Innovating binocular vision tests

Thomson Software Solutions showcased the latest developments in its technology at 100% Optical.

Professor David Thomson, founder and CEO of Thomson Software Solutions, talked OT through three systems that had “caused a bit of a stir” amongst delegates at the show.

The company’s Thomson Near Chart enables optometrists to display a range of near charts and tests on mobile devices such as an iPad.

Thomson explained: “The downside of that is you have to hand the patient the iPad, and if you want to change the test you have to take it back, change the test, and hand it back. The holy grail has always been; wouldn’t it be nice if we could control the iPad directly from a programme on your PC. That’s what we developed.”

The software is runs from a PC and linked with mobile devices by scanning a QR code. Calibration measurements are taken from the device to ensure all tests are correctly sized, and an array of tests can then be displayed on the device and controlled from the PC.

Identifying a key trend, Thomson shared: “There is a lot of interest in virtual reality.”

Embracing this, the company has developed the Virtual Synoptophore. Using a VR headset that accepts smartphones, the software runs a range of binocular vision tests, controlled from a PC.

Thomson shared: “You can do a whole range of binocular vision tests. You can measure phoria, torsion, fixation disparity, all the synoptophore slides for exercising, do random-dot stereograms, 3D images, and measure anisocromia.”

The Clinical Eye Tracker measures eye movements and the position of each eye using a tracker bar created by a Swedish company, Tobii.

“It’s a very powerful binocular vision test because it measures what is happening to binocular vision while doing a real-world task like reading,” Thomson said.

Thomson provided a demonstration of the system and how the information is measured and displayed.

The system allows users to record eye movements and replay the pattern to see exactly where the patient is looking while reading. It also includes a pupillometry module.

Thomson explained: “Binocular vision tests haven’t really changed for decades. They are all very static.”

Static tests give the patient a lot of time to fixate, he suggested, unlike in real world settings, adding: “It is a bit artificial.”

“What this allows you to do is get the patient to do a real-world task like reading, making saccades, or searching something, and you see what happens to their binocular vision. That is a real advantage for those of us who look after binocular vision,” he said.

The software can also be beneficial as an objective way of assessing the effect of an intervention: measuring a pattern of eye movements while reading, and then again with the intervention.

In the background, a lot of development work around the technology is ongoing, Thomson told OT, with new modules coming online.

This also includes a project with a team at the University of Central Lancashire to analyse eye movements in individuals with dyslexia.

“What we are hoping is eventually we will have a module which will at least give a traffic light system to detect dyslexia,” Thomson said, suggesting it could be used for screening children in schools and identifying those with a high probability of having dyslexia.