Abstract: the ocular axis of patients with true myopia is significantly longer than the original. According to expert analysis, the degree of myopia increases by 300 degrees for every 1mm increase in the ocular axis in patients with myopia. Generally, myopia below 300 degrees is called low myopia, those between 300 and 600 degrees are called moderate myopia, and those above 600 degrees are called high myopia.
myopia deepens year by year, which has plagued many small partners and formed a phenomenon: as long as you wear glasses, the degree of myopia will continue to deepen. That step by step to develop to high myopia, what changes have taken place in our fundus? What causes our fundus to change and develop to high myopia step by step?
will give you a rough understanding of our human eye structure again, so as to know how our fundus changes. From the outside to the end, our human eyes are composed of cornea, iris, lens, ciliary muscle, vitreous body, retina, choroid and aqueous humor. Finally, light should be imaged on our retina. The refractive media passing through in turn are cornea, lens, vitreous body and aqueous humor, which also constitute what we often call diopter, When we look from far to near, it is mainly the ciliary muscle that regulates the lens.
develop to high myopia, which can be divided into three stages
. This stage mainly plays a role in the decline of the regulation ability of intraocular ciliary muscle spasm. When we look close, the ciliary muscle is tense, which is equivalent to lifting an object with one hand, Focusing on close eye use for a continuous period of time is likely to lead to ciliary muscle spasm. For example, we read and write, play the piano, play mobile phones, iPads and other electronic products for a long time. If we don’t pay attention to rest, there will be a temporary decline in vision. The main reason for this myopia stage is the temporary spasm of ciliary muscle, which can be recovered through sufficient rest and eye movement, However, if the previous habit of using eyes continues, it will develop to the second stage: true myopia
true myopia stage
academically, true myopia is also known as axial myopia. The main reason for this stage is the growth of our ocular axis. How does the ocular axis grow? If you continue to use your eyes too closely for a long time, the ciliary muscles will be further tired and the adjustment ability will continue to decline. Due to excessive adjustment, the radiation effect will be strengthened, so that the extraocular muscles will exert pressure on the eyeball, the intraocular pressure will increase, and the intraocular tissue will be congested. In addition, the juvenile eyeball tissue is delicate, the eyeball wall will be compressed and gradually extended, and the anterior and posterior axis of the eyeball will become longer, Beyond the normal value, axial myopia is formed. The ocular axis of patients with true myopia increased significantly than before. According to expert analysis, the degree of myopia increased by 300 degrees for every 1mm increase in the ocular axis in patients with myopia. Generally, myopia below 300 degrees is called low myopia, those between 300 and 600 degrees are called moderate myopia, and those above 600 degrees are called high myopia.
generally, the average axial length of emmetropia is about 24 mm. The average length of the ocular axis at birth is about 17.3 mm. With the development of physique, the eyeball is also developing continuously, and the ocular axis gradually grows until it is normal. If the ocular axis grows too fast, myopia will be formed. Therefore, the 10-16 years old with the fastest growth and development is also the fastest period of myopia deepening. After the age of 18, the growth of ocular axis generally stops or basically stops with the end of the growth and development period.
patients’ eyeballs continue to expand with the increase of ocular axis, which is much larger than normal eyeballs in eye specimens. In the process of eyeball enlargement, the sclera and choroid can grow continuously according to the signal requirements inside the eye, but the retina cannot grow with it. In order to stick to the increased sclera and choroid, the retina will have many cracks or lattice degeneration around the retina, resulting in early lesions for retinal detachment in the future. In addition, high myopia generally has a slightly higher intraocular pressure. If you pay improper attention to your eyes, glaucoma is likely to occur. The complications of high myopia are also potential hidden dangers due to the changes of fundus: cataract, glaucoma, flying mosquito, posterior scleral staphyloma, retinal degeneration, hemorrhage, hole and detachment, etc.