Evaluation of depth perception in elder with Parkinson's disease

This study is to investigate the difference of depth perception between normal elder and Parkinson's disease (PD) patients. This study manipulate different clues (overlapping and perspective), reference material (with and without), and size of the vehicle (motorcycles, vehicles and trucks). Subject is required to judge the difference in the distance of the objects of the picture. This is in order to analyze the spatial depth perception difference between two groups. Twenty-four PD patients and twenty-four control participants were recruited to participate in this study. The results showed that perspective accuracy of Parkinson's disease patient was significantly weaker than the normal group, but no significant difference in the accuracy of overlapping reaction. This study also found an interesting result, where in a situation with difference in vehicle size frontal and rear, for example, an vehicle in the front and a motorcycle in the rear, the judgment was worsened by such scenario, which was true for both the Parkinson's patient and the normal control group, but with the former bearing higher degree of severity. In daily life, different size vehicles are mixed on public road, it is not possible to have just a single vehicle on the road. Hence, the Parkinson's patient should pay more attention to the approaching vehicle.