Glaucoma: Causes, Symptoms, and Treatment Options

Glaucoma is a group of eye conditions that damage the optic nerve, which is vital for good vision. This damage is often caused by abnormally high pressure in the eye. Glaucoma is one of the leading causes of blindness for people over the age of 60. However, blindness from glaucoma can often be prevented with early treatment.

What is Glaucoma?

Glaucoma is an eye disease that affects the optic nerve, which transmits visual information from the eye to the brain. The health of the optic nerve is essential for good vision. Glaucoma is typically caused by an increase in intraocular pressure (IOP), the pressure within the eye. If not treated, this increased pressure can cause damage to the optic nerve and result in vision loss.

Types of Glaucoma

1. Open-Angle Glaucoma: This is the most common form of glaucoma. The trabecular meshwork (the eye’s drainage system) appears open, but the fluid passes too slowly through the meshwork, leading to increased eye pressure. Often, there are no symptoms in the early stages. Vision loss progresses slowly and can go unnoticed until it affects central vision.

2. Angle-Closure Glaucoma: This type occurs when the iris bulges forward to narrow or block the drainage angle formed by the cornea and iris, leading to a sudden increase in eye pressure. It can be chronic (develops gradually) or acute (sudden onset). Symptoms can include severe eye pain, nausea, vomiting, blurred vision, halos around lights, and redness in the eye.

3. Normal-Tension Glaucoma: Even with normal eye pressure, optic nerve damage can occur due to a sensitive optic nerve or a reduced blood supply to this nerve. Similar to open-angle glaucoma, it can progress without noticeable symptoms.

4. Congenital Glaucoma: This type is present at birth and results from an abnormal development of the eye’s drainage system. Symptoms can include cloudy eyes, excessive tearing, and sensitivity to light.

5. Secondary Glaucoma: This form develops as a result of an injury, inflammation, tumour, or in association with conditions like diabetes or cataracts. Symptoms vary depending on the underlying cause but can include similar symptoms to other types of glaucoma.

Symptoms of Glaucoma

Glaucoma is a group of eye conditions that damage the optic nerve, which is crucial for vision. This damage is often caused by abnormally high pressure in the eye. The symptoms of glaucoma can vary depending on the type and stage of the condition. Here are the detailed symptoms for the different types of glaucoma:

1. Open-Angle Glaucoma

Open-angle glaucoma is the most common type and develops gradually.

Early Symptoms:

• No Symptoms: In the early stages, there are typically no symptoms, which is why it is often called the "silent thief of sight."
• Gradual Loss of Peripheral Vision: Over time, patients may notice a gradual loss of peripheral (side) vision, which can go unnoticed until significant vision is lost.

Advanced Symptoms:

• Tunnel Vision: In the advanced stages, patients might experience tunnel vision, where they can see objects directly in front of them but not to the sides.

2. Angle-Closure Glaucoma

Angle-closure glaucoma can occur suddenly or gradually and is characterized by a rapid increase in intraocular pressure.

Acute Angle-Closure Glaucoma Symptoms:

• Severe Eye Pain: Sudden and intense eye pain is common.
• Headache: Accompanying the eye pain, patients might experience a severe headache.
• Nausea and Vomiting: These symptoms can occur due to the sudden increase in eye pressure.
• Blurred Vision: Vision may become blurry suddenly.
• Halos Around Lights: Seeing halos or rainbow-coloured rings around lights is a frequent symptom.
• Red Eyes: The eyes may appear red and bloodshot.

Chronic Angle-Closure Glaucoma Symptoms:

• Gradual Loss of Peripheral Vision: Similar to open-angle glaucoma, there may be a gradual loss of peripheral vision.
• Intermittent Blurred Vision: Vision may become blurry periodically.
• Halos Around Lights: Seeing halos around lights, particularly in low light conditions.

3. Normal-Tension Glaucoma

Normal-tension glaucoma occurs even when intraocular pressure is within the normal range.

Symptoms:

• Gradual Loss of Peripheral Vision: Similar to open-angle glaucoma, with a slow and unnoticed loss of peripheral vision.
• Tunnel Vision: In advanced stages, tunnel vision may occur.

4. Congenital Glaucoma

This type of glaucoma is present at birth and may be diagnosed in infancy or early childhood.

Symptoms in Infants and Young Children:

• Enlarged Eyes: One or both eyes may appear larger than normal.
• Cloudy Corneas: The clear part of the eye may look cloudy.
• Excessive Tearing: Persistent tearing without obvious irritation or infection.
• Light Sensitivity: The child may show signs of discomfort in bright light (photophobia).
• Irritability: Due to eye discomfort, infants might be unusually irritable.

5. Secondary Glaucoma

Secondary glaucoma results from an underlying condition such as eye injury, inflammation, tumour, or advanced cataract.

Symptoms:

• Symptoms of the Underlying Condition: Depending on the cause, symptoms may include eye pain, redness, or vision changes.
• Gradual or Sudden Vision Changes: This can vary based on the type and progression of the underlying condition.

Early detection of glaucoma is crucial to prevent irreversible vision loss. Regular eye exams, including measurements of intraocular pressure and optic nerve assessment, are essential, especially for those at higher risk (e.g., individuals with a family history of glaucoma, older adults, people with high intraocular pressure, and those of African, Asian, or Hispanic descent).

If you experience any symptoms of glaucoma, it is vital to seek prompt medical attention from an eye care professional. Early treatment can help manage the condition and preserve vision.

Diagnosis

Regular eye exams are crucial for early detection. Comprehensive eye exams may include:

• Tonometry: Measures the intraocular pressure.
• Ophthalmoscopy: Examines the shape and colour of the optic nerve.
• Perimetry: Tests the complete field of vision.
• Gonioscopy: Inspects the drainage angle of the eye.
• Pachymetry: Measures the thickness of the cornea.

Treatment Options

1. Medications: Prescription eye drops are often the first treatment for glaucoma. They help to either reduce the production of fluid within the eye or improve its outflow.

Prevention and Management

While glaucoma cannot be prevented, the risk of developing the disease can be reduced through regular eye exams, especially if you are in a high-risk group (over 60, have a family history of glaucoma, are of African, Asian, or Hispanic descent, have high eye pressure, or are nearsighted).

Glaucoma is a serious eye condition that requires early detection and ongoing management to prevent vision loss. Regular eye exams are crucial, especially for those at higher risk. If you experience any symptoms or have concerns about your eye health, consult with an eye care professional promptly.