Vitreous hernia is a pathological protrusion of the vitreous body into the anterior chamber of the eye. The main clinical manifestations of the disease are represented by a decrease in visual acuity, the appearance of a “fog” or “veil” in front of the eyes, headache. To make a diagnosis, biomicroscopy, OCT, ultrasound, gonioscopy, visometry are performed. Therapeutic measures are aimed at achieving the target level of intraocular pressure. Vasodilators, diuretics and mydriatics are prescribed. With a complicated course of the disease, vitrectomy is indicated.
Vitreous hernia is an ophthalmic pathology, which is very often considered as a complication that occurs during the surgical treatment of cataracts, although this is not always true. The prevalence of secondary vitreal hernias has significantly decreased due to the widespread introduction of microsurgical techniques into ophthalmology. At the same time, carrying out a number of modern surgical interventions is associated with a high risk of developing the disease. In 20% of cases, intraoperative leaching of viscoelastic entails the formation of a hernia. During cryoextraction of cataracts, hernial defects are formed in 5-55%.
The etiology of the disease is not fully understood. Scientists believe that people suffering from connective tissue pathologies are more at risk of hernia formation. The likelihood of developing a complicated form of the disease increases in patients with high-grade myopia, long-existing ophthalmohypertension. The main causes of vitreal hernia are:
- Penetrating injury of the eyeball. In case of injury with damage to the boundary membrane, a hernial protrusion is formed at the site of its rupture. A reactive increase in intraocular pressure contributes to the smooth movement of the contents of the vitreous body.
- Contusion of the eye. Pathology is detected even after mild contusion. Uncomplicated hernias are formed at I-II degrees. At grade III, in almost all cases, membrane ruptures are formed, which causes the development of a secondary hernia. The IV degree of contusion leads to crushing of the eyeball.
- Surgical interventions. During surgical treatment of secondary cataracts, dislocation of the intraocular lens (IOL) is possible. When it is displaced towards the posterior pole of the eyeball, the vitreous body is damaged. Similar complications occur with intracapsular cataract extraction.
- Malformations of the eye. Such congenital anomalies of the eyeball as microphthalmos and coloboma of the iris are often accompanied by a displacement of the vitreous body anteriorly. In coloboma, hernial protrusion is found in the area of the iris defect.
With a puncture wound, the integrity of the border plate of the vitreous body is violated, which leads to the formation of a hernia. The volume of hernial protrusion depends on the size of the wound canal, intraocular pressure (IOP) and the condition of the surrounding tissues. In complicated hernia, vitreal masses in combination with blood clots migrate to the anterior chamber area. In case of contusion of the eye due to mechanical pressure, intraocular structures are deformed, IOP sharply increases. The vitreous body shifts in the direction of the anterior pole of the eye and partially extends beyond the pupillary opening. The contact of the anterior surface of the hernial defect with the endothelium of the cornea leads to its edema. This causes the progression of visual dysfunction.
A vitreous hernia is usually an acquired disease. The congenital form is extremely rare and always occurs against the background of severe malformations of the eyes. There are complicated and uncomplicated forms of pathology. According to the time of appearance, postoperative protrusions are classified into early and late. From a clinical point of view , the following types of hernias are distinguished:
- Primary. This is the most favorable variant of the disease, not accompanied by a violation of the integrity of the anterior boundary membrane. Hernial protrusion resembles a small “bubble” that deviates towards the pupillary edge of the iris, the anterior chamber of the eye is not involved in the pathological process.
- Secondary. This type of hernia is complicated by damage to the anterior border plate. Dilution of the vitreous leads to a decrease in the strength of the membrane. A linear discontinuity zone is formed at the thinnest point. The elements of the vitreous body freely penetrate into the anterior chamber and are freely located in it.
The clinical picture directly depends on the form of the disease. With uncomplicated hernia of small size, an asymptomatic course is observed. When a large defect comes into contact with the posterior surface of the cornea, patients complain of the appearance of “fog” and a decrease in visual acuity. When trying to view an image located near, the symptoms become more pronounced, eye strain can provoke the development of headaches and dizziness. With a complicated type of hernia, in addition to the deterioration of vision, there is the appearance of floating opacities in front of the eyes.
