Keratoconus 2 3 degrees what to do. Keratoconus – what is it? Cost of the operation. Get treatment in Korea, Israel, Germany, USA

Keratoconus is a progressive non-inflammatory disease of the cornea, manifested in the form of protrusion of its central part at a normal level. intraocular pressure.

Due to the irregular shape of the cornea, light rays entering the eye are refracted with different strengths and cannot be focused at one point. Since there is no single focus, the image turns out fuzzy and distorted. The progression of keratoconus leads to clouding of the cornea and a significant decrease in visual acuity.

Causes of keratoconus

The exact etiological factor has not been established. There are several reasons, the combination of which can lead to the appearance of keratoconus:

• genetic predisposition;
• corneal injuries;
• endocrine disorders in common diseases;
• presence of allergic diseases;
• exposure to adverse factors environment.

Genetic predisposition to the appearance of keratoconus is based on the presence of genetically determined fermentopathy, which manifests itself under the influence of hormonal levels in adolescence. In this case, metabolic processes in the cornea are disrupted and its elastic properties are disrupted, leading to the formation of a protrusion.

Injuries, as well as constant exposure of the cornea to adverse environmental factors, for example, excessive exposure to ultraviolet rays, lead to an imbalance of enzymes in the cornea. An imbalance of enzymes triggers mechanisms of structural damage to the cornea, its thinning and protrusion. Long-term wearing of incorrectly fitted contact lenses can also trigger the development of keratoconus.

Keratoconus: degrees, forms and types of disease

Keratoconus of the cornea has several classifications that affect the tactics of observation and treatment.

There is a division of keratoconus into degrees, namely:

• Grade 1 is characterized by minimal changes in the cornea, not detected by biomicroscopy, and a slight decrease in visual acuity, which is corrected with glasses or contact lenses. Pachymetry is normal or slightly less than normal;
• 2nd degree - clinically manifested by pronounced astigmatism, but which can still be corrected. There are no biomicroscopic features. With pachymetry, the thickness of the cornea is 400-500 microns;
• 3rd degree - thinning of the cornea is observed, its protrusion occurs, the first biomicroscopic signs appear (Vogt's stretch marks, Kayser-Fleischer ring). Visual acuity sharply decreases, which cannot be corrected with glasses or conventional contact lenses;
• 4th degree - the cornea takes on a conical shape, the apex of the cone is thinned, vision is significantly reduced, clouding of the cornea, local edema of the stroma, and pronounced Vogt lines are determined. The thickness of the cornea is less than 370 microns.

By type, keratoconus is divided into:

• anterior (true) - the most common type. The anterior surface of the cornea undergoes structural changes;
• posterior - the topography of the posterior surface of the cornea is changed;
• latent - appears only after LASIK surgery;
• acute - occurs when Descemet's membrane ruptures and aqueous humor penetrates the layers of the cornea;
• keratoglobus - the protrusion has a spherical shape.

There is also secondary keratoconus, or secondary keratectasia, which appears only after refractive surgery.

Important! Accurate determination of the degree and type of keratoconus plays a major role in choosing a treatment method.

Symptoms and diagnosis of keratoconus

Most often, both eyes are affected. Sometimes changes appear first in one eye and then in the other.

Main clinical manifestations diseases are:

• decreased visual acuity;
• blurred image;
• double vision;
• the appearance of circles near light sources;
• lacrimation.

A decrease in visual acuity occurs due to changes in refraction. The progression of keratoconus leads to a change in the refractive power of the cornea and, consequently, a decrease in vision. Refractive errors are corrected only in the initial stages of the pathological process, and in advanced stages correction is impossible.

A particular condition that requires immediate treatment is acute keratoconus. It is characterized by sudden loss of vision, severe pain, swollen cornea and redness of the eye. If treatment is started late, corneal perforation is possible.

Diagnosis of keratoconus is based on following methods examinations:

• autorefractometry;
• pachymetry;
• computer keratotopography;
• biomicoscopy;
• confocal microscopy of the cornea.

Autorefractometry allows you to determine the average refractive power of the cornea in different meridians. If the difference between the readings in the two meridians is more than 1.4 diopters, then keratoconus can be suspected.

Pachymetry allows you to determine the thickness of the cornea in its different parts. The average thickness is 550 microns.

When keratotopography is made topographic map cornea. It reflects the refractive power of the cornea in all sections. Deviations in measurement parameters make it possible to identify keratoconus at the preclinical stage. As the disease progresses, keratotoporghaphy helps to assess the degree of increase in pathological changes.

Biomicroscopic examination is included in the diagnostic standard when visiting a doctor, but it allows you to determine the presence of only gross changes in the corneal stroma. Considering that the first biomicroscopic signs of keratoconus appear only at stage 3, during a routine medical examination in a clinic the doctor may not notice stages 1 and 2 of the disease.

Microscopy reveals changes at the cellular level and helps evaluate the morphological structure of the cornea. This way it is possible to identify the initial stages of the disease.

Treatment of keratoconus

Treatment of keratoconus is long-term and should be carried out under the mandatory supervision of an ophthalmologist. There are two main directions in treatment: conservative and surgical.

Conservative treatment is possible only in the initial stages of the disease, which includes:

• wearing contact lenses;
• drug treatment.

Contact lenses used for keratoconus can be either regular soft or hard. Soft silicone hydrogel lenses can only be used for stage 1 disease; such lenses, as a rule, do not help with more pronounced changes. In this case, they switch to using hard contact lenses.

Important! Contact lenses for keratoconus are prescribed only by a doctor!

Drug treatment is symptomatic, aimed at improving the biochemical processes in the cornea, but it cannot completely slow down pathological process and restore vision. For treatment, special vitamin preparations or physiotherapeutic treatment are used.

The use of traditional methods of treatment for keratoconus is ineffective, for example, honey eye lotions.

If the development of acute keratoconus is suspected, urgent hospitalization to a hospital is necessary for a complex of therapeutic measures.

The main treatment for keratoconus is surgery. The operation is performed not only on grades 3-4 of the disease, but, in some cases, even on grades 1 or 2. Indications for surgery and the type of surgery are determined in each case individually.

There are several types of operations that differ in the technique of execution:

• crosslinking;
• refractive laser surgeries;
• implantation of intrastromal corneal rings or half-rings;
• keratoplasty.

Before the operation, a full diagnostic examination is carried out to determine the degree of the disease and the severity of changes in the structure of the cornea, and identify the presence of contraindications to a particular type of operation.

Prevention of keratoconus

Prevention of keratoconus is aimed at early detection and treatment of common somatic and allergic diseases, reducing the impact of damaging environmental factors and traumatic factors on the cornea.

People with existing refractive errors need to undergo medical checkup at the doctor's.

Yulia Chernova, ophthalmologist, especially for the site

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Keratoconus is a non-inflammatory disease of the cornea, in which, due to degenerative processes, the cornea becomes thinner and deformed, forming a conical shape. Keratoconus is more common among the male population and mainly begins to manifest itself during puberty. According to statistics, 1 case of the disease occurs in 2000 people, usually among southern peoples.

Keratoconus was first scientifically described in 1748 by the German ophthalmologist Burchard Mauchart. However, a more detailed description of keratoconus was made by the British physician John Nottingham in 1854 and listed the main symptoms: double vision, changes in the shape and strength of the cornea, polyopia, difficulty in choosing glasses. In 1859, British surgeon William Bowman began performing operations on keratoconus to improve vision by tightening the iris through small punctures in the cornea, giving it a slit-like shape like a “cat’s” pupil. Later, the German ophthalmologist Alberta von Graef proposed cauterizing the cornea with a solution of silver nitrate to stabilize its shape, applying after the operation a tight bandage with tissue impregnated with a drug that causes the restoration of corneal cells. For a long time, the only method of trying to slow the progression of keratoconus and somehow improve the vision of patients was the use of a cruel contact lens invented in France in 1888 by the doctor Eugene Kalt.

