New Imaging Tool Can Spot Glaucoma Risk
But experts say it will be several years before there's widespread use
MONDAY, June 9, 2008 (HealthDay News) -- A sophisticated new imaging device could one day help doctors detect the devastating eye disease known as narrow-angle glaucoma earlier and more accurately, researchers report.
If left undetected and untreated, narrow-angle glaucoma can lead to a sudden or acute glaucoma attack, which can result in permanent vision loss.
Researchers at Duke University Medical Center detail the new technology in the June issue of the Archives of Ophthalmology.
"Narrow angle glaucoma is one-third the prevalence of open-angle glaucoma worldwide but it is more blinding than open-angle glaucoma. It will be the leading cause of irreversible blindness in the world by the year 2050," said study author Dr. Sanjay Asrani, an associate professor of ophthalmology with the Duke Eye Center. "That's why this [new imaging instrument] has such strategic significance."
Asrani predicted that the technology -- called Fourier-domain optical coherence tomography (FDOCT) -- would be available at teaching or university hospitals within five years, but it will be longer before there's widespread use.
"The approach is exciting as it may offer us another tool to help us detect this potential risk," said Dr. Andrew Iwach, a spokesman for the American Academy of Ophthalmology and executive director of the Glaucoma Center of San Francisco. "It will also help us further refine our ability to decide who needs laser surgery or not."
Narrow-angle glaucoma affects some half million people in the United States, making it much less common than open-angle glaucoma, which affects six times that many, according to the Glaucoma Research Foundation.
As people age, changes in the eye's lens can occur, including thickening. "There's a slight shift in the position of the eye to the point that there could be a rupture of the normal, free flow of fluid in the eyes," said Iwach. This can change the relative position of the iris (the colored portion of the eye) and affect the angle of the eye, meaning the distance between the cornea and the iris.
"The problem with narrow-angle glaucoma is that it's sometimes difficult to diagnose," said Dr. Robert Cykiert, an associate professor of ophthalmology at New York University Langone Medical Center in New York City. "You have to apply a special lens to diagnose narrow-angle glaucoma, [but] when we apply this lens, we're changing the anatomy of the eye. Sometimes we change the appearance of the angle. You can't be sure of the diagnosis because part of the examination is actually changing what you're looking at."
Currently, doctors use lasers to cut an opening in the iris to reduce the risk for a sudden attack.
FDOCT, by contrast "shines a light in a special infrared frequency onto the eye," Cykiert explained. "That's connected to a computer which does a very highly sophisticated analysis of how the light penetrates the eye."
"It's an imaging device that allows us to image the eye without cutting," Iwach added. "The nice thing is it doesn't touch the eye."
Beyond that, the technology will enable physicians to standardize or quantify changes in the eye and also visualize other structures in the eye that may have problems.
To learn how to take better care of your eyes, visit the American Academy of Ophthalmology.