Angle-Closure Glaucoma

Angle-closure glaucoma is a serious eye condition where the drainage angle in your eye becomes blocked, causing a sudden and often painful increase in eye pressure. This pressure can quickly damage the optic nerve, which is vital for vision. Prompt treatment is crucial to prevent permanent vision loss.

What is Angle-Closure Glaucoma?

Angle-closure glaucoma, also known as narrow-angle or acute glaucoma, occurs when the iris (the colored part of your eye) bulges forward and blocks the drainage angle of the eye. This blockage prevents the fluid inside your eye (aqueous humor) from draining properly, leading to a rapid and significant rise in eye pressure. This condition is an emergency that requires immediate medical attention.

Your eye constantly produces a clear fluid called aqueous humor. This fluid nourishes the eye and normally drains out through a mesh-like channel called the trabecular meshwork, located in the angle between your iris and cornea (the clear front surface of your eye). In angle-closure glaucoma, this drainage angle becomes suddenly blocked. When the fluid cannot drain, it builds up inside the eye, causing the pressure to increase rapidly. This high pressure can damage the optic nerve, which sends images from your eye to your brain. Damage to the optic nerve can lead to permanent vision loss if not treated quickly. This condition is different from open-angle glaucoma, which develops slowly over time. Angle-closure glaucoma often comes on suddenly, causing severe symptoms like eye pain, blurred vision, halos around lights, headache, nausea, and vomiting. It can affect one or both eyes.

Why it's done

Treatment for angle-closure glaucoma is performed to quickly lower the dangerously high eye pressure and prevent permanent damage to the optic nerve. Without immediate intervention, the sustained high pressure can lead to irreversible vision loss or even blindness. The goal is to restore proper fluid drainage and protect your vision.

The primary reason for treating angle-closure glaucoma is to relieve the acute pressure buildup in the eye. This high pressure can cause rapid and severe damage to the delicate fibers of the optic nerve. Once the optic nerve is damaged, the vision loss is usually permanent. Treatments aim to create a new pathway for the aqueous humor to drain from the eye or to open the existing drainage angle. This helps to stabilize the eye pressure and prevent further damage. Early treatment is critical to preserve as much vision as possible and to prevent future attacks in the same or other eye.

How to prepare

Preparing for angle-closure glaucoma treatment typically involves a thorough eye examination and discussion with your eye doctor (ophthalmologist). You may receive eye drops to help lower eye pressure before the procedure. It's important to follow all instructions, arrange for transportation home, and inform your doctor about any medications you are taking.

Before the procedure, your eye doctor will conduct a comprehensive eye exam. This includes measuring your eye pressure, examining the drainage angle, and checking your vision. They will explain the procedure, its benefits, and potential risks. Your doctor may prescribe eye drops to help reduce the eye pressure before the procedure. You might also receive medication to help shrink your pupil or reduce fluid production. It is crucial to use these medications exactly as directed. You should also inform your doctor about all prescription and over-the-counter medications, supplements, and herbal remedies you are currently taking. You will likely need someone to drive you home after the procedure, as your vision may be temporarily blurry.

What happens during

During treatment for angle-closure glaucoma, a trained eye doctor typically performs a laser procedure called a laser peripheral iridotomy. This involves using a laser to create a tiny hole in your iris, allowing fluid to flow more freely and relieve pressure. In some cases, a surgical procedure called a peripheral iridectomy may be necessary.

The most common treatment is a laser peripheral iridotomy. During this outpatient procedure, your eye will be numbed with eye drops. Your doctor will then use a special laser to create a small opening in the outer edge of your iris. This tiny hole allows the fluid to bypass the blocked drainage angle and flow from the back of the iris to the front of the eye, where it can drain more easily. This helps to flatten the iris and open the drainage angle. The procedure usually takes only a few minutes. You might see bright flashes of light and feel a mild stinging sensation. After the laser treatment, you may receive anti-inflammatory eye drops to use for a short period. In situations where laser treatment is not effective or appropriate, a surgical peripheral iridectomy might be performed. This involves surgically removing a small piece of the iris to create a new drainage pathway.

Recovery & timeline

Recovery after angle-closure glaucoma treatment is usually quick, especially after a laser peripheral iridotomy. You may experience some temporary blurry vision, mild discomfort, or light sensitivity for a few hours to a few days. Your doctor will schedule follow-up appointments to monitor your eye pressure and ensure the treatment was successful.

