Glaucoma is a disease that has no noticeable symptoms and is difficult to detect early. However, the incidence rate is high, with one in twenty people over the age of 40 and one in ten people over the age of 60 suffering from the condition, and it is also the leading cause of blindness among Japanese people. This page explains the causes of glaucoma, how it affects vision, and the types of treatment and tests available.

Causes, symptoms, treatment and surgery for glaucoma

What is Glaucoma?

Glaucoma is a disease that damages the optic nerve and narrows the field of vision. It progresses very slowly, and the field of vision gradually narrows. It often progresses one eye at a time. Therefore, it is a disease that has almost no subjective symptoms and is difficult to detect early.

Image of vision in glaucoma

From the early to mid-stages, some parts of the field of vision become gradually harder to see, narrowing the field of vision. However, because both eyes can complement each other, it is difficult to notice until the condition has progressed significantly. By the time symptoms become noticeable, the area of vision may be significantly narrowed, and in some cases, the patient may be barely able to see at all.

Causes of Glaucoma

Glaucoma occurs when the eye nerves cannot withstand the intraocular pressure (eye hardness). Intraocular pressure varies depending on the amount of fluid (called aqueous humor) in the eye.

Glaucoma is divided into several categories based on the factors that change the amount of aqueous humor.

• Primary open-angle glaucoma
• Normal Tension Glaucoma
• Primary angle-closure glaucoma
• Pediatric Glaucoma
• Secondary glaucoma

Symptoms of Glaucoma

In the majority of cases of glaucoma, there are no noticeable symptoms at all in the early stages because damage to the optic nerve occurs slowly and the field of vision (range of vision) narrows little by little.

At our clinic, it is usually discovered in patients who visit for other reasons, such as contact lens prescriptions, hay fever, or cataracts.

Once the optic nerve is damaged, it cannot be restored, so it is important to detect it early and prevent it from worsening any further. There is also acute glaucoma, in which intraocular pressure rises suddenly, causing severe symptoms such as eye pain, headache, nausea, and blurred vision. In such cases, there is a risk of blindness, so immediate treatment is required.

Glaucoma treatment process

Glaucoma cannot be cured completely because the optic nerve once lost cannot be restored.
The treatment of glaucoma is based on lowering intraocular pressure to protect the optic nerve and prevent further narrowing of the field of vision.

If glaucoma is diagnosed during a medical examination, and the condition is mild, eye drops will be prescribed first. The aim is to control intraocular pressure with eye drops. The patient will be monitored for a certain period of time with eye drops, and if the condition does not improve with eye drops, surgery or laser treatment will be performed.

Glaucoma Testing

Glaucoma is diagnosed from a multifaceted perspective after undergoing several tests. The following tests are mainly used to diagnose glaucoma.

• Intraocular pressure measurement
• Goniometry
• Fundus examination
• OCT scan
• Visual field test, etc.

Intraocular pressure measurement

Intraocular pressure is measured using a tonometer, which temporarily indents the surface of the eye by blowing air on it.
If the intraocular pressure is high, the indentation will return to its original state in a short time, but if the intraocular pressure is low, it will take longer to return to its original state. The intraocular pressure is measured by measuring the time it takes for the indentation to return to its original state. Since only air is applied to the eye, it is gentle on the eyes and causes little discomfort.

Goniometry

Gonioscopy is a test to check whether a person is prone to angle-closure glaucoma. By looking at the condition of the angle, it is possible to determine whether a person needs laser treatment for glaucoma. It is also useful for diagnosing uveitis, which is inflammation of the iris, ciliary body, and choroid.

Fundus examination

Fundus examination is an examination that uses a special lens to directly view the inside of the eye, such as the retina at the back of the eye, the entrance and exit of the optic nerve, blood vessels, etc. It is also used to examine eye diseases such as cataracts and glaucoma, as well as internal diseases such as high blood pressure, arteriosclerosis, and diabetic retinopathy.

OCT scan

OCT is a test that uses a device called an optical coherence tomography to take a cross-section of the retina. It allows for the observation of cross-sections of the retina, something that could not be done with regular medical examinations or fundus examinations, and allows for more accurate diagnoses of retinal diseases and macular lesions.

Visual field testing

A visual field test is a test that measures the range of vision when looking straight ahead and the sensitivity of the retina. The presence or absence and size of visual field defects (range of vision loss) are used to determine the progression of glaucoma. This is an important test not only for diagnosis, but also to confirm and understand the effectiveness of treatment.

Types of Glaucoma Treatment

eye drops

Eye drops that are often used to treat glaucoma are used to lower intraocular pressure. Side effects include "redness of the eye," "eye discomfort," and "eye pain." Also, if intraocular pressure can be properly controlled with eye drops, it is possible to maintain vision and visual field without deterioration. Please be sure to follow the prescribed frequency and type of eye drops.

SLT (Selective Laser Therapy)

This is a treatment to lower intraocular pressure in patients with primary open-angle glaucoma, the most common type of glaucoma. The human eye is naturally equipped with a function to promote the outflow of aqueous humor (which serves to supply nutrients to the cornea and lens) from within the eyeball. SLT is a treatment to lower intraocular pressure by improving this function using laser energy when it has been impeded for some reason.

Cost of Glaucoma Surgery

The cost is 10% of the cost, about 9,000 yen
Approximately 27,000 yen with 30% copayment
The official name is "goniophotocoagulation" and benefits may be available from life insurance and medical insurance.

Benefits of Laser Glaucoma Treatment

A laser treatment called SLT (selective laser therapy) is used for glaucoma. The benefits of SLT laser treatment are as follows:

• Treatment time is short (only 10 minutes or so)
• Highly safe (no side effects)
• Can be used in combination with other treatments
• Can be treated repeatedly

SLT is a safe and gentle treatment that does not harm the body. The power of the laser used in SLT is extremely low, about 1/6000 of that of conventional laser treatment, so there is almost no pain and no damage to the eye. By undergoing SLT, the burden of using eye drops for a long time and the risk of forgetting to apply them may be reduced. SLT only evaporates the cell debris that is stuck in the trabecular meshwork filter, so the trabecular meshwork itself is not damaged, and if the filter becomes clogged again and intraocular pressure rises, "the treatment can be repeated as many times as necessary." In addition, since it is performed on an outpatient basis, hospitalization is not required.

Disadvantages of laser treatment for glaucoma

Although there are no major risks or disadvantages to SLT laser treatment, it may not be suitable for some glaucoma symptoms or progression. In such cases, other treatments, such as surgery, may be required.

Glaucoma treatment testing equipment

OCT scan

Intraocular pressure testing

Fundus examination

Visual field testing

Frequently asked questions about the causes, symptoms, treatment and surgical treatment of glaucoma