if there is a predisposition, it is necessary to register with an ophthalmologist after reaching twenty years.

Kinds

The development of keratoconus can take place in stages:

In order to prevent the transition to a new stage, keratoconus therapy must be started immediately when the first symptoms occur.

Types of pathology are also divided according to the form of deformation:

Causes

At the moment, the exact causes of this pathology are not fully understood. However, the following prerequisites are reliably known:

Symptoms

Among the first signs of the disease, as a rule, pain and a sharp deterioration in vision are noted. However, the course of keratoconus is not limited to this. With it, a rapid increase can be observed, and as a result, tissue rupture. These signs are inherent in the acute form of the disease. Chronic has the following symptoms:

In the presence of ruptures of membranes and tissues, scars may remain when edema is removed. To avoid this, you must be prepared for swelling and avoid serious complications.

Possible Complications

Complications of the disease are possible final stages which suggest severe clouding and protrusion of the cornea. In this case, there is often a strong decrease in visual acuity, blurring of the image, persistent damage and tissue tearing. Edema can also be persistent, often accompanied by painful sensations and profuse lacrimation.

The most severe degree of complication is the occurrence of dropsy, which can lead to loss of the eyeball.

Treatment

Diagnosing keratoconus in the early stages is quite difficult, but medical devices, examination and questioning of the patient can help with this. During the examination, the ophthalmologist needs to check and, as well as the possible presence of astigmatism. Based on the results of the examination, treatment is prescribed depending on the stage and type of the disease.

Ophthalmic examination

In a medical way

Treatment with drugs can be effective only in the early stages of the disease. In this case, assign:

Also used in eye ointments various injections. In some cases, it is possible to wear special glasses, contact or.

Surgically

Correction of the deformity is possible at the fourth and fifth stages of progression of keratoconus. With the help of the operation, the cornea is flattened due to the introduction of artificial corneal rings into the tissues. At the same time, the possibility of rejection of the ring has a very low probability (less than one percent), and after the intervention, the patient almost immediately feels an improvement and an increase in visual acuity. Currently, two types of operation are used: through and layered.

Epikeratophaky is also used. It involves removing the top layer of the affected cornea and replacing it with donor tissue. With the help of radial keratomy, the deformity is eliminated by small incisions in the shell, thermokeratoplasty - by applying point applications.

Carrying out thermokeratoplasty with a laser.

Only the use of surgical intervention can completely restore vision in the last stages of pathology.

Folk remedies

For the treatment and relief of keratoconus, you can use traditional medicine recipes:

• Gadgets. For them, you can use decoctions medicinal herbs: chamomile and sage. This remedy will help relieve irritation, redness and discomfort.
• echinacea tea(sold in pharmacies) and honey can increase the level of immunity.

Folk methods cannot be used as alternative way treatment. They can only act as aids.

Prevention

In order to prevent the possible occurrence of pathology, it is necessary:

1. Protect eyes from exposure to sunlight and other sources of ultraviolet radiation;
2. Do not touch your eyes with your hands;
3. Avoid traumatic situations;
4. Timely undergo professional therapy for diseases of the visual apparatus;
5. Choosing the right contact lenses
6. Follow the basic rules of eye hygiene.

Useful in this situation would be a preventive visit to the ophthalmologist at least once every six months.

Video

conclusions

Keratoconus is an extremely unpleasant disease, accompanied by external changes in the eye, deterioration in the quality of vision, swelling and pain. With progression, this anomaly can even lead to. However, with proper professional therapy, it is possible to completely restore vision and return the patient to their usual way of life. The most important thing is to start treatment on time and choose the right method.

Many doctors believe that the tendency to develop keratoconus in most people is present from birth. True, the disease begins to progress much later. Most often, such a pathology of the cornea occurs in adolescence and in people not older than 30 years. Moreover, this ailment up to a certain point can be disguised as astigmatism or myopia. The disease is very dangerous, because in advanced cases it can lead to rupture of the cornea and even loss of the eye.

Keratoconus: what is it?

This eye disease is a chronic progressive process in which the cornea becomes thinner. A similar condition develops due to a weakening of the connection between the collagen fibers of its inner layers. As a result, under the influence of pressure inside the organ of vision, a change in the cornea occurs, which leads to the formation of astigmatism and myopia.

