The effect of diabetes and ageing on the initiation of smooth pursuit eye movement

Aim: To examine the initiation of smooth pursuit in a group of elderly, diabetic subjects, and to compare their performance with a group of age-matched non-diabetic subjects and a group of healthy young subjects.

Methods: Smooth pursuit was assessed quantitatively in 10 diabetic subjects (mean age 69.2 ± 6.8: range 58-80 years), 10 age-matched non-diabetic subjects (mean age 69.8 ± 5.2; range 64-81 years) and 10 healthy young subjects (mean age 21 ± 2.3: range 19-26 years), using infra-red oculography.

Results: Qualitatively, pursuit performance was similar in the healthy elderly, diabetic and young subjects. However, quantitatively statistical analysis indicated smooth pursuit latency was significantly higher in both elderly diabetic and age-matched healthy individuals when compared with healthy young individuals (p < 0.0001). Diabetes itself did not affect smooth pursuit latency for either leftward or rightward pursuit (p > 0.05).

Conclusion: Given that we have demonstrated there is no statistically significant difference in smooth pursuit latency between healthy elderly and diabetic elderly subjects, systemic disease in general does not appear to exacerbate the age-related alteration in pursuit we have previously reported. This result suggests that quantitative assessment of smooth pursuit might provide a means of assessing the general state of the cortex in elderly subjects.