Shauna Glenn Zemken, an optometrist who works in Fort Plain, said many people are confused about glaucoma and what causes the disease.
Especially when it comes to having a high intraocular pressure in the eye, she said, people need to be aware there are other risk factors for glaucoma.
"That's the major thing," Zemken said.
Shauna Glenn Zemken, an optometrist in Fort Plain, left, shows how an electronic indentation tonometer works with the help of her administrative assistant, Nora Collins, at her office Thursday. Zemken applied the device to the cornea of an eye to get a reading on the intraocular pressure inside. Having a high IOP is a risk factor for glaucoma. Collins does not have glaucoma, and Zemken said she uses the device to get an IOP measurement on many patients.
The Leader-Herald/Rodney Minor
According to the U.S. National Library of Medicine - www.ncbi.nlm.nih.gov - glaucoma refers to a group of eye conditions that lead to damage to the optic nerve. The nerve carries visual information from the eye to the brain.
According to a news release from the New York State Optometric Association, glaucoma can strike without pain or other symptoms and is a leading cause of blindness in the United States.
However, awareness and understanding surrounding glaucoma is relatively low, the release said.
"According to data from the American Optometric Association's latest American Eye-Q consumer survey, less than 20 percent of all Americans know that glaucoma primarily causes deterioration to peripheral vision," the release said.
About 50 percent of Americans believe glaucoma is preventable, the release said, which is not correct.
Steven Hammer, an optometrist at Williamson Optical in Johnstown, said people sometimes get glaucoma confused with cataracts.
According to the National Library of Medicine, a cataract is a clouding of the lens of the eye.
Hammer also said people need to be aware IOP is not the sole determinant for glaucoma.
"Some people have relatively high pressure and they are OK," he said.
Zemken and Hammer noted the thickness of the cornea was an issue for years with IOP ratings.
However, now a pachymetry test can be done to measure the thickness of the cornea, Hammer said. This can aid a more accurate reading of eye pressure, he said.
"A thick cornea will protect the eye, so it can tolerate higher pressure," he said.
Zemken noted about 30 percent of people with glaucoma have normal eye pressure.
"There are a number of factors that appear to influence who develops glaucoma," she said.
Both said regular, comprehensive eye exams are the only way to spot glaucoma.
Hammer said open-angle glaucoma - its most common form - happens when damage to the optic nerve is slow and painless. A large portion of peripheral vision can be lost before problems are noticed.
"[Glaucoma] can be there but someone may not be aware of it," he said.
Jonathan Nickel, an ophthalmologist with?Adirondack Eye Care in Gloversville, said some people expect they will notice the symptoms of glaucoma. Unfortunately, glaucoma tends to be asymptomatic.
Nickel said people sometimes incorrectly say something such as, "My mom had glaucoma, but I see fine so I'm OK."
Other types of glaucoma include: angle-closure glaucoma, a less common form of the disease that occurs when the drainage angle in the eye closes or becomes blocked; secondary glaucoma, which occurs as the result of injury or another eye disease; and normal-tension glaucoma, which occurs when the optic nerve is damaged but eye pressure remains within a normal range.
At her office on Thursday, Zemken demonstrated how she can test IOP of fluid inside the eye. One is a handheld device which - after the patient is given some eyedrops to numb the eye - is briefly pressed and held against the eye.
Another device she uses, called the Pascal Dynamic Contour Tonometer, which unlike older methods is supposed to avoid any problems with corneal thickness throwing off IOP measurements.
Zemken said ultimately, it's a good thing many people are aware of the importance of intraocular pressure. However, they need to be aware there are other risk factors.
According to the release, only 16 percent of people surveyed indicated knowing that race or ethnicity may increase their risk.
Those at higher risk for glaucoma include: African-Americans older than age 40; anyone older than 60, and people with a family history of glaucoma.
Nickel said although glaucoma can cause people to lose their eyesight, it is a disease that is very treatable if it is caught early.
According to the National Library of Medicine website, treatment of glaucoma typically involves those with the disease taking eye drops or pills to lower pressure in the eye. Surgery also is sometimes used to help fluid escape from the eye.
For more information, visit the Glaucoma Research Foundation website at www.glaucoma.org