Etiology and pathogenesis

The reasons for the development of keratoconus have not yet been fully established; there are many theories suggesting the causes and trigger mechanism for its development.

One of the first to emerge was the endocrine theory. The occurrence of keratoconus was associated with dysfunction of the endocrine glands, accompanied by a violation of the pituitary-diencephalic system, hyper- or hypothyroidism, adipose-genial insufficiency, and a decrease in 17-ketosteroids. It is important to note that the peak progression of keratoconus occurs during the puberty period, when the activation of the endocrine glands occurs during the growth of the body.

There is also a viral theory, proposed due to the observed infection with the hepatitis B virus in patients with keratoconus in 80% of cases.

Exchange theory: in studies of patients with keratoconus, a decrease in the activity of glutathione reductase and glucose-6-phosphate dehydrogenase was found in the anterior chamber fluid. Such enzyme disorders provoke an increase in the level of lipid peroxidation, which in turn activates the release of lysosomal hydrolytic enzymes leading to lysis of intracellular structures.

Allergic theory: Occurs against the background of allergic blepharoconjunctivitis, asthma, hay fever, eczema. This suggests a mechanism caused by a disruption of immune homeostasis by an increase in Ig M, C3, C4 complement components. It was found that as keratoconus progresses, there is an increase in the defectiveness of T-suppressors and an increase in IG, leading to a breakdown in autotolerance to corneal antigens. Moreover, in biopsy samples of the conjunctiva of patients with keratoconus, a high infiltration of lymphocytes, monocytes, macrophages, plasma cells, as well as a significant concentration of mast cells was revealed. Such signs are characteristic of immune inflammation.

Mechanical trauma: With permanent damage to the epithelium, which may be caused by prolonged wearing of contact lenses or constant scratching of the eyelids during allergic reactions. Long-term trauma provokes the launch of the following processes: chronic apoptosis of keratocytes - increase in lysosomal enzymes and proteinase inhibitors - destruction of collagen and, as a result, degenerative processes in the corneal epithelium.

The cause of the development of secondary keratoconus can also be: inflammatory diseases corneas, consequences of injuries and burns, postoperative complications leading to ectasia.

However, the most widespread is the hereditary or genetic theory. Keratoconus is often associated with hereditary syndromes and developmental anomalies such as Leber amaurosis, Crouzon syndrome, pigmentary degeneration retina, Down syndrome, Marfan syndrome, granular corneal dystrophy, blue sclera syndrome. It should be emphasized that 68% of patients with keratoconus have one or another connective tissue pathology. Keratoconus also occurs in diseases that are accompanied by mental disorders, such as schizophrenia.

There is an autosomal dominant mode of inheritance of keratoconus and it can occur in members of the same family, transmitted through the male line. In the course of scientific research conducted in the USA, it was possible to determine the gene locus responsible for the occurrence of keratoconus; it is believed that this is the COL6A1 gene with DNA encoding the production of type IV collagen. Research continues.

Mechanism of disease development

Due to the inclusion of keratocyte apoptosis, the structure of collagen fibers is disrupted. The order and arrangement of stromal plates is disrupted, and the density of endothelial cells decreases. This leads to a “discharge” of the stroma and the cornea begins to lose one of its most important functions - sphericity. There is a disorder in the cellular structures of cells, a change in their shape. On early stages Opacities may form in Bowman's membrane.

On late stages separation of the corneal plates occurs when the stroma is stretched - parallel Vogt lines. Subsequently, thinning and scar lines form in the area of ​​the apex of keratoconus. In severe forms of the disease, ruptures and cracks may form in Descemet's membrane. A pathognomonic sign for keratoconus is the Fleischer ring - a subepithelial pigment ring of brown - yellow or green color; its individual arcs can also form around the apex of the cone as a result of hemosiderin deposition. In 7% of cases, various epitheliopathies are observed. In the later stages, Munson's symptom appears - this is a protrusion of the eyelid when looking down and a Y-shaped notch on the conjunctiva of the lower eyelid, caused by stretching of the tissues by the conical cornea.

When Descemet's membrane is damaged, the cornea begins to become saturated with moisture from the anterior chamber, which leads to its hydration and appears as a milky white spot, which increases scarring of the cornea. Patients experience pain and a sharp decrease in vision; transparency can be restored within 6 to 8 weeks.

At the terminal stage, the outcome of keratoconus can be a partial rupture of the cornea. Bullae filled with liquid form on its surface. In such cases, the threat of complete rupture of the cornea and loss of the eye increases, as a result of which a donor cornea transplant is performed on an emergency basis.

Classification of keratoconus

There are several types of classification of keratoconus. The classification of Z. D. Titarenko (1982) includes 5 stages of the disease: At stages I and II, small, subclinical changes in the cornea are noted (areas of “liquefaction”, thickening of nerve fibers); At stage III, visual acuity decreases to 0.1, clouding of the cornea forms at the apex of the cone, and Vogt's lines are formed. Stage IV is characterized by a sharp decrease in visual acuity (up to 0.02), thinning and clouding of the cornea, and the appearance of cracks in Descemet’s membrane. Stage V – severe changes in the cornea with almost total corneal opacification are formed.

The classification of Yu. B. Slonimsky (1993) is mainly intended to identify diagnostic signs, determining the possibility and timing of surgical treatment. Stage I, pre-surgical, is characterized by decreased vision, poorly corrected with spectacle glasses, but successfully corrected with contact lenses. Stage II surgical - accompanied by the presence of epitheliopathy and poor tolerance of contact lenses. Stage III terminal - characterized by rough cicatricial processes with a sharp decrease in visual acuity.

Classification by J. Buxton (1973) according to the degree of increase in corneal curvature: I degree - corneal radius of about 7.5 mm and irregular astigmatism; II degree - radius from 7.5 to 6.5 mm and changes in ophthalmometric parameters; III degree - radius less than 6.5 mm; IV degree - final stage- corneal radius less than 5.6 mm;

The most popular classification is according to M. Amsler, 1961: It is based on the biomicroscopic picture of the cornea and ophthalmometric changes. Stage I - characterized by “discharge” of the stroma, the appearance of corneal nerves, changes in endothelial cells and ophthalmometric changes. Visual acuity at this stage is within 0.1-0.5, corrected with cylindrical glasses, the minimum radius of curvature of the cornea is more than 7.2 mm.

Stage II - visual acuity does not exceed 0.1-0.4 and is also corrected with astigmatic glasses, mild ectasia and thinning of the cornea are possible, the minimum radius of curvature is 7.19-7.1 mm.

Stage III - a noticeable protrusion of the cornea and its thinning are formed. Visual acuity is 0.02-0.12, corrected only with hard contact lenses, which patients often cannot tolerate. The minimum radius of curvature of the cornea is 7.09-7.0 mm, and opacity of Bowman's membrane occurs.

IV (terminal) stage - stromal opacities and changes in Descemet's membrane appear. Ophthalmometry is often impossible. Visual acuity is 0.01-0.02 and cannot be corrected, the minimum radius of curvature is less than 6.9 mm. The formation of a Fleischer ring can be observed at any stage.

The modern classification of keratoconus according to Rabinowitz - McDonell subdivides the stages of the disease according to M. Amsler:

Stages I and II - as a subclinical or refractive stage.

III and IV - as clinical stage. Separately, the following types of classification of keratoconus should be highlighted: Anterior or true keratoconus. Differs in chronic course. Pathological processes occur in Bowman's membrane. It is characterized by the formation of almost transparent ectasia.

Acute keratoconus or hydrops of the cornea. Descemet's membrane is damaged, the barrier function is disrupted and aqueous humor leaks from the anterior chamber into the layers of the cornea, as a result of which the stroma becomes cloudy and swells.

