Consultation Corner

Preserving Your Sight

What You Need to Know About Glaucoma

Glaucoma Specialists-Eye Laser Center

Robert M. Kershner, MD, FACS

          Most people are unaware that glaucoma is a serious health concern. As people get older and start seeing doctors more regularly, they are often advised to get their eyes examined.  One of the important parts of a comprehensive eye exam by an ophthalmologist is the measurement of eye pressure.  An individual may hear that “my eye pressure is good”, or “my eye pressure is too high”.   But how does pressure relate to glaucoma?

Glaucoma is a disease of the optic nerve.  The optic nerve carries images from the eye to the brain, allowing one to see.  When the optic nerve is damaged as in glaucoma, peripheral vision, the vision off to the side of your line of sight, may be lost.  Sometimes the effect is so minimal as to be unnoticeable, and people are often unaware of the loss of a localized area of vision. If glaucoma goes undetected or untreated, it is possible for it to progress to complete blindness.  Treatment of glaucoma is aimed at controlling eye pressure. This is accomplished with medicine in the form of eye drops, but sometimes may involve the use of lasers or eye surgery.

Who is at risk for glaucoma?  Glaucoma is common in the elderly.  It is rarely seen in the younger age groups, but people in their 70’s have a 2% chance of having it, and 4% of those may develop it in their 80’s.  African-Americans tend to develop glaucoma far more commonly than other ethnic groups.  If it’s in your family, there’s about a 10% chance you too may develop glaucoma.  So if you have a family member with glaucoma-you are at risk and should have regular eye examinations with an ophthalmologist.

There are many forms of glaucoma. The two most common are primary open angle glaucoma and low tension (“normal pressure”) glaucoma.  Unless the disease is far advanced, most people with glaucoma have no eye or vision symptoms.  Eye pressures can be much higher (greater than 22mm as measured by a "tonometer"), than the normal range (18-20mm and may go unnoticed for years.  If an individual feels a sensation of pressure in the eye it is more likely due to sinus pressure or allergies than  from high pressure in the eye itself.  Visual loss associated with glaucoma tends to progress gradually, over a period of years, so slowly in fact that most people don’t notice any change at all.  Unfortunately, because the loss of vision from glaucoma is gradual and without symptoms, the vision that is lost is not recoverable; when the damage is done, it’s done.  The angle closure form of glaucoma is less common and usually appears as a sudden rise in pressure, accompanied by blurred vision and pain.  It requires immediate intervention.  Those susceptible include people who are very farsighted or have a family history of angle closure glaucoma.

Preserving sight is the goal of treating glaucoma. Because it is relatively easy to measure, pressure is the hallmark of glaucoma testing. That is why glaucoma patients talk about their pressures, which are routinely checked in eye exams.  Vision loss is measured by a visual field test, which measures peripheral vision with an automated computer.  By looking at a screen and pushing a button to signal when a spot of light is seen, a map of an individual's field of vision can be constructed.  Comparing this map with normal alerts the examiner when there is vision loss.

Thirty percent of patients with glaucoma have normal pressures at detection, and may never have pressures above normal.  The visual field test and examination of the optic nerve are particularly important in these cases.  The optic nerve normally shows a central depression or “cup”, which can become enlarged in glaucoma patients as a result of tissue atrophy.  This optic nerve “cupping” can be seen directly by the examining doctor using a variety of instruments, and its appearance can be recorded with photographs and other techniques.

The only proven treatment for glaucoma is lowering of the intraocular pressure, and is effective even in cases of normal-pressure glaucoma.  Medication in the form of eyedrops or by mouth can be used to lower eye pressure, much in the same way a doctor lowers blood pressure with medicine. In underdeveloped nations, surgery may be used as a first line of defense against loss of vision, in part due to the expense or lack of availability of medication.  Surgery always carries some risk of complications, however, which is why it is generally reserved in this country for more difficult cases.  Laser treatment is a good alternative.  Laser trabeculoplasty, as it is termed, may decrease the eye pressure sufficiently, and for many people may allow them to eliminate or avoid additional medications to control their pressure.  The effect of laser may fade over time, which is why anyone with glaucoma needs to been followed carefully throughout the year to detect a change in the effectiveness of their treatment.

          Can glaucoma be cured?  Though, the disease may not be eliminated entirely, new treatments are being developed all the time which are more effective than ever before in reducing eye pressure over a long period of time.  New eyedrops are now effective for once-a-day dosage, making the treatment more effective without the inconvenience or side effects of previous medications.

How serious a threat is glaucoma to your sight?  The answer is different for each individual.  A Mayo clinic study published three years ago reviewed the files of 295 patients treated there.  It was estimated that people with glaucoma have a 27% chance of going blind in one eye if they have the disease for 20 years or more.  This frightening statistic must be tempered with the knowledge that we are now better able to diagnose and treat glaucoma than ever before. For example, if the patient is 88 years old, and we anticipate the visual field loss to be slowly progressive over many years, that patient may not require any treatment.  On the other hand, a 40-year-old with visual field loss and high pressures despite medical therapy, may require surgery to preserve sight.  The recent availability of better medications and improved surgical techniques promise a new level of hope of treating all forms of glaucoma.

Now that you know what you need to know, what do you need to do to preserve your vision? The first step is a comprehensive eye exam by an eyecare professional.  Glaucoma is diagnosed by examination, not by symptoms. At the Eye Laser Center, Dr. Robert Kershner and a highly trained staff of medical professionals utilize the latest technology in the early diagnosis and treatment of this potentially blinding disease.  Our newly acquired HRT (Retinal-Optic Nerve Tomograph) utilizes a powerful high speed computer to quickly scan the retina and optic nerve and map out the appearance and contour of the eye's anatomy.  Using this test, a color 3-D image is created and can be analyzed to detect even the slightest changes to the optic nerve.  In many cases, these changes can appear before they can be detected  by your doctor with the naked eye, conventional equipment and before vision loss can be detected with the visual field test.  This fantastic breakthrough in technology may make earlier diagnosis a reality. Reduce your risk of losing your sight and see for the rest of your life.  Get your eyes examined now and make it a regular part of taking care of your health.


Robert M. Kershner, MD, FACS Eye Laser Center, 1925 W. Orange Grove Road, Suite 303, Tucson, AZ 85704-1152, (520)797-2020. 

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Eye Laser Center
Robert M. Kershner, M.D., F.A.C.S.
TUCSON, AZ 85704-1152
Phone: (520) 797-2020
Fax: (520) 797-2235

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