Angle closure glaucoma

As in all forms of glaucoma, the end-organ damage is the optic nerve head. A sufficiently elevated IOP will damage the optic nerve, which is the structure that connects what the eyes see to the brain.

The “angle” is the part of the eye where the iris meets the cornea and the sclera. The drainage system of the eye is located at this region – trabecular meshwork. (See Open angle glaucoma.)

In primary angle closure glaucoma, the part of the angle where the trabecular meshwork is located is closed/obstructed by the peripheral iris. This angle closure leads to IOP rise and damage to the optic nerve. Angle closure glaucoma usually affects anatomically “small eyes” – in which intra-ocular structures within a limited space area results in a crowded anterior segment.

It typically affects more women than men, and although it may occur in any individual, it is more common in some ethnic groups (i.e. Chinese). Most of the cases are asymptomatic, but some show quite intense symptoms. (See Acute angle closure.)

The most common mechanism of angle closure is called pupillary block, and it occurs due to relative block of fluid flow at the level of the pupil (from the posterior to anterior part of the eye), which makes the pressure at the posterior chamber to increase, leading to a forward bowing of the iris and narrowing of the angle

Differentiation between an open angle and a closed angle glaucoma is important because the treatment approach differs, as we may use additional procedures to treat angle closure glaucoma when compared to open angle glaucoma cases.

Vid. 1. How does angle closure glaucoma occur?

Angle closure glaucoma Fig. 1

Fig. 1. Normal open angle (left figure) and normal aqueous drainage (middle figure). Right figure shows pupillary block and closed angle - due to the contact between the iris and trabecular meshwork.

World Glaucoma Association

Important message for glaucoma patients

It is important for you to get yourself regularly screened for glaucoma. If you have been diagnosed to have glaucoma, effective treatment options are now available and regular treatment and follow up can help you to preserve your vision for your lifetime, avoiding unnecessary fear of going blind.

You can live happily with glaucoma and enjoy an excellent quality of life, particularly if the disease is detected early and treated in time. Always remember that once you have glaucoma, you will have to be under the care of an eye doctor for the rest of your life.

There is a lot of research going on and new treatments may become available for glaucoma in the near future.

World Glaucoma Association