Researcher taking the pressure off glaucoma diagnosis

June 9, 2014 by Adela Talbot
Mansur Mulk, a PhD candidate in Biomechanical Engineering, is working to improve the standard, yet fallible, techniques used to diagnose glaucoma, the second leading cause of irreversible blindness in the world’s aging population.If successful, Mansur Mulk might not only help glaucoma sufferers retain their sight, but save health-care providers big bucks as well. Credit: Adela Talbot

(Medical Xpress)—Glaucoma represents the second-leading cause of irreversible blindness in the world's aging population, with 400,000 Canadians and 67 million people worldwide suffering from the condition.

The standard diagnosis is based on an individual having increasingly high eye pressure, also known as (IOP). There are no early indications for the condition; it is usually caught while advancing and, once spotted, the only way to treat it – and prevent a potential loss of vision – is to lower the patient's IOP.

Therefore, Mulk said, measuring the patient's IOP is key to diagnosing glaucoma. But, as it stands, IOP tests are inadequate when it comes to giving accurate pressure readings and, as such, cannot provide consistently accurate diagnoses.

"Sometimes people have low pressure, but still they have glaucoma. Some people measure to have high pressure and they are assumed to (have it), but they do not," explained Mulk, a Western PhD candidate in Biomechanical Engineering.

While an elevated IOP is considered a major indicator of glaucoma, many clinical studies have shown evidence of the condition at normal intraocular pressures.

Leaning on the current 'gold standard' in testing eye pressure, optometrists use Goldmann tonometer and derivative forms of applanation tonometry tests – those tests where a puff of air is blown into your eye or you are asked to stare at a screen and respond when you see a visual cue. However, these tests fall short as evidence shows the presence of glaucoma in individuals with normal IOP. Therefore, it is likely a number of patients get an incorrect diagnosis.

This is the problem Mulk looks to address.

"Some patients, who (have glaucoma) but are diagnosed as not having it, are delaying treatment and they are losing their vision," Mulk said.

"Other patients, who don't (have glaucoma), but were diagnosed as having it, are spending money and getting the wrong treatment. They are at risk for second-degree glaucoma. By taking the drugs, they are (developing) glaucoma symptoms and losing sight," he continued.

"This increases significant amounts of your medical costs – testing all these people, going to eye specialists, who make false diagnoses."

In the United States and Canada alone, direct medical costs associated with glaucoma are roughly $3 billion each year.

Mulk is looking at corroborating eye pressures with other correlated symptoms and early indicators of glaucoma to provide more consistently accurate diagnoses to patients, ultimately helping them get proper treatment, saving their sight and saving the system money.

One of these indicators is the bending stiffness of one's cornea – the transparent front part of the eye that covers the iris, pupil and anterior chamber. In order to determine correct IOP, one must accurately quantify the cornea's bending stiffness, Mulk explained.

But, there are still no satisfactory techniques for determining that stiffness. Using ultrasound technology, he hopes to improve current testing methods of stiffness, and, ultimately, a patient's eye pressure.

Mulk will be experimenting on the cornea's biomechanical and elastic wave propagation behavior, in response to changes in intraocular pressure, corneal hydration and collagen cross-linking.

"Our cornea has a special thickness – 520 micrometers. It's very thin and when people get high eye pressure the cornea is stressed and starts becoming flattened," he explained.

Mulk's experiments will be conducted with equipment designed to create ultrasound waves in combination with tonometric measurements. This will provide assessments of corneal bending stiffness and its correlations with intraocular pressure measurements.

"The research I'm working on would (help) develop equipment that will not detect any false reading or give you any false eye pressure," Mulk said, noting his research would corroborate corneal thickness, eye pressure, alongside other related indicators, to help provide an accurate diagnosis of glaucoma every time.

"We are trying to improve the gold standard for measuring eye pressure, which will reduce . It will give you true, real ."

Explore further: British study may improve glaucoma assessment and treatment

Related Stories

British study may improve glaucoma assessment and treatment

October 24, 2011
Results from a recent scientific study in the U.K. may change the way that healthcare professionals measure eye pressure and allow them to assess the risk of glaucoma with greater accuracy. Glaucoma is the second most common ...

Research identifies risk factors associated with progression of glaucoma

May 9, 2011
Elevated pressure inside the eye, cornea thinning, and visual field loss are all markers that glaucoma may progress, according to a report in the May issue of Archives of Ophthalmology.

Home measurement of eye pressure in children may improve management of glaucoma

March 7, 2012
Measurement of pressure within the eye, or intraocular pressure (IOP), is known to fluctuate throughout the day, and wide swings in patients with glaucoma are believed to be related to the progression of the disease, which ...

New eye layer has possible link to glaucoma

February 16, 2014
A new layer in the human cornea—discovered by researchers at The University of Nottingham last year—plays a vital role in the structure of the tissue that controls the flow of fluid from the eye, research has shown.

Recommended for you

Genome editing with CRISPR-Cas9 prevents angiogenesis of the retina

July 24, 2017
A research team from the Schepens Eye Research Institute of Massachusetts Eye and Ear has successfully prevented mice from developing angiogenesis of the retina—the sensory tissue at the back of the eye—using gene-editing ...

Too little vitamin D may hinder recovery of injured corneas

July 24, 2017
Injury or disease in combination with too little vitamin D can be bad for the window to your eyes.

Combination of type 2 diabetes and sleep apnoea indicates eyesight loss within four years

July 4, 2017
Research led by the University of Birmingham has discovered that patients who suffer from both Type 2 diabetes and obstructive sleep apnoea are at greater risk of developing a condition that leads to blindness within an average ...

Nearly 60% of pinkeye patients receive antibiotic eye drops, but they're seldom necessary

June 28, 2017
A new study suggests that most people with acute conjunctivitis, or pinkeye, are getting the wrong treatment.

Magnetic implants used to treat 'dancing eyes'

June 26, 2017
A research team has successfully used magnets implanted behind a person's eyes to treat nystagmus, a condition characterised by involuntary eye movements.

Drug shows promise against vision-robbing disease in seniors

June 21, 2017
An experimental drug is showing promise against an untreatable eye disease that blinds older adults—and intriguingly, it seems to work in patients who carry a particular gene flaw that fuels the damage to their vision.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.