by Jessica Philbrook, O.D.
Q: I heard that January is Glaucoma Awareness month, but I don’t even know what Glaucoma is. Could you give me some details so I will know if I am at risk?
A: Glaucoma is a disease of the eye that can cause gradual loss of peripheral vision and eventual blindness due to a loss of fibers in the optic nerve. The optic nerve is a nerve inside the eye that transmits visual information from the eye to the brain. The true cause of glaucoma is still unknown, however there are two major theories. The first theory is related to pressure in the eye called intraocular pressure. Within the eyeball a fluid, called aqueous humor, is produced by a structure called the ciliary body. The fluid drains from the eye through a structure called the trabecular meshwork. This fluid is necessary to maintain the shape and health of the eye, but when too much fluid builds up, the intraocular pressure increases and this can damage the optic nerve. Build up of fluid can be caused by too much production by the ciliary body or too little drainage by the trabecular meshwork. The second theory of the cause of glaucoma is related to poor blood flow to the optic nerve due to vascular problems and/or diabetes.
When your eye doctor examines your eyes, they will check your eye pressure and also look at your optic nerves to assess if you may be at risk for glaucoma. They may take photographs or use special retinal imaging equipment to better assess your optic nerves as well. A visual field test that measures your peripheral vision in each eye may also be performed because optic nerve damage in glaucoma results in side vision loss. If any of these assessments show suspicious findings, your eye doctor may perform additional testing to determine if you actually have glaucoma. New high tech instruments, similar to an MRI, allow many eye doctors to measure the thickness of the retinal nerve fiber layer so as to watch for thinning. Such instruments allow your eye doctor to diagnose and follow glaucoma patients much more accurately than in years past.
In addition to high eye pressure and suspicious optic nerves, family history is another significant risk factor. If you have a sibling with glaucoma you are more likely to develop the disease than if your parent has glaucoma. Other risk factors include heart/vascular disease, diabetes, age (over 60), and African American heritage. Any of these risk factors should be mentioned to your doctor.
If your doctor has determined that you do have glaucoma, there are a few different treatments available. Generally, the first course of treatment involves eye drops that must be used daily for an indefinite period of time to help decrease the pressure in your eyes. If drops do not lower the pressure enough to satisfy your doctor, they may refer you for a surgical procedure.
Glaucoma is a disease that can gradually steal your sight and in the early stages there are no symptoms. Due to this it is very important that you see your eye doctor on a regular basis because only they can diagnose the disease and help to prevent vision loss and blindness.