With a pronounced deformation, the shape of the eye cornea becomes cone-shaped. And later certain time, due to the progression of the disease, clouding and swelling of this membrane occurs, which further reduces vision.

Such an ailment can begin to develop in adolescence, while the main signs of the disease can appear only in 20-30 years. The formation of the disease in older people is extremely rare. In such patients, a similar ailment occurs mainly after laser correction in the eyes. Not every one of them knows what it is - keratoconus, so they seek help late.

Contact lenses and glasses with such an ailment do not help to completely get rid of vision problems. The disease can lead to complete blindness, moreover, it remains with a person for life.

Keratoconus: degrees of disease

This ailment is primary and secondary, it all depends on the cause of its occurrence. Moreover, in 95% of cases, the deformation is bilateral, in other words, both eyes are subject to thinning of the cornea. Unilateral keratoconus occurs in only 5% of patients. Corneal deformity may be as follows:

• Mastoid. The cone is enlarged to 5 mm, the change is located in the center.
• Oval. The protrusion of the cornea is about 6 mm, the deformation is directed downward.
• spherical. The size of the cone exceeds 6 mm, most of the cornea is covered by the disease.

Progression of keratoconus may take longer for a long time(up to 15 years), while the stages of the disease will gradually increase. The detection of pathology is often delayed, since concomitant symptoms she is very blurry. In other cases, the disease develops in jerks, the symptoms with it first appear, and then disappear for a long period.

But the most difficult form of the disease is considered to be dropsy of the cornea - acute keratoconus of the eye. This degree of pathology is detected in 7% of patients. With it, a rupture of the thinned cornea occurs, as a result of which aqueous humor flows out and forms a cloudy spot on the organ of vision. After about 1.5 months, the process of scarring of the cornea occurs and the patient may experience a temporary improvement, but the resulting opacities will interfere with good vision.

The described disease is also classified according to the degree of increase in signs. The entire period of the disease is divided into the following stages:

1. At an early stage, the curvature of the cornea is less than 45 diopters. Ophthalmologists fix small morphological changes.
2. In the second stage, doctors detect myopia and astigmatism, which are poorly corrected by glasses.
3. Further, the deformation of the cornea is 45-52 diopters. With it, the appearance of cracks in the Descemet's membrane is observed, through which moisture from the anterior chamber penetrates into the cornea, and the top of the cone also becomes cloudy. Cloudy points form on the cornea, there is a possibility of developing acute keratoconus. A person sees almost nothing at night.
4. The curvature of the cornea reaches 52-62 diopters, clouding covers most of it. The patient does not see well during the day, his visual acuity is greatly reduced, even more clouding points appear. Visually, he can see the bulge of the cornea.
5. In this severe form of the disease, the cone-shaped deformation of the cornea exceeds 62 diopters. At this stage, the cornea becomes completely cloudy, and vision is greatly reduced. There is a danger of its rupture, which can lead to loss of the eye. Therefore, immediate surgical intervention is required.

Why does disease occur?

What it is - keratoconus, and how it develops, it is necessary for every person to know, this is the only way to avoid complications. True, the pathology under consideration has not yet been fully studied. Many doctors believe that keratoconus is a chronic degenerative disease. Its main causes include hereditary factors, structural features of the cornea and the negative impact of the environment.

In keratoconus, Bowman's membrane is destroyed in the cornea. This pathological process leads to the fact that the cornea acquires an uneven thickness, with areas of clouding and thinning. As a result, it stretches and deforms under the influence of pressure inside the eye, which leads to a deterioration in visual acuity.

There are several hypotheses that explain the reasons that contribute to the development of this disease. For example, endocrine diseases. In patients with such disorders, the activity of protease inhibitors in the lacrimal fluid and cornea is reduced. At the same time, the activity of proteases, enzymes that destroy collagen, increases. A decrease in the amount of protease inhibitors leads to the fact that they cannot resist damage to the collagen ligaments in the transparent layer of the cornea.

In addition, the progression of the disease is facilitated by the accumulation of oxidants and free radicals in the cornea, due to a decrease in the activity of aldehyde dehydrogenase. With an increase in the number of markers of oxidative stress, keratoconus can also develop.

