iPad-based tool for accurate measurement

Dr Joshua Barton, Brain and Mind Centre, University of Sydney was awarded a Postgraduate Scholarship funded by the Trish Foundation, which was supervised by Professor Michael Barnett.

Dr Barton has developed an iPad-based tool that is able to accurately measure an individual’s function of visual contrast sensitivity. The benefit of this measure, as opposed to the traditional visual outcome measures used in clinical trials, is that the contrast sensitivity function encompasses both visual spatial sensitivity and visual contrast sensitivity. Dr Barton collaborated with the University of Sydney’s School of Information Technology to develop the iPad tool. This iPad tool is much faster than standard testing, taking approximately two minutes per eye tested and has the added benefit of being able to be used independently by patients. This allows home-based self-testing by people with MS at a time that is convenient to them.

Dr Barton has recruited a group of people with MS to use the iPad tool to perform fortnightly self-assessments on their vision. These people have also undergone regular MRI scans to determine whether any lesions develop. This will allow Dr Barton to see if the iPad tool is able to detect any lesion development which is clinically silent (doesn’t result in an obvious relapse).

Dr Barton has also recruited 50 people who are receiving the MS medication, alemtuzumab, to use the iPad visual test to detect any visual changes. Dr Barton has tracked the participants over a two-year period to determine if there is a link between visual function measures, MRI changes and multifocal visual evoked potentials (mfVEP). MfVEP is used to measure the function of the visual pathway through the optic nerves and brain from many regions of the visual field – it should provide a more accurate assessment of nerve speed than other techniques currently available. From this part of his work, Dr Barton has determined three different ways to analyse mfVEP to extract additional information, potentially increasing the value of this clinical tool. Using these different analyses, he was able to determine differences in people whose eyes were affected by optic neuritis (a condition where the immune system attacks the nerves of the eyes) compared to those whose eyes weren’t.

Dr Barton has also performed a pilot study looking at the effect of temperature on mfVEP signals on 7 people with MS and 5 people without MS. It was conducted in conjunction with the University of Sydney’s Thermal Ergonomics Laboratory, which has previous experience in safely increasing and decreasing body temperature in people with MS. The aim of this study was to reveal nerve injury that isn’t obvious in the form of Uhthoff’s phenomenon, which is the worsening of MS symptoms as the body is overheated. Dr Barton found that people with MS had differences in mfVEPs upon heating compared to people without MS, although there wasn’t any difference between people with or without optic neuritis.

Dr Barton has presented his findings at a national conference and is preparing several scientific manuscripts for publication.