What Is Glaucoma?
Glaucoma is a disease of the optic nerve, which is the part of the eye that carries the images we see to the brain. The optic nerve is made up of many nerve fibers, like an electric cable containing numerous wires. When pressure inside the eye increases, damage to the optic nerve fibers may occur, causing blind spots to develop. These blind spots usually go undetected until the optic nerve is significantly damaged. If the entire nerve is destroyed, serious consequences could result.
A scene as it might be viewed by a person with glaucoma. (National Eye Institute, NIH)
What Causes Glaucoma?
Clear liquid, called the aqueous humor, circulates inside the front portion of the eye. A small amount of this fluid is produced constantly, and an equal amount flows out of the eye through a microscopic drainage system, maintaining a constant level of pressure within the eye. (This liquid is not part of the tears on the outer surface of the eye.)
Because the eye is a closed structure, if the drainage area for the aqueous humor-called the drainage angle-is blocked, the excess fluid cannot flow out of the eye. Fluid pressure within the eye will increase, pushing against the optic nerve and potentially causing damage.
Who Is At Risk For Glaucoma?
Your Ophthalmologist considers many kinds of information to determine your risk for developing the disease.
The most important risk factors include:
- Family History of Glaucoma
- African Ancestry
- Past Eye Injuries
The single most important factor in early diagnosis is a dilated eye examination for the doctor’s evaluation of a patient’s optic nerves. Suspicious nerves are imaged by our Heidelberg Spectralis OCT Scanner(below left) to follow very specific neural layers that may become progressively thinner through glaucoma. Furthermore, at Ludwick Eye Center we routinely test patients visual fields with Humphrey Perimeters (below right) to monitor for blind spots and peripheral vision changes.
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 methods used to help prevent further damage by lowering eye pressure. In some cases, oral medications may also be prescribed.
Selective Laser Trabeculoplasty (SLT, shown below left) is utilized as a repeatable office laser procedure to safely reduce eye pressure in combination with drops or in place of medication.
Endoscopic Cyclo Photocoagulation (ECP, shown above right) is an intraocular surgical technique that inhibits the production of aqueous in the eye with laser technology, typically resulting in a decrease in intraocular pressure, and the reduction or elimination of a patient's dependence on glaucoma medications. ECP is typically performed on glaucoma patients undergoing cataract surgery.
An introduction to Endoscopic CycloPhotocoagulation
With any type of glaucoma, periodic examinations are very important to prevent vision loss. Because glaucoma can progress without your knowledge, adjustments to your treatment may be necessary from time to time.
Loss of Vision Can Be Prevented
Regular medical eye exams may help prevent unnecessary vision loss. Recommended intervals for dilated eye exams are:
- Age 20-39: Individuals of African descent or with a family history of glaucoma should have a medical exam every 3 to 5 years. Others can be seen at least once during this period
- Age 40-64: Every 2 to 4 years
- Age 65 or older: Every 1 to 2 years