Heredity is also the cause of the formation of this disease. According to some scientists, corneal pathologies are transmitted at the genetic level. These diseases are inherited in an autosomal dominant manner. True, they have not yet been able to find the gene in which the disorder appears, however, according to statistics, in patients suffering from Down syndrome, thinning of the cornea occurs much more often than in healthy people.

Experts also suggest that keratoconus is based on a genetically or hereditarily determined feature of the body, which is expressed in a decrease in activity, absence, deficiency of one or another enzyme. Hereditary fermentopathy does not manifest itself in any way until a certain moment. A similar process can be triggered by a sharp deterioration in the functioning of the immune system, a restructuring of the hormonal background, or a serious illness - all this leads to changes in the cornea.

The reasons for the development of keratoconus should also include immunological. According to this hypothesis, bioactive substances are formed in the cornea, under the influence of which the processes of regeneration of the eye epithelium are disrupted. Such disorders lead after some time to thinning of the cornea. Simultaneously with keratoconus, the patient may experience the following problems: atopic dermatitis, eczema, allergic reaction, pollinosis and bronchial asthma.

The researchers also noted that among patients suffering from the hepatitis B virus, there are many who have thinning of the cornea.

Often, keratoconus appears with constant use and the use of incorrectly selected contact lenses. Such a disease can also develop after surgery, for example, laser vision correction.

Some experts associate the occurrence of keratoconus with psychological disorders: psychotrauma, stress, or strong negative experiences. But such a theory, like many others, is just the assumptions of scientists.

Signs of corneal thinning

Understanding what it is - keratoconus, it is necessary to note its signs. So, there is a change in the shape of the cornea and its clouding. It comes down to astigmatism with a tendency to constantly change axes as the disease progresses and visual acuity deteriorates. Myopia with keratoconus develops gradually, diplopia (double vision) also joins it.

Vision in keratoconus deteriorates in stages. Patients have to change glasses all the time due to an increase in the number of diopters. Often such vision correction is unfavorably tolerated, since it does not give positive results. And sometimes the patient does not have time to acquire new glasses, as the disease progresses too quickly. In this case, it is necessary to treat keratoconus.

The reviews left by specialists make it clear that in advanced cases, contact lenses do not help either, since they cannot fit snugly against the cornea of ​​\u200b\u200bthe eye.

Quite often, with keratoconus, while watching TV or reading, patients begin to see double. In addition, the following symptoms may also be present:

• itching and irritation of the organs of vision;
• photophobia;
• eye fatigue;
• burning sensation.

If at the first stage of the pathology there is only deterioration twilight vision, then as it progresses, even in daylight, a person ceases to distinguish objects. On the final stages disease becomes visually noticeable bulging of the cornea.

As a rule, all stages of progression of keratoconus take about 10-15 years. In most patients, the disease can stop its development, entering a state of long-term remission. But in 5% of people, on the contrary, the disease rapidly turns into an acute form. At this stage, the Descemet's membrane ruptures and aqueous humor leaks out.

In acute keratoconus, a person is disturbed by unpleasant sensations, severe discomfort and corneal edema. After 2 weeks, the corneal tissue is scarred, which can lead to a temporary improvement in visual acuity.

Diagnostic procedures for keratoconus

As a rule, in the early stages of the development of this disease, the patient complains of a sharp deterioration in vision. In the process of progression of the pathology during a physical examination, the specialist detects clouding of the Bowman's membrane and protrusion of the cornea. Diagnosis of keratoconus also involves procedures such as:

• Skiascopy. It is performed to determine the ability of the pupil to refract light.
• Refractometry. This examination can detect astigmatism and myopia.
• Pachymetry. Needed to establish uneven thickness of the cornea.
• Biomicroscopy of the organ of vision. This study helps to detect cracks in the membrane, growths of nerve endings in the center of the cornea, clouding, changes in epithelial cells and stromal degeneration.
• Ophthalmoscopy. Such an examination is carried out to evaluate the vessels of the fundus, disk optic nerve and retina.

If there are any doubts, then to clarify the diagnosis, you can contact the intersectoral scientific and technical complex "Eye Microsurgery" named after. acad. S. N. Fedorova to conduct computer keratometry. This research method is used for exact definition the degree of astigmatism, the refractive power of the cornea and the thickness of the eye membrane. May also be assigned CT scan to determine the size of the cone-shaped protrusion.