Posterior keratoconus. This is an anomaly that occurs due to defective development of the mesoderm. Thinning forms in the center or forms a saucer-shaped shape. The cornea becomes quite flat and optically weak. This condition is stable.

Symptoms of the disease

The first symptoms of keratoconus progression appear as the appearance of blur, image distortion, polyopia, and decreased visual acuity due to irregular astigmatism. The diopter of glasses and contact lenses often changes, and intolerance to the latter is possible.

As it progresses, blurred vision appears, halos, glare, and increased sensitivity to light appear. When the cornea swells, pain occurs.

As a rule, both eyes are affected, but the development of keratoconus is asymmetrical. Progression may spontaneously stop at any stage, from mild to severe.

Diagnosis of the disease

The main points important in diagnosing keratoconus are:

Anamnesis collection. Presence of keratoconus in the family, history of predisposition. Progression of astigmatism, blurred vision, double vision, etc.

Autorefractometry. A progressive increase in the maximum refractive power with keratoconus in the center of the cornea is more than 47.2 diopters. The difference between the K1 and K2 radii of the cornea is more than 1.4 diopters.

Biomicroscopy. Changes in the cornea during progression and clinical manifestations of keratoconus indicate stretching and ectasia of the cornea, the main symptoms of which are:

Vogt's striae– linear stripes that form in the stroma in front of Descemet's membrane represent visible nerve endings.

Fleshner's ring– accumulation of hemosiderin in the deep layers of the epithelium, emphasizing the base of the cone.

Munson's symptom– protrusion of the eyelid when looking down and a Y-shaped notch on the conjunctiva of the lower eyelid.

Pachymetry. The keratoconus index (KI) is the ratio of the peripheral corneal thickness (PCT) to the thinnest part (TCT) or the difference between the superior (S) and inferior points (I). With initial keratoconus, this difference exceeds 75-100 microns.

Keratotopography. The sign of subclinical keratoconus is a single protrusion in the inferior nasal or inferior central segment (the “droplet” sign), or a protrusion in the form of a “bow tie”. A high refraction is formed in the central zone of the cornea, a difference in the optical power of the center of the cornea in paired eyes, a difference in the refraction of the cornea at opposite points of one meridian. As it progresses, it is characterized by increased curvature, usually located below the center line. This is especially important for early diagnosis keratoconus when other signs have not yet appeared. By comparing several topographic images, it is possible to assess the nature and rate of corneal deformation.

Confocal microscopy of the cornea. Allows you to identify and clarify the degree of morphological disorders in all layers of the cornea at the cellular level in the early stages. Epitheliopathy, initial structural changes in Bowman's membrane, thickening of stromal nerve fibers and an increase in active keratocytes are noted.

Treatment

All methods used are aimed at stabilizing and inhibiting the progression of this pathology.

• Until recently, wearing a rigid contact lens was the only method of reducing the development of keratoconus.
• Implantation of INTACS intrastromal rings. A channel is formed in the stroma of the paraoptic region of the cornea, into which two thin arcs made of polymethyl methacrylate are implanted. As a result, the cornea flattens, taking on a more natural shape.
• Collagen (cross-linking from English - crossed bonds). The epithelial layer is removed from the cornea, a riboflavin solution is instilled, and the cornea is simultaneously irradiated with ultraviolet light. This method enhances the mechanical density of the cornea by strengthening the intercellular connections of collagen fibrils.
• In the terminal stages of keratoconus, a donor cornea transplant is used.

RCHR ( Republican Center healthcare development of the Ministry of Health of the Republic of Kazakhstan)
Version: Clinical protocols Ministry of Health of the Republic of Kazakhstan - 2016

Keratoconus (H18.6)

Ophthalmology

general information

Short description

Approved
Joint Commission on the Quality of Medical Services
Ministry of Health and social development Republic of Kazakhstan
from September 8, 2016
Protocol No. 16

Keratoconus is a progressive, non-inflammatory, bilateral (but usually asymmetric) central corneal dystrophy, characterized by a cone-shaped deformation of its surface.

Correlation of ICD-10 and ICD-9 codes:

Date of development of the protocol: 2016

Protocol users: ophthalmologists.

Level of evidence scale:

A	A high-quality meta-analysis, systematic review of RCTs, or large RCTs with a very low probability (++) of bias, the results of which can be generalized to an appropriate population.
IN	High-quality (++) systematic review of cohort or case-control studies, or high-quality (++) cohort or case-control studies with very low risk of bias, or RCTs with low (+) risk of bias, the results of which can be generalized to an appropriate population .
WITH	Cohort or case-control study or controlled trial without randomization with low risk of bias (+). The results of which can be generalized to the relevant population or RCTs with very low or low risk of bias (++ or +), the results of which cannot be directly generalized to the relevant population.
D	Case series or uncontrolled study or expert opinion.

Classification

Classification: Currently, there is no single generally accepted classification of keratoconus that satisfies all ophthalmologists; therefore, specialists, as a rule, use those that correspond to their specific tasks.

Amsler classification:
· ctadiaI: There are no changes during biomicroscopy. Visual acuity is slightly reduced. Skiascopy is possible despite the oncoming movement of shadows. Keratotopography: noticeable asymmetry. The bend angle of the horizontal axis is 1-4;
· ctadiaII: There are no changes during biomicroscopy. Visual acuity is significantly reduced and is corrected with cylindrical glasses. Skiascopy is difficult. Counter movement of the shadow. Keratotopography: Asymmetry of the central disk and circles. The bend angle of the horizontal axis is 3° or more;
· ctadiaIII: Biomicroscopy: slight thinning without opacities, pigment line. Visual acuity is sharply reduced and is poorly corrected with glasses. Skiascopy is impossible, the shadow moves in a circle. Keratotopography: pronounced asymmetry, the image is shifted temporally and downward, the horizontal axis is not curved;
· ctadiaIV: Biomicroscopy: thinning and clouding in the apex area, pigment line. Visual acuity is low and cannot be corrected with glasses. Skiascopy is not possible. Keratotopography: the image is small, irregular (pointed or blunt type).

Classification by Abugova T.D. (2010)

By stage:
· I - rarefaction of the stroma, changes in the shape of endothelial cells, an abundance of nerve endings;
· II - lines of keratoconus;
· III - opacity of Bowman's membrane;
· IV - stromal opacities.

Type:
· pointed;
· blunt-topped;
· peaked;
· low-top;
· low-top atypical;
· peaked atypical.

By clinical form:
failed keratoconus;
· abortive form;
· classic keratoconus.

Diagnostics (outpatient clinic)

OUTPATIENT DIAGNOSTICS

Diagnostic criteria

Complaints:
· decreased visual acuity;
· visual discomfort;
· sensitivity to light;
appearance of an areola around the light source;
· blurred image;
double vision in one eye;
· distortion of objects.

Anamnesis:
· repeated “unsuccessful” selection of glasses in the anamnesis;
· not equal increase in myopia in two eyes recently;
· the appearance of astigmatism, which was not there before;
· change of cylinder axes in dynamics;
· age 15-20 years.

Physical examination: No.

Laboratory examinations:
· bacteriological culture from the conjunctival cavity with identification of the pathogen and determination of sensitivity to antibiotics (UD - C).

Instrumental studies:
Visometry:
· relatively high visual acuity without spectacle correction with significant refractive errors, the impossibility of selecting full spectacle correction to a visual acuity of 1.0; increased visual acuity when using diaphragms.

Biomicroscopy:
· stromal rarefaction: thickening of the whitish substance in the area of ​​the apex of the cone; under direct focal illumination, it has a grayish marble-speckled appearance;
· abundance of clearly visible nerve endings in the cornea;
· strengthening of the endothelial reflex, changes in the shape of endothelial cells, their elongation and irregular shape (visible at high magnification);
· Fleischer rings: yellowish-brown rings or its individual arcs at the border of the conical deformation zone (deposition of hemosiderin);
· Vogt's lines: further stretching of the corneal stroma and divergence of the corneal lamellae. They often look like vertical, sometimes horizontal or oblique lines, localized in the middle or deep layers of the stroma.

