Your eyes and glaucoma: The types, symptoms and treatment

By Steven A. Nielsen

Often referred to as “the sneak thief of sight,” glaucoma is the second leading cause of preventable blindness globally and the leading cause of blindness among those of African-American and Hispanic descents.

Glaucoma is a group of eye conditions that lead to optic nerve damage. In most cases, this damage is associated with a dangerous build up of internal eye pressure, known as Intraocular Pressure (IOP). Because there are no symptoms or warnings, as much as 40 percent of vision can be lost without a person noticing. Glaucoma usually progresses undetected until the optic nerve has been irreversibly damaged, with varying degrees of permanent vision loss.

There are two major types of glaucoma: Primary Open-Angle Glaucoma (POAG) and angle-closure glaucoma. Open-Angle Glaucoma is the most common type. Its cause is unknown; however, it does tend to run in families. Risk is higher if a parent or grandparent has open-angle glaucoma. With this type of glaucoma, Intraocular Pressure (IOP) increases due to blockage of the channels, or angles, that allow the clear fluid behind the eye to drain. The resulting pressure causes damage to the optic nerve, hindering the visual information carried to the brain.

The first sign of POAG is often the loss of peripheral, or side, vision, which can go unnoticed until late in the disease. This is why annual routine eye exams are critical. During this exam, an ophthalmologist dilates, or enlarges, the pupil of the eye using dilating drops. Once dilated, the appearance of the optic nerve can be studied. The ophthalmologist also performs a procedure called tonometry to check eye pressure, and a visual field test to determine whether or not any peripheral vision loss has occurred. If glaucoma is detected, a treatment plan is determined. While detecting glaucoma early will not reverse any vision loss that has already occurred, measures can be put in place to reduce, and in many cases, stop any further vision loss.

The goal of treatment is to reduce pressure in the eye. Open-angle glaucoma is most commonly treated with various combinations of eye drops, microsurgery, and a laser procedure called laser trabeculoplasty, in which a laser is used to pull open the meshwork drainage area behind the eye.  During this procedure, a new channel is created to drain the eye’s clear fluid, thereby reducing the intraocular pressure causing glaucoma. While surgical procedures are used to slow or prevent further vision loss, most people can be successfully treated with eye drops.  As with any treatment plan, success depends on consistency and following the treatment plan as prescribed.

Angle-closure glaucoma occurs when the exit of the eye’s clear fluid is suddenly blocked, causing a quick, severe and painful rise in the pressure behind the eye. Angle-closure glaucoma is an emergency, and medical attention should be sought immediately. Other symptoms associated with this type of glaucoma include cloudy vision, nausea and vomiting, rainbow-like halos around lights, and red eye.

While glaucoma is a serious condition, early detection is the key to preventing further vision loss or blindness. Having routine annual eye exams not only aids in the detection of this eye disease, but also increases the ability to maintain healthy eyes for years to come.