Corneal diseases are widespread in the ophthalmic sphere and make up 30% of all eye diseases. This can be explained by the fact that the cornea forms the outer chamber of the eye and is more exposed to pathogenic factors. In the conjunctiva, its own microflora is always formed, so even a minimal external effect and trauma to the outer layer of the cornea can trigger the onset of pathology.
Corneal function
The cornea is located immediately behind the conjunctiva and looks like a colorless membrane that provides free penetration of light to the deep parts of the eye. The shape of the cornea resembles a convexly concave lens, the radius of curvature of which reaches 8 millimeters. In men, the curvature is greater by 1.4%. Impaired functioning of this part of the visual organ can be caused by the presence of a disease.
The main functions of the layers of the cornea of the eye:
- Refractive. The cornea is part of the optical system of the eye. Due to its transparency and unusual shape, it helps to conduct and refract the rays of light.
- Protective function. Such a shell is distinguished by its strength, as well as the ability to quickly recover when damaged.
- Support for the general shape of the eye.
Corneal diseases pass against the background of a rapid deterioration in visual acuity, in some cases a person even becomes blind. Since there are no vessels in the cornea, and most of the tissue has a homogeneous structure, diseases can occur when exposed to various pathological processes. Before starting treatment, you should familiarize yourself with the list of diseases of the cornea of the eye.
All eye diseases have similar symptoms, which complicates the work of the doctor during diagnosis. In addition, since the cornea does not contain blood vessels, and in its anatomy it is similar to the conjunctiva, then the inflammatory process very quickly begins in it and just as quickly ends. In the cornea, all metabolic processes proceed in slow motion.
The main types of diseases
List of human eye diseases:
- hereditary problems with the development of the shell;
- inflammatory processes - keratitis;
- keratectasia - anatomical disorders in the size and shape of the cornea;
- the beginning of dystrophic or degenerative processes;
- benign and malignant tumors;
- getting various injuries.
Anomalies resulting from heredity
Hereditary problems in the development of the membrane are changes in the shape and size of the cornea. Megalocornea is a determinate disease of the cornea of the human eye, in which it becomes a huge size, more than 10 mm. Other violations, as a rule, the doctor does not detect during diagnosis. The patient may have a secondary nature of the pathology as a result of glaucoma.
Microcornea - the cornea is too small in size, its diameter does not exceed 5 mm. The disease may be accompanied by a decrease in the size of the eyeball. As a result, complications may occur in the form of clouding of the cornea and glaucoma.
Keratoconus is an inherited disease of the cornea of the eye. With such a lesion, the shape of the cornea changes greatly, it becomes conical. Significantly thinner shell in the center of the eye and his entire camera loses its natural elasticity. The disease begins to appear in children aged 11 to 12 years and leads to astigmatism, which cannot be cured. The patient has to change lenses all the time due to the fact that the axis and shape of astigmatism often change.
In the early stages of development, keratoconus can be corrected through lenses. But with the appearance of pathology, the lens no longer holds on to the enlarged eye and simply falls off. In this case, the doctor may prescribe surgery to remove part of the cornea - through subtotal keratoplasty.
Keratoconus may appear in the patient as a complication after surgery LASIL. In this case, the disease develops for a long time and is poorly detected. It can make itself felt only 20 years after surgery.
The appearance of keratitis
Keratitis is a disease of the cornea of the eye, characterized by its widespread prevalence in patients. The infection enters the membrane through adjacent tissues. The complexity of the development of the disease will directly depend on microorganisms and the resistance of the membrane.
Keratitis can be:
- Endogenous. They appear in a person against the background of an infectious lesion, a systemic disease, an allergic reaction, vitamin deficiency, or leprosy. Often this problem is provoked by neuroparalytic and neurotrophic disorders. These include allergic, infectious, tuberculosis, syphilitic and neuroparalytic keratitis.
- Exogenous. Appear when exposed to environmental factors - infectious lesions, burns, injuries, diseases of the meibomian glands, eyelids and conjunctiva. Infections can be parasitic, viral and bacterial in nature. The following forms of keratitis are included in this group: infectious (bacterial flora of the cornea), traumatic, and also fungal.
The main symptoms of keratitis
Symptoms of corneal inflammation in diseases occur due to irritation of sensitive nerve fibers. It all starts with a slight discomfort. The patient may also experience the following symptoms of corneal disease: intolerance to bright light, severe lacrimation, blepharospasm. With keratitis of a neurotrophic nature, such symptoms are not diagnosed. Also, with keratitis, vessels of the marginal loop due to inflammation of the nerves form a red corolla with a bluish tint along the circumference of the cornea.
