Understanding the Difference Between Open-Angle and Angle-Closure Glaucoma

Glaucoma is a group of eye conditions that damage the optic nerve in the back of your eye. The optic nerve sends electrical signals to your brain about what you see, so if it’s damaged in any way, you can lose your vision.

At Omphroy Eye Care, ophthalmologist Dr. Luis C. Omphroy diagnoses and treats glaucoma in his patients in Aiea, Hawaii. He tests for glaucoma each time you come in for a complete eye exam. Early detection can prevent the disease’s progression and help save your sight.

There are two different types of glaucoma: open-angle and angle-closure. Here’s what you need to understand about the difference between them.

Understanding glaucoma

Glaucoma occurs when the fluid (aqueous humor) inside your eye builds up, increasing the pressure on the optic nerve and damaging or destroying it. It’s one of the leading causes of vision loss in people older than 60.

Normally, the humor drains out of the eye through a channel called the trabecular meshwork. But if something blocks the channel, or if the eye produces too much fluid to drain properly, the pressure inside the eye increases.

Doctors don’t always know what causes the blockage or the excess fluid to develop, but they do know some part is hereditary. That means you’re more likely to develop the disease if you have a family member who has it.

Glaucoma can also result from blunt-force trauma to the eye, a chemical injury, diabetes, a severe eye infection, high blood pressure, and some inflammatory conditions. Still, most cases can be pinned down to age or genetics.

Glaucoma comes in two forms:

Open-angle (wide-angle) glaucoma

This is the more common form of the disease. Here, the trabecular meshwork appears normal, but fluid still doesn’t drain properly.

Glaucoma is often referred to as the "sneak thief of vision" because most people don’t develop symptoms until late in the disease, when they lose most of their peripheral vision. Any vision you lose can’t be recovered, which means that regular eye exams that include a test for intraocular pressure (IOP) are critical.

Angle-closure (narrow-angle) glaucoma

This form is more common in Asia, though the reasons why are unclear. Here, the drain space between the iris and cornea narrows until the eye can’t drain properly, leading to a sudden buildup of pressure.

Symptoms appear quickly, and damage occurs equally as quickly, so if you experience any of the following symptoms, contact our office ASAP or go to the nearest emergency room:

Halos around lights
Severe eye pain
Vision loss
Eye redness
Eyes that appears hazy (especially in infants)
Nausea or vomiting

Treatment to drain the fluid causing the pressure buildup is essential to prevent further vision loss.

Treatments for glaucoma

No matter which form of glaucoma you have, the treatment goal is to lower your IOP without causing further damage to the optic nerve. Treatments include:

Medications such as beta blockers (reduce fluid entering eye), prostaglandins (allow better fluid outflow), and alpha-adrenergic agonists (decrease humor production)
Laser trabeculoplasty to unblock clogged drainage tubes and restore normal fluid flow
Surgery such as filtering (like trabeculoplasty), inner eye drainage tubes, and other minimally invasive procedures

Dr. Omphroy discusses all your options with you before deciding what’s best for your particular case.

If you’re at risk for developing glaucoma, or if you haven’t had an eye exam in a while, it’s time to come into Omphroy Eye Care for an evaluation, including glaucoma testing. Give the office a call at 808-491-6513 to set up an appointment with Dr. Omphroy today.