The disease is often complicated by rupture of the boundary membrane. Hemorrhages in the hernial sac with its delamination are possible. With the traumatic genesis of pathology, foreign bodies often get inside the eye, which contributes to the growth of destructive changes. With concomitant damage to the iris, not only blood, but also pigment inclusions are detected in the vitreous body. The most unfavorable complications are secondary glaucoma and retinal detachment. The shape of the pupil is often distorted. Violation of intraocular hydrodynamics leads to the development of ophthalmohypertension. When a vitreal hernia comes into contact with the cornea, endothelial-epithelial corneal dystrophy develops.
When formed directly at the time of surgical intervention, a hernia is detected by an ophthalmic surgeon intraoperatively with the naked eye. In case of a traumatic origin of the disease or the formation of hernial protrusion in the postoperative period, the following studies are prescribed to clarify the diagnosis:
- Biomicroscopy of the eye. With a primary hernia, the pathological protrusion has the appearance of a formation overhanging the pupillary edge. The anterior boundary membrane looks like a smooth homogeneous surface without damage. The transparency of optical media is not reduced.
- Gonioscopy. When the boundary plastic breaks, individual components of the vitreous body are detected in the anterior chamber area, represented by structureless gelatinous masses freely located in watery moisture. In the severe course of the disease, the entire anterior chamber is filled with fragments of the vitreous body.
- Ultrasound of the eyes. With ultrasound examination, it is possible to reliably differentiate the primary and secondary forms of the disease. In the primary form of hernia, a homogeneous formation with clearly bounded edges is visualized, in the secondary form, signs of vitreous crushing are observed.
- Optical coherence tomography. The study is carried out to assess the condition of the inner shell of the eyeball. The technique allows you to visualize the first signs of retinal detachment even with a severe through wound and massive endovitreal hemorrhage.
- Visometry. With an uncomplicated course of the disease, visual functions do not suffer. Secondary hernias lead to a marked decrease in visual acuity. After the surgical intervention, there is a gradual restoration of visual functions.
Differential diagnosis is carried out with fibrinous exudate in the anterior chamber, which is most often detected in inflammatory diseases of the uveal tract. Fibrinous effusion has the appearance of the same jelly-like masses, however, with increased exudation, the pupil retains its normal shape, fibrin settles at the bottom of the anterior chamber and does not have the ability to move freely. The exudate resolves or organizes over time, and the hernia does not change dynamically when observed.
Treatment of vitreous hernia
Treatment tactics will be determined by the form of the disease. If the anterior edge of the hernial protrusion does not come into contact with the posterior parts of the cornea, there is no need for medical intervention. Conservative therapy is indicated for uncomplicated large vitreal hernia. The essence of treatment is to normalize the indicators of ophthalmotonus. Patients are prescribed instillations of antihypertensive agents, additionally mydriatics, vasodilators and diuretics are used. When the effectiveness of therapeutic measures is low, air is injected into the cavity of the anterior chamber, which creates a mechanical obstacle to the dislocation of the vitreous body.
With complicated hernias, surgical treatment is required. Subtotal or anterior vitrectomy with vitreous reposition is considered to be the most effective. Surgical intervention is performed through two ports in the flat part of the ciliary body. To prevent injury to the corneal endothelium during vitreous removal, it is forbidden to move the instruments outside the pupil. If a complicated vitreal hernia was detected intraoperatively, it is recommended to remove it immediately with a vitreotome and microsurgical scissors. Additionally, a revision of the anterior chamber is shown, followed by the removal of jelly-like masses from it.
Prognosis and prevention
The outcome of the disease is determined by the size and type of hernia. With a small hernial protrusion and preserved integrity of the boundary membrane, the defect decreases over time, the shape of the vitreous body is restored independently. Uncomplicated large hernias do not decrease without appropriate treatment. Secondary protrusions cause the development of severe complications that can lead to amaurosis. Specific preventive measures have not been developed. Non-specific prevention is reduced to compliance with the technique of operations, following the safety rules at work (using a protective mask, glasses).