Keratometry:
· Stage I - 44.75 - 45.40 D;
· Stage II - 46.03 - 46.93 D.

Refractometry:
· significant difference in spherical and astigmatic indicators between the right and left eyes;
· the presence of a refractive power of the cornea above 46 diopters;
· reduction of corneal curvature to less than 7.3 diopters and oblique axes of astigmatism.

Tonometry:
· intraocular pressure is within normal limits.

Skiascopy:
· there is a kind of “folding” shadow, reminiscent of opening and closing doors.

Ultrasound examination of the eyeball:
· approximately the same dimensions of the anterior-posterior segment of the eyeball of both eyes with a significant difference in refractive data.

Pachymetry*:
· the presence of a paracentral change in corneal thickness that is smaller or equal in size to the change in the optical center of the cornea.

Endothelial microscopy*:
· in the early stages of the disease does not reveal changes in the density of endothelial cells, polymetalysis and polymorphism.

Corneal confocal microscopy*:
· formation of lacunae and cellular structures in the corneal stroma;
· vertical orientation of keratocyte nuclei;
needle-shaped formations in the posterior stroma;
· increased light reflection effect in the area of ​​Descemet's membrane.

Keratotopography*:
· paracentral increase in corneal curvature in the inferotemporal quadrant, as it progresses, it spreads to the nasal side, capturing the infero-nasal quadrant;
· in advanced stages of keratoconus, the radius of curvature increases rotationally, gradually including the center of the cornea and the superotemporal quadrant up to 12 o’clock;
· peripheral keratoconus is characterized by a “bow tie” appearance, each part of which is called petals;
· with central keratoectasia and keratoconus, the most typical image is in the form of a single projection localized in the center, the so-called “bull's eye”.
* N.B. - carried out in institutions with specialized equipment.

Diagnostic algorithm:

Diagnostics (hospital)

DIAGNOSTICS AT THE INPATIENT LEVEL

Diagnostic criteria at the hospital level:

Complaints:
· lacrimation;
photophobia;
· feeling of a foreign body in the eye;
· decreased vision.

Anamnesis:
· sharp decrease in visual acuity;
· See an ophthalmologist for keratoconus.

Physical examination: No.

Laboratory research: see outpatient level.

Instrumental studies (UD - C):
Visometry:
· Visual acuity is sharply reduced and cannot be corrected with glasses.

Biomicroscopy:
cornea: thinning and clouding at the apex, pigment line;
anterior chamber: depth > 4.5 mm;
· deep-lying environments: in areas accessible to review.

Ultrasound examination of the eyeball:
· assess the condition of the posterior segment.

Electrophysiological examination of the eye:
· estimated visual acuity, functional activity of the retina and conductivity of the optic nerve.

Diagnostic algorithm: see outpatient level.

List of main diagnostic measures(UD - C):
· rinsing the lacrimal ducts;
· visometry (without correction and with correction);
· biomicroscopy;
· ophthalmoscopy;
· Ultrasound of the eyeball;

List of additional diagnostic measures (UD - C):
· EFI of the eye;
· Schirmer's test;
· tonometry.

Differential diagnosis

Differential diagnosis and rationale for additional research:

Diagnosis	Rationale for differential diagnosis	Surveys	Diagnosis exclusion criteria
Keratoconus	Rapid progression, vision not corrected by glasses and lenses, intolerance to old glasses, rapid decrease in vision, increased corneal curvature,	Biomicroscopy Refractometry, Keratometry, Keratotopo- graphy Pachymetry	Keratometry indices up to 45D, corneal thickness > 540 µm, no changes in the curvature of the corneal surface
Astigmatism	Well corrected with cylindrical lenses, slow progression, no significant difference in refraction in both eyes.	Biomicroscopy Refractometry, Keratometry, Skiascopy	Rarefaction of the corneal stroma with turbidity, the presence of a Fleischer pigment ring, Vogt lines on biomicroscopy. Keratometry above 45 D, corneal thickness< 500 мкм, изменение кривизны поверхности роговицы при кератотопографии.
Myopia	Well adjusted spherical lenses, slow progression, no significant difference in refraction in both eyes.	Biomicroscopy Refractometry, Keratometry Skiascopy	Cloudiness of the central zone of the cornea, the presence of a Fleischer pigment ring, Vogt lines on biomicroscopy. The presence of a cylindrical component during refraction, Keratometry above 45 D, corneal thickness< 500 мкм, изменение кривизны поверхности роговицы при кератотопографии.

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The term keratoconus comes from two Greek words: “kerato”, meaning “cornea”, and “konos” - “cone”. Keratoconus is a degenerative eye disease in which the cornea, due to structural changes, thins and takes on a conical shape as opposed to the normal spherical shape. This pathology usually occurs in adolescence, but sometimes also occurs in children and young people under 30 years of age. Changes in the shape of the cornea occur slowly, usually over several years. However, there are also cases of more rapid progression of keratoconus.

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

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

Symptoms

The first signs of keratoconus are often the need to frequently change glasses and blurry vision that is not corrected by them. The classic symptom of this disease is the appearance of many virtual images, known as monocular polyopia. This effect is most noticeable when viewing high-contrast visual images, such as a light dot on a dark background. Instead of seeing a single point, the eye with keratoconus sees a chaotic pattern of many images.

Causes

Despite extensive research, the etiology of keratoconus remains unknown. Presumably, this disease has several causes. These include: genetic predisposition, stress, corneal trauma, cellular factors and environmental influences. All of them can serve as an impetus for the development of keratoconus.

Classification of keratoconus

Based on the amount of corneal curvature, the following types of keratoconus are distinguished:
- mild (less than 45 D)
- medium (from 45 to 52 D)
- developed (from 52 to 62 D)
- severe (more than 62 D)
Morphological classification is based on differences in cone shape:
- 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 shifted downward from the center
- spherical - dimensions exceed 6 mm, more than 75% of the cornea is involved in the pathological process.

The advanced stage of keratoconus can sometimes progress to corneal hydrops, also called “acute keratoconus,” when fluid penetrates into the stroma through breaks in Descemet’s membrane, leading to its edema and, possibly, secondary severe scarring of the cornea.

Diagnosis of keratoconus

With technical improvements in medical equipment used to perform 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 in the early stages, since vision is still slightly affected. One of the early signs that cause concern to the ophthalmologist is the difficulty of achieving maximum visual acuity in the patient, even with ideal spectacle correction.

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

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

Treatment of keratoconus

There are currently no known medications to reverse or prevent the development of keratoconus, but patients may be able to slow the progression of the disease by refraining from rubbing their eyes. In cases where glasses or soft contact lenses are no longer effective, conservative (hard contact lenses) and surgical treatment methods are used, including penetrating and lamellar keratoplasty, implantation of intrastromal corneal rings, epiceratophakia, asymmetric radial keratotomy, corneal collagen crosslinking.

Contact lenses for keratoconus

Refractive error
for keratoconus

Correction of keratoconus
contact lens

In the early stages of keratoconus, distortion of visual images is corrected with the help of glasses that correct the slight myopia and astigmatism that are caused by this disease. At an advanced stage, contact lenses are the first choice for vision correction. In most cases, they are worn continuously. There is no single lens design that is ideal for any type or stage of keratoconus. An individual approach to each patient is required in order to make a carefully considered decision about the use of certain contact lenses to 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 irregular surface of the cornea, takes its shape. At the same time, a space filled with tear fluid is not created between them, which, in turn, does not contribute to increasing the efficiency of the refractive surface of the cornea in comparison with the original one in keratoconus.

Rigid gas permeable contact lenses
Rigid gas permeable contact lenses are the main method of vision correction for 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 models of hard contact lenses.