Unfortunately, in many cases, the detection of keratoconus at the earliest stages is difficult. Therefore, quite often, with such a disease, patients are sent to the MNTK named after. Fedorov.

Therapeutic methods

The ophthalmologist prescribes treatment procedures depending on the degree of the disease. At stages 1-2 of keratoconus, patients are recommended to wear glasses and soft contact lenses for vision correction, the price of which is not too high. These optical devices help correct astigmatism and non-critical myopia.

However, conservative therapy is not able to completely eliminate the deformation of the cornea. Such treatment is resorted to in order to increase its tone, reduce irritation and discomfort. Experts usually recommend using special drops with keratoconus: "Taufon", "Oftan-Katahrom", "Floxal", "Quinax". In addition, they recommend taking anti-inflammatory drugs such as Diklof and Naklof.

With this disease, doctors also prescribe:

• applying an eye patch using sodium chloride ointment;
• "Emoxipin" in injections;
• immunostimulating agents and vitamin complexes;
• hormonal preparations ("Maxidex");
• sea ​​buckthorn oil as eye drops.

Treatment for keratoconus involves taking these medications to protect the cornea from external influences, activation of the regenerating function and elimination of irritation. Additionally, they resort to physiotherapeutic methods that give good results: phonophoresis and magnetotherapy.

With thinning of the cornea, “Sidorenko glasses” are often worn. This ophthalmic device is used for vacuum massage around eyes.

Corneal crosslinking

Such an operation in our country can be done at the MNTK Fedorov, they do it qualified specialists. This effective and modern procedure consists in the photopolymerization of stromal fibers, which, under the influence of ultraviolet and riboflavin, release oxygen. As a result, they begin to form special bonds in collagen fibers, which improves their resistance to various mechanical factors and strengthens the cornea.

Riboflavin (in other words, vitamin B2) is an essential substance for redox processes. It is needed for the production of antibodies and red blood cells that maintain the health of the appearance of nails, skin, hair and the whole organism as a whole.

The crosslinking procedure is carried out under local anesthesia with the help of special drops. Physicians remove with surgical devices upper layer corneal epithelium and riboflavin is instilled into the liberated area. Then the area to be treated is exposed to ultraviolet light. The next stage of the operation is the application of an antibiotic, on top of which a special contact lens. This optical device will have to be worn for about 4 days after the operation.

Elimination of the disease by surgery

Surgical treatment of keratoconus is not prescribed for all patients. The specialist, only after examining the patient and receiving all the tests, can send him for medical reasons for the operation.

With thinning of the cornea, penetrating keratoplasty is performed. But they resort to surgical intervention in extreme cases. This method of treatment involves the transplantation of a donor cornea to a patient who has keratoconus.

An operation to implant annular corneal intrastromal segments is also performed for this eye disease. During the procedure, thin arcs made of polymeric materials are implanted in the cornea tissue. These devices put pressure on the cornea, balancing the intraocular, which is directed outward. As a result, the shape of the cornea is corrected.

But it should be remembered that with keratoconus, laser vision correction is contraindicated. The price for this procedure is in the range of 25-30 thousand rubles per eye.

Elimination of pathology by non-traditional methods

It is best to resort to such treatment in the early stages of the disease in order to stop the progression of the disease. More folk recipes help during rehabilitation period. However, you need to know what to set the cornea unconventional ways treatment is impossible, they only help to slow down the pathological process. Without medical care get rid of this disease will not work.

With keratoconus, compresses from chamomile and sage flowers will help eliminate itching and tension from the eyes. To strengthen the immune system, you should take a rosehip decoction. To improve eyesight, it is recommended to drink blueberry or carrot juice every day.

How to avoid the development of keratoconus?

In most cases, the described disease progresses slowly. Sometimes its development can even stop at any stage. The later in age corneal keratoconus appeared, the better prognosis and slower flow.

And in order to exclude the possibility of the appearance of this pathology of the eyes, it is necessary to treat the disorders that contribute to its occurrence in time - inflammatory, endocrine, immune, allergic and others.