Are you familiar with glaucoma?
Glaucoma is a progressive eye disease characterized by damage to the optic nerve, which transmits visual information from the eye to the brain. As the disease progresses, it can lead to gradual and irreversible loss of the visual field.
In its early stages, glaucoma often causes no noticeable symptoms. As a result, the condition may progress undetected, even in individuals who do not experience any apparent changes in their vision.
In Japan, glaucoma is one of the leading causes of acquired visual impairment. The risk of developing the disease also increases with age.
However, early diagnosis and appropriate ongoing treatment can help slow disease progression and preserve visual function over the long term.
In this article, we will provide an overview of glaucoma, including its underlying causes, clinical symptoms, and the potential consequences of leaving the condition untreated.
Contents
1. What Is Glaucoma?
Glaucoma is an eye disease characterized by damage to the optic nerve, resulting in visual field defects.
Our eyes receive light from the surrounding environment through the retina, which then transmits visual information to the brain via the optic nerve. This process allows us to see the world around us.
The optic nerve plays a vital role in connecting the eye to the brain.
In glaucoma, the optic nerve becomes progressively damaged, reducing the amount of visual information transmitted to the brain. As a result, parts of the visual field may become missing or gradually narrowed. This is known as visual field loss or visual field defects.
One of the key characteristics of glaucoma is that damage to the optic nerve is generally irreversible.
Therefore, the primary goal of glaucoma treatment is not to restore vision that has already been lost, but to prevent further damage to the optic nerve and slow the progression of the disease.
2. Is Glaucoma Caused by High Intraocular Pressure?
One of the major factors associated with the development and progression of glaucoma is intraocular pressure (IOP).
Intraocular pressure refers to the pressure exerted by the fluid inside the eye against the walls of the eyeball.
The eye contains a clear fluid called aqueous humor, which circulates continuously and helps nourish structures such as the cornea and lens.
The balance between the production and drainage of aqueous humor helps maintain a stable level of intraocular pressure.
However, when the drainage of aqueous humor is impaired, IOP may increase. Elevated IOP can place additional stress on the optic nerve and potentially lead to damage.
However, glaucoma does not occur only in people with elevated IOP.
In Japan, a particularly common form of the disease is normal-tension glaucoma, in which the optic nerve becomes damaged despite IOP remaining within the statistically normal range.
In other words, having normal IOP does not necessarily mean that you are free from glaucoma.
3. What Are the Symptoms of Glaucoma?
The most characteristic symptom of glaucoma is the gradual loss of parts of the visual field.
Some common changes may include:
- Difficulty seeing certain areas within the field of vision
- A gradual narrowing of the visual field
- Missing areas of vision when looking with one eye
However, these changes are rarely noticeable during the early stages of glaucoma.
This is partly because visual field loss usually progresses very slowly. In addition, when vision in one eye is impaired, the other eye may compensate to some extent.
The brain may also fill in missing visual information based on the surrounding environment, making it difficult to recognize abnormalities in everyday life.
As a result, glaucoma may continue to progress even in people who have good visual acuity and experience no noticeable difficulties in their daily activities.
It is important to note that an acute angle-closure glaucoma attack, which involves a sudden and significant increase in IOP, can cause symptoms such as sudden eye pain, redness, blurred vision, headache, and nausea.
If you experience any of these symptoms, seek immediate medical attention from an ophthalmologist.
4. What Happens If Glaucoma Is Left Untreated?
Without appropriate treatment, glaucoma can continue to damage the optic nerve, resulting in progressive and irreversible visual field loss.
In the early stages, only small areas of the visual field may be affected. However, as the disease progresses, these areas of vision loss may expand and begin to interfere with everyday activities.
For example, patients may have difficulty noticing obstacles while walking or recognizing steps and changes in floor levels when using stairs.
In advanced stages, glaucoma can cause severe and permanent visual impairment.
It is important to understand that, with current medical treatments, vision lost due to glaucoma generally cannot be restored.
However, early detection and appropriate treatment can help slow the progression of visual field loss and preserve existing visual function.
Being diagnosed with glaucoma does not necessarily mean that you will lose your sight. Rather than becoming unnecessarily anxious, it is important to focus on early detection, appropriate treatment, and regular long-term monitoring.
5. Early Detection of Glaucoma Is Essential
Because glaucoma often causes few or no noticeable symptoms in its early stages, it can be difficult to detect on your own.
For this reason, regular eye examinations are important, even if you do not experience any visual problems.
Regular examinations are particularly recommended for people over the age of 40 and those with a family history of glaucoma.
Diagnosing glaucoma requires a comprehensive evaluation using several tests, rather than relying on intraocular pressure measurements alone.
These examinations may include:
- Intraocular Pressure (IOP) Measurement
- Fundus Examination
- Visual Field Testing
- OCT (Optical Coherence Tomography)
Since glaucoma can occur even when IOP is within the normal range, it is important not to rely solely on intraocular pressure measurements when assessing the possibility of glaucoma.
Summary
Glaucoma is an eye disease in which damage to the optic nerve leads to gradual and progressive visual field loss.
Because the disease often causes few or no noticeable symptoms in its early stages, it may progress without the patient realizing it.
Although vision lost due to glaucoma is generally irreversible, early detection and appropriate ongoing treatment can help slow disease progression and preserve visual function.
To protect your long-term eye health, regular ophthalmic examinations are important, even when you have no noticeable symptoms.
Understanding glaucoma and prioritizing early detection and timely treatment are essential steps toward protecting your vision.