It is the silent thief of sight, but new technology is allowing optometric physicians to detect the progression of glaucoma before it causes blindness.

Glaucoma is the leading cause of preventable blindness in the U.S., affecting between 3 and 4 million Americans, including an estimated 1.5 to 2 million people who do not even know they have the disease. Glaucoma is caused by a build-up of fluid in the eye, which increases eye pressure and damages the optic nerve leading to vision failure. It most often occurs in people over age 40, and those who are African American, have a family history of glaucoma, are very nearsighted or diabetic are at higher risk of developing the disease. The most common type of glaucoma develops gradually and painlessly, often without symptoms until after vision is impaired.  Reductions of peripheral vision and/or blurred vision are the first noticeable symptoms of glaucoma, and are irreversible. While glaucoma is not curable, it can be slowed or halted. The earlier glaucoma is detected, the less damage it can cause and the longer vision will be maintained.

“Glaucoma can sneak up on a patient without warning and before he or she may think to visit an Optometric Physician for an eye exam, vision loss is already occurring,” said Dr. Kathy Yang-Williams of the Optometric Physicians of Washington.  “New technology is helping us to find changes earlier in the disease, and patients have to understand the sooner glaucoma is detected the better chance we have to slow vision loss.”

Standard, Effective Tests    

Optometric Physicians use a variety of methods during an eye exam to detect glaucoma, often before any vision loss has occurred.  Tonometry measures the pressure in the eye or intraocular pressure (IOP).  Risk for glaucoma is directly related to eye pressure, but there are considerations such as optic nerve structure and thickness of the cornea.  Another test, pachymetry uses optical or ultrasound technology to measure the thickness of the cornea and adjust the pressure measurement, and visual field testing uses a patient’s response to lights of varying brightness to document any loss of peripheral vision related to glaucoma.  New, more sophisticated technology is allowing Optometric Physicians to complement these standard tests for glaucoma.

New Technology

Digital imaging technology enables Optometric Physicians to do a quantitative assessment of the optic nerve and nerve fiber layer, with imagery that allows them to compare computerized measurements from exam to exam, helping to determine if glaucoma damage is present or has worsened. There are several instruments available for these assessments, including the Carl Zeiss Meditec Stratus Optical Coherence Tomographer (OCT), Heidelberg Retinal Tomograph (HRT ), Laser Diagnostic Technologies GDxVCC and the Talia Retinal Thickness Analyzer (RTA).  These technologies are more sensitive to the subtle changes in the eye that occur early in the course of glaucoma, allowing Optometric Physicians to keep each image on file and compare past and present images. This means better diagnostic decisions, including earlier diagnosis and modification of therapy. These tests do not eliminate the need for regular examinations and visual field testing, but do provide an additional and very useful means of diagnosing and monitoring glaucoma. 

In addition to improved tracking of eye changes, patients find these new technologies to be more convenient because dilation is usually not required and results are often available immediately.  It is thought that glaucoma can be caught six times sooner using these instruments.

Optometric Physicians are also using SWAP (Short Wave Automated Perimetry, also known as "blue-on-yellow") visual field testing. Unlike standard perimetry which flashes a white spot of light onto a white background, SWAP projects a blue light onto a yellow background. This type of visual field targets optic nerve fibers that may become damaged earlier in glaucoma.  Patients may show visual field defects earlier with the blue-on-yellow field than with standard white-on-white fields, leading to earlier diagnosis and treatment of glaucoma.

The Optometric Physicians of Washington recommends an annual eye exam to detect glaucoma, and other problems, at their earliest stages.  Because the effects of glaucoma can not be reversed, early detection is the key to retaining vision.  Visit www.eyes.org for more information on glaucoma, its symptoms and how to prevent it.

The Optometric Physicians of Washington (OPW) is the professional association of Washington   State optometric physicians. The OPW is comprised of 13 optometric societies throughout thestate numbering approximately 600 private, corporate and HMO optometric physicians.

The mission of the OPW is to advance, improve and enhance the vision care and eye health ofthe public and to promote the continued development of the profession of optometry.

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Attachments
•	Glaucoma Fact Sheet

Contact Information
•	Lisa Cargill or Tamitha Anderson (509) 444-2350