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Glaucoma Care

Glaucoma FAQ

The following are some of the common questions answered by UMMC ophthalmologists regarding glaucoma care and services.

What causes glaucoma?

There are different theories for the cause of glaucoma. It is important to understand that the end result for all the theories is progressive damage to the optic nerve (optic neuropathy).

One such theory is based on elevated intraocular pressure. It is important to note that high intraocular pressure is not synonymous with glaucoma. There are certain types of glaucoma that have normal intraocular pressure.

A clear liquid called aqueous humor circulates the front portion of the eye. To maintain a healthy level of pressure within the eye, a small amount of this fluid is produced constantly while an equal amount flows out of the eye through a microscopic drainage system. Because the eye is a closed structure, if the drainage area for the aqueous humor – called angle – is blocked, the excess fluid cannot flow out of the eye. Fluid pressure within the eye increases, pushing against the optic nerve and causing damage.

Another theory is based on compromise of the blood supply to the optic nerve resulting in progressive damage to the nerve. There may be many factors that come in to play to cause vascular compromise.

What are the different types of glaucoma?

There are different types of glaucoma but they can be broadly divided into these two groups – chronic open-angle and closed-angle.

Chronic open-angle glaucoma is the most common form of glaucoma in the United States, and risk of development increases with age. The drainage angle of the eye becomes less efficient over time and pressure within the eye gradually increases, possibly resulting in damage to the optic nerve. In some patients, the optic nerve becomes sensitive even to normal eye pressure and is at risk for damage. Treatment is necessary to prevent further vision loss.

Open-angle glaucoma typically has no symptoms in its early stages and vision remains normal. As the optic nerve becomes more damaged, blank spots develop in the field of vision. You may not notice these blank spots in your day-to-day activity until the optic nerve is significantly damaged and these spots become large.

Closed-angle glaucoma occurs when the iris is very close to the drainage angle in certain eyes. These eyes are often small and farsighted, and the iris could be sucked into the drain and block it completely. Since the fluid cannot exit the eye, pressure can build up rapidly, resulting in acute closed-angle attack.

Symptoms may include blurred vision, severe pain, headaches, rainbow halos around lights, nausea, and vomiting. This is a true eye emergency, and if you have any of these symptoms constantly or intermittently, call your ophthalmologist immediately. If not treated quickly, this type of glaucoma can result in blindness.

Who is at risk for glaucoma?

Your ophthalmologist considers different kinds of information to determine your risk for developing the disease. The most important risk factors include:

  • Age.
  • Elevated intraocular pressure.
  • Family history of glaucoma.
  • African or Spanish-American ancestry.
  • Farsightedness (closed-angle) or nearsightedness (open–angle.)
  • Past eye injuries.
  • Thinner central corneal thickness.
  • Systemic health problems including diabetes, migraine headaches and poor circulation.

Your ophthalmologist will weigh all these factors before deciding whether you need treatment or monitoring as a glaucoma suspect. This means your risk of developing glaucoma is higher than normal and you need to be followed closely to detect early signs of glaucoma.

How is glaucoma detected?

Regular eye examinations by your eye doctor are the best way to detect glaucoma. A glaucoma screening that only checks pressure is insufficient to determine if you have glaucoma.

During your glaucoma evaluation, your ophthalmologist will measure your intraocular pressure (tonometry), inspect the drainage of your eye (gonioscopy), evaluate any presence of optic nerve damage (ophthalmoscopy) and test the field of vision of each eye (visual field testing of perimetry). Photography of the optic nerve or computerized imaging may be recommended. These tests may need to be repeated on a regular basis to monitor any changes in your condition.

How is glaucoma treated?

As a rule, damage caused by glaucoma cannot be reversed. Eye drops, laser surgery and surgery in the operating room are used to help prevent further damage. In some cases, oral medications may also be prescribed. With any type of glaucoma, periodic examinations are important to prevent vision loss. Glaucoma can progress without your knowledge, hence the need for routine follow-up visits to check the progression of the disease and adjust therapy as needed.

Medication

Glaucoma is usually controlled with medicated eye drops each day. The drops lower eye pressure by reducing aqueous production or increasing outflow through the drainage angle or other tissue. Never change or stop taking your medication without consulting your ophthalmologist. Glaucoma medications can preserve your vision, but may also produce side effects.

Notify your ophthalmologist if you think you may be experiencing side effects, including:

  • A stinging or itching sensation.
  • Red eyes or redness of the skin surrounding the eyes.
  • Changes in pulse and heartbeat.
  • Changes in energy level.
  • Changes in breathing (especially with asthma or emphysema).
  • Dry mouth.
  • Changes in taste sense.
  • Headaches.
  • Blurred vision.
  • Changes in eye color.

All medications can have side effects or possible interaction with other medicines. It is important that you make a list of the medication you regularly take and share it with each doctor you see.

Laser Surgery

Laser surgery treatment may be recommended for different types of glaucoma. In open-angle glaucoma, the drain itself is treated. The laser is used to modify the drain (trabeculoplasty) to help control eye pressure. In closed-angle glaucoma, the laser creates a hole in the iris (iridotomy) to improve the flow of aqueous fluid to the drain.

Microsurgery 

When surgery in the operating room is needed to treat glaucoma, your ophthalmologist uses fine, microsurgical instruments to create a new drainage channel for the aqueous fluid to leave the eye. Surgery is recommended if your ophthalmologist feels it is necessary to prevent further damage to the optic nerve.

What is the patient's part in treatment?

Treatment for glaucoma requires teamwork between you and your doctor. Your ophthalmologist can prescribe treatment for glaucoma but only you can make sure you follow your doctor’s instructions and take your eyedrops.

Once you are taking medication for glaucoma, your ophthalmologist will want to see you regularly. Typically you will need to follow up every three to four months, depending on your treatment needs.

How often should I be screened for glaucoma?

Regular medical eye exams may help prevent unnecessary vision loss. People with risk factors listed above have a higher risk for developing glaucoma and require more frequent screening examinations. Recommended intervals for eye include:

  • Age 20-29
    Individuals of African descent or those with a family history of glaucoma should have an eye exam every three to five years. Others should have an exam at least once during this period.
  • Age 30-39
    Individuals of African descent or those with with family history of glaucoma should have an eye exam every two to four years. Others should have an exam at least twice during this period.
  • Age 40-64
    Everyone in this age group should have an eye exam at least every two to four years.
  • Age 64 or older
    Everyone in this age group should have an eye exam at least every one to two years.