Application of visual field examination in ophthalmology

What is the field of vision? As the name implies, it is the spatial range seen by the eyes, also called peripheral vision. Specifically, when you look at a space object, you can not only see the object clearly, but also see the object in a certain space around the gaze point. The range of space you can see is called "field of vision". The field of vision is determined by the distance between the eyes and the staring target and the size of the object in space. It represents the function of visual cells outside the fovea. If you find that your vision drops intermittently in your daily life, your vision will gradually blur and your vision will gradually narrow. The field of vision is incomplete, as if a shadow is blocking the line of sight. Sometimes a corner is completely dark and nothing can be seen. Especially at night. Then you should pay attention. Your eyes may indicate that you have some diseases, or some diseases with visual field defects (such as glaucoma, optic nerve and visual path diseases, retinitis pigmentosa, intracranial tumors and so on). ), these are all serious diseases in ophthalmology. If it is not checked or treated in time, it will delay the illness and eventually lead to blindness. From a professional point of view, external light is refracted by cornea, lens and vitreous body, and imaged on retina to form light stimulation. Photosensitive cells (cone cells and rod cells) on the retina are transformed into nerve impulses after being stimulated by light, which are transmitted to the visual center of the cerebral cortex through the optic nerve, in which the optic nerves of both eyes intersect at the optic chiasma, the nerve fibers in the nose of the retina cross each other to the opposite side, but the optic nerves on the temporal side do not cross, so it goes from the retina to the occipital part. If any part of the visual path is diseased, it will be reflected in the field of vision. Ophthalmologists and neurologists can analyze the location, nature and prognosis of lesions according to the changes of visual field and other clinical examination results. Visual field examination is of great significance to the diagnosis of various eye diseases. These diseases are sometimes difficult to diagnose in clinic, so visual field examination is of great significance. Visual field examination provides important information for ophthalmologists to diagnose and follow up the main blinding eye diseases. But what kind of visual field inspection can we pass to get accurate and reliable inspection results? With the development of science and technology, the visual field meter was born gradually. Ophthalmometer is a professional ophthalmic instrument, which is used to measure eyeball visual field in physiological teaching and make necessary measurements on medical ophthalmic nerve. Visual field examination plays an important role in the diagnosis and treatment of ophthalmic diseases. Visual field examination is a basic method to diagnose and monitor glaucoma and other visual and optic nerve diseases. Advanced visual field examination provides the possibility for early diagnosis and close monitoring of the development of these diseases, and creates conditions for successful treatment. Perimetry has become a widely used main visual function examination method, which has unique clinical application value. With the progress of vision theory, modern detection technology and information technology, it will continue to develop and improve. It is more accurate to check the visual field with a perimetry, which can be divided into dynamic visual field inspection and static visual field inspection. Dynamic visual field inspection is a method to remove the target with certain stimulation intensity from the invisible area such as the periphery of the visual field or the center of the dark spot, and to explore the boundary point between the invisible area and the visible area. Dynamic visual field examination is mainly used to draw the range of isochromatic and scotoma, and the plane visual field and arc visual field commonly used in clinic at present belong to this category. Static visual field examination is a method to measure the photosensitivity or light threshold of a point in the visual field by gradually increasing the stimulus intensity of the visual field. At present, computer automatic perimeters, such as imported fully automatic computer perimeters (Zeiss Humphrey perimeters in Germany) all belong to this inspection method. Humphrey visual field analyzer (HFA), a German Zeiss visual field analyzer, is a very popular representative optical projection microcomputer visual field analyzer in the United States after Octopus. HFA is a fully automatic, independent and complete system, which is now recognized as a standard visual field examination. German Zeiss Humphrey perimetry has important diagnostic value for optic neuropathy, and it is a recognized standard for the diagnosis, treatment and management of visual field loss caused by early glaucoma. It accurately analyzes the changes of the threshold of each monitoring point in the field of vision with time, and makes a scientific judgment on the progress of glaucoma from the numerical changes. The system is used in hundreds of clinical reports. Aspherical design, compactness and humanization make patients feel comfortable even when testing at 90 degrees. The eye monitoring system allows the operator to aim at and track the position of the patient's eyes, and the line-of-sight tracking system can provide real-time evaluation of the line of sight of the eyes. At present, the system introduced by our department is easy to operate and easy to understand. The corresponding examination results can be made according to the conditions of different patients. It can effectively, quickly and accurately help patients and doctors to further understand the pathophysiology and visual field defect of the disease, and better prevent and treat the disease as soon as possible. It plays an important role in ophthalmic examination. I hope my friends will check and treat my eyes as soon as possible for the health of their eyes. The ophthalmology department of Red Cross Hospital will escort you tomorrow.