Abstract: the abnormal nutritional metabolism in myopia changes the capsular permeability of the lens, and the lens is gradually turbid due to nutritional and metabolic disorders. The visual acuity is gradually reduced, resulting in complicated cataract. This kind of cataract develops slowly, mainly core opacity and posterior capsule opacity.
generally myopia will not develop in adulthood, and those who continue to develop after the age of 25 are called progressive myopia. We know that over 600 degrees is high myopia, and almost all high myopia have the characteristics of axial growth and significant thinning of sclera at the posterior pole of the eye. The main pathological changes are atrophy and thinning of retina and choroid, most of which can cause blindness. It is the sixth blinding disease in China. The main complications were:
1 Retinal detachment
are the most common complications of myopia. Due to axial elongation and intraocular dystrophy in myopia, cystic degeneration and lattice degeneration often occur around the retina. The retina in the degeneration area is very thin and prone to perforation. In addition, vitreous liquefaction and increased mobility lead to retinal detachment. In patients with retinal detachment, 70% are myopia.
myopia has abnormal intraocular nutrition metabolism, which changes the capsule permeability of the lens, gradually produces turbidity due to lens dystrophy and metabolic disorder, and gradually reduces vision, resulting in concurrent cataract. This kind of cataract develops slowly, mainly core opacity and posterior capsule opacity.
3. Macular hemorrhage and macular degeneration
myopia has poor ocular blood supply and retinal ischemia. The retina produces a kind of neovascular growth factor. These factors make the subretinal neovascularization grow. The wall of these neovascularization tubes is very thin and easy to rupture and bleed. Macular hemorrhage is formed after bleeding. After the bleeding is absorbed, the new blood vessels can rupture and bleed again. After multiple bleeding, short marks are formed locally, causing macular degeneration, which permanently damages vision.
4. Vitreous liquefaction denaturation
vitreous is colorless and transparent jelly. When the eyeball of myopia increases, the vitreous body will not increase again, so the vitreous body can not fill all the space in the eye, resulting in liquefaction, increased mobility and turbidity, causing dark shadow in front of the eyes and inducing retinal detachment.
myopia have abnormal filter curtain structure at the atrial angle, so the outflow resistance of aqueous humor is large, which is easy to cause the increase of intraocular pressure. According to statistics, 30% of high myopia have glaucoma, which will cause the gradual loss of vision.
① children should develop the correct posture of reading and writing, and the distance between eyes and books should be about 30 cm.
② when reading and writing, the light should be moderate, not too strong or too dark.
③ the reading time should not be too long. Every 40 ~ 50 minutes, you should rest for 10 ~ 15 minutes, close your eyes or look at the distance for several minutes or so to prevent excessive eye fatigue.
④ don’t read books and newspapers with too small or vague handwriting.
⑤ educate children to correct unreasonable eye habits, such as lying on the table, reading or writing with their heads tilted, reading in bed, reading when eating, reading under strong light or dim street lights and moonlight, and reading in a moving car and walking. These bad habits will make their eyes too tired and reduce their eyesight.