The bioengineering research by Mehrdad Sangi means the old subjective eye charts used for vision screening might soon be a thing of the past.

“There was a real unmet need within the current eye charts used for vision screening. It requires the patient to be cooperative – which we know children aren’t always. And the old test is intrinsically subjective so again, it doesn’t always work for children,” says Sangi.

He hopes his new method will be more effective in picking up issues earlier. Working on the basis that the sooner problems are detected, the better the chances for treatment, Sangi has developed a new system that doesn’t need the patient to make a decision about what they are seeing.

“I wanted to develop a system which was objective, rather than asking the children questions about shapes they might not be able to see, which often results in them guessing an answer.”

His new system is based on ‘optokinetic nystagmus’, an involuntary reflex of the eyes that occurs when an individual sees a moving object or pattern. Subjects are shown a moving pattern on a screen, with a camera recording eye movement. This allows patterns to be measured and algorithms used to screen for visual acuity.

Sangi has founded a medical technology company called Objective Acuity with his supervisors Dr Jason Turuwhenua and Professor Ben Thompson. The quick measurement system they are developing has already completed a proof of concept paediatric trial in Dallas, Texas, and Australia and New Zealand.

The difference in the results of the first clinical trials they carried out was marked, said Sangi.

“There was a problem of over-referral within the old system. Previously only a small percentage of the children in New Zealand’s B4 School Check referred for testing actually had a problem.

“With our testing, we would have had considerably fewer incorrect referrals to eye specialists. In terms of money, budgeting and preventing loss of learning time for individual children for example, that’s huge.”

The trials demonstrated the new test’s reliability, said Adam Podmore, CEO of Objective Acuity.

“They showed high agreement between the Objective Acuity test and the electronic HOTV visual acuity test, which is currently considered the global clinical trials’ gold standard, but not used in screening.

“Most countries have local and national vision screening programmes for children at four years old, but our test could be used to identify vision problems earlier,” said Podmore.

“The technology uses proprietary moving patterns on a computer screen, coupled with a system designed to record and interpret eye movements. A child simply looks at the pattern to complete the screening test. It doesn’t matter what language the children speak, or if they are unable to vocalise what they see. The system removes many of the problems with current vision screening,” he says.

Sangi came to New Zealand from Iran in 2013 to do his PhD at Auckland Bioengineering Institute. He already had a master’s degree in biomedical engineering and an undergraduate background in electrical engineering.

“It’s amazing to see my PhD research developed like this,” he says.

“Some people say they want to make the world a better place. And I feel that with my research and the technology we are developing; I really feel like I am making the world a better place.”

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