Abstract: with the increase of age, the normal colloidal structure of vitreous in patients with high myopia is liquefied, and vitreous turbidity is very easy to occur. With the rotation of eyeballs, dark shadows often flutter in front of eyes, just like mosquitoes and flies flying. Ametropia with
myopia degree greater than 600 degrees (children > 400 degrees) is called high myopia. Because most of these myopia have ocular pathological changes, high myopia is equivalent to pathological myopia or degenerative myopia. The cause of high myopia is unknown. Pathological myopia occurs in a genetic relationship. The acquired environment also plays an important role in the pathogenesis of myopia.
the most direct effect of high myopia is the lengthening of the ocular axis. Axial lengthening is the pathoanatomical basis of myopia. The main lesions were in the posterior part of the eyeball, which was pear shaped or egg shaped. The lengthening of the eye axis may cause the following 6 different changes in the internal structure of the eye, Thus causing serious eye diseases:
(1) scleral thinning in scleral myopia is one of the characteristics of pathological changes. Longitudinal fibers become thinner and transverse fibers separate or disappear. This is related to abnormal scleral collagen.
(2) ciliary body mainly shows atrophy and can be limited to circular fibers.
(3) Due to degeneration and liquefaction of vitreous body, the normal grid structure is damaged, and gray fibers and vacuoles increase. Adhesion can occur around and detachment can occur at the rear.
(4) choroid mainly changes to progressive atrophy and thinning of choroid, including degeneration, destruction of melanocytes and neovascularization. The elastic layer is cracked, showing paint cracks
(5) Due to the backward extension of the eyeball, the choroid around the optic disc is pulled away from the optic disc. Bruch membrane also terminates here, and the sclera is exposed at the absence of the outer layer of the retina and pigment epithelium, forming a white arc spot.
(6) The retina mainly shows degenerative changes, including atrophy and degeneration. The normal hexagonal arrangement of retinal pigment epithelial cells is replaced by an irregular cell layer. There are many pigments outside the cells. There is hyperpigmentation and accumulation of pigment at the crack of Bruch membrane. Circular Fuchs spots can be formed in the macular area. The absence of elastic layer makes the retina choroid fuse together, and finally scars and pigments appear 。 Choroidal neovascularization can break through Bruch membrane and grow under the retina to form subretinal neovascularization membrane. Rupture of neovascularization causes macular hemorrhage. The vitreous body can attach and draw the atrophic retina. It can cause retinal hole and detachment.
changes in the internal structure of the eyeball caused by high myopia will also lead to the following pathological changes to a certain extent:
1. Posterior scleral staphyloma: the greater the myopia, the easier it is to form posterior scleral staphyloma, which is mainly manifested in the backward expansion of the posterior pole of the eyeball, degeneration and atrophy of the optic nerve and the retina around the macula, and the decline of corrected visual acuity.
2. Vitreous opacity: with age, the normal colloidal structure of vitreous in patients with high myopia is liquefied, which is very prone to vitreous opacity. With the rotation of eyeballs, dark shadows often flutter in front of eyes, just like mosquitoes and flies flying.
3. Macular hemorrhage: Patients with high myopia will cause macular hemorrhage and great damage to central vision when the eyeball becomes larger, resulting in continuous traction on the eyeball wall and rupture of small blood vessels in the macular area due to traction and other factors.
4. Glaucoma: the probability of glaucoma in patients with high myopia is 6-8 times that in normal people, and some patients are related to heredity.
5. Retinal detachment: the retinal tissue of patients with high myopia becomes fragile due to degeneration and atrophy. It is very easy to make retinal detachment and blindness under the influence of various factors.
6. Subretinal neovascularization: Patients with high myopia combined with subretinal neovascularization show subretinal neovascularization at the posterior pole, causing bleeding and affecting vision. How to prevent
(1) Development methods to prevent high myopia: continuous close eye use should not be too long. Actively participate in outdoor activities. Reasonable adjustment – collective training. Usually ensure adequate sleep, combination of work and rest, balanced diet, reasonable nutrition, etc. special attention should be paid to rational eye use, select appropriate work, and avoid excessive eye use and adverse visual stimulation. It may reduce high myopia You can choose to wear glasses (bifocal lens, high oxygen permeable rigid contact lens), and if you want to stop the development of myopia, you can choose refractive surgery, that is, choose amashi ophthalmic all femtosecond laser center.
(2) The main cause of blindness caused by high myopia is complications, such as retinopathy, glaucoma and amblyopia. In addition to paying attention to the changes of vision, we should also pay attention to any other abnormal phenomena in the early stage of the eye, such as flash sensation, flying mosquito disease, visual field defect, progressive or sudden decline of vision, as well as eye acid swelling, pain and night blindness. If necessary Perform other special eye examinations.