Specific signs of corneal inflammation are called corneal syndrome. In addition to the signs described above, the patient has a clouding of the cornea (a thorn appears) and an inflammatory form of infiltrate is formed - a dense accumulation of inflammatory products (leukocytes, lymphocytes and other cells) that penetrate the eye membrane from the vessels of the marginal loop.
The color of the inclusions will directly depend on the composition and number of cells forming it. With a purulent lesion, the color will be yellow, with strong neovascularization - the color is rusty-brown, with an insufficient number of leukocytes - a shade of gray. The border of the infiltrate becomes blurry, and adjacent tissues swell strongly and change to white.
The cornea of the eye ceases to shine, loses transparency, in the place of turbidity it is rough, insensitive and increases in thickness.
After some time, the compaction disintegrates, the epithelium begins to exfoliate, the tissue dies, and ulcers form on the membrane. The patient should conduct timely diagnosis and begin treatment of corneal diseases.
Shell ulcers
An ulcer is a violation of the integrity of the corneal tissue. Education may vary in size and shape. The bottom of the ulcer is painted in a dull gray color (it can be clean or contain pus). The edge of the ulcer is smooth or rough. Education on the shell can take place independently or progress over time.
With self-destruction in the ulcer, the process of detachment of dead tissue begins, the bottom is cleaned of pathogens and eventually covered with a new epithelium, which is constantly updated. After the epithelium is replaced by a connective tissue scar, which forms a clouding of the cornea of different severity. In this condition, the patient may begin the process of vascularization and proliferation of blood vessels in the area of the thorn.
With the progression of formation, the area of necrosis begins to increase in size, both in depth and in width, spreading to new tissues. The defect can spread throughout the cornea and grow deeper into the anterior chamber. When the lesion reaches the Descemetic membrane, a hernia will form. It is a bubble with dark contents, which is separated from adjacent tissues by a separate capsule with a small thickness. Most often, the integrity of the capsule begins to break, and the ulcer becomes passable, affecting the iris, which fuses with the edges of the lesion.
Parenchymal keratitis
It is important to consider the symptoms and causes of corneal diseases. Parenchymal keratitis is a symptom of congenital syphilis. Most often, the disease is transmitted through 2-3 generations. Symptoms of the disease can vary greatly, but doctors have found some common signs of damage: the absence of ulcers, affecting the choroid, the disease spreads to both eyes at once. The prognosis of doctors is favorable - 70% of sick people are completely cured of damage and restore the health of the cornea.
The main stages of the disease:
- The first stage is infiltration. Due to diffuse infiltration, the cornea begins to cloud. Its color changes to grayish white. The patient informs the doctor about severe tearing of the eyes and intolerance to light. Further, the infiltrate begins to actively spread to all shells of the eye. The stage continues to develop in the patient for 1 month, after which it moves to a new stage.
- The second stage of keratitis is vascularization. On the cornea, vessels actively spreading form in the deep layers of the eye. As a result, the shell becomes much thicker and begins to resemble frosted glass. The main signs of the second stage: severe pain, narrowing of the pupil, deterioration in visual acuity. On the back side of the cornea, sebaceous formations are formed - precipitates. They negatively affect the endothelial layer and increase its permeability, as a result of which a strong swelling of the boundary membrane occurs. The progression time of the second stage is 6 months.
- The third stage of the lesion is resorption. Corneal repair processes continue in the same sequence as clouding. Most recently, clouding in the center of the cornea resolves. Recovery continues for a long time, over several years.
Keratitis and the prognosis of doctors
With a favorable development, the disease ends with the resorption of the infiltrate, a thorn forms on the cornea, which can be of different sizes and severity. Vascularization is also a good end to the disease, as it helps nutrients to penetrate the cornea faster and die off ulcers. Belmo can lead to complete or partial loss of vision.
An unfavorable course of the disease is a process in which ulcers actively grow on the cornea, the lesion spreads to the descemet membrane. In this case, pathogenic organisms penetrate into the deep layers of the eye. As a result, this condition leads to secondary glaucoma, endophthalmitis and panophthalmitis.
Dystrophic and degenerative processes
Corneal dystrophy is a congenital disease that is characterized by the rapid development and clouding of most of the lining of the eye.
Such a lesion does not occur against a background of systemic diseases and does not have an inflammatory nature of origin. The main cause of the condition is an autosomal dominant disorder in some genes. To identify the symptoms and causes of corneal disease, the doctor conducts a thorough examination of the patient and prescribes a genetic study of each family member.
