Vitreous degeneration is a pathology of the organ of vision, accompanied by a violation of the physico–chemical properties of the colloidal gel of the vitreous body. Clinically, the disease is manifested by “flies” and other “floating opacities” in front of the eyes. With progression, visual acuity may decrease. Diagnostics is based on the results of ophthalmoscopy, biomicroscopy, ultrasound in B-scan mode, optical coherence tomography, tonometry and visometry. Specific treatment methods have not been developed. Conservative therapy is carried out in the early stages. Pronounced destruction is an indication for surgical intervention (vitreolysis, vitrectomy).
The vitreous degeneration is called the complete or partial destruction of the structure of this anatomical formation. Pathology is most common among the elderly. In young people, it usually occurs as a result of mechanical damage to the eye or the progression of myopia. Male and female representatives get sick equally often. Vitreous degeneration is statistically more common in residents of economically developed countries, which may be due to an increase in life expectancy, excessive eye strain in the course of professional activity and a number of other factors. Modern methods of eye microsurgery allow not only to eliminate the clinical manifestations of the disease, but also partially restore visual functions.
Vitreous degeneration occurs when the physicochemical characteristics of its colloidal gel change as a result of local inflammation of the eye and surrounding tissues (with endophthalmitis, keratitis, blepharitis, dacryocystitis). The composition of colloids depends on the functional state of the liver, kidneys and endocrine glands. With the dysfunction of these organs, the physiological ratio of fluid, proteoglycans, glycosaminoglycans and stroma components is violated. Metabolic disorders, pathological changes in the vessels of the retina and brain worsen blood circulation and provoke neurocirculatory spasm of the eye muscles, preceding the development of destructive processes. In old age, the rheological properties of the colloidal gel deteriorate in the central parts, and the colloid thickens on the periphery. Under the influence of gravity, the deposited crystals or collagen masses in the retinal region peel off and accumulate in the center of the vitreous body.
The trigger of this pathology is myopia, in which the rounded shape of the eyeball is replaced by an ellipsoid, which leads to deformation of intraocular structures. The disease can be provoked by a blow to the eye socket area. Mechanical trauma leads to loss of the integrity of the gel-like mass, disruption of the primary structure of collagen and the development of hemophthalmos against the background of damage to the vascular bed. The risk group includes patients with decompensated diabetes mellitus, asthenopia and Parkinson’s disease. Iatrogenic destruction is possible if the vitreous body is damaged during cataract surgery.
Pathogenesis and classification
There are complete and partial vitreous degeneration. Most often, destructive processes affect the central parts of the colloidal gel. The first stage is the formation of a cavity containing liquid and coagulated collagen masses. Subsequently, more and more fibrillar proteins succumb to coagulation and go beyond the formation, which leads to the liquefaction of a gelatinous substance filling the space between the lens and the retina. It forms films and strands of various nature, which can be fixed to the fundus, causing wrinkling and the formation of adhesions. The vitreous body decreases in volume and deforms, which provokes tension of the vitreoretinal joints, followed by retinal detachment.
Filamentous, granular and crystalline destruction are distinguished by their shape. The trigger of the filamentous form is atherosclerosis or progressive myopia. With the development of inflammatory processes, granular lesions of the vitreous body form in the inner retinal layer. In rare cases, the colloidal gel is damaged by deposited cholesterol and tyrosine crystals.
Symptoms and diagnosis
Patients note photopsias, hemophthalmos, a “veil” in front of the eyes and a decrease in visual acuity. A specific symptom of destruction are “flies”, which most often appear when looking at the sky or a white monitor. An attempt to focus on the “flies” leads to their movement or disappearance. Usually the pathology develops gradually. The sudden appearance of black dots in front of the eyes is an early symptom of retinal or vitreous detachment.
To confirm the vitreous degeneration, it is necessary to perform ophthalmoscopy, ultrasound of the eyeball, biomicroscopy, optical coherence tomography, visometry and tonometry. The method of ophthalmoscopy determines optically empty cavities, which often look like vertical slits. The boundary membrane has no specific changes, fibrous structures of gray or white color are visualized behind it. Complete destruction is characterized by the formation of a single cavity with fragments of fibrils. Possible destruction of the boundary membrane, in which there is a lack of retrolental space. When the opacity is localized at the edge of the retina, specific changes are not detected.
Using a slit lamp, during biomicroscopy, it is possible to detect a change in the consistency of colloidal gel and the presence of flake-like opacities. With filamentous destruction, collagen fibers acquire a loop-like structure. Granular destruction is manifested by the accumulation of small particles of gray or brown color. In the later stages of the disease, clusters of grains in the form of conglomerates are visualized.
Ultrasound examination is a more informative method. The technique is recommended for concomitant hemorrhages in the vitreous body, ultrasound should be performed in the B-scan mode. The procedure allows to identify the source of hemorrhage and echonegative signals from crystal structures inside the colloid. The dilution of the vitreous body is indicated by the detection of mobility of crystals, granular conglomerates or clusters of collagen fibers.
Optical coherence tomography (OCT) of the eye is performed when other diagnostic techniques are uninformative. The study reveals a decrease in the size and shape of the vitreous body, its turbidity and heterogeneity of the structure. A contraindication to optical coherence tomography is massive hemophthalmos. Visometry allows you to assess the degree of visual acuity reduction. A slight increase in intraocular pressure is determined by tonometry.
Specific methods of treatment of vitreous destruction have not been developed. The ophthalmologist’s tactics depend on the degree of colloidal gel damage and decreased visual acuity. Conservative therapy and lifestyle correction are recommended in case of minor impairment of eye functions and detection of partial destruction. Patients should normalize sleep and wakefulness, perform eye exercises when working at a computer or reading for a long time. Conservative therapy consists in the local administration of potassium iodide to provide a resorbing effect and antioxidants to improve eye microcirculation (methylethylpyridinol). It is recommended to take vinpocetine and cinnarizine orally, which help to improve cerebral circulation. The use of angioprotectors and microcirculation correctors (L-Lysine escinate) is indicated.
Surgical treatment is required for severe vitreous degeneration. In modern ophthalmology, vitreolysis is used for targeted crushing of large fragments of collagen. The operation is performed under local anesthesia. Before using a special YAG laser, the pupils are dilated with short-acting mydriatics (tropicamide). Violations of visual function after vitreolysis of collagen structures of the vitreous body are not observed. The course of surgical intervention is hampered by the high mobility of pathological clusters inside the colloidal gel.
Total destruction is an indication for vitrectomy under local or general anesthesia. In the process of surgical intervention, the vitreous body is removed using microsurgical techniques. At the first stage, the colloidal gel is divided into small sections, which are then subjected to aspiration. Intraocular pressure is normalized by introducing a balanced saline solution, silicone oil or gas into the eyeball cavity.
Prognosis and prevention
To prevent the vitreous degeneration, it is necessary to undergo regular examination by an ophthalmologist with mandatory ophthalmoscopy, visometry and tonometry. It is recommended to reduce the visual load, perform therapeutic exercises for the eyes, eat fortified food, exclude foods with a high content of animal fat from the diet. All patients with myopia should take timely measures to correct vision. In diabetic retinopathy, an ophthalmologist’s consultation is indicated 2 times a year.
The prognosis for the vitreous degeneration in the case of timely diagnosis and treatment is favorable for life and performance. Even in the later stages of the disease, vitrectomy can significantly improve the visual acuity and quality of life of the patient.