About the optic nerve

The mechanism by which we can see things
Did you know?

When light enters the eye, electrical signals are generated from cells in the retina at the back of the eye and transmitted to the brain via the optic nerve. It is at this point that the brain perceives "seeing." In a healthy eye, approximately 1.4 million nerve fibers come together to form the optic nerve, which connects the eye to the brain.

What is glaucoma?

Glaucoma is an eye disease caused by damage to the retinal ganglion cells that make up the optic nerve.

When these cells are damaged, a portion of the associated field of vision is lost, and this condition progresses gradually. Once damaged, the cells cannot regenerate, but early detection can halt the progression, allowing you to maintain your current daily vision.

What causes glaucoma?

The causes of glaucoma are diverse, including elevated intraocular pressure *, aging, blood flow, nearsightedness, and genetics.
* Pressure applied from the inside to the outside of the eye

Epidemiological studies (such as the Tajimi Study) have shown that more than half of Japanese glaucoma patients have "normal-tension glaucoma," meaning they develop glaucoma despite having normal intraocular pressure. Therefore, it is important to consider other glaucoma risk factors besides intraocular pressure.

The relationship between intraocular pressure and glaucoma

As mentioned earlier, there are various causes of glaucoma, but it is known that lowering intraocular pressure is effective in preventing the progression of symptoms. Even in patients with normal-tension glaucoma, it is possible to slow the progression of the disease through treatment that lowers intraocular pressure.
Furthermore, intraocular pressure (IOP) levels are not constant throughout the day, but fluctuate, sometimes rising and sometimes falling. Even if your IOP was normal when measured in the past, you should consult an ophthalmologist if you have any concerns.

What are the symptoms of glaucoma?
Is it progressing quickly?

Glaucoma usually has almost no noticeable symptoms until it has progressed significantly.

In fact, a large-scale study conducted by the Japanese Glaucoma Society (the Tajimi Study) revealed that approximately 90% of people diagnosed with glaucoma were unaware of their symptoms.

The reason is that even if the field of vision in one eye is impaired, the other eye compensates by filling in the gaps. Furthermore, the brain creates a consistent image by compensating for the missing information.

The initial symptom may be just a slight blur, but in​ ​most cases, the blur gradually expands over a long period of several decades. This makes it difficult to notice the change, which can lead to delayed diagnosis.

As glaucoma causes worsening blurred vision, symptoms such as difficulty seeing your feet and stumbling, missing traffic signals while driving, and slower reading speed due to difficulty seeing parts of text may appear, making daily life difficult.

How does glaucoma develop?
Are you going to diagnose it?

To detect glaucoma, it's necessary to have a fundus examination and other tests done at a hospital, rather than relying on self-diagnosis. If detected early, treatment can slow its progression.

If you feel something is wrong, you should go to the hospital immediately.