Corneal ulcer in dogs and cats. Corneal ulcer in dogs is a serious disease with dangerous consequences.

Corneal ulcer(ulcerative keratitis) - an inflammatory process of the cornea of ​​​​the eye, accompanied by a violation of the integrity of its tissues and the formation of a defect of various sizes and depths. Corneal ulcers are among the most dangerous ophthalmic diseases and are one of the leading causes of significant visual impairment, complete blindness or loss of the eye as an organ.

The appearance of ulcers on the surface of the cornea, entails infection of the organ of vision with pathogens, which further contributes to the aggravation pathological process.

Depending on the depth of the lesion, there are superficial ulcers (with the loss of less than half the thickness of the stroma), deep ulcers (with the loss of more than half of the thickness of the stroma), descemetocele (with the loss of the entire thickness of the stroma up to the Descemet's membrane), penetrating ulcers (with loss of the entire thickness of the cornea).

What causes a corneal ulcer?

By origin, corneal ulcers are usually divided into viral , bacterial (septic), xerotic , neurogenic , traumatic , dystrophic and unknown etiology.

Corneal ulcers are characterized by a pronounced breed predisposition - most often, animals suffer from them. brachycephalic breeds, which is explained by the anatomical and physiological features of the structure of their eye and its auxiliary apparatus (exophthalmos, lagophthalmos, xerosis of the central zone of the cornea, loose organization of collagen fibers of the stroma with large quantity matrix).

Viral ulcers of the cornea- arise as a result of infection with the herpes virus and can occur in the form of a tree-like or landcart-like keratitis, as well as in the form of a generalized process in cats - rhinotracheitis. Tree keratitis occurs when the virus spreads along the nerve fibers. The corneal lesion is usually superficial and is visualized in the form of the thinnest stripes or tree twigs only after staining with vital dyes. Landcard or geographic ulcerative keratitis is characterized by the formation of a defect in the epithelial layer of the cornea, shaped like the outlines of islands or continents on a geographical map.

Bacterial (septic) corneal ulcers- occur when the damaged tissues of the cornea are infected with pyogenic microflora. Collagenolytic enzymes and bacterial toxins play the main role in the destruction of corneal tissues. Under the action of proteases and peptidases, the collagen plates that make up the main frame of the stroma of the cornea of ​​​​the eye are destroyed. Corneonecrosis and keratomalacia lead to a deepening of the defect to the Descemet's membrane and the formation of a descemetocele, followed by corneal perforation. Septic ulcers of the cornea are acute and are characterized by a pronounced corneal syndrome, abundant purulent exudation, hyperemia and edema of the conjunctiva, the presence of a defect on the surface of the cornea, as a rule, round shape and various depths. Bottom and walls ulcer defect loose or slimy consistency, gray or yellowish color. Surrounding corneal tissues are edematous and opaque; pericorneal vessels and perilimbal vascularization are pronounced. In some cases, hypopyon is observed ( purulent exudate in the eye chamber) and reactive iridocyclitis. With the destruction of the stroma of the cornea to the Descemet's membrane, the latter is visualized at the bottom of the ulcer and in the form of a transparent, somewhat swelling film - descemetocele. And although the Descemet's membrane is resistant to the aggressive effects of bacterial proteolytic enzymes, it gradually stretches under the action of intraocular pressure and breaks with the expiration of intraocular fluid. This condition is called a perforated corneal ulcer. If the diameter of the perforated ulcer is insignificant, its opening is temporarily thrombosed with a fibrinous plug. The restoration of IOP due to the production of intraocular moisture leads to its periodic outflow. When extensive corneal ulcers are perforated, the iris, lens, and vitreous can fall into the ulcer. The outcome of perforated corneal ulcers without prompt assistance in most cases is panophthalmitis due to infection of the intraocular structures.

Xerotic corneal ulcers- arise as a result of a violation of the hydration of the cornea with exophthalmos, lagophthalmos and dry eye syndrome. Develop with the introduction of pathogenic microflora into the defect of the cornea. They proceed like septic ulcers of the cornea, but less acutely.

Neurogenic corneal ulcers- occur when branches are damaged trigeminal nerve, in particular the long ciliary nerves. The cause of such damage can be trauma, inflammatory, neoplastic and degenerative processes, as well as pathologies in the area of ​​the trigeminal ganglion and nerve branches. Most often, neurogenic corneal ulcers occur due to traumatic proptosis. eyeball. Such ulcers, as a rule, have a superficial localization, their course is sluggish and prolonged, the sensitivity of the cornea is weak or absent.

Dystrophic ulcer of the cornea- most often recorded in boxer dogs, however, characteristic pathological changes were noted in other breeds - Staffordshire Terriers, french bulldogs, American Bulldogs, Dogue de Bordeaux and some others. In dystrophic corneal ulcers, an epithelial defect of irregular shape is clinically detected, with a violation of the adhesion of the epithelium to the stroma in the region of the edge of the ulcer, which is easily confirmed by the penetration of a fluorescein solution under the exfoliated epithelium. Most often, the ulcer is localized in the lateral sector of the cornea in the paralimbal zone, somewhat less often - in the paralimbal zone of the medial sector of the cornea. It is extremely rare in other departments. If the ulcer is localized in the right sector of the cornea, it is necessary to carefully examine inner surface third century to exclude the presence of a foreign body. The course of the pathological process in dystrophic ulcers is quite specific. In the affected areas of the cornea, two edges are determined: regressing (regenerating) - located closer to the limbus and characterized by active regeneration with the formation of coarse vascularized tissue; and progressive (active), where the process of detachment of the epithelium occurs. The progressive edge gradually shifts to the central parts of the cornea, constantly changing its localization. Such ulcers are prone to repeated recurrence on both the affected and healthy eye.