The main symptoms of the lesion:
- severe pain and a feeling of having a foreign body in the eye - this condition indicates the onset of erosion;
- strong redness of the eye, intolerance to bright light, profuse lacrimation;
- vision problems, its gradual deterioration, as well as clouding of the cornea and the formation of swelling.
With damage to the erosive surface, the disease is complicated by keratitis. Symptomatic treatment is prescribed. The doctor prescribes special drops that provide good nutrition with the beneficial components of the cornea. But they do not always give the desired result. With a severe deterioration in visual acuity, doctors most often prescribe an end-to-end keratoplasty or corneal transplant.
Fuchs dystrophy is a disease that affects the endothelium of the cornea, but it rarely occurs in humans. In the cornea, such a site is the thinnest and most distant. It is almost not regenerated. When infected, the cells begin to age and cease to function normally. The second name for Fuchs dystrophy is primarily endothelial-epithelial dystrophy, most often it occurs with physiological loss of cells in the elderly. When the lesion begins, the cornea becomes very cloudy, its width increases, and the visual acuity of the patient worsens. Treatment for corneal disease can be one thing - a transplant.
Corneal epithelium
The cause of inflammation in the cornea of the eye can be the epithelialopathy of the outer layer of the membrane. In this case, the patient has a detachment of the epithelium from the lower membrane, resulting in poor adhesion. Most often, this condition is observed after an injury to the eye, a burn, or a dystrophic process. The patient develops severe pain, there is a sensation of the presence of something foreign in the eye, the fear of light and rapid visual impairment are diagnosed.
Diagnostic measures
Diagnosis and treatment of diseases of the cornea is carried out using the following methods:
- eye biomicroscopy ;
- keratotopography;
- confocal microscopy.
Operation
Surgical treatment of a diseased cornea can be carried out using various techniques. The patient's condition and associated symptoms are taken into account. Treatment methods for dystrophy of the cornea of the eye:
1. Corneal crosslinking - surgical intervention, which eliminates keratonus. During the procedure, the doctor cuts off the upper layer of the cornea, then the eyes are irradiated with ultraviolet light and treated with antibacterial drops. Over the next 3 days after the operation, it is important to constantly wear special lenses.
2. Keratectomy - removal of small opacities in the central region of the cornea. Surgery is used, in some cases, laser treatment of the cornea is used. The formed defect after the operation overgrows on its own.
3. Keratoplasty (corneal transplant) is used for:
- problems with transparency of the cornea;
- the presence of astigmatism;
- trauma to the eye, acute keratoconus and keratitis;
- to strengthen corneal tissue and improve eye condition in preparation for optical keratoplasty.
Benign and malignant formations on the cornea of the eye occur very rarely, most often tumors appear on the conjunctiva, sclera or limbus.
Papilloma is a tumor located on the outer edge of the cornea. The surface of the papilloma is tuberous, and its color is pale pink.
The disease progresses slowly, spreads both in height and in width, and can also spread across the entire surface of the cornea, which is extremely dangerous and requires immediate treatment.
Drug treatment
Antibacterial and anti-inflammatory drugs:
- Antibacterial drugs can be used for corneal infections after preliminary studies (Torbeks, Ciprolet).
- Local glucocorticoids are used to suppress inflammation and limit scarring, although inadequate use may support microbial growth (Sofradex, Maxitrol).
- Systemic immunosuppressive drugs are used for some forms of severe peripheral ulceration of the cornea and its thinning associated with systemic damage to the connective tissue (Advagraf, Imuran).
Drugs that accelerate the regeneration of corneal epithelium:
1. Artificial tears ("Taufon", "Artelak") should not contain potentially toxic (for example, benzalkonium) or preservatives that increase the sensitivity of the cornea (for example, thiomersal).
2. Closure of the eyelids is an emergency measure for neuroparalytic and neurotrophic keratopathies, as well as in eyes with persistent defects of the epithelium.
- Temporary bonding of eyelids using Blenderm or Transpore tapes.
- Toxin CI injection. botulinurn in m. levator palpebrae to create temporary ptosis.
- Lateral tarsoraphia or plastic medial angle of the eye.
3. Bandage soft contact lenses improve healing by mechanically protecting the regenerating epithelium of the cornea under conditions of constant trauma for centuries.
4. Transplantation of the amniotic membrane may be appropriate to close a persistent, not susceptible to treatment of an epithelial defect.