Closed Angle Glaucoma: Types, risk factors and symptoms

Closed angle glaucoma is a type of glaucoma caused by a narrow drainage angle in the eye.

This condition often leads to a sudden increase in eye pressure, which can be harmful if not treated promptly.

What is closed angle glaucoma?

Closed angle glaucoma, also known as angle closure glaucoma, arises when the drainage angle of the eye is too narrow. The drainage angle is crucial for the regulation of aqueous fluid, which maintains the eye's shape. When this angle is narrow, the fluid's outflow is obstructed, causing a rise in eye pressure. This type of glaucoma is less common than open angle glaucoma, representing less than 10% of cases, but it tends to present with more noticeable symptoms.

Types of closed angle glaucoma

Closed angle glaucoma can be classified into two main types:

1. Primary closed angle glaucoma
• This type is due to an anatomically narrow drainage angle that a person is born with. Such a narrow angle restricts fluid outflow, leading to increased eye pressure and potentially causing acute angle closure glaucoma. This is a medical emergency requiring immediate treatment.
2. Secondary closed angle glaucoma
• Phacomorphic glaucoma: Occurs when a growing cataract narrows the drainage angle, raising eye pressure.
• Latrogenic glaucoma: Caused by certain medications or surgical procedures that affect the drainage angle.
• Traumatic glaucoma: Results from physical injury to the eye, which can displace the lens or cause bleeding, blocking the drainage angle.

Risk factors for closed angle glaucoma

Several factors can increase the likelihood of developing closed angle glaucoma:

• Age: Older individuals are at higher risk.
• Gender: Women are more susceptible than men.
• Family history: A family history of glaucoma increases risk.
• Long-sightedness (Hyperopia): Those with long-sightedness often have smaller eyes, leading to narrower drainage angles.
• Race: Individuals of Asian descent are more prone to this type of glaucoma.

Symptoms of closed angle glaucoma

Unlike open angle glaucoma, which develops gradually, closed angle glaucoma often presents suddenly with severe symptoms. These include:

• Red and painful eye: Noticeable discomfort and redness.
• Blurred vision: Difficulty seeing clearly.
• Halos around lights: Visual disturbances.
• Severe pain: Often accompanied by headaches, nausea, and vomiting.
• Distorted pupil: The pupil may appear irregular.

If you experience these symptoms, seek immediate medical attention as closed angle glaucoma is an ophthalmic emergency.

Read more about open angle glaucoma.

Treatment for closed angle glaucoma

Treatment initially involves using eye drops to lower eye pressure. Long-term management may require surgical intervention to prevent future episodes:

• Laser peripheral iridotomy: A YAG laser creates a small hole in the iris to improve fluid drainage and reduce eye pressure. This procedure takes 10-15 minutes per eye, and both eyes can be treated simultaneously if needed. Post-treatment, vision may be blurred and the eye may appear red for up to 24 hours, but these effects are usually temporary.
• Clear lens extraction (Refractive Lens Exchange): This involves removing the natural lens of the eye and replacing it with an artificial lens. This not only helps to open the drainage angle but can also correct refractive errors, potentially reducing or eliminating the need for glasses.
• Filtration surgery: For younger individuals, where lens extraction may not be sufficient, filtration surgery might be necessary. This involves creating a new drainage channel to lower eye pressure, through procedures such as trabeculectomy or tube surgery.

For more information on glaucoma treatments, please visit our treatment page.