What Is Glaucoma?
Glaucoma is a family of different diseases affecting the optic nerve (the cable connecting the eye to the brain) often, but not always, associated with increased pressure within the eye. When glaucoma damages the optic nerve, visual information from the retina is impeded from reaching the vision centers of your brain. As the optic nerve is damaged over time, blind spots may appear in your peripheral vision and your central vision will eventually be affected as well.
Glaucoma is one of the leading causes of blindness in the United States and the leading cause of blindness for people over the age of 60, although it can occur at any age. Unfortunately, symptoms usually do not become evident until vision is already severely damaged. If caught early, however, the disease can be controlled and permanent vision loss prevented.
What Causes Glaucoma?
The exact cause of glaucoma is still not completely known; however, we have identified many risk factors. A major risk factor for glaucoma is increased pressure within the eye. This occurs when there is a buildup of fluid, called aqueous humor, that flows throughout the inside of your eye. This fluid is necessary to maintain the shape of the eye and it acts to maintain the function of the optically clear parts of the eye including the lens and cornea. Aqueous humor is normally drained through a tissue called the trabecular meshwork. If fluid is overproduced or does not drain properly, it can lead to increased pressure within your eye. As the pressure increases, it can damage your optic nerve and potentially lead to blindness.
Glaucoma tends to run in families for those with genes related to high eye pressure (intraocular pressure) and optic nerve damage. Other risk factors for developing glaucoma include:
- Being over the age of 60
- Being African American, Asian, or Hispanic
- Extreme nearsightedness or farsightedness
- Having corneas that are thin in the center
- Certain eye injuries or eye surgeries
- Taking corticosteroids, such as eye drops, for long periods of time
In general, most ophthalmologists divide glaucoma into two major categories: open-angle and closed-angle glaucoma. Within these two categories, there are many types of glaucoma that are typically characterized by the degree of eye pressure and its onset.
- Open-Angle Glaucoma – This is the most common form of glaucoma. As its name implies, the drainage angle of the eye where the iris meets the cornea is open, but it does not work properly. The disease usually has no symptoms and goes unnoticed until damage to the optic nerve is more severe.
- Angle-Closure Glaucoma (also called closed-angle glaucoma or narrow-closure glaucoma) – In angle-closure glaucoma, the drainage angle is blocked usually by the iris and prevents drainage of the fluid inside the eye known as aqueous humor. In acute cases, it develops very quickly causing noticeable symptoms and significant damage requiring immediate medical intervention.
In its early stages, glaucoma can be difficult to diagnose, however, if caught early during a glaucoma evaluation, it can be controlled and permanent vision loss prevented. If you are diagnosed with glaucoma, you’ll generally need treatment for the rest of your life to prevent the disease from progressing. Treatments for glaucoma focus on decreasing intraocular pressure to prevent damage to the optic nerve and the loss of vision or blindness that can result.
Depending on the severity of your glaucoma, your ophthalmologist may recommend a combination of the following treatment options:
- Eye Drops – Eye drops can reduce intraocular pressure by either reducing the rate at which fluid in the eye is produced or increasing the outflow of fluid from the eye.
- Laser Treatments – The object of laser treatments for glaucoma is to open the drainage angle of the eye and reduce intraocular pressure. Depending on the type of glaucoma and its severity, your ophthalmologist may recommend a laser iridotomy, laser trabeculoplasty, or laser cyclophotocoagulation. These procedures are often done in-office and are relatively painless.
- Glaucoma Surgery – Surgical options may be explored if your glaucoma cannot be controlled by medication or laser treatments. Surgical approaches that may be used include microinvasive glaucoma surgery (MIGS), trabeculectomy, or aqueous shunt insertion.
Glaucoma Research from Dean McGee
The Dean McGee Eye Institute is involved in several areas of clinical research, including glaucoma. Below you can learn about the ongoing glaucoma trials being conducted by the researchers at DMEI.
Study Name: Phase 3b Study to Evaluate the Duration of Effect of Bimatoprost SR (TRITON)
Condition(s) under Study: Open-angle Glaucoma or Ocular Hypertension
Study Summary: To compare the effectiveness of either 10 µg or 15 µg Bimatoprost SR in patients with Open-angle glaucoma or Ocular Hypertension who are not adequately managed with topical medications.
Investigator(s): Dr. Mahmoud Khaimi
ClinicalTrials.gov Information: NCT03850782
Study Name: Condition(s) under Study: XEN-45 Gel Stent Versus Trabeculectomy in Glaucoma: Gold-Standard Pathway (GPS)
Condition(s) under Study: Glaucoma
Study Summary: Phase IV open-label clinical trial to evaluate the ability of XEN to reduce IOP and reduce the amount of topical IOP-lowering medications in subjects poorly controlled on topical therapy.
Investigator(s): Dr. Ben Harvey
ClinicalTrials.gov Information: NCT03654885