Fig. 1

Evolution of ocular abnormalities in PSP presented in chronological order. The clinical stages are divided into three stages related to clinical appearance, namely (1) early stage: clinical features apparent in less than 4 years of disease duration; (2) middle stage: clinical feature apparent for between 4 and 8 years of disease duration; and (3) late stage: clinical feature apparent for more than 8 years of disease duration. Solid white rectangles indicate timeline occurrences of each ocular abnormality, presented in years after onset of disease. Solid arrows indicate the presence ophthalmoplegia and square wave jerks, which continue to be present in the late disease stage