What are the risks of high myopia?

1 Mar 2024Eye Health & General Information

Myopia or short-sightedness is one of the most common eye issues worldwide. In fact, a study estimated that of the world’s 7.79 billion people in 2020, 2.64 billion were myopic. That represents 33.9% of the total!

For most of these people, myopia is a relatively minor issue. It can inconvenience them in some ways, such as by requiring that they use glasses or contact lenses to see clearly, but that’s usually all.

But for those who have high myopia (as per the study referenced earlier, about 0.46 million of the total), matters are different.

Today, we’ll examine why high myopia is a more dangerous eye disorder than myopia, and identify the eye diseases for which it increases risk. Let’s begin by understanding it and its milder version.

Understanding myopia 

Myopia is a vision problem where objects nearby are relatively clear but objects farther away are not.

In a normal eye, light that enters it should be focused nicely on the retina. However, in myopic patients, the eye is shaped differently and more elongated, and this causes light that enters to focus in front of the retina, in the middle of the eye. Therefore, the light that eventually falls on the retina is not focused, and therefore, the image is blurry.

As mentioned earlier, myopia is a common visual problem, with predictions that it can potentially affect 49.8% of the world population by 2050. Alarmingly, the same study predicted that 9.8% of the global population will also have high myopia by then.

What is high myopia?

High myopia is defined as myopia requiring at least -6.00 diopters (or 600 degrees) of glasses correction. A simpler way of putting it is to say that it’s very severe nearsightedness.

People who are high myopes tend to have very elongated eyeballs. This means that all the layers of the eye and retina are spread out more thinly than normal patients. A way to picture this is to think of the eye as a balloon. It can only be elongated or stretched, but as it does so, the skin of the balloon gets thinner.

When the layers of the eye are thin, this can predispose patients to other problems within the eye.

The risks of high myopia

High myopia has been shown to increase the chances of a person suffering from a number of other serious eye conditions. The risks of high myopia include the following:

1. Glaucoma

Glaucoma or the “silent thief of sight” appears to occur more often in those who have high myopia. Unfortunately, as glaucoma barely shows symptoms until its later stages, it can be very hard to address swiftly.

Curiously enough, glaucoma detection also appears to be more difficult in those with high myopia.

2. Cataracts

Cataracts occur when the clear lens of the eye develops a clouded area obstructing vision. We do not yet know why cataracts tend to appear earlier in those with high myopia, there are a number of theories being proposed.

For example, some suggest that it may be because the elongated eyeballs of high-myopics make nutrient delivery more difficult to the lenses.

3. Retinal tears

Retinal tears happen when the retina or light-sensitive tissue in the eye is broken. High myopia makes that more likely because the retina is stretched more thinly, making them weaker and more prone to tearing.

4. Retinal detachment

This happens when the retina separates from the wall of the eye. This ties in with retinal tears – because the retina is thinner and more prone to being torn, when it goes untreated or unnoticed, then retinal detachments ensue.

5. Myopic maculopathy 

Another outcome of an abnormally elongated eye is the layers of the retina end up getting stretched past the limits of their elasticity. At some point, they may even stretch and split along a critical point: the macula.

The macula is at the very rear of the eye and is basically responsible for processing our direct and central vision. When it’s damaged, serious vision impairment can occur.

Interestingly, maculopathy is among the conditions where the risk of occurrence rises most drastically in response to increased myopia. Certain conditions in maculopathy can be treated and controlled, but some have a tendency to progress as you age.

Preventative measures

Once you reach adulthood, myopia usually stops progressing, and there are no precise measures that can stop you from developing complications of myopia.

Therefore, it is important to arrest the progression of myopia when you are still young. 

Parents can do this by ensuring that their children spend more time outdoors and in the open. When doing work, take regular breaks in between, and remind the child to keep the reading material at a good arm’s length away from the eyes. In addition, avoid reading in the dark or when lying down.

For children who have rapidly progressing myopia, there are options to slow this process down – please discuss this with your ophthalmologist.

Examples of strategies you can try would be the following:

These are more or less in line with our other tips for maintaining good eyesight, which you can read here.

Making lifestyle adjustments like switching to a diet that supports healthy eyesight

Avoiding sources of eye strain, like working in dim or dark conditions

Limiting the amount of time you spend staring at digital screens

Protecting your eyes from physical trauma by wearing appropriate eyewear for things like sports

Get examined for high myopia by a professional eye doctor

High myopia can be a troublesome eye ailment, not least because it seems to increase the risk of developing other vision problems. However, there are ways to try and reduce the odds of that happening.

If you want to check whether or not your nearsightedness qualifies as high myopia, call us or book an appointment for an eye screening with us today. We can provide guidance on what treatments or measures are available to you so that you can mitigate the risks of high myopia. Enquire now!