Immediately after a laser iridotomy, your vision might be temporarily blurry, and you may experience some mild irritation or a feeling of grittiness in your eye. These symptoms typically resolve within a day or two. You will likely be prescribed anti-inflammatory eye drops to use for about a week to help with healing and reduce any inflammation. It's important to attend all follow-up appointments. Your eye doctor will check your eye pressure and examine the treated eye to ensure the hole in your iris is open and functioning correctly. They will also monitor the other eye, as angle-closure glaucoma often affects both eyes. Most people can resume their normal activities within a day or two, but it's wise to avoid strenuous activities for a short period as advised by your doctor.

Risks & side effects

While angle-closure glaucoma treatments are generally safe and effective, like any medical procedure, they carry some potential risks and side effects. These can include temporary blurry vision, mild eye discomfort, inflammation, or a temporary increase in eye pressure. More rarely, bleeding, infection, or the need for repeat treatment can occur.

Common and usually temporary side effects after a laser peripheral iridotomy include mild eye pain or discomfort, temporary blurry vision, and light sensitivity. Some people may experience a temporary spike in eye pressure immediately after the procedure, which is usually managed with additional eye drops. Less common but more serious risks can include bleeding inside the eye, inflammation that persists, or damage to the cornea or lens. In some cases, the small hole created by the laser might close up over time, requiring a repeat procedure. There is also a small risk of developing glare or seeing an extra line of light, especially at night, due to the new opening in the iris. Your doctor will discuss these risks with you before the procedure.

Success rate

The success rate for treating acute angle-closure glaucoma with laser peripheral iridotomy is generally high, especially when performed promptly. The procedure is usually effective at opening the drainage angle and lowering eye pressure, which helps prevent further damage to the optic nerve and preserves vision. However, some individuals may still require ongoing management.

Laser peripheral iridotomy is highly effective in breaking an acute angle-closure attack and preventing future attacks in most cases. The procedure successfully creates a new pathway for fluid flow, which helps to flatten the iris and open the drainage angle, thereby reducing eye pressure. This can prevent the rapid and severe vision loss associated with untreated angle-closure glaucoma. While the laser procedure is often successful in resolving the immediate crisis, some individuals may still need medication to manage their eye pressure long-term, especially if there was pre-existing damage or if the pressure remains elevated. Regular follow-up with an eye doctor is crucial to monitor eye pressure and overall eye health, as the condition can sometimes recur or affect the other eye.

Frequently asked questions

Can angle-closure glaucoma be cured?

Angle-closure glaucoma cannot be "cured" in the sense that the underlying narrow angle may still exist, but treatments like laser iridotomy can effectively manage the condition by opening the drainage pathway and preventing future attacks. This helps to control eye pressure and prevent further vision loss, but ongoing monitoring is usually necessary.

What causes angle-closure glaucoma?

Angle-closure glaucoma is caused by a blockage of the eye's drainage angle, usually when the iris bulges forward and presses against the cornea. This can be triggered by factors like pupil dilation (from certain medications or dim light), anatomical features of the eye, or age-related changes that narrow the angle.

What are the symptoms of an angle-closure glaucoma attack?

Symptoms of an acute angle-closure glaucoma attack often appear suddenly and severely. They can include intense eye pain, blurred vision, seeing halos around lights, headache, nausea, and vomiting. The eye may also appear red and feel hard to the touch. Seek immediate medical attention if you experience these symptoms.

Is angle-closure glaucoma hereditary?

While angle-closure glaucoma is not directly inherited like some genetic conditions, having a family history of the disease can increase your risk. Certain eye structures that predispose individuals to narrow angles, such as a shallower front chamber of the eye, can run in families. Regular eye exams are important if you have a family history.

Can I prevent angle-closure glaucoma?

You cannot always prevent angle-closure glaucoma, especially if you have an anatomically narrow drainage angle. However, regular comprehensive eye exams can help your eye doctor identify risk factors before an acute attack occurs. If you are at risk, a preventative laser iridotomy may be recommended to widen the drainage angle and reduce the chance of an attack.

What happens if angle-closure glaucoma is left untreated?

If angle-closure glaucoma is left untreated, the extremely high eye pressure will quickly and permanently damage the optic nerve. This can lead to irreversible vision loss, including blindness, within a short period. Prompt treatment is essential to relieve pressure and preserve vision.

Sources

• MedlinePlus — Angle-Closure Glaucoma
• Mayo Clinic — Angle-Closure Glaucoma
• Cochrane Library — Angle-Closure Glaucoma