University of Waterloo optometrist Elizabeth Irving and research assistant Cristina Yakobchuck-Stanger have demonstrated that a lens using an alternative design reverses induced myopia, commonly known as nearsightedness.
Their paper, detailing the testing in an animal model of a lens design based on the NaturalVue® Multifocal 1 Day Contact Lens, was published recently in the journal Opthalmic & Physiological Optics.
Myopia is one of the most common eye conditions worldwide - and the rate is increasing with some populations seeing numbers as high as 90 per cent. A separate study by University of Waterloo and CNIB found myopia in local school children increased by nearly 30 per cent over eight years.
Most people turn to prescription lenses to correct their nearsightedness and they usually need to update their lenses with a stronger prescription over time as the eye continues to change shape.
“This study opens the door to the possibility of not just treating or slowing progression, but actually reversing myopia in humans,” says Irving, a professor and University Research Chair in the School of Optometry and Vision Science.
The lenses have a set prescription in the centre of the lens that gradually decreases toward a different prescription at the periphery. Irving and Yakobchuck-Stanger tested two different versions of the lens, one with a steeper prescription gradient than the other. The researchers found that while both designs reversed previously induced myopia to some extent, the steeper prescription gradient reversed it completely.
“Our overriding conclusion from this study is that lens design, specifically what you do in the periphery, matters,” says Irving.
Irving’s next steps include trying to understand at a fundamental level why this design works at preventing the eye from growing too long.
“To our knowledge, the results from this research with the NaturalVue Multifocal Lens design are the first in which myopia was completely reversed in an animal model,” said Dr. Sally Dillehay, Chief Medical Officer and Vice President of Clinical and Regulatory Affairs for Visioneering Technologies, Inc. who developed the lens and in part funded the study. “We believe these findings are especially noteworthy as they come from respected vision care researchers who were highly skeptical when they entered into the study.”
Irving also received funding from the Natural Sciences and Engineering Research Council of Canada (NSERC) that supported the project.