How to measure the axis of the eye? _Industry News_

A method of measuring the length of the eye axis to understand the condition of the eye to a certain extent. Many patients with myopia will have eye axis lengthening, and the vision of the eye can be understood by measuring the axis of the eye. At present, there is more than one method for measuring the eye axis, but it is still widely used. Let's take a look at the eye axis measurement together. The distance of the eye axis can be used to judge a person's vision. Generally, the length of the eye axis of a normal person is 24mm, if it is myopia, it is generally greater than 24mm. For hyperopia, it is generally less than 24mm. If the axis of the eye increases by 1mm, the degree of myopia will increase by 300 degrees, so measuring the axis of the eye can understand the vision of a person. Because the child is still in the growth stage, the eye axis is still in the growth and development stage. Children generally have a short eye axis, which can reach the level of an adult with continuous growth and development. For children aged 3-6, there is currently no uniform standard, but if the child’s eye axis is over-developed, it may be prone to myopia. There are A-mode ultrasound and B-mode ultrasound for measuring the axis of the eye. A-mode ultrasound is more accurate in measuring the axis of a normal eye, but A-mode ultrasound has its limitations. This is because the macular area is an important area of u200bu200bvision. Most of the cone cells are distributed in the macular area. When measuring the axis of the eye, it is better to fall in the macular area. However, some people with high myopia are accompanied by posterior Scleral staphylotoma, and staphylostasis grows with the growth of the eye axis, which causes the macular area to be farther away from the cone of the staphyma. It is impossible to accurately determine the location of the macular area, and therefore it cannot be very accurate. Measure the axis of the eye. There are also those because of severe vitreous turbidity, organization and retinal proliferative disease, if you use A-mode ultrasound measurement, measurement errors are prone to occur. B-mode ultrasound measurement is not affected by refractive interstitial turbidity, so it can improve the accuracy of the measurement. The position of the macular area can be determined through the axial phase diagram, and the corneal apex and the center of the lens can be determined. The connection between the two points is backward and the retina The intersection point of is equivalent to the position of the fovea in the macular area, and then the axis of the eye is measured. The basis for A-mode ultrasound to measure the axis of the eye is based on the product of the sound velocity and time of different tissues in the eye. It is more commonly used in normal eye cataract surgery and intraocular lens power calculation, and B-mode ultrasound is better than A-mode ultrasound when measuring the axis of eyes with high myopia or vitreoretinopathy.