Have you been told by your eye doctor that you have preglaucoma or "glaucoma suspect?" This doesn't means that you have glaucoma, which can damage the eye’s optic nerve and may result in vision loss and even blindness. It also means that you haven't sustained any proven damage to your vision.  

But it does signal that you are at increased risk for glaucoma and that you likely have higher than normal eye pressure, or intraocular hypertension—a common health issue that affects up to 10 percent of people over the age of 40.

Tissue-nourishing fluid moves in and out of the eye on a regular basis. If the fluid flows out of the eye too slowly, over time, it can build up. This can increase pressure on the optic nerve, potentially damaging it—the hallmark of glaucoma.

Normal eye pressure is between 12 and 22 millimeters of mercury (mmHg); anything above 22 is considered higher than normal. Not everyone with high eye pressure develops glaucoma, and some people with normal eye pressure develop glaucoma anyway. But about 10 percent of people with at least moderately high eye pressure (about 21 to 32 mmHg or more) will develop glaucoma within five years. The higher your eye pressure and the thinner your cornea, the greater your risk of glaucoma. Some research also suggests that high blood pressure may increase the risk for older adults.

Do You Need Glaucoma Treatment?

Some research suggests that almost half of the people with suspected glaucoma get prescription eye drops when they don't need them. But for those with moderate to high eye pressure, prescription eyedrops can reduce the likelihood of developing glaucoma by more than 50 percent over a five year period.

So, if your eye pressure reading is higher than normal, your doctor should first perform additional tests to determine your risk for full glaucoma. These may include ophthalmoscopy, which examines your optic nerve for glaucoma damage, and pachymetry, which measures the thickness of your cornea.

Depending on what the tests suggest, you may not need treatment—only monitoring by a health care professional, says Andrew Iwach, M.D., a spokesman for the American Academy of Ophthalmology.