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

Hybrid lens system
Softperm contact lenses (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 greater comfort compared to rigid gas-permeable lenses, better alignment on the eye and acceptable visual acuity. But these lenses are usually 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 for the treatment not of keratoconus, but of normal-shaped corneas. 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 ultimately led to complications.

Scleral lenses
These are large diameter lenses that rest on the white outer shell the eye, called the sclera, and at the same time completely covers the cornea. Their size may seem intimidating, but wearing them has many benefits. Due to their size, scleral lenses do not fall out of the eye, and dust and dirt particles cannot get under them while being worn. These lenses are very comfortable to wear, since their edges are hidden under the edges of the upper and lower eyelids, which makes them invisible.

Crosslinking

Crosslinking is new method stopping the progression of keratoconus. The full name is “corneal collagen cross-linking with riboflavin (abbreviated as C3R/CCL/CXL).” This is a procedure that increases the stiffness of the cornea, allowing it to resist further deformation.

With keratoconus, the cornea weakens, thins, and its shape becomes more convex, with the development of irregular astigmatism. Cross-linking strengthens the connections between collagen microfibrils in the cornea, as well as 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 of 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 removing 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 the UV-X system. Postoperative care is essentially the same as after excimer laser photorefractive keratotomy and includes wearing a therapeutic contact lens, as well as topical treatment over the next 3 days to increase comfort and accelerate epithelialization.

An increase in the number of connections between collagen fibrils in the cornea gives it stiffness, similar to that observed during natural aging. The biomechanical strength of the human cornea can be increased by 2-3 times. It is believed that this increased rigidity is what slows or stops corneal ectasia.

The crosslinking technique using a riboflavin solution in combination with exposure to long-wave ultraviolet light was developed in Germany in 1993, and the first operation using this technique was performed in 1998. It has been steadily gaining momentum since the results of clinical trials became available, ongoing at several centers around the world, and the FDA recently approved a cross-linking study.

Published data clearly show no progression of keratoconus over a 3- to 5-year period after the procedure. For example, in a Dresden study in 60 eyes after crosslinking, no further development of the process was observed for 5 years, and in more than half of them there was some flattening of the cornea by up to 2.87 D. A slight improvement in visual acuity was also detected: with optimal correction - by 1.4 lines.

Potential candidates for cross-linking are those who have progression of keratoconus or other keratoectasia (transparent marginal corneal degeneration, iatrogenic cases). For surgery, the corneal thickness must be at least 400 microns to provide endothelial protection from potentially toxic ultraviolet radiation (UVA) index 8 after epithelial removal. This parameter is measured before treatment: if the cornea is too thin, then it can be applied hypertonic solution riboflavin to cause sufficient swelling to allow the procedure to be performed safely. 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 is aimed at stopping the progression of this disease. After the procedure, patients will continue to wear glasses or contact lenses, although their prescription may need to be changed. The main goal of cross-linking is to arrest the progression of keratoconus and thereby 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 there is currently no reliable data on its safety and effectiveness. The opinions of ophthalmologists, as well as the available research results on this issue, are contradictory. Those few who perform it speak about the effectiveness of the technique: it combines not only stabilizing properties regarding the progression of keratoconus, but also refractive ones that correct ametropia and help improve visual acuity. Unfortunately, it is impossible to conduct adequate research on various reasons is not possible, therefore it is necessary to consider this technique experimental.

Below are the options for performing keratotomy for keratoconus.

Asymmetrical 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 in the cornea to smooth out or enhance irregularities in 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 asymmetrical “mini” surgical technique was developed. The “Fedorov” radial keratotomy had to be adapted to combat the variability in corneal shape 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 thorough assessment of the indications for it and 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 surgeon's experience plays a very important role when performing this procedure, since it takes many years to learn how to use this method to treat 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 the 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, allows you to maintain stable results even 20 years after the operation. It not only stops the progression of keratoconus, but also improves visual acuity. Incisions made using this method for 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 restoration functions. After surgery, in most cases, the cornea is completely restored, and visual acuity increases. This method is 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. Postoperative treatment has also been developed to provide conditions for better scarring of microincisions, which creates the basis for strengthening the cornea. Since 1983, Dr. Artsybashev has performed more than 1,000 operations for stages I-IV of keratoconus, and more than 30,000 refractive operations 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 keratomy options are not included in any protocol for the treatment of keratoconus and cannot be recommended for use along with the generally accepted ones. The methods require full-fledged research, the results of which can lead to a decision on their introduction into global practice or a complete ban on these interventions in ophthalmology.

Intrastromal corneal rings

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

Currently, two types of intrastromal rings are available: Intacs, which have a hexagonal cross-section and are installed further from the center than the second type - Ferrara Rings, which have a triangular prism. The rings can be implanted deep into the middle of the corneal substance (stroma). The operation is performed quickly and painlessly, on an outpatient basis, using anesthetic drops. In this case, a specially designed vacuum layer-by-layer dissector is used, which creates an arc-shaped pocket for the rings, or, using the latest technology, a femtosecond laser. The exact mechanism of action of the rings is not understood, but it is believed that they exert buoyant pressure directed outward from the curvature of the cornea, flattening the apex of the cone and returning 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.

Intrastromal corneal rings Ferrara 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 the fact that, despite smaller size, there is less chance of glare after installation due to the prismatic shape. Any light beam that hits the ring is reflected in the opposite direction so that it does not enter the field of view. Because Ferrara Rings are smaller and positioned closer to the center of the cornea, they provide a stronger effect and can correct myopia up to −12.0 D, more than can be corrected with Intacs rings. The appearance of glare was noted in some patients with large pupil diameters. In such cases, it is recommended to install Intacs.

As a rule, the results of treatment in most patients are positive, as evidenced by a significant decrease in the degree of astigmatism after surgical intervention, accompanied by an increase in visual acuity as with optimal spectacle correction, and without it. So far, the groups of patients studied for the most part remain small, but favorable outcomes have been achieved within 24-36 months of follow-up. The best results were obtained on eyes with light and medium shape keratoconus.

Perforation of the anterior chamber during surgery, lack of the expected result, infection, aseptic keratitis, postoperative extrusion (pushing out) of the ring are included in the list of 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 approximately 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 subsequently performing layer-by-layer or penetrating keratoplasty.

Corneal transplantation

Corneal transplantation, or keratoplasty, is a surgical procedure to remove damaged corneal tissue and replace it with healthy tissue 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 is severely deformed after treatment with other methods or when it is damaged due to disease, infection or injury.

A corneal transplant involves removing part (layered keratoplasty) or all of the layers (penetrating keratoplasty) of clouded or deformed tissue and replacing it with a graft taken from a deceased donor.

Dr. Edvard Zirm in 1905, in what is now the Czech Republic, was the first in the world to perform a successful corneal transplant into a human, and the transplant remained viable throughout the patient’s future 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 transplantation)
Penetrating keratoplasty (see photo) involves the complete removal of the cornea (all 5 layers) and replacing it 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!).

Usually the sutures are removed after a year. The same amount of time may be needed 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. Graft survival after this operation averages 15 years.

Deep anterior lamellar keratoplasty (DALK)
Such surgical intervention is performed in cases where the endothelium lining the inside of the cornea is healthy, and the stroma is pathologically altered. The operation allows you to remove the affected stroma and preserve healthy underlying tissues deep layers. The pathologically changed 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 inside of the cornea. Since its internal layers do not shift, the risk of rejection is lower, and the prognosis for long-term graft survival is better. However, the patient after deep anterior lamellar keratoplasty faces a longer recovery period, in addition, the same quality of vision is not always achieved as with penetrating keratoplasty.