What are the symptoms of a corneal ulcer?

Symptoms associated with a corneal ulcer can vary greatly, from minimal discomfort to significant pain and visible changes on the cornea, which is determined by the etiology of the disease and the degree of development of the pathological process. The main signs that should alert the owner of a pet are:

• intense lacrimation;
• complete or partial or closing of the eye (blepharospasm);
• photophobia;
• the appearance of foci of turbidity;
• redness of the conjunctiva;
• purulent or serous discharge from the eyes;
• the appearance of tuberosity on the surface of the cornea;
• neovascularization (ingrowth of blood vessels);
• the appearance of scars;
• miosis (narrowing of the pupil);
• the appearance of one or more rounded or linear defects;
• decrease in intraocular pressure.

How is corneal ulcer diagnosed in dogs and cats?

Symptoms that characterize the appearance of a corneal ulcer are clearly visualized even at the initial stage of the development of the disease, however, put accurate diagnosis only a highly specialized veterinarian can.

Diagnostic measures include a detailed examination of the edges of the eyelid and the conjunctival sac; determination of the defect depth; assessment of the state of the anterior chamber of the eye through biomicroscopy; staining with vital dyes to visualize violations of the integrity of the cornea; laboratory research etc.

How is a corneal ulcer treated?

Most often, the affected animal is hospitalized for inpatient observation in a veterinary institution.

Treatment of corneal ulcers viral origin - complex, including the use of root protectors, immunostimulants, antiseptics or antibiotics (to suppress the development of secondary microflora).

At septic ulcers - the treatment in most cases is surgical, consisting in the transplantation of tissues of an artificial or donor cornea. Medical treatment includes systemic and local antibiotic therapy, as well as the use of immunostimulants and root protectors.

At xerotic ulcers - therapy is carried out similar to the treatment of septic ulcers.

The main goal of therapy for neurogenic ulcers - is to prevent infection of the wound defect with pathogenic microflora and ensure constant hydration of the cornea. For this purpose, antibiotics, antiseptics, drip or gel forms of root protectors are used. Epithelialization of the ulcer in such cases takes an average of two to eight weeks.

Corneal defect and ocular vascular injection in a dog

Under the corneal ulcer is meant an unlimited process that extends to the layers of the cornea, accompanied by a loss of substance with prolonged purulent decay of cells. In most cases, this process is irreversible. Corneal ulcers in dogs show a complete absence of epithelium, exposing the underlying stroma. Corneal diseases occupy the first place among eye diseases.

The causes of ulcerative keratitis can be either primary - trauma, exposure to chemical and physical agents, or secondary - due to a violation of the barrier function of the precorneal tear film, corneal innervation, systemic diseases internal organs. Clinical picture different forms ulcerative keratitis is characterized by polymorphism.

Causes of corneal ulcers - what causes damage to the eye?

The cornea is made up of five layers:

1. pericorneal tear film;
2. epithelium and its basement membrane;
3. stroma;
4. Descemet's membrane;
5. endothelium.

Endothelial cells remove fluid from the stroma into the aqueous humor. Intraocular pressure (IOP) promotes the flow of fluid into the cornea. When IOP rises, more fluid enters the cornea than is removed, leading to corneal edema. The epithelium also removes fluid. If the epithelium is damaged, fluid enters the cornea, leading to corneal edema.

Ulcers are caused by structural disturbance, foreign bodies, trauma, chemicals, failure to close the eyelids completely, and corneal diseases such as keratoconjunctivitis sicca.

Some types of hair can irritate the cornea and cause ulceration. If this cause is not removed, the cornea will not heal. It should be known that not all animals with distichiasis should have abnormally growing hair removed. Most Cocker Spaniels have rows of these hairs, but they don't cause problems.

Staining of the ulcerated area of ​​the eye

Trichiasis is the friction of the cornea with normally growing hair, which is caused by a violation of the structure of the eyelids. Examples of such situations leading to trichiasis are prominent nasal folds and entropion. Most cases of trichiasis can be successfully treated with surgery.

Other causes of persistent irritation:

• foreign bodies in the eyes can be deposited under the third eyelid and cause deep corneal ulcers;
• decrease in total tear production;
• inversion of the eyelid into the eye, in which the epithelium is regularly injured by eyelashes and bacteria enter the wounds, which causes ulceration of the cornea;
• neurological disorders.
• chemical burn of the cornea when the dog comes into contact with household chemicals.

