Angle-Closure Glaucoma: Causes, Symptoms, and Treatment

A brief struggle to focus may sometimes be the first warning of an eye ailment. Lights stretch into glowing rings, and within hours, vision may begin to deteriorate if left untreated. Angle-closure glaucoma acts fast, making awareness essential.

What is Angle-Closure Glaucoma?

The eye works like a camera, adjusting light and focus to create clear images. But when its drainage system gets blocked, pressure builds rapidly. This is angle closure glaucoma, a condition so serious that it can damage the optic nerve. Without immediate medical attention, vision loss may become permanent.

In a healthy eye, fluid flows smoothly through a drainage angle. When this angle becomes too narrow or closes completely, fluid gets trapped, raising intraocular pressure. The sudden spike in pressure can cause intense pain, blurred vision, and even blindness if untreated.

Unlike open-angle glaucoma, closed angle glaucoma develops suddenly and requires immediate care. Without prompt treatment, permanent damage can occur. Severe eye pain, headaches, or sudden vision loss demand urgent medical attention.

Types of Angle Closure Glaucoma

There are different types of angle closure glaucoma , including primary  and secondary forms:

Primary angle closure Glaucoma:

Not all cases of angle closure glaucoma are the same. The condition can develop suddenly or progress gradually, each form affecting vision differently. Understanding these types helps in seeking timely care.

• Acute angle closure glaucoma: A sudden and severe blockage causes a rapid rise in eye pressure. Symptoms appear instantly. They can be intense pain, nausea, red eyes, and blurred vision. This is a medical emergency requiring urgent treatment.
• Chronic angle closure glaucoma: The drainage angle narrows slowly over time. Vision loss may go unnoticed at first. By the time symptoms appear, damage to the optic nerve may already be significant.
• Intermittent angle closure: The angle partially closes and reopens intermittently, often serving as a precursor to acute angle-closure glaucoma. Symptoms such as mild headaches or temporary vision disturbances come and go, making the condition harder to detect.

Secondary angle closure Glaucoma:

This form happens along with another condition. These include:

• Poorly managed Diabetes which can cause proliferative diabetic retinopathy.
• Poorly managed BP and other vascular disease leading to Ischemic vein occlusion
• Uveitis

At Nethradhama Super Speciality Eye Hospital, expert ophthalmologists use advanced diagnostics to detect and treat all types of angle closure glaucoma.

How common is Angle-Closure Glaucoma?

Angle closure glaucoma is less common than open-angle glaucoma but poses a greater risk of sudden vision loss. It accounts for approximately one-third of global glaucoma-related blindness, with a higher prevalence in Asian populations. The condition is more prevalent in Asia, especially among older adults, women, and individuals with short axial length and shallow anterior chambers.

Studies suggest that people with farsightedness have a higher risk, as their eyes naturally have a narrower drainage angle. Those with a family history of glaucoma or conditions like uveitis also face increased susceptibility.

In India, cases of closed angle glaucoma are rising due to ageing populations. Increased awareness is also leading to the identification of the condition. Early diagnosis is crucial, as many people remain unaware of their risk until symptoms appear. Regular eye exams can detect early signs before irreversible damage occurs.

Causes of Angle-Closure Glaucoma

The eye constantly produces fluid to maintain pressure and nourish internal structures. In a healthy eye, this fluid drains smoothly. But in angle closure glaucoma, the drainage pathway narrows or shuts completely, causing a rapid pressure build-up.

Several factors, as outlined below, contribute to this blockage situation.

1. Eye anatomy: People with naturally small eyes or narrow drainage angles face a higher risk. Farsightedness also increases susceptibility.
2. Age and genetics: The risk rises with age, particularly after 40. A family history of glaucoma further raises the chances.
3. Eye conditions: Disorders like uveitis and cataracts can push the iris forward, blocking drainage.
4. Pupil dilation: In some cases, pupil dilation in dim light or during stress can trigger an episode of closed-angle glaucoma.

Symptoms of Angle Closure Glaucoma

Closed-angle glaucoma symptoms can appear suddenly or develop gradually. In acute cases, the warning signs are severe and demand immediate attention. Chronic cases may progress silently, causing slow vision loss.

Common closed-angle glaucoma symptoms include the following.

• Blurred vision: Objects appear hazy, so reading or focusing can become difficult.
• Halos around lights: Bright rings form around bulbs, especially at night.
• Severe eye pain: A deep, throbbing ache often spreads to the forehead.
• Headaches and nausea: Eye pressure spikes can cause dizziness and vomiting.
• Red eyes: The affected eye may appear inflamed and irritated.
• Sudden vision loss: If untreated, vision can fade within hours.

Diagnosing Angle-Closure Glaucoma

An eye specialist examines the drainage angle using a slit lamp and gonioscopy lens. This helps assess how fluid exits the eye and whether the angle is narrowing. 

Tonometry measures intraocular pressure, while optical coherence tomography (OCT) captures detailed images of the optic nerve. If vision appears blurry or halos around lights become frequent, a visual field test may reveal early loss of peripheral sight.

Treatment Options for Angle Closure Glaucoma

Once angle closure glaucoma is detected, treatment must begin immediately to prevent vision loss. The approach depends on the severity of the condition and how much the intraocular pressure has risen.

Medications like eye drops or oral drugs help lower pressure quickly. These work by reducing fluid production or increasing drainage. In acute cases, laser procedures such as laser peripheral iridotomy create a small opening in the iris, allowing trapped fluid to escape. If the angle remains narrow, surgery may be necessary to remove part of the iris or treat underlying conditions like cataracts.

Delaying treatment can cause permanent nerve damage. With modern advancements in eye care, managing closed angle glaucoma treatment has become safer and more effective.

Can Angle-Closure Glaucoma Be Prevented?

Regular eye exams help detect angle closure glaucoma before symptoms appear, reducing the risk of sudden vision loss.

For those with a narrow drainage angle, early laser treatment may prevent a full blockage. Managing conditions like uveitis and cataracts can also lower the chances of pressure build-up. If symptoms like blurred vision or eye pain occur, seeking immediate medical attention is crucial.