Risks of 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 transplant patient. Most rejections are suppressed by effective treatment, and the graft survives and continues to function. The key to a successful outcome is timely initiation of treatment. When symptoms of rejection first appear, patients should consult a specialist as a matter of urgency. Symptoms to look out for include:
photophobia, or photophobia (increased sensitivity to bright light);
irritation or pain;
redness;
decreased or blurred vision.
Treatment consists of instillation of steroid eye drops and, sometimes, oral or parenteral administration of drugs of this group.

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

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

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

Keratoconus is a non-inflammatory degenerative disease in which the cornea of ​​the eye thins and takes on a cone shape.

As a result, the patient's vision may deteriorate significantly. Deformation of the cornea in keratoconus occurs under the influence of various biochemical changes. As a rule, patients with this pathology have a decrease in the production of collagen and protein, there is a deficiency of enzymes, and the activity of antioxidants decreases. As a result of this, the cornea of ​​the eye loses its elasticity, stretches and eventually becomes cone-shaped. Keratoconus is one of the rarest dystrophic eye diseases. According to statistics, 1 person out of 1000 faces this pathology. Moreover, this does not depend on his gender or nationality.

As a rule, pathology is detected in patients in childhood, however, the most advanced cases occur in patients aged 20-30 years.

Despite the development of modern medicine, the causes of this pathology have not yet been identified. This is why it is so difficult for doctors to predict the further course of the disease after diagnosis.

If treatment for keratoconus is not carried out or is carried out incorrectly, then over time it will become difficult for the patient to operate various mechanisms or even just read text that is written in a standard printed font. However, the disease very rarely causes blindness, and the condition of patients with keratoconus can be improved with the help of contact lenses.

Despite the fact that corneal keratoconus is still a little-studied condition for doctors, it no longer frightens patients, because at the moment there are various ways its effective treatment.

Causes of keratoconus

The causes of keratoconus are not known to doctors, but today factors have been identified whose presence can trigger the emergence of a pathological process or simply aggravate the course of the disease. These include:

• poor environmental conditions in the patient’s place of residence;
• disruptions in the endocrine sphere;
• injuries to the cornea or eyeball.

In this case, it is also worth mentioning genetics. Keratoconus is often inherited. Moreover, dominant genes are responsible for the development of the disease. This means that even if one parent has completely healthy eyes, and the other has keratoconus, the child is also likely to inherit the disease. Therefore, all children whose relatives suffered from this pathology should undergo a preventive examination from an ophthalmologist from time to time. After all, in the early stages the disease is always easier to treat. When the first symptoms of keratoconus appear, the child may have to comply with some restrictions in sports.

Recently, doctors have noted a sharp increase in the number of cases of keratoconus. On the one hand, this can be explained by improved diagnostic capabilities, and on the other, by the deterioration of the environmental situation.

Keratoconus of the eye is often combined with such pathologies as:

• asthma;
• hay fever;
• Down syndrome;
• chronic failure adrenal cortex;
• eczema;
• inflammation of the conjunctiva of the eye and its cornea.

Danger of disease

Due to the fact that with this pathology the cornea of ​​the eye takes on a cone-shaped shape, it cannot refract light rays in all its areas equally, so the patient experiences a decrease in visual acuity (as well as with myopia). In this case, the patient may see objects in a distorted form, and straight lines broken.

If keratoconus progresses, it will be quite difficult for a person to choose glasses or lenses on their own. Sometimes even regular vision correction with contact lenses for keratoconus can cause some problems (especially if you are intolerant to contact lenses).

With further progression of the pathological process, severe thinning of the cornea occurs, and in some cases it may even rupture. All this is usually accompanied by pain or severe discomfort.

Classification

There are several classifications of keratoconus, however, doctors most often use the Amsler classification.

According to it, there are 4 degrees of keratoconus:

• 1st degree of keratoconus – patients have astigmatism, which can be easily corrected with contact lenses (vision 1-0.5);
• 2nd degree of keratoconus - astigmatism is also present and also treated (vision 0.4-1);
• Grade 3 keratoconus – the cornea of ​​the eye becomes thinner and begins to stretch (vision 0.12-0.02). For treatment at this stage, doctors recommend using a special type of lenses;
• Stage 4 of keratoconus – the cornea of ​​the eye becomes cone-shaped and completely cloudy (vision 0.02-0.01). This stage is very difficult to treat.

Under no circumstances should you carry out treatment at home on your own. This will not bring any benefit, but postponing a visit to the doctor until later can significantly aggravate the situation (in the early stages of keratoconus, surgical intervention can still be avoided, but many patients miss this point). Treatment at home can only be done after consulting a doctor. In this case, only those drugs prescribed by the ophthalmologist are allowed to be used.

Pregnancy with keratoconus

For the first time, doctors presented studies regarding the course of the disease during pregnancy in 2011. Only 4 patients who were planning to give birth with keratoconus took part in the experiment, since this is a fairly rare pathology.

At the end of the experiment, scientists were unable to draw any concrete conclusions, although there were suggestions that pregnancy could aggravate the disease, which is associated with swelling of body tissues as a result of hormonal changes.

The pathology has absolutely no effect on the pregnancy itself. Women with keratoconus should be seen by a gynecologist just like others. In the absence of contraindications, natural childbirth is possible.

Symptoms

Symptoms of keratoconus are:

• gradual deterioration of vision;
• significant eye fatigue;
• itching and burning of mucous membranes;
• tearing eyes;
• characteristic change cornea. Upon examination, it is clear that it is becoming too convex;
• decreased concentration;
• the image that the sick person sees begins to double;
• monocular polyopia – perception of several pictures as one;
• rapid changes in vision that rapidly deteriorates;
• tearfulness, which manifests itself from sunlight;
• corneal clouding;
• distortion of the image that a sick person sees;
• corneal edema;
• decreased performance;
• complete loss of vision;
• a person has to change glasses very often.

Treatment of this disease is most often surgical, but sometimes less radical methods are allowed.

Astigmatism and keratoconus

On initial stage Keratoconus disease manifests itself with symptoms that are characteristic of astigmatism:

• distortion of the picture that a person sees. It becomes blurry and indistinct;
• the appearance of discomfort and a feeling of “cooking” in the eyes, especially in the evening;
• a person cannot concentrate vision on small objects;
• the appearance of a headache, which is most often localized in the superciliary area;
• rapid eye fatigue;
• a person cannot clearly see both distant objects and those that are nearby.

Over time, these symptoms become more pronounced and indicate the development of keratoconus. Also a characteristic sign of this disease is a change in the degree and type of visual impairment in a short period of time, which is not observed with ordinary astigmatism.

Vision in keratoconus

When keratoconus develops, both eyes are most often affected. At the beginning of the disease, problems may affect only one side, but over time they appear on the other. In this case, the degree of visual impairment and eye damage may vary and have varying degrees. A characteristic change in the cornea is clearly visible, but does not appear immediately, which can sometimes complicate the diagnosis of eye disease.

First of all, a patient with keratoconus notices a significant deterioration in vision. At the first stage, a person complains about the blurriness of objects and the blurring of their contours in the dark. As the disease progresses, vision deterioration occurs, which may be accompanied by photophobia. All patients complain that the picture they see resembles the view from a window in rainy weather. They may also experience double vision.

In addition, a person with keratoconus has another visual impairment - monocular polyopia. It manifests itself in the fact that the patient begins to perceive several separate pictures as one image. When examined by an ophthalmologist, this symptom manifests itself as follows. The doctor shows a black sheet with one bright dot on it. In this case, the patient sees several light circles, which are placed in a chaotic order. If you show the same picture to a person after some time, nothing will change. Over time, the image may become even more distorted. For example, in the last stages of the disease, this image may pulsate in time with the rhythm of the heart.

Also, the nature of visual impairment is constantly changing. If a person wears glasses or contact lenses that fit perfectly, after a few weeks they become unusable. Vision deteriorates sharply, and the nature of the disorder in most cases changes. Over time, a person cannot wear soft contact lenses because they do not adhere to the cornea. It takes on a convex shape, which is characteristic of keratoconus. When identifying this symptom It can be said with high probability that this eye disease is progressing.

