What is the retina? The retina is the end tissue of the visual nerve extending outward from the brain and has a complex, delicate, fragile and metabolically active structure. Its blood vessels belong to the terminal vascular system, and any pathological damage and vascular obstruction caused by tissue hypoxia can lead to tissue necrosis and loss of its function of sensing and conducting light stimuli. The neural tissue of the retina belongs to the ectoderm and the blood vessels belong to the mesoderm, and the latter are the only small blood vessels that can be seen directly in the human body. Fundus changes are the manifestation of systemic diseases and intraocular disorders in the fundus. Therefore, it is often clinically significant to judge systemic diseases based on fundus changes, especially for the diagnosis and treatment of arteriosclerosis, hypertension and diabetes. What is retinal detachment? Retinal detachment is the separation of the neuroepithelial layer of the retina from the pigment epithelial layer. There is a potential gap between the two layers, and the fluid trapped in the gap after separation is called subretinal fluid. According to the etiology, it can be classified as foraminogenic, traction and exudative retinal detachment. The part of the retina that is detached does not work properly and the brain receives incomplete or total absence of images from the eye. What are the clinical signs of retinal detachment? When a partial detachment of the retina occurs, the patient has a cloudy shadow in the visual field on the opposite side of the detachment. If a macular detachment occurs, central vision is greatly reduced. Detachment is often preceded by aura symptoms, with flashes of light during eye movements. Due to vitreous clouding, there are often dark shadows floating in the visual field. The degree of visual loss depends on the site and extent of the detachment, the degree of vitreous opacity and degeneration, and other factors. If the retina is completely detached, vision is reduced to light perception or completely lost. The loss of vision is often preceded by distortion of vision and a sensation of object tremor during eye movements. What causes retinal detachment? The disease is most common in middle-aged or elderly people, most of whom are nearsighted and can develop in both eyes. The causes include lattice and cystic degeneration in the peripheral part of the retina, vitreous liquefaction degeneration and retinal adhesions, which are in turn related to age, genetics, trauma and other factors, and vitreous traction on the retina, which is more important in the pathogenesis.