The influence of the vitreous body on the development of glaucoma

Relevance Comprehensive studies of the vitreous body (VH) have been conducted recently, covering its morphology, biochemistry, age-related changes and its role in a healthy and diseased eye [1]. In modern ophthalmology, the vitreous body is considered a key element that provides not only the optical properties and stability of the eye shape, but also normal hydrodynamics, hemodynamics, transport of substances, as well as the coordinated work, nutrition and metabolism of all eye structures. Vitrectomy made it possible to assess the role of VH in vision and nutrition of the eye [2, 3]. Violations or absence of VH lead to excess oxygen in the eye, causing oxidative stress, which damages tissues, including the nerve fibers of the optic nerve. After vitrectomy, a temporary and then persistent increase in intraocular pressure may be observed, leading to the development of various forms of glaucoma. Initially, this was associated with tamponade of the vitreous cavity with silicone oil. However, in the course of further observations it was found that tamponade by other methods also led to ocular hypertension [4]. During vitrectomy, there is a redistribution of blood flow in the eye: tissue perfusion in the anterior structures of the eye improves and worsens in the tissues of the posterior part of the eye, including in the retinal ganglion cell layer. Modern diagnostic methods have shown that vitrectomy changes the structures and biometric parameters of the eye, including a decrease in the depth and width of the anterior chamber angle (ACA), an increase in the lens and the length of the eye, as well as a change in the position of the structures. These changes disrupt the outflow of intraocular fluid (IOF), increasing the risk of developing glaucoma. With age, the IA undergoes changes, losing its structure and connections with the surrounding tissues [5]. This disrupts the nutrition and metabolism of the eye, changes its mechanical properties, blood flow and outflow of IOF, leading to irreversible metabolic disorders. Age-related changes can also be considered as a risk factor for the development of closed-angle glaucoma. Collapse and detachment of the vitreous body contribute to the forward displacement of the iris-lens diaphragm, which leads to a functional block in eyes with a narrow angle of view. Conclusion Current data indicate a significant role of pathological changes, including age-related changes in the vitreous body, in the etiology and pathogenesis of all clinical forms of glaucoma. Key words: vitreous body; vitrectomy; glaucoma; intraocular pressure