A novel tablet-based software for the acquisition and analysis of gaze and eye movement parameters: a preliminary validation study in Parkinson’s disease

Abstract

The idea that eye movements can reflect certain aspects of brain function and inform on the presence of neurodegeneration is not a new one. Indeed, a growing body of research has shown that several neurodegenerative disorders, such as Alzheimer’s and Parkinson’s Disease, present characteristic eye movement anomalies and that specific gaze and eye movement parameters correlate with disease severity. The use of detailed eye movement recordings in research and clinical settings, however, has been limited due to the expensive nature and limited scalability of the required equipment. Here we test a novel technology that can track and measure eye movement parameters using the embedded camera of a mobile tablet. We show that using this technology can replicate several well-known findings regarding oculomotor anomalies in Parkinson’s disease (PD), and furthermore show that several parameters significantly correlate with disease severity as assessed with the MDS-UPDRS motor subscale. A logistic regression classifier was able to accurately distinguish PD patients from healthy controls on the basis of six eye movement parameters with a sensitivity of 0.93 and specificity of 0.86. This tablet-based tool has the potential to accelerate eye movement research via affordable and scalable eye-tracking and aid with the identification of disease status and monitoring of disease progression in clinical settings.

Eye movement function captured via an electronic tablet informs on cognition and disease severity in Parkinson’s disease

“…The present study provides several clinically relevant lines of evidence supporting the usefulness of monitoring the oculomotor system as a means to assess both disease severity and cognitive function in PD. First, our findings confirm those from our previous study 20 using the same technology with PD patients, that several oculomotor parameters strongly correlated with measures of disease stage and severity such as the UPDRS-III score. Second, in line with previous publications in the literature we provide confirmatory evidence that individual oculomotor motor parameters significantly correlate with various measures of cognitive function in individuals with PD.…”

“…This approach allows for the precise quantification of several eye movement parameters with a precision comparable to those of research-grade infrared eye tracking devices, such as the latency, velocity, accuracy of saccades, and the presence of saccadic intrusions during fixation. Using this novel technology, we recently replicated sets of well-known oculomotor findings in both individuals with MS 19 and PD 20 , with the latter study having primarily focused on distinguishing individuals with PD from healthy controls on the basis of recorded eye movement parameters. The main objective of the present paper was to determine to what extent the oculomotor parameters extracted by this mobile eye-tracking tool could serve as viable markers of both disease stage (or severity) using standard PD clinical staging tools, and of cognition in individuals with PD.…”

“…Finally, we developed a support vector classifier to discriminate between individuals with mild PD from those with moderate PD (based on UPDRS cut-off scores). Given the strong relationship known to exist between several oculomotor parameters and the UPDRS scores and our own previously published data 20 , we hypothesized that we should be able to distinguish between both PD patient subgroups with a high level of accuracy. The overall aim of the study is to generate evidence that oculomotor parameters collected with a novel tablet-based technology can assist in clinical assessment and management of PD patients by informing on disease severity and cognitive abilities.…”

Oculomotor function captured via an electronic tablet informs on cognition and disease severity in Parkinson’s Disease

“…Gaze-tracking and oculomotor parameter extraction including the xation, pro-saccade, anti-saccade, and smooth pursuit tasks has been detailed previously 19,20 and is reproduced here for clarity.…”

Detecting Abnormal Eye Movements in Patients with Neurodegenerative Diseases – Current Insights

“…New technologies for clinical practice need to emerge through the development of mobile eye tracking devices, either using a portable eye tracker or developing smartphone-based approaches. 115 These new technologies should allow for an easy ocular motor assessment that could be performed both by specialists and non-specialists. However, they face the challenge of providing a lower sampling rate than experimental set-up and this will need to be controlled to ensure still a high quality of data so that markers extracted from such device are reliable and informative.…”