Violation of the integrity and nutrition of the cornea, necrosis of areas of the cornea, lack of innervation ultimately lead to disruption of metabolic and microcirculatory processes in the cornea, reduce the resistance of the cornea to microorganisms. It should also be noted that a complex of factors that affect the physiological barriers of the eye that perform a protective antimicrobial function can lead to the appearance of an ulcer: meibomitis, blepharitis various etiologies, exophthalmos, lagophthalmos.

Signs and diagnosis of the disease

The course of an ulcer is usually acute or chronic and depends on the origin and stage of development. At clinical examination, an ulcerative crater is observed on the cornea, around which diffuse opacification appears. Associated features are lacrimation, soreness, photophobia, blepharospasm. The ulcer itself can be of various shapes, outlines and depths.

Symptoms:

• pain and blepharospasm (often acute);
• photophobia;
• epiphora;
• corneal edema;
• the presence of a gaping wound of the cornea;
• infringement in the wound of partially fallen out internal membranes and environments;
• the presence of a wound channel in the projection of the corneal wound;
• the presence of a foreign body or air bubble in the anterior chamber;
• vascularization or pigmentation of the cornea (in chronic cases).

Purulent corneal ulcer is accompanied by severe pain, photophobia, blepharospasm, copious excretion from the conjunctival sac of mucopurulent exudate. Expressed conjunctival and pericorneal injections, corneal vascularization. A defect of various shapes is found on the cornea, the edges of which are uneven, necrotic, undermined, edematous along the periphery of the corneal tissue, white-gray in color.

A creeping ulcer is characterized by the fact that diplococci or pneumococci that have got into the cornea during injuries live and multiply in it. The disease begins acutely, severe pain, lacrimation, photophobia, hyperemia and swelling of the conjunctiva appear. A grayish-yellow infiltrate develops on the cornea, which quickly spreads and turns into an ulcer. The ulcer has undermined edges, the bottom is covered with a dirty yellowish coating. With a creeping ulcer, iritis often occurs, as a result of which the fluid becomes cloudy or exudate accumulates in the anterior chamber.

AT severe cases a perforated ulcer occurs. The outcome of corneal ulcers - scars of varying intensity: leukoma, nubecula and macula.

In an animal with corneal ulcers, pain is always observed due to the development of epiphora, blepharospasm and conjunctival hyperemia. Diagnosis of corneal ulcers is very simple and is based on the inability of fluorescin to pass through the hydrophobic epithelium while being well absorbed by the hydrophilic stroma. After staining the ulcerated cornea with fluorescein and illuminating it through a cobalt blue filter, the ulcers are visible as green areas. Ulcers can extend through the entire thickness of the stroma to the Descemet's membrane, forming a descemetocele. When stained with fluorescein, a descemetocele appears as a green ring in the stroma with a clear center of Descemet's membrane that does not absorb fluorescein.

neuropathy ( seizures, paralysis facial nerve) led to a long-term disruption of the blinking process and the distribution of tears over the surface of the cornea, which inevitably led to malnutrition, respiration and dryness of the cornea, which led to the formation of ulcers and their seeding with pathogenic microflora. Clinical symptoms correlated depending on the severity of the pathological process in the cornea. The initial formation of an ulcerative defect was noted in the upper part of the cornea due to dysfunction upper eyelid. There was a pronounced corneal edema, blepharospasm, photophobia, superficial corneal vascularization, serous-mucous and purulent outflows from the eye, perforated corneal ulcer with iris prolapse, lagophthalmos.

Methods for the treatment of peptic ulcer of the eye

Many tissues in the body heal on their own – dogs often recover from corneal ulcers without further assistance. If only the epithelium is damaged, the epithelial cells surrounding the edges of the lesion grow to close the lesion. The entire cornea can recover in 4-7 days. With deep damage, another mechanism is noted:

• surface defects are filled with epithelial cells.
• deep defects are covered by epithelium, but further avascularization or vascular healing then occurs in the stroma.
• during avascular healing, neutrophils from the tear film or from the limbal conjunctival vessels migrate to the defect. Keratocytes in the focus transform into fibroblasts and synthesize collagen and mucopolysaccharides, which fill the defect. Collagen fibers are laid irregularly, which leads to the formation of an opaque scar. The density of the scar decreases with time, but the scar itself does not disappear.
• vascular healing: vessels grow from the limbus into the lesion, allowing inflammatory cells and melanocytes to enter the lesion. Formed granulation tissue and a denser scar is formed than with avascular healing. The vessels will eventually thin out and be difficult to see. However, they can be seen with a slit lamp.

But in most cases, veterinary care is required for the pet. The cause is determined and specific therapy is used to correct the underlying cause (eg, eyelid torsion is corrected or foreign bodies are removed). Combined treatment. If an ulcer occurs on the basis of a non-contagious etiology, the cornea is disinfected with a 1% solution of hydrogen peroxide, a solution of ethacridine lactate (1:500), the bottom of the ulcer is quenched daily with a 5% solution of iodine, followed by instillation of drops into the eyeball (Sofradex, 10 % sodium sulfacyl).

