A study, published Online First by Archives of Neurology, reveals that persistent eye tremors seem to be common in individuals suffering from Parkinson’s disease (PD). Ocular tremors can prevent eye stability during fixation and results from the study indicate that precise oculomotor testing could provide an early physiological biomarker for diagnosing Parkinson’s disease.

George T. Gitchel, M.S., of the Southeast Parkinson’s Disease Research, Education, and Clinical Center, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Va., and his team explain:

“Although a number of studies describe various oculomotor abnormalities in subjects with PD, conflicts about the specific deficits remain.”

The researchers conducted the study in order to examine oculomotor function in 112 individuals with Parkinson’s disease and a group of 60 healthy individuals. Participants’ oculomotor function was assessed during fixation, as well as while they tracked a moving target on a computer screen.

The researchers explained:

“The major finding of the present study was that using modern eye movement tracking, oscillatory fixation instability was universally seen in a large cohort of 112 patients with PD.

The fact that this behavior was universally observed in every tested patient with PD, including unmedicated patients, suggests that ocular tremor is a function of the disease process and not induced by medication.”

Persistent ocular instability while fixating on a target was observed in all 112 participants with Parkinson’s disease, compared with only 2 of the 60 healthy participants. In addition, the researchers found that oculomotor parameters were no different between individuals with Parkinson’s disease on medication and unmedicated patients with PD.

The researchers conclude:

“All patients with PD 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 PD.”

Written By Grace Rattue