Retinal hemorrhage after exercise, why does aerobics still "strain your eyes"?

Has everyone done the “blanket exercise” that has become popular on the Internet this year?

I don’t know when it started, but all the friends around me have become fitness experts, and all kinds of new and interesting memes have emerged one after another. However, gradually, many different ways of injury have also appeared, such as muscle soreness, ligament strain, ankle sprain... I will not go into details about these common sports injuries here.

However, not long ago, a news headline on Weibo's hot search list attracted a lot of attention, "22-year-old girl suffered retinal hemorrhage after doing aerobics with Liu Genghong". How can the eyes be injured by doing aerobics? Today, the editor will talk to you about this matter.

Source: Weibo screenshot

1. Why does high myopia pose a risk of blindness?

When our eyes are in a state of relaxation, parallel light from the outside world enters the eyes and focuses on the retina to form a clear image. This state is called emmetropia. When the light cannot focus on the retina, it is called non-emmetropia, which is often called refractive error. Myopia is a type of refractive error, which refers to the state when the eyes are in a state of relaxation and the light enters the eyes and focuses in front of the retina. In previous articles, we have introduced the mechanism of myopia. (Click to view previous articles)

Diagram of the basic structure and function of the eyeball

Source: People's Education Press seventh-grade biology textbook

Generally speaking, myopia above 600 degrees is defined as high myopia. The lenses of the glasses are thicker than the bottom of a bottle, and you have to guess whether you can distinguish between people and animals ten meters away. You may even miss out on your ideal profession due to limited vision... Do you think these are the only inconveniences that high myopia brings to your life?

In fact, compared with the risk of blindness, these are not worth mentioning at all! So why do people with high myopia have the risk of blindness? That's because high myopia not only increases the degree of myopia, but more seriously, it also lengthens the eye axis, which leads to changes in the fundus. The axial length of a normal adult is about 23-24mm. Compared with ordinary people, the axial length of patients with high myopia is usually longer. As the axial length gradually lengthens, the eyeball wall tissue will be stretched and become thinner.

Schematic diagram of eye axis lengthening

Source: Jingmen Daily

The wall of the eyeball can be roughly divided into three layers: the fibrous membrane, the vascular membrane, and the retina. The choroid is the posterior 2/3 of the vascular membrane, rich in blood vessels and pigment cells, which play a role in nutrient supply and absorption of scattered light in the eye. The retina, located in the innermost layer of the eyeball wall, has an average thickness of only 0.4mm, but its structure is very precise. According to the order of cell arrangement, it can be divided into 10 layers, including a single-layer pigment epithelium and 9 layers of retinal nerve sensory layers, also known as the neuroepithelium. The retina plays a photosensitive role like the film of a camera. At the same time, the retinal central vascular system is also distributed on the retina to provide nutrition for the inner retina.

Schematic diagram of retinal tissue

Source: Ophthalmology

For patients with high myopia, as the eye axis grows, the retina and choroid are stretched and thinned. Vigorous exercise or blood pressure fluctuations may cause retinal holes, through which fluid enters the subretinal space. The pigment epithelium is closely connected to the innermost structure of the choroid, the vitreous membrane, but there is a potential gap between the pigment epithelium and the neuroepithelium , which makes it more likely to separate, leading to severe visual field defects and decreased vision. In severe cases, only light perception remains or even complete loss of vision, which is what people often call retinal detachment.

Retinal tears & retinal detachment

Source: enter.news

Not only that, the retinal blood vessels of patients with high myopia are also thinner and more fragile. When the head shakes violently, or when actions such as holding the breath or exerting force that increase the intraocular venous pressure are performed, the retinal blood vessels are prone to rupture , leading to retinal hemorrhage. This is why the girl we mentioned at the beginning of the article had retinal hemorrhage after doing aerobics.

2. How can we stay away from the danger of blindness?

About 90% of the information we obtain from the outside world through our sensory organs is obtained through vision. Therefore, it is very important for each of us to have and maintain normal visual function. So, what should patients with high myopia do to stay away from the danger of "blindness"?

First of all, we must use our eyes scientifically. When studying or working, you can look into the distance or do eye exercises every once in a while to relieve eye fatigue and avoid further worsening of myopia, which would make your already poor vision worse.

Looking into the distance can relieve eye fatigue

Source: unsplash

Secondly, in daily life, we should try to avoid heavy physical labor, or sports that cause violent head shaking, such as bungee jumping, diving, boxing, roller coasters, and other sports that are easy to cause eye impact. Once symptoms such as black shadows floating in front of the eyes, flashes, and blurred vision occur, we should seek medical attention as soon as possible and receive timely treatment to save visual function. Even patients with high myopia who are "safe and sound" should have fundus examinations every six months to detect fundus lesions in time and eliminate hidden dangers.

Source: unsplash

In addition, behaviors such as blood donation and natural childbirth may cause fluctuations in intraocular venous pressure. Although high myopia is not an absolute contraindication, you should still conduct an examination in advance to assess whether the fundus condition allows it, so as to avoid irreversible consequences.

It turns out that high myopia is not just as simple as thickening the lenses of the glasses. I hope everyone can take good care of their eyes and stay away from the threat of "blindness".