Longer Parkinson Disease Duration May Worsen Visual Field

Longer Parkinson disease duration may lower patients’ mean sensitivity and increase sensitivity variability on visual field exams, according to research presented at the North American Neuro-Ophthalmology Society (NANOS) 49th annual meeting held in Orlando, FL, March 11-16, 2023.  Researchers say it remains to be seen if visual fields could be used as a Parkinson disease biomarker.

The study reviewed 35 eyes of 18 patients with Parkinson disease to determine the effect longer Parkinson disease duration had on visual fields. They accepted patients of any disease duration or severity who had no history of ocular disease affecting visual fields or family history of glaucoma. All participants had a best corrected visual acuity of 20/200 or better. The participants were evaluated with a virtual reality visual field exam using a head-mounted visual field device. They also measured intraocular pressures (IOP) using a handheld portable device. 

The researchers also collected Parkinson disease duration and first motor symptoms, as well as Movement Disorder Society-Unified Parkinson’s Disease Rating Scale Part III scores, taken both on and off medication.

Of the total, 24 (68.6%) eyes had reliable fields. The findings demonstrate that longer Parkinson disease duration from diagnosis and from first motor symptoms significantly correlate with lower mean sensitivity in overall visual field exams, and in the inferotemporal and inferonasal quadrants and peripheral region. 

Longer Parkinson disease duration from diagnosis and from first motor symptoms significantly also correlate positively with sensitivity standard deviation in the overall visual field and in the superonasal and inferonasal quadrants and peripheral region, according to the researchers. 

They also found that increased medication use is associated with a lower mean sensitivity in the inferotemporal quadrant and middle region. 

“Ocular manifestations of Parkinson’s Disease (PD) have been attributed to retinal dopamine deficiency. Studies examining anatomical changes in the retina have yielded mixed findings, though those examining functional changes suggest patients with PD may have worse visual field exam results than non-PD controls,” the researchers explain.