Let’s learn about the “four steps” to diagnose myopia?

Many parents think that myopia is not a complicated eye disease and is easy to diagnose. In fact, in hospitals or optometry centers, the examination and diagnosis of myopia are very strict and careful. There are at least four steps. In this article, Dr. Jingcai will talk to you about it.

The first step is to check the vision .

If the child is old enough and can cooperate with the parents, this step can be completed at home. The tool needed is called a standard logarithmic eye chart, which can be sold on Taobao and JD.com.

Our common eye chart looks like this. The "E"s on the top facing different directions are called sight marks. Each row of sight marks represents a different level of vision. The lower you go, the smaller the sight marks are. If you can see clearly, it means your vision is better.

When checking at home, the child is required to stand 5 meters away from the eye chart, and then check both eyes separately. The parent is responsible for standing next to the eye chart, pointing the sight marks from top to bottom to see if the child can accurately determine the direction of the notch of the letter E, until the last line that the child can see clearly is the child's vision in this eye.

How to record? On the standard eye chart, the same row of sight marks has two recording methods: "five-point recording" and "decimal recording". For example, the vision of 5.0 that we often say often represents very good vision. It is actually the five-point recording method, which corresponds to the decimal recording, which is 1.0. In hospitals, both methods are used. Parents should record both numbers when measuring at home.

The following three steps of examination need to be completed in the hospital. Here is a brief introduction for your understanding:

The second step is refractive examination.

This is what we call checking the degree. There are two ways to do this:

One is to use a computer ophthalmometer to perform computer ophthalmology. This method is convenient and fast, but the accuracy may not be sufficient.

The other is called subjective refraction, which takes longer and has more accurate results, but the child must be able to cooperate. It cannot be checked if the child is too young.

Through these examinations, we can get the accurate refractive status of the child’s eyes - myopia, hyperopia, and astigmatism can be seen at a glance.

Before the refractive examination, the doctor will sometimes dilate the child's pupils as needed. Why is this? Children under the age of 6 have stronger eye accommodation, so mydriatic drugs can be used to paralyze the ciliary muscles of the eyes. This can measure a more realistic refractive state and rule out the possibility of pseudomyopia. If the child's pupils are dilated, they may experience blurry vision, photophobia, and discomfort at close range. Pay attention to reducing outdoor activities and avoid accidental injuries due to unclear vision. This situation may last from a few hours to a few weeks depending on the mydriatic drug. Please consult a doctor for details.

The third step is to measure the axial length of the eye.

The axial length can be understood as the longitudinal diameter of the eyeball from front to back. Generally, the higher the degree of myopia, the longer the axial length, so measuring the axial length can assess the degree of myopia in children. Too fast an axial length growth also reflects the deepening of myopia. On average, a 1 mm axial length growth is accompanied by a 250 degree increase in myopia. This examination is performed using an eye biometer, and the examination report looks like this. It looks confusing at first glance, right? In fact, as a parent, you only need to grasp a few key points:

-The eye-catching large characters OD stands for right eye; OS stands for left eye;

-There are a lot of other values ​​that you can't understand without studying optometry and ophthalmology for a few years. You only need to understand AL, which is the axial length of the eye, and the unit behind it is mm (millimeter).

Step 4: Other eye examinations.

It is mainly to exclude other eye diseases, including slit lamp microscopy, intraocular pressure measurement, corneal topography examination, etc.

If you find this content helpful, you are welcome to share it with other parents. Maybe they need it too. Thank you.

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About Dr. Jingcai: The creators of Dr. Jingcai's popular science content all have a professional background in ophthalmology, a master's degree or above, and are former ophthalmologists. For some popular science content with a higher degree of professionalism, we will also invite working ophthalmologists and optometry experts to review and check it, striving to be responsible for the accuracy of the content and avoid misleading readers.