Understanding Glaucoma
Glaucoma is one of the leading causes of blindness in the U.S., but only half of those with glaucoma are aware they have it. Glaucoma refers to a group of eye diseases, which damage the optic nerve – the nerve that transmits visual information to the brain. Untreated glaucoma can damage the optic nerve so severely that permanent blindness, vision loss or visual distortion may occur.
Types of glaucoma
The most common type of glaucoma, affecting 90 percent of those with the disease, is primary open- angle glaucoma. With this type, drainage canals in the eye become blocked and lead to a buildup of fluid and pressure within the eye. This pressure can damage the optic nerve and lead to vision loss. Often, there are no warning signs with open-angle glaucoma. Vision loss is typically slow and gradual.
The second type of glaucoma is angle-closure glaucoma. This type of glaucoma develops because the eye cannot drain normally due to a narrow or blocked drainage canal. Eye pressure may rise quickly and symptoms such as sudden eye pain, nausea, blurred vision and headaches can occur.
Other less common types of glaucoma include:
- Normal-tension glaucoma: the optic nerve is damaged, but eye pressure is not high
- Secondary glaucoma: there is an identifiable cause for increased eye pressure, causing damage to the optic nerve, such as an eye injury, diabetes, cataracts and certain medications
- Congenital (childhood) glaucoma: occurs in infants during the prenatal stage when the eye’s drainage canals develop incorrectly or incompletely
- Traumatic glaucoma: caused by injuries to the eye
- Pigmentary glaucoma: occurs when flecks of pigment from the colored part of the eye (iris) gather in the clear fluid inside the eye, causing the drainage canals to clog slowly, which raises eye pressure
- Pseudoexfoliative glaucoma: caused by material peeling off the outer layer of the eye’s lens, which can block the drainage canals and increase eye pressure
- Neovascular glaucoma: this form is always associated with another condition – most frequently diabetes – and occurs when new blood vessels abnormally form on the iris and over the eye’s drainage canals, raising eye pressure
Symptoms of glaucoma
Source: National Eye Institute (NEI)
While the most common form of glaucoma typically has no symptoms at first, if it remains untreated, the following may occur:
- Slow loss of peripheral (side) vision
- Tunnel vision
- Low vision
- Blindness
Risk factors for glaucoma
Though glaucoma can develop in anyone at any age, certain factors increase one’s risk of developing the condition.
- Having a family history of glaucoma
- Being over 60 years old
- Having an increase in eye pressure
- Being African-American or Hispanic
- Having certain medical conditions such as: high blood pressure, diabetes, heart disease, sickle cell anemia
- Taking certain medications
- Undergoing certain eye surgeries or having an eye injury
How is glaucoma diagnosed?
Glaucoma can only be diagnosed through a comprehensive eye exam by an optometrist or ophthalmologist. During the exam, some of the tests performed may include:
- Visual acuity: reading letters from an eye chart at a distance
- Visual field test: the optometrist measures one’s peripheral vision
- Dilated eye exam: drops are placed into the eye to dilate the pupils. The optometrist will exam the eye’s health, including the retina and optic nerve for signs of damage
- Tonometry: eye pressure is measured through this special tool
How is glaucoma treated?
While there is no cure for glaucoma, there are certain treatment options available to delay the progression of the disease.
Medication: Pills or medicated eye drops are some of the most common early treatment options for glaucoma. Medication treatments focus on lowering eye pressure or making the eye produce less fluid. Patients should tell their optometrist about any other medications or supplements they are taking; sometimes, eye drops can interfere with other drugs. Taking the medication as directed is crucial to managing glaucoma.
Laser surgery: A laser surgery (laser trabeculoplasty) can be performed in your eye doctor’s office. It aims to drain fluid out of the eye, helping to relieve eye pressure. The optometrist will place numbing drops into the patient’s eye then hold a special lens in front of the patient’s eye and direct a laser beam at the eye. Inflammation may occur after the surgery and medicated eye drops may be prescribed.
Conventional surgery: This surgery, called trabeculectomy, is performed in an operating room. The patient is given medication prior to the surgery and the eye is numbed. The doctor will remove a small piece of tissue to allow fluid to drain, lowering the eye’s pressure. Medicated eye drops must be applied to protect against inflammation and infection for a few weeks after the surgery. This type of surgery is about 60-80 percent effective in lowering eye pressure, according to the National Eye Institute.
Optometrists at The Eye Institute of Salus University are experts in diagnosing glaucoma. They will provide customized management plans, suited for each patient’s needs.