Closed-angle glaucoma

Closed-angle glaucoma (CAG), also known as angle-closure glaucoma, is a type of glaucoma that occurs when the flow of aqueous humor (the clear fluid in the eye) is suddenly blocked, leading to a rapid increase in intraocular pressure (IOP). This condition is considered a medical emergency and requires immediate treatment to prevent permanent vision loss.

Causes and Risk Factors

Closed-angle glaucoma is caused by a physical blockage of the drainage canals in the eye, which prevents aqueous humor from exiting the eye, thereby increasing IOP. The risk factors for developing CAG include:

• Age: Individuals over the age of 40 are at higher risk.
• Ethnicity: People of Asian and Inuit descent have a higher predisposition.
• Family history: A family history of glaucoma increases the risk.
• Hyperopia: Far-sighted individuals are more prone due to shallower anterior chambers.
• Certain medical conditions: Conditions like cataracts and eye tumors can contribute to the development of CAG.

Symptoms

Symptoms of closed-angle glaucoma can be acute or chronic, with acute symptoms being more severe and sudden. They include:

• Severe eye pain
• Blurred vision
• Headache
• Nausea and vomiting
• Sudden visual disturbances
• Halos around lights
• Eye redness

Diagnosis

Diagnosis of closed-angle glaucoma involves a comprehensive eye examination, including:

• Measurement of intraocular pressure (Tonometry)
• Inspection of the drainage angle (Gonioscopy)
• Assessment of the optic nerve (Ophthalmoscopy)
• Visual field testing

Treatment

Treatment for closed-angle glaucoma aims to reduce intraocular pressure and prevent vision loss. Treatment options include:

• Medications: Eye drops or systemic medications to lower IOP.
• Laser therapy: Laser peripheral iridotomy (LPI) creates a small hole in the iris to improve fluid drainage.
• Surgical procedures: In cases where laser therapy is not effective, surgical intervention may be necessary to create a new drainage path.

Prevention

While some risk factors for closed-angle glaucoma cannot be changed, regular eye examinations can help detect the condition early and prevent significant vision loss.

See Also

• Glaucoma
• Open-angle glaucoma
• Ophthalmology
• Intraocular pressure