Trace elements are essential substances for the human body. They are closely related to the occurrence and development of many diseases, such as cardiovascular diseases, nervous system diseases, cancer, brain diseases, liver diseases, nutritional deficiencies, etc. Many studies have found that trace elements also play an important role in the prevention and treatment of eye diseases.
Among the trace elements in human body, the content of zinc occupies the second place. The content of 1.5~23g in normal human eyes can exceed 21.86 μ mol/g (dry weight of eye tissue), with the highest zinc content in choroid and retina. Eye tissue also contains a variety of zinc enzymes, such as carbonic anhydrase in the ciliary body, aldehyde dehydrogenase in the retina, leucine aminopeptidase in the lens and collagenase in the cornea.
Zinc participates in the activities of a series of important metalloenzymes and vitamin A metabolism, and can maintain the normal tissue morphology and normal visual function of retinal pigment epithelium. Zinc deficiency can affect the synthesis of visual pigment, resulting in night blindness and dark adaptation disorder.
Selenium is one of the essential trace elements for human body. The ideal daily intake of normal people is 250~300 micrograms. When the amount of selenium is insufficient or lacking, it will have adverse effects on the human body.
At present, it is generally recognized that the pathogenesis of cataract is oxidative damage to the lens, mainly because oxygen free radicals oxidize reduced glutathione to oxidized glutathione, resulting in the reduction of reduced glutathione, thus weakening the protective barrier against oxidative damage to the lens. Selenium plays an important role in the metabolism of HO and other perhydrides, which can effectively prevent the generation of free radicals and tissue damage. Because the glutathione peroxidase containing selenium has antioxidant effect, if the trace element is lacking for a long time, glutathione peroxidase will be reduced. The lens will be damaged, causing the oxidation of sulfhydryl protein, and then causing cataract.
Copper is the highest in the iris and ciliary body of the human body. It mainly exists as an important component of some enzymes, which is closely related to the normal activities of cells, especially the formation of pigments. Some studies believe that retinal pigment degeneration is caused by the disorder of copper metabolism.
In high myopia, due to the loss of pigment from the pigment epithelium, the retina can undergo degenerative changes, which can cause atrophy of the pigment epithelium in the macular region.
Not only that, if the human body lacks vitamins, it will also affect the health of the eyes, leading to some eye diseases. Studies have found that there is a lack of different vitamins. The resulting eye diseases are also different.
Vitamin A deficiency is one of the most common causes of dry cornea, conjunctiva and keratomalacia. Especially for children under 3 years old, improper artificial feeding often leads to diarrhea, chronic digestive tract diseases, and inappropriately taboo, which will lead to a serious lack of nutrition and vitamin A, so that the children's eyes are photophobic, unwilling to open, the dark adaptation function is reduced, and they cannot see in the dark environment and at night, that is, night blindness.
If vitamin A cannot be supplemented in time, let it develop. After the pre drying and drying periods, the cornea will slowly soften, and soon become turbid. Corneal autolysis necrosis will form ulcers, and even the entire corneal tissue will dissolve and perforate, eventually leading to blindness.
The lack of vitamin B will keep the metabolic process of carbohydrate in the pyruvate phase, and the increase of pyruvate will damage neural tissue. In the eyes, it is manifested as paralysis of extraocular muscles, resulting in ptosis, eye movement disorder, diplopia or eye fatigue. If there is optic nerve damage, the vision will gradually decline, and even the mouth will develop into atrophy of the optic papilla.
If vitamin B is lacking, multiple new blood vessels can be formed around the cornea and gradually invade the cornea, thus making the cornea gradually turbid.
It can be seen that maintaining the trace elements and vitamins needed by the human body is crucial to eye health. Don't be too picky or partial at ordinary times. Pay attention to the diversification of diet. Eat more pig liver, eggs, cod liver oil, lean meat, milk, black fungus, bean curd skin and other foods rich in vitamins and trace elements to ensure the body's demand for various nutrients. As parents of infants and adolescents, more attention should be paid to the diet to prevent eye damage caused by excessive or insufficient intake.