Initially, with aseptic processes, hydrocortisone is used in drops or ointment. In the future, with preventive and therapeutic purpose, especially when infected, drops and ointments of antibiotics (penicillin, tetracycline, chloramphenicol), sulfonamides (albucid), etc. are prescribed. When pus accumulates, the conjunctival sac is washed with solutions of boric acid, ethacridine, lactate, furacilin, furalgin, penicillin. For resorption of cloudiness with cessation acute inflammation apply yellow mercury ointment, calomel with sugar in the smallest powder, dionin in drops and ointments, in increasing concentrations (0.5-5%), tissue therapy, novocaine blockade.

The scheme of treatment of corneal ulcers

Treatment regimen No. 2:

• antiherpetic eye ointments Virolex or Zovirax (acyclovir) are placed in the conjunctival sac 3 times a day for 14 days;
• antiviral, immunomodulatory drops Aktipol, Poludan or Derinat 0.25% solution are applied 1 drop 3 times a day for 14-21 days;
• antibacterial drops Floksal or Tobrex - 1 drop 3-4 times a day for 7-14 days;
• non-steroidal anti-inflammatory drugs Indocollir, Naklof or Diklof - 1 drop 2 times a day for 5 days;
• mydriatics and cycloplegics (atropine sulfate 1% solution or Cyclomed eye drops) should be used for the first 3 days, 1 drop 2 times a day;
• if dry keratoconjunctivitis was observed, then the hydrating tear substitute Vidisik was used 1 drop 4-5 times a day;
• subcutaneous injections of Cycloferon are also made at 0.1 ml / kg of animal weight according to the scheme: 1, 2, 4, 6, 8, 11, 14, 17, 20, 23 days;
• systemically used vitamin preparations inside: Neuromultivit 0.5-1 tablet 1 time per day for 20 days and Aevit 1 capsule 1 time in 2-4 days 5 doses.

Should be used topical antibiotics either prophylactically or based on culture results if an eye infection is present. For superficial and deep purulent keratitis and ulcers of the cornea intramuscularly use antibiotics a wide range actions:

• kanamycin;
• monomycin;
• gentamicin.

The use of an antibacterial ointment or solution is indicated local action every 6 hours as the cornea lacks a normal blood supply and is susceptible to infection. The best choice for the original destination are actions. Locally prescribed 1% eye ointments with erythromycin, dibiomycin, ditetracycline, oletethrin, eye films with neomycin or kanamycin. At severe course keratitis, antibiotics are administered subconjunctivally at 10-25 thousand units). Tobramycin, amikacin, and fluoroquinolones are also used to treat infected corneal ulcers, but are not indicated for uncomplicated ulcers.

Atropine can be used as an iridocycloplegic.

Measures are taken to prevent progression of the disease (eg, use of protease inhibitors or removal of all loose epithelial tissue, especially in the case of slow-healing ulcers). Local glucocorticoids are contraindicated in active corneal ulcers, because they increase the activity of collagenase by 14 times and inhibit the regeneration of the epithelium, endothelium, fibroblast activity and infiltration inflammatory cells. Topical glucocorticoids may help resolve vascularization and scarring, but should only be used after corneal healing has been completed. Systemic glucocorticoids are indicated if there is concomitant uveitis.

Purulent corneal ulcer in dogs

May be required surgical intervention to preserve corneal integration and create optimal healing conditions (eg, corneal repair with third eyelid flap, conjunctival flap, corneal transplant, corneal suture). The third eyelid flap should only be used for superficial, uninfected ulcers. It minimizes contact local funds with the surface of the cornea and prevents visualization of any progression of the lesion. It is never used for deep ulcers or descemetocele as it puts pressure on the eyeball and hastens corneal rupture.

Deep or creeping corneal ulcers, as well as descemetocele, are cases requiring immediate surgical intervention and transplants of the conjunctiva or cornea. With a creeping ulcer of the cornea, diathermocoagulation of the edges of the ulcer is performed. Then apply a 1% solution of atropine, a 0.25% solution of chloramphenicol, with sodium sulfapyridazine, eye ointments.

If a large area of ​​the cornea is affected, then a flap from the third eyelid or temporal tarsorrhaphy is used to close it. Of these two procedures, tarsorrhaphy is preferred because in the medial part, corneal lesions will remain visible to regular examination. Moreover, in partial tarsorrhaphy, direct application of medications is possible, and a flap from the third eyelid may make it difficult for drugs to reach the cornea.

For persistent corneal ulcers, a cribriform keratotomy is performed. The first step is to remove all the exfoliated epithelium with a cotton swab (the owner should be warned that the ulcer will be much larger than it appears on the surface). Then, with a needle, a lattice is created. Keratotomy starts with a healthy cornea, then progresses to an ulcer, and ends again on a normal cornea. To avoid perforation of the cornea, the author recommends holding the needle almost parallel to the surface of the cornea, placing the hand on the head of the animal. At the same time, the keratotomy must be of an appropriate depth, so the lattice must be visible after the operation. After the operation, contact lenses are put on to increase adhesion between the epithelium and the stroma. Sanitation and keratotomy painful procedures therefore, topical atropine is used for pain relief every 12-24 hours for 2-3 days and oral aspirin is given for several days. Topical antibiotics are also indicated, as with any ulcers.

