By Adrian Galbreth
Although many people who have experienced tremors in their eye may have dismissed it as being trivial, such an occurrence may actually be a sign of Parkinson's according to a new study.
Experts in the US note that persistent ocular tremors that prevent eye stability during fixation appear to be common among patients with Parkinson disease, which suggests that precise oculomotor testing could provide an early physiological biomarker for diagnosing the neaorological condition.
The study was published Online First by Archives of Neurology and carried out by George T Gitchel, from the Southeast Parkinson's Disease Research, Education, and Clinical Center in Richmond, Virginia.
The research involved experts comparing oculomotor function between 112 patients with Parkinson's disease and 60 age-matched controls during fixation, and while tracking a randomly displaced target on a PC monitor.
According to Dr Gitchel, who is also a member of Hunter Holmes McGuire Veterans Affairs Medical Center, the major finding of the study was that, through the use of modern eye movement tracking, oscillatory fixation instability was seen to be universally present in a large cohort of 112 patients with Parkinson's.
"The fact that this behaviour was universally observed in every tested patient with Parkinson's, including unmedicated patients, suggests that ocular tremor is a function of the disease process and not induced by medication," the study author explained.
The study found that all 112 patients with Parkinson's showed persistent ocular instability while fixating on a target, compared with only two of the 60 control patients.
In addition, the authors found no differences in oculomotor parameters between medicated and unmedicated patients with Parkinson's.
"All patients with Parkinson's exhibited persistent ocular tremor that prevented stability during fixation. The pervasiveness and specificity of this feature suggest that modern, precise oculomotor testing could provide a valuable early physiological biomarker for diagnosing Parkinson's," the experts concluded.
by Emily Tait