Saccades are fast eye movements that shift visual focus for tasks like reading, visual searching and coordinating safe movement. Research has shown that the speed, accuracy and control of saccades is related to cognitive functioning in Parkinson’s disease, and may be more sensitive to subtle changes than traditional neuropsychological tests. This study aims to validate a computer-based task to enable clinicians and researchers to measure saccades without the cost and complexity of traditional eye-tracking equipment.
Researchers will ask 80 patients with Parkinson’s disease, representing the full spectrum of motor and cognitive symptoms, to participate. Participation will include measurement of eye movements using two methods: the new computer-based saccade battery and the best available video-based eye-tracking equipment. The evaluation will be repeated about 30 days later. Data will be analyzed to determine whether the computer-based tasks are reliable and able to provide the same quality of information as the gold standard in eye-tracking.
Relevance to Diagnosis/Treatment of Parkinson’s Disease:
Many neuropsychological tests lack the sensitivity to detect the subtle cognitive decline sometimes seen in Parkinson’s disease, particularly during the earliest stages of illness and for those with very high education achievement. There are also large practice effects and measurement errors that can obscure meaningful changes produced by breakthrough medications. While saccade measures are not affected by such confounds, the cost and complexity of eye-tracking equipment limits practical application. If valid, the free and user-friendly computer-based saccades tasks would provide clinical utility for examination of individuals and response to interventions in research.
It is expected that the computer-based tasks will provide valid and reliable measurement of saccades in patients with Parkinson’s disease. If demonstrated, the tasks will immediately be made freely available to other researchers for replication, validation and further development. Investigators hope to extend the current study to include a two-year follow-up visit to track changes on saccade measures with respect to cognitive and motor symptoms. They will also administer the tasks to a large and diverse sample of cognitively intact older adults; data from this study will provide a basis for comparison in individual assessments.