Washing eyes with peptic ulcer

In calm animals, keratotomy can also be performed in the emergency room. To calm nervous animals sedatives. After sedation and contact lens placement, temporal tarsorrhaphy is performed to increase contact lens retention. If it is not possible to purchase contact lenses, then a flap is created from the third eyelid. According to the author, non-healing ulcers are a direct indication for the creation of a flap from the third eyelid. The owner should be warned about the length of the recovery period, as well as possible relapses.

The animal is put on a protective elizabethan collar” if it tries to rub the eye. After scarring of the corneal ulcer, it is necessary to use absorbable preparations (fibs, aloe, etc. - intramuscularly), and locally - drops of "oftan-catahrom", vitamin and their analogues. good effect provides local laser therapy.

Elizabethan collar on a dog to prevent secondary injury

Along with the conventional drug treatment, animals can receive physiotherapy with a low-frequency pulsating magnetic field of 10 mT at a frequency of 50 Hz using the Magniter AMT-02 apparatus according to a stable method, with a gap from the eye surface of 1-2 cm. The course of treatment with low-frequency magnetotherapy is 10 minutes daily . Depending on the observed objective improvement, sick dogs receive a course of 1 to 10 sessions. At the end of treatment, there is a decrease or complete disappearance of photophobia and blepharospasm. Objective symptomatology was expressed in a decrease in edema, both in the endothelium and epithelium, the roughness of the cornea is smoothed out. Magnetotherapy can improve the recovery of the cornea in case of peptic ulcer and trauma.

Chronic or non-healing corneal ulcers common among dogs and cats and is a serious problem for both pet owners and veterinary ophthalmologists.

In dogs given type corneal ulcers also called " boxers ulcer».

Chronic non-healing corneal ulcer occurs due to the fact that the connection of the upper epithelial layer of the cornea with the lower layer, the stroma, is disrupted.

Clinical features of chronic corneal ulcers in dogs and cats

Such corneal ulcers in dogs usually superficial and not very painful, although in area they can occupy almost the entire surface of the cornea. The edges of the ulcer are torn and uneven. When stained with a special dye fluorescein, fluorescein penetrates along the edge of the ulcer under the corneal epithelium. The epithelium is easily removed from the surface of the ulcer with a cotton swab.

Part chronic non-healing ulcers cornea are "creeping". Such ulcers move along the surface of the cornea due to the fact that one edge of the ulcer epithelizes (heals), while the other one progresses.

Ophthalmology for dogs: photo 1.
Boxer with a chronic non-healing corneal ulcer in his right eye and
with corneal scarring and pigmentary keratitis after a corneal ulcer in the left eye

Ophthalmology for dogs: photo 2. The right eye of the same boxer-
chronic non-healing ulcer stained with fluorescein

Ophthalmology for dogs: photo 3.
The left eye of the same boxer - scars on the cornea after
chronic non-healing ulcer, pigmentary keratitis

Ophthalmology for cats: photo 1.
Chronic non-healing corneal ulcer stained with fluorescein
in a cat with rhinotracheitis

What breeds of dogs and cats have chronic corneal ulcers?

Veterinary ophthalmologists register chronic non-healing corneal ulcers in dogs different breeds. Most common in Boxers, Pit Bull Terriers, American Staffordshire Terriers, French Bulldogs, and occasionally in Poodles and other breeds.

In cats chronic corneal ulcers occur in all breeds, most commonly in British shorthair cats.

How do veterinary ophthalmologists treat chronic corneal ulcers?

Professional Veterinary ophthalmologists offer two main lines of treatment for chronic non-healing corneal ulcers in dogs.

This is a long-term therapeutic treatment combined with several types of mechanical treatment of the ulcer surface and a radical surgical method of treatment - superficial keratectomy with tarsorrhaphy.

Despite the fact that superficial keratectomy is a microsurgical operation, it is the therapeutic management of patients with non-healing corneal ulcers that is the most complex and jewelery business, which not everyone knows. Moscow veterinary ophthalmologists.

Chronic non-healing corneal ulcer in dogs is therapeutically treated for a long time, 2-3, and sometimes 4 months. But in this case, the animal does not undergo surgery and general anesthesia.

Cats with chronic non-healing corneal ulcers often occur against the background of infection. Usually it is a herpes virus infection. Veterinary ophthalmologists also perform surgical or therapeutic treatment of chronic non-healing corneal ulcers in cats. If the ulcer occurs against the background of an infection, an antiviral or antibacterial systemic treatment depending on the pathogen.

Corneal ulcer - features of cats

In cats, there is one feature - a complication of any damage to the cornea, including chronic non-healing corneal ulcers, is corneal sequestration, so the tactics of treating chronic non-healing corneal ulcers have their own characteristics.

If your pet has discharge from the eyes different nature, if the color of the eye changes, if the eye squints - contact a specialist immediately - veterinarian ophthalmologist. These signs may indicate the occurrence of an ulcerative process of the cornea.

"Konni" is a veterinary clinic with home visits of veterinarians. Remember, help is near!

Corneal ulcer or ulcerative keratitis This is an inflammation of the cornea of ​​​​the eye, accompanied by necrosis (death) with the formation of a defect in its tissues. At the same time, the eye of the animal becomes "cloudy", an infection develops, and the visual functions of the eye decrease.