Other signs of keratoconus

Pain with keratoconus is not uncommon. Due to poor vision, a person begins to strain his eyes, squints, which leads to rapid fatigue. This is manifested by burning and itching. The patient wants to constantly rub his eyes.

This condition is also often accompanied by headaches. Most often they are localized in the superciliary area and can be chronic. Due to the development of these problems, a person’s concentration and performance decrease. When reading for a long time or straining the eyes, significant tearing occurs. This significantly complicates the normal functioning of a person. He often has difficulty doing ordinary things. This is especially dangerous if the patient’s professional activity involves a high concentration of attention, when image distortion can lead to serious consequences.

Another sign of keratoconus is that over the course of several months, and in some cases years, there is a sharp deterioration in vision. But then the progression of the disease stops. The nature of vision changes remains at the same level and may not change for the worse for a long time.

Acute keratoconus - characteristic symptoms

• clouding of the cornea of ​​the eye;
• appearance severe pain in the eye that last a long time;
• the picture that sick people see is very blurred;
• redness of the eyes;
• sudden loss vision;
• swelling of the cornea.

This condition is accompanied by serious changes in the cornea of ​​the eye. With timely treatment, the condition of a sick person returns to normal after a few weeks. In many cases, vision even improves. In severe cases of the disease, the cornea ruptures due to severe swelling. This leads to complete loss of vision, which can only be restored by transplanting this organ.

Symptoms of keratoconus in children

Keratoconus can develop with early age. In children, this disease is characterized by the following symptoms:

• the child may begin to study worse. This is due to the fact that he has difficulty seeing the information that is on the school board or in the textbook;
• you may notice that the patient begins to squint;
• while reading, the child holds the book very close to his eyes;
• parents notice redness of the eyes, which may be accompanied by tearing;
• the child often complains of headaches;
• children with this disease may become capricious and have decreased concentration;
• The child complains of a blurry image.

Parents notice that the glasses prescribed by the doctor do not help. At first, the child sees better and does not complain about the symptoms that bothered him earlier. But after a few weeks everything comes back. The child again complains about a blurry image and cannot read or write normally. The consequence of this condition is a significant decrease in academic performance and rapid fatigue. Without proper treatment Swelling of the cornea may occur, which in many cases leads to complete loss of vision.

Diagnostics

Diagnosis of keratoconus in its early stages remains quite difficult, even despite the successes and achievements of modern medicine in this matter.

The diagnosis is established by an ophthalmologist both on the basis of the patient’s clinical presentation with characteristic complaints, medical history and symptoms, and with the help of additional examination data.

The latter mainly include instrumental methods diagnostics:

• keratometry,
• skiascopy,
• slit lamp examination,
• refractometry,
• diaphanoscopy,
• mapped pachymetry,
• computer topography,
• biomicroscopy, confocal and endothelial microscopy of the cornea,
• optical coherence tomography (OCT).

Already at the appointment, the doctor can assume a diagnosis of keratoconus and assess the condition of the corneal curvature based on a standard examination protocol.

Initially, visual acuity is assessed using special tables. Keratoconus is characterized by a decrease to 0.5 or more, as with low or moderate myopia.

Keratometry - measuring the cornea with the study of possible places of its curvature - also allows you to make a preliminary diagnosis. A special device or a modern computer keratometer measures the curvature of the cornea and compares it with the norm. If keratoconus is of a large degree, then such an analysis is sometimes impossible due to the lack of measuring capabilities of these instruments.

A diagnosis can also be suspected by carrying out skiascopy - a study that uses a light beam, which, when directed at the iris, is reflected from it in the opposite direction to form a luminous strip on the cornea. Two light lines connected at an angle appear, which normally maintain a constant angle of inclination between themselves along the entire perimeter of the iris.

Deformation of the cornea, including keratoconus, causes an optical effect similar to the cutting movements of scissor blades, when light moving in a circle causes fluctuations in the angle between these stripes, which is associated with the uneven convexity of the cornea.

The slit lamp also helps identify keratoconus without additional methods, but only with its sufficient development. The main symptom is the appearance in the superficial epithelial layer of the cornea of ​​a yellow-brown Fleischner ring, consisting of iron salts. It occurs up to 50% and is determined by applying a special blue filter.

Also considered a significant feature are Vogt lines, which are “stretch marks” of the cornea also in its surface layer, easily removable when pressed.

The third sign that can be identified when this study- Munsen's sign - deformation of the edge of the lower eyelid in contact with the protruding cone of the cornea when looking down. The symptom is characteristic of severe stages of the disease.

In the advanced stage of the pathology, a picture of a conically changed surface of the cornea is visible.

Refractometry is additional research, confirming the presence of corneal protrusion by identifying myopia and altered astigmatism. The method is based on determining the refractive power and focusing of a light beam as it passes through the cornea.

Diaphanoscopy is the study of the configuration of the shadow on the iris depending on a particular pathology. In keratoconus, it is presented in the form of a wedge.

Keratopachymetry is valuable because it helps to identify and diagnose keratoconus even before the onset of its symptoms. By analyzing the data obtained computer program determine the radius, the central point of the convex part of the cornea and other important signs of the onset of pathology.

A very interesting technique is carried out using a hand-held keratoscope by projecting concentric circles onto the cornea (Placido's disk). Its curvature at the site of keratoconus becomes more clearly visible due to the deformation of the perimeter and the displacement of the center of the reflected rings.

A similar type of study is called topography of the cornea, when the projection and evaluation of the drawing with the issuance of a topology conclusion is carried out using special computerized equipment.

The maps obtained in this way are especially important precisely at the early stage of the development of the disease, when a detectable increase in curvature at the site of keratoconus is the only sign of the presence of pathology. The same method is used dynamically to assess the rate of development of pathology, as well as to identify posterior keratoconus.

When examining the eye under a microscope (biomicroscopy, confocal microscopy), early changes in cellular structures in the surface layer of the cornea are also revealed. With endothelial microscopy, pathology is observed in its deeper layers.

Optical coherence tomography is used mainly in clinical research.

Thus, keratoconus in the later stages does not create difficulties in making a diagnosis. However, its initial manifestations require not only a set of clinical symptoms, but also complex diagnostic methods to confirm the diagnosis.

Differential diagnosis of keratoconus, especially in the early phase of the disease, is carried out both with progressive myopia, astigmatism, and with keratoglobus, steep cornea, and herpetic lesions in acute keratoconus.

And the sooner the patient seeks medical ophthalmological help, the greater the chance of stopping the pathological process in time. And treatment prescribed on time can preserve vision.

Treatment

Correction of keratoconus can be carried out using therapeutic (conservative) or surgical methods. The choice of treatment regimen depends on the patient’s condition and the degree of visual impairment. This disease is diagnosed by an ophthalmologist.

Keratoconus can be treated in the following ways:

• use of hard contact lenses;
• using corrective glasses, lenses or a combination of these devices;
• strengthening the cornea with the help of specially selected chemical compounds and ultraviolet radiation;
• the use of UV radiation to which the eyes of a sick person are exposed (corneal collagen cross-linking);
• use of segmental ring implants;
• the use of keratoplasty - corneal transplantation from a donor;
• partial keratoplasty – epikeratophakia.

Treatment at the initial stage of the disease can occur at home, but with constant monitoring by a doctor. It is important to regularly conduct eye examinations, which will help determine the effectiveness of therapy and prevent rapid regression. It is impossible to cure keratoconus with folk remedies. Therefore, it is best to use modern techniques that will help eliminate this defect. It should also be taken into account that with keratoconus it is impossible laser correction vision, because the cornea of ​​a sick person is too thin.

How to treat keratoconus at the initial stage?

