High myopia is not just myopia? It is hereditary! It can cause many complications!

Author: Yin Lianrong, Chief Physician, Eye Hospital, China Academy of Chinese Medical Sciences

Reviewer: Qiu Lixin, Chief Physician, Beijing Tongren Hospital, Capital Medical University

Clinically, myopia of more than 600 degrees is called high myopia, and myopia of more than 1000 degrees is called super high myopia. The incidence of myopia is increasing year by year. High myopia develops from low and moderate myopia, so the incidence of high myopia is also increasing year by year.

There are two main causes of high myopia: one is genetic factors and the other is environmental factors.

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High myopia is an autosomal recessive genetic disease. If both parents are highly myopic, the child has a 98% chance of developing high myopia; if one parent is highly myopic and the other is a high myopia gene carrier, the child has a 57.5% chance of developing high myopia; if both parents are high myopia gene carriers, the child has a 21%-22% chance of developing high myopia.

Environmental factors are mainly bad eye habits and living habits. Bad eye habits include incorrect sitting posture, inappropriate lighting, close reading, reading in a shaking or moving environment, etc. Bad living habits, such as not getting enough sleep and unbalanced nutrition, etc.

High myopia can cause many complications compared to low and moderate myopia. Most of the high myopia is axial myopia. The so-called axial myopia means that as the degree increases, the eye axis is constantly lengthening, and the equator is constantly expanding. The blood vessels supplying the retina and choroid will also be stretched. After being stretched, the blood vessels become thinner and narrower, which will lead to ischemia of the retina and choroid, causing corresponding lesions.

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For example, when the vitreous is cloudy, there are black shadows floating in front of the eyes and a sense of flashing at night. This is because the vitreous ischemic and degenerated, leading to complications such as posterior vitreous detachment and vitreous liquefaction. Choroidal and retinal ischemia will lead to choroidal and retinal atrophy, posterior scleral staphyloma, peripheral retinal degeneration, retinal holes, and retinal detachment. At the same time, high myopia can also cause macular atrophy, macular holes, splits, etc. High myopia can also be complicated by cataracts, secondary glaucoma, strabismus, and amblyopia.

High myopia is a highly blinding eye disease, second only to cataracts, and carries a risk of blindness, but it does not necessarily lead to blindness. The main cause of blindness is the possible macular degeneration, which gradually develops from the initial disease-free state to early disease, and may eventually lead to blindness.

Therefore, the prevention and treatment of high myopia is of vital importance. Intervention measures should be taken before fundus lesions occur to prevent the occurrence of lesions; and for individuals who have already developed fundus lesions, the lesions should be prevented from progressing from the early stages to blinding lesions. In this way, the blindness rate and disability rate caused by high myopia can be significantly reduced.

In addition, for patients with high myopia, if they suddenly experience a decrease in vision or complete loss of vision, or suddenly feel a dark shadow blocking their field of vision or a sense of flashing light, they should seek medical attention immediately to prevent possible more serious complications.

What kind of sports are not recommended for patients with high myopia? First of all, diving is not recommended for patients with high myopia. The axial length of the eye of patients with high myopia is elongated, the equator is expanded, the blood vessels are thin, and the eyes are in a state of ischemia. The pressure will change during diving, which may lead to arterial and venous thrombosis and ischemic retinopathy. Vision may suddenly decrease or even become blind. Second, strenuous exercise such as bungee jumping and roller coaster riding is not recommended. If the vitreous body is liquefied, it will pull on the retina. This traction will increase in the case of strenuous exercise, which may cause retinal detachment. In addition, in daily life, it is not recommended for patients with high myopia to do violent head shaking exercises, and it is not advisable to carry heavy objects with excessive force to prevent increased abdominal pressure, which may cause the vitreous body to affect the retina and cause complications. Patients with high myopia can choose a gentler form of exercise when exercising, such as Tai Chi, yoga, and brisk walking. The main thing is to avoid strenuous head movements and exercises that change eye pressure.

Eye lesions in patients with high myopia are often more serious, and may include vitreous liquefaction and peripheral retinal degeneration. For female patients with high myopia who plan to have a normal birth, it is recommended to first undergo a fundus examination and consult an ophthalmologist. Because the increase in abdominal pressure during a normal birth will cause changes in eye pressure, which may cause the vitreous to pull on the retina, thereby increasing the risk of retinal detachment and ocular ischemia.