This pathology is one of the most common eye diseases in dogs and cats. The most common among dogs of brachiocephalic breeds:

• pug;
• Pekingese;
• bulldogs;
• boxers, etc.

Among cats, it is most common in the Persian breed.

The reasons

Causes corneal ulcers are quite numerous. Among them - (as a consequence), corneal trauma (penetrating trauma, corneal burn), corneal sequestration of cats, dry keratoconjunctivitis, viral, eyelid volvulus, trichiasis and districhaasis, etc.

Symptoms

Clinical signs ulcerative keratitis in dogs and cats are quite characteristic. Edema and clouding of the cornea develops, vascularization appears in the thickness of the cornea (vascularization), purulent discharge from the eye, the animal squints and scratches the eyes, with a strong infectious process and a running course, the general condition of the animal may worsen (loss of appetite, lethargy, severe pain in the area of ​​the affected eye).

Diagnostics

Diagnosis placed on the basis visual inspection veterinary ophthalmologist, ophthalmoscopy and examination of the anterior segment of the eye with a slit lamp. To identify the boundaries and depth of corneal defects, it is stained with a 1% fluorescein solution. In complicated cases, bacteriological cultures are made from the surface and edges of the ulcer, and laboratory tests are carried out.

With a long course of this pathology, a purulent, perforated corneal ulcer, penetration of infection into the eye, panophthalmitis can develop, which can lead to removal (enucleation) of the eye.

Treatment

Treatment corneal ulcers is primarily aimed at suppressing the infection and eliminating the root cause of keratitis (for example, blepharoplasty for eyelid torsion or general antiviral therapy for viral conjunctivitis cats). Antibiotics, anti-inflammatory, immunostimulating drugs are used. Frequent ophthalmic instillations are combined with oral medications and injections. As a rule, the animal must wear a protective collar to prevent scratching of the diseased eye. It is necessary to sanitize the conjunctival sac with antiseptic solutions.

In severe and advanced cases, surgical treatment of a corneal ulcer is performed, with keratoplasty and evacuation of purulent contents and necrotic tissues.

After the ulcer has healed, a scar or thorn is formed. white color on the cornea.

Prevention development of this pathology is reduced to timely handling to a veterinary ophthalmologist.

Erosion and ulceration of the cornea are very common eye pathologies in animals. The clinical signs of these pathologies are similar: in animals, lacrimation, blepharospasm, conjunctival hyperemia, and corneal edema are observed. However, treatment tactics and prognosis regarding the condition of the eye and vision can vary greatly depending on the diagnosis and associated conditions.

Anatomy

Pathologies

For diagnosis, examination with a slit lamp is used - a surface defect is visualized, diverse in shape and size, as well as a fluorescein test - a fluorescein solution is dripped into the conjunctival sac: a place on the cornea, devoid of epithelium, absorbs the dye and has a bright green color. Previously, according to indications, a Schirmer test is performed to determine the amount of lacrimal fluid and taking material from the conjunctival sac for research on infections (cats).
After corneal erosion is detected, a thorough examination of the edges of the eyelids and the conjunctival sac is carried out to exclude possible causes erosions: ectopic eyelashes, aggressively growing hard distichia eyelashes, neoplasms of the eyelids, foreign bodies in the conjunctival sac.

When the cause is detected and eliminated, the erosion is closed by the epithelium after a few days (48-72 hours). Apart from specific treatment aimed at eliminating the cause, apply antimicrobial drops and moisturizers (gels) to the conjunctival sac for 5-7 days.