At the initial stage of keratoconus, when the symptoms of this disease are more reminiscent of astigmatism, the ophthalmologist may prescribe therapeutic treatment. It is aimed at eliminating the main visual defects. Glasses for keratoconus will help a person feel full. Their type is determined depending on the nature of the visual impairment. The selection of glasses for keratoconus is carried out exclusively by an ophthalmologist. Only he can determine the degree of development of the disease.

You also need to be prepared for the fact that after a while you will need other glasses. Vision with keratoconus can rapidly deteriorate. In such cases, they resort to another more effective treatment, which eliminates the problem itself, and not its manifestations.

Keratoconus and lenses

When treating keratoconus in the initial stages, a variety of contact lenses are considered very effective. The decision to use them must be made by an ophthalmologist, who determines the degree of visual impairment and the possibility of developing various complications. The doctor must select lenses that will be as comfortable as possible for the person. It is also important to achieve high visual acuity and get rid of corneal defects.

Depending on the picture of the disease, the following are used:

• soft contact lenses. Rarely used due to the altered shape of the cornea. Can be prescribed exclusively at the initial stage of the disease;
• hard lenses. For keratoconus, they are ideal because they change the irregular shape of the cornea and correct vision. A free space is formed between the hard lens and the surface of the eye, which is filled with tear fluid. This feature significantly increases visual acuity due to the creation of a new refractive surface;
• double layer lenses. They combine two parts - hard and soft. They are used when a person does not tolerate traditional lenses for the treatment of keratoconus. Also, double-layer lenses are used when a sick person is diagnosed with thinning of the cornea or the formation of erosions on its surface;
• hybrid lenses. They have a hard surface with soft edges. They are used when a sick person has complete intolerance to hard lenses. This system is well fixed on the surface of the eye and helps improve visual acuity. Despite this, it can cause swelling and neovascularization of the cornea, conjunctivitis. Therefore, they are used in the presence of strict indications;
• scleral lenses. Keratoconus is often treated with this device, which partially covers the white part of the eyeball, the sclera. In this way, you can securely fix the lenses and correct the shape of the cornea. They are also very comfortable, prevent dust and dirt from getting into your eyes and are almost invisible.

Strengthening the cornea with riboflavin

This method of treating keratoconus is conservative because it does not require surgical intervention. During this procedure, a special drug, riboflavin, is instilled into the eyes. After this, the cornea is exposed to UV radiation for 30 minutes. In this way, it is significantly strengthened, and the development of keratoconus stops. In some cases, when using additional aids visual acuity is restored.

This technique allows you to avoid eye surgery for keratoconus, which is complex and expensive.

Crosslinking for keratoconus

During this procedure, the altered cornea is treated with a special substance. It hardens when exposed to ultraviolet radiation. After crosslinking, the cornea acquires the necessary elasticity, which allows the progression of keratoconus to be stopped.

The advantages of this procedure are:

• obtaining lasting results for at least 7 years. At this time, the disease does not disappear completely, but does not progress either;
• increasing visual acuity. During an examination by an ophthalmologist, the patient sees letters that are placed 1-2 lines lower than during his previous examination;
• the emergence of the opportunity to delay surgery for keratoconus, which involves a corneal transplant.

Application of segmental ring implants

This procedure implies:

• A thin incision is made at the periphery of the cornea using special equipment.
• On both sides of the pupil, two arcs, made of polymethyl methacrylate, are inserted into the formed recess.
• The incision is closed.

The implanted segments put pressure on the cornea, causing it to gradually take on its natural shape. The procedure is performed under local anesthesia. If she didn't show good result, the segments are easily removed without harming the sick person.

Keratoplasty for keratoconus

If more conservative methods Treatments have not yielded results, keratoplasty is used. It involves a cornea transplant from a donor. Also such radical measures are used when numerous scars have formed on the surface of the eye (partly from wearing hard contact lenses).

During this operation, the surgeon uses special instruments to remove upper layer cornea and replaces it with donor material. In this case, a person's blood type does not play a role. The cornea does not have a blood supply, so it can be transplanted from any donor.

The resulting wound on the eye heals within 4-6 weeks. After surgery for keratoconus, vision is fully restored in approximately 1 year or more. Typically, the donor cornea takes root well and is not rejected by the recipient's body.

When treating children, partial keratoplasty (epiceratophakia) can sometimes be used. This procedure is very complex and requires the use of high-precision equipment.

Medicines

There are no medications that can cure a disease of the eyeball such as keratoconus; this disease can be overcome with the help of surgery and a number of procedures. However, some medications can be used to maintain and improve the condition.

Medications for keratoconus

Drops that will help relieve keratoconus:

• Taufon;
• Balarpan;
• Emoxipin;
• Quinax.

Medicines used in gel form:

• Solcoseryl;
• Cornergel.

At his discretion, the ophthalmologist may prescribe the use of another drug that will prevent the progression of the disease and improve the condition of the eye membrane.

Using eye drops and gels for keratoconus

Positive statistics, according to patients using these drugs for diseases of the cornea of ​​the eye, predominate in Taufon, Belarpan and Kornergel drops.

The use of Belarpan for keratoconus is due to the active ingredients of the drug. Data eye drops developed on the basis of sulfated glycosaminoglycans. Before use, you should consult with your doctor who will prescribe the right dosage drops As a rule, Belarpan is used for dryness of the cornea of ​​the eyeball and any damage to it.

The main active ingredient of Kornergel is dexpanthenol. The medicine can be classified as a vitamin group. When using it, it is not recommended to wear contact lenses (including soft ones). The drug will have an anti-inflammatory effect, and Kornergel also stimulates regenerative processes. Eye gel is instilled into the eyes for diseases associated with damage and degeneration of the cornea. The exact dosage should be prescribed by an ophthalmologist.

Ophthalmologists also advise using Solcoseryl gel for keratoconus; its composition is very rich and unique in its own way, because the preparation contains a large number of components of calf blood serum. Thanks to the gel, tissues become more resistant to hypoxia, the supply and accumulation of oxygen and glucose improves, and cellular tissues are activated. metabolic processes and metabolism accelerates.

Folk remedies

Effective treatment of keratoconus with folk remedies

For a disease such as keratoconus, not only surgical and medicinal treatment methods are applicable, but also non-traditional ones (using folk remedies). It is important to remember that before treating keratoconus with folk remedies, you must consult an ophthalmologist and get advice on the use of folk remedies as an additional treatment. Self-administration of such medications without a doctor's approval may worsen the patient's health.

Treatment methods for keratoconus with folk remedies

Herbs, infusions, healing ointments, prepared according to certain recipes, have long been considered effective and beneficial for the body (provided there is no allergic reaction).

When treating keratoconus with folk remedies, teas with the addition of lemon balm, mint or rose hips can have an effective effect; they support immune system, tone the body, calm the nervous system. Folk remedies for keratoconus are used not only to restore the functioning of the eyes, but also to generally strengthen various body systems and prevent diseases. Honey has a good effect on treating keratoconus; it can be consumed orally or prepared as a solution for rinsing and eye lotions.

Medicinal herbs (sage, chamomile, coltsfoot, echinacea) have a beneficial effect on the condition of the eyes in keratoconus (suppress fatigue, eliminate burning and itching). Aloe juice is often used as a remedy; when diluted with water, it can be instilled this remedy into the sore eye. For prevention and general strengthening of the immune system, it is recommended to eat blueberries, carrots, and various beekeeping products.

Do not forget that folk remedies only relieve symptoms and have a beneficial effect for the purpose of prevention in the earliest stages of the occurrence of keratoconus. The result of treating this disease with traditional methods practically does not give any positive effects in later stages. If you use such methods (the use of medicinal herbs, infusions), and the disease progresses and reduces the body’s performance, you must immediately consult an ophthalmologist and continue to rely on traditional methods of treatment.

The information is for reference only and is not a guide to action. Do not self-medicate. At the first symptoms of the disease, consult a doctor.