What’s gradual, painless and dubbed the Silent Thief of Sight?

The answer is Glaucoma, an eye disease that slowly causes you to lose your vision.  If you’ve been proactive in monitoring your health, you should hopefully have a pretty good idea of certain health conditions that run in the family.  For example, mom has high cholesterol, dad has diabetes and you remember your grandmother uses eye drops for something.  Knowing your family eye history is very important because most eye diseases tend to be genetic.  Glaucoma, for example, tends to run on the mother’s side of the family.  If your mom has glaucoma, make sure you tell your optometrist.

glaucomadimming_55Laney69

Courtesy of 55Laney69 on Flickr
(Left – Normal Vision, Right – with glaucoma)

What exactly is Glaucoma?  It’s a disease where the optic nerve slowly deteriorates as a result of poor blood flow and is often accompanied by high intraocular pressures.  The optic nerve is a bundle of smaller nerve fibers, similar to a conduit, which transmits electrical signals from the retina to the brain.  In glaucoma, the smaller nerve fibers slowly deteriorate, resulting in a gradual loss of vision.  The first areas of vision loss will occur in the periphery, off to the sides, which is very difficult to detect since we are not often aware of our peripheral visual field.  If a patient experiences symptoms, the first symptom may be poor night vision.  As the disease progresses, vision loss creeps in toward the center of your visual field.  By the time you notice that you are losing your peripheral vision and developing “tunnel vision,” you will be in the late stages of glaucoma.

The good news is that glaucoma is the leading cause of PREVENTABLE blindness.  Routine eye examinations will allow an optometrist to detect glaucoma sooner.  There are a variety of tests necessary to detect glaucoma such as a visual field screening, measurement of the intraocular pressures, and careful evaluation of the optic nerve to detect changes.  Many offices now incorporate retinal photos into their routine examinations that are invaluable in detecting many retinal diseases including glaucoma.  Glaucoma is a diagnosis over time, it is rarely diagnosed on a first visit.  When change is detected in the structure of the optic nerve or in the thickness of its surrounding nerve layer over time, then glaucoma is diagnosed.  This is where comparing current retinal photos to older ones are helpful in detecting small changes over time.  Another important tool in the last few years is the Optical Coherence Tomography, which measures microscopic layers of the retina to detect microscopic changes.

So what happens if you do have glaucoma?  Treatment is often pretty simple.  There are a few different forms of glaucoma.  The majority of them are treated with eye drops with dosages as little as once a day.  The medicated eye drops lower the intraocular pressures in the eyes, which help to slow down the progression of glaucoma.  Some patients require laser treatments to lower their pressures.  Most cases of glaucoma are manageable and treatable if detected early.

I usually tell my patients that the ages of 20s and 30s is for establishing a baseline.  This is where routine examinations and photos are useful.  The ages of 40s and onward is for detecting change and eye diseases, and treating early.  Of course, as with any other diseases of the body, staying healthy is key.  Those with diabetes have a much higher likelihood of developing glaucoma so keep your blood sugar under control.  Those of Asian, Latino and African descent have a higher tendency for developing glaucoma.  Having a high amount of nearsightedness also puts you at greater risk.

The take home message is that glaucoma is treatable if detected early.  So know your family health history, stay healthy and see your optometrist routinely for comprehensive eye examinations.

~Cindy P. Wang, O.D., F.A.A.O.
California Optometric Association
http://www.coavision.org