Separately, it is worth considering chronic non-healing corneal erosion in dogs (boxer ulcer, indolent erosion, spontaneous chronic epithelial defect). Boxer dogs, dachshunds, bulldogs and many other breeds are susceptible, most often dogs older than 5-6 years. This type of corneal erosion is characterized by the fact that the defect does not heal for weeks or even months despite the absence of apparent causes and the use of drugs. The reason for this condition is a violation of the contact of epithelial cells with the underlying basement membrane, which leads to the fact that the normally regenerating epithelium is not fixed on the membrane and sloughs off, as a result, erosion cannot close. Chronic erosion has characteristic appearance when viewed with a slit lamp: the edge of the defect is usually uneven and elevated above the stroma; staining with fluorescein shows leakage of the dye under loosely adjacent edges of the epithelium, the staining area is larger than the area of ​​the cornea devoid of epithelium.
Therapeutic methods treatment for chronic erosion are not effective because they do not solve the problem of epithelial cell attachment. There are several treatments for chronic erosion:
1) removal of loose epithelium cotton swab(the defect that is exposed after this is usually larger in area than the original one) followed by the use of antimicrobial drops and gels. This procedure passes using local anesthesia– eye drops, takes 3-5 minutes. The effectiveness of this procedure is low: repeated treatments are required at least 2-3 times, healing proceeds slowly, often with the formation of a rough scar.
2) Pinpoint/lattice keratotomy - a method in which point or line notches are applied to the surface of the cornea with an insulin needle, forming depressions in the superficial stroma. This procedure can be performed using local anesthesia only in very calm animals (most animals require sedation), the procedure is often combined with covering the eye with a third eyelid apron, which promotes better healing. The efficiency of keratotomy is 60-80%.
3) Treatment of the pathological area with a diamond bur. Diamond pine forest – special device for scarification of the cornea, allowing to remove loose epithelium and create a surface for good engraftment of the new epithelium. The advantage of this technique is the ability to carry out the procedure without the use of general anesthesia, only using local anesthetic. Sometimes it is required to repeat the procedure after 7-14 days, a rough scar may form during the healing of the defect.
4) An effective method for solving the problem is superficial keratectomy - surgery, in which the surface layer of the cornea is removed, including a portion of the basement membrane and surface part stroma; the formed defect heals due to the complete regeneration of the surface layer, and not only due to the epithelium.
The procedure is performed using general anesthesia, after keratectomy, the eye is protected with a temporary third eyelid apron or partially sutured the edges of the upper and lower eyelids. AT postoperative period use antimicrobial drops in the conjunctival sac, wearing is recommended protective collar. After 14 days, temporary sutures are removed from the eyelids, by this time the defect is completely epithelialized. The effectiveness of this procedure is 100%, the defect heals with a moderate formation of corneal fibrosis, which is almost invisible after 3-6 months.
It is important to understand that since this type of erosion is caused by an abnormal contact between the cells and the basement membrane, there is a risk of chronic erosion in areas adjacent to the surgically treated or in the other eye.
A corneal ulcer is a defect in the cornea involving the stroma. The depth of the ulcer can be different: ulcers with a loss of less than ½ of the thickness of the stroma can be considered shallow, with a loss of more than ½ of the thickness - deep, an ulcer with a loss of the entire thickness of the stroma, reaching the Descemet's membrane - a descemetocele, with a loss of the entire thickness of the cornea - a through corneal ulcer (perforation ).
The causes of corneal ulcers are similar to the causes of erosions, however, in the case of an ulcer, the condition is complicated by aggressive secondary microflora, lack of adequate regeneration (for example, with the use of steroid hormones), pathology of the auxiliary apparatus of the eyeball (lagophthalmos, torsion of the eyelids, pathological eyelashes, dry keratoconjunctivitis).
Diagnostic methods for corneal ulcers include examination with a slit lamp, which allows you to determine the depth of the defect, assess the condition of the anterior chamber of the eye (fluid transparency, depth of the anterior chamber), fluorescein test, a thorough examination of the edges of the eyelids and the conjunctival sac. Additional use of an ultrasound of the eyeball is recommended for infected ulcers and / or severe corneal edema to detect anterior synechia, lens pathology and assess the condition of the posterior segment (vitreous and retina). It is desirable to conduct ultrasound after sedation of the animal in order to eliminate the risk of injury to the eye when the animal resists.

Shallow corneal ulcers that occur without corneal melting (keratomalacia), in the absence of abnormal eyelashes, or foreign bodies in the conjunctival sac and without complicating factors (keratoconjunctivitis sicca, lagophthalmos), may require only therapeutic treatment: antimicrobial drops and moisturizing gels in the conjunctival sac 3-4 times a day, a protective collar.
If positive dynamics is noted at the control appointment, therapeutic treatment is continued until the ulcer heals with the formation of corneal fibrosis, which becomes hardly noticeable after 3-6 months. If there is no improvement at the control visit, it is recommended to resort to surgical method treatment: surgical treatment of a corneal ulcer (cleaning the bottom of the ulcer from necrotic tissues and updating its edges), followed by covering the eye with a temporary apron of the third eyelid or temporary suturing the edges of the upper and lower eyelids. Surgical treatment is carried out using general anesthesia, immediately before treatment, a thorough revision of the conjunctival sac is carried out under an operating microscope. After the operation, the animal should receive a systemic antimicrobial drug, wear a protective collar, and drops with an antibiotic are also instilled into the conjunctival sac, since even after closing the eye with temporary sutures, there is space for the instillation of drops. The sutures from the eyelids are removed on the 10-14th day: by this time, the defect has healed with the formation of moderate corneal fibrosis.

Deep corneal ulcers, as well as ulcers complicated by aggressive microflora, occurring with keratomalacia, hypopyon, miosis, require surgical treatment.

The operation is performed under general anesthesia, the conjunctival sac is carefully examined before the procedure. The essence of the operation is to clean the bottom and edges of the ulcer from dead tissues and cover the formed defect with a “patch”, which may consist of the conjunctiva of the animal itself, the donor cornea or special synthetic materials. The use of a “patch” allows you to replace the lost thickness of the cornea and reduce the risk of its perforation, as well as accelerate the healing of the defect. One of the reliable methods is the fixation of a flap of the animal's conjunctiva (the tissue is taken from the eyeball or from the third eyelid) to the cornea with sutures, subsequently the conjunctiva adheres to the bottom of the defect.
After conjunctival plasty, the eye is covered with an apron of the third eyelid or the edges of the eyelids are temporarily sutured. Postoperative care includes systemic and topical antimicrobials, the use of mydriatics and/or drugs with antiprotease activity; wearing a protective raven is mandatory. On the 14th day, the sutures from the eyelids are removed, the area of ​​the cornea, covered with a conjunctival flap, remains opaque, covered with vessels. 4-6 months after the operation, the conjunctival flap turns pale, becomes smoother, and its partial transparency is possible.
A descemetocele is a very deep ulcer that causes total loss thickness of the corneal stroma, and the integrity of the eyeball is supported only by the Descemet's membrane and endothelium.

