Glaucoma is the primary cause of blindness in adults over age 60. Known as the “silent thief of sight,” vision loss from glaucoma occurs slowly over time. Since there are no initial symptoms, the disease can go undetected for years — most patients don’t realize they have glaucoma until they experience vision loss.
The good news is, it’s possible to diagnose and treat glaucoma before it causes irreversible damage. Preventative care such as scheduling routine eye exams and maintaining good health will help reduce your risk of blindness from glaucoma.
What is glaucoma?
Glaucoma is a term used to describe a group of diseases that cause serious damage to the optic nerve, the part of the eye that sends visual information to the brain. If left untreated, glaucoma can result in vision loss or permanent blindness.
What causes glaucoma?
Glaucoma is caused by an increase in eye pressure levels, also known as ocular hypertension. This occurs when the area at the front of the eye (anterior chamber) fills with extra fluid. When the fluid doesn’t drain out of the eye properly, the pressure levels inside the eye increase, which causes the optic nerve to be damaged. The change to the optic nerve disrupts the transmission of visual data to the brain, which results in vision loss.
Types of glaucoma
- Open-Angle Glaucoma. Open-angle glaucoma, the most common type of glaucoma, occurs when the drainage system or “open angle” of the eye becomes clogged, which results in a rise in eye pressure. The open angle is the part of the eye where the cornea meets the iris.
- Angle-Closure / Narrow-Angle Glaucoma. Some people have narrow angles, which means that the angle between the outer edge of the iris (the colored part of the eye) and cornea (the surface of the eye) is narrower, or more closed, than normal. Narrow angles can lead to a blockage in the eye’s drainage system, which causes a sudden, rapid increase in eye pressure. This sudden spike in pressure levels can cause severe headaches, eye pain, nausea, or blurred vision.
- Low-Tension / Normal-Tension Glaucoma. This type of glaucoma occurs in people who have normal eye pressure levels. Despite there being no presence of ocular hypertension, people with normal-tension glaucoma are still at risk of optic nerve damage. More research needs to be done in order to fully understand the cause of this form of the disease.
- Secondary Glaucoma. Secondary glaucoma occurs in patients with another eye condition such as a tumor, uveitis, or trauma to the eye. Advanced stages of cataracts or diabetes can also contribute to the development of secondary glaucoma.
- Congenital Glaucoma. People with congenital glaucoma are born with the disease, which is caused by a defect in the eye’s drainage system. While rare, babies and small children are at risk of developing congenital glaucoma if there is a family history of the disease.
What are the symptoms of glaucoma?
Most often, there are no symptoms of open-angle glaucoma. Many patients don’t know they have the disease until vision loss occurs. In cases of closed-angle glaucoma, however, patients may experience severe eye pain, nausea, headaches, or blurry vision. If any of these symptoms appear suddenly, it’s important to contact your eye doctor or emergency services.
Treatment for glaucoma
While there is no definitive way to prevent or cure glaucoma, it is possible to control the progression of the disease. The following medications and surgeries can slow or prevent vision loss due to glaucoma:
- Eye Drops. Medicated eye drops are typically the most common form of treatment to stabilize eye pressure in patients with open-angle glaucoma.
- Laser Trabeculoplasty. During this procedure, an eye surgeon applies laser energy to the drainage angle of the eye. As a result, fluid drains properly, and eye pressure is reduced. Laser trabeculoplasty is typically performed on open-angle glaucoma patients.
- Laser Iridotomy and Iridectomy. These treatments are for closed-angle glaucoma. A laser is used to create a small hole in the iris, the colored part of the eye, which helps fluid travel out of the drainage angle. The release of excess fluid helps lower pressure in the eye.
- Trabeculectomy. An eye surgeon makes a small incision in the white part of the eye to remove a minimal amount of mesh tissue, which helps excess fluid drain out of the eye.
- Shunts. Aqueous shunts are tiny devices that are implanted in the eye to drain a buildup of fluid and reduce eye pressure.
- MIGS. Minimally invasive glaucoma surgery can be combined with cataract surgery to implant very small devices into the drainage meshwork of the eye. These devices reduce eye pressure in adults with mild or moderate open-angle glaucoma and cataracts.