Closed Angle Glaucoma | Types, Risk Factors & Symptoms

What is closed angle glaucoma?

Closed angle (angle closure/narrow angle) glaucoma is a type of glaucoma, which is a condition usually associated with a rise in eye pressure. This type of glaucoma results from a narrow drainage angle in the eye. Drainage angle is important because this is how aqueous fluid (which helps the eye keep its spherical shape) is regulated. If drainage angle is narrow, the aqueous outflow is restricted and eye pressure can rise, leading to glaucoma. Closed angle glaucoma generally comes on suddenly and with more obvious symptoms than open angle glaucoma. Closed angle glaucoma is also less common, constituting less than 10% of cases.

Types of closed angle glaucoma

Narrow angle glaucoma can be divided into two main types: primary and secondary. These types are based on whether the closed angle is inherent in the patient’s eye, or whether there is a secondary cause for it.

Risk factors for closed angle glaucoma

There are a number of factors which may increase a patient’s chance of developing angle closure glaucoma. These include:

• Age: glaucoma is more common in older patients
• Gender: women are more likely to develop closed angle glaucoma than men
• Family history of glaucoma: someone is more likely to develop the condition if a close family member (a sibling or parent) also has it
• Long Sightedness (hyperopia): those who are long sighted often have smaller eyes, which makes them more likely to have narrow drainage angles
• Race: those of Asian origin are more prone to developing closed angle glaucoma

What are the symptoms of closed angle glaucoma?

Unlike open angle glaucoma, a patient with closed angle glaucoma usually experiences symptoms due to the rapid nature of the rise in eye pressure. They will generally have a red and painful eye, as well as blurred vision and halos. The severe pain can cause headaches, nausea and even vomiting. The patient’s pupil may also look distorted. Someone experiencing these symptoms should seek immediate medical attention.

Closed angle glaucoma treatment

Eye drops will initially be used to reduce eye pressure when a patient has closed angle glaucoma. Surgery will then be needed to prevent a future attack.

One option is laser peripheral iridotomy. In this procedure, a YAG laser is used to make a tiny hole in the iris to create a new outflow for aqueous fluid, in turn lowering eye pressure. This treatment takes 10-15 minutes per eye, and both eyes can be treated at the same time if necessary. Generally vision will be blurred and the eye will be red for up to 24 hours after the procedure, but vision should quickly return to normal.

Clear lens extraction (also known as refractive lens exchange) is a surgical procedure which is also used to treat cataracts. It involves removing the natural lens of the eye and replacing it with an artificial lens which is more slim-line, hence permanently opening the drainage angle and reducing eye pressure. The new lens can also remove the need for the patient to wear glasses, as it will correct existing refractive errors, depending on the type of lens chosen.

In younger patients (45 and below), where lens extraction may not be sufficient, filtration surgery will be the treatment option. As the name suggests, this essentially leads to creating a new drainage angle in the eye to lower the pressure. It includes trabeculectomy surgery or tube surgery.

Read more about the different types of glaucoma treatment available here.