When viewed with a slit lamp, a descemetocele has characteristics: Descemet's membrane protrudes slightly forward from the bottom of the ulcer (stretched by intraocular pressure), and given area looks darker (due to the transparency of the Descemet's membrane relative to the peripheral cornea, which has a normal or even greater thickness due to edema.

Also, a feature of descemetocele is that the Descemet's membrane is hydrophobic and does not absorb fluorescein solution, and the peripheral stroma of the cornea is hydrophilic and acquires green color, thus, the defect is painted annularly.
Descemetocele is an emergency condition of the eye, since there is a high risk of perforation of the eyeball with a drop in IOP, fixation of the animal, self-injury. Surgical treatment of descemetocele consists in cleaning the defect from dead tissues (care must be taken to avoid intraoperative perforation) and replenishing the thickness of the cornea with an isolated conjunctival flap, the animal's own cornea, donor cornea, and synthetic materials. The material is fixed to the edges of the defect with sutures, the eye is closed with an apron of the third eyelid. Postoperative care is similar to that for deep ulcers.

Through ulcer of the cornea (perforation) - a state of complete destruction of the cornea throughout its entire thickness, accompanied by depressurization of the anterior chamber, sharp decline intraocular pressure, the outflow of intraocular fluid, can be complicated by the prolapse of the iris into the formed hole (iris prolapse), the penetration of microflora into the eyeball, followed by the development of panophthalmitis.

The history of a patient with a penetrating ulcer is characterized by a preliminary presence of a corneal ulcer that does not respond to therapy, and it can take from 2-3 days from the onset of the first symptoms to perforation, and the owner may also note a sudden profuse flow"tears" from the pet's eye, accompanied by severe soreness. Clinical signs of perforation: pronounced blepharospasm, hypotonicity of the eyeball, small anterior chamber, miosis, observed outflow of fluid from the anterior chamber of the eye (Seidel test can be confirmed: concentrated fluorescein is applied to the ulcer and the outflow of intraocular fluid of a transparent green color is observed). An animal with perforation, but without active outflow of intraocular fluid, can be admitted to the reception, this is possible with prolapse of the iris (mechanically closes the hole), already formed anterior synechia, or when the corneal hole is clogged with a fibrin clot.
fresh perforation - acute condition requiring urgent surgical sealing, most often replace the lost thickness of the cornea with an isolated conjunctival flap. In the case of prolapse of the iris, it is reduced, in the case of the formation of a strong synechia and the impossibility of reduction, the necrotic tissue of the iris is cut off. Before suturing the conjunctival flap to the cornea, the anterior chamber is washed, restoring its volume. Postoperative treatment includes the use of local and systemic antibiotics, local and systemic anti-inflammatory drugs, local mydriatics, drugs with antiprotease activity. Wearing a protective collar is mandatory, rigid fixation, squeezing of the neck, pressure in the eye area is contraindicated.
Complications associated with the loss of the integrity of the eyeball include the formation of anterior synechia - adhesions of the iris with the cornea at the site of perforation, with small synechiae visual function does not decrease. Serious complication perforations - reproduction in the intraocular tissues of aggressive microflora, leading to inflammation of all tissues of the eye - panophthalmitis. This state leads to loss of visual function and can threaten the life of the animal. Causes of panophthalmitis: lack of timely surgical treatment of a penetrating ulcer and subsequent antimicrobial therapy or microflora resistance to the used antimicrobial drug. For diagnosis, they use an examination with a slit lamp, test the reaction to blinding light (“dazzle” reflex), and do an ultrasound of the eyeball. In the absence of a reaction to blinding light and ultrasound detection of hyperechoic contents in the vitreous body and anterior chamber of the eye, as well as retinal detachment, enucleation of the eyeball is recommended.

Results:

• In the case of corneal erosion, it is necessary to identify the cause of its occurrence as quickly as possible and eliminate it; in this case, the erosion will heal within a few days without traces and without affecting visual function.
• In the case of chronic erosion are effective surgical techniques, allowing the cornea to heal quickly, and the clouding that occurs after healing is minimal and becomes even less pronounced over time, visual function does not deteriorate.
• In the case of a corneal ulcer, its depth is assessed, the presence of concomitant complicating conditions, a thorough revision of the conjunctival sac; according to the results of the examination, a reliable treatment tactic (therapeutic or surgical) is chosen. Some types of corneal ulcers (ulcer with keratomalacia, descemetocele, penetrating ulcer) are emergency conditions requiring surgical treatment and aggressive postoperative therapy. The transparency of the cornea after the healing of shallow ulcers is satisfactory for the normal orientation of the animal in space; in the case of replacing the thickness of the cornea with some material, transparency and visual function can be either satisfactory or significantly reduced depending on the depth, area, location of the damage, as well as on the type of material used to cover the defect.