Stereopsis in Drug Naïve Parkinson's Disease Patients

Abstract

Background:Motor deficits associated with Parkinson's disease (PD) have been well described, yet little attention has been paid to non-motor symptoms, especially cortical visual dysfunction. We investigated stereopsis, as well as the relationship between stereopsis and other cognitive function, in a sample of PD patients.Methods:We used Titmus stereotest plates for assessing stereopsis. Fifty-nine subjects (29 PD patients and 30 normal controls) were included in this study. The included patients underwent a neurological examination, clinical rating scale and neuropsychological tests.Results:Drug naïve PD patients showed decreased stereopsis on the Titmus fly stereopsis test (Pearson χ2=23.80, p<0.001) compared to PD patients with normal stereopsis. The Hoehn-Yahr stages and Unified Parkinson's Disease Rating Scale motor scores were significantly higher in patients with PD with abnormal stereopsis than in patients with PD with normal stereopsis (p=0.026; p=0.046). The frequency of abnormal visual perception/constructive function was greater in patients with PD with abnormal stereopsis compared to patients with PD with normal stereopsis (Pearson χ2=5.11, p=0.024).Conclusion:These findings suggest that stereopsis deficits and visual perception/constructive dysfunction are common in de novo PD patients.

Stereopsis impairment is associated with decreased color perception and worse motor performance in Parkinson’s disease

“…Recently, in a small study of PD patients, researchers found stereopsis dysfunction to be related to visual cognitive dysfunction [13]. Interestingly, to date, there has been no simultaneous assessment of the potential influence of peripheral abnormality on stereopsis impairment, which could also be triggered once normal cortex is fed with erroneous information from peripheral pathways such as retinal ganglion cells.…”

The Neuro-Ophthalmological Assessment in Parkinson’s Disease

“…In order to perceive objects accurately, a subject basically needs a normal retina, normal visual acuity and proper alignment of the eyes. Two small studies report a stereopsis prevalence of 42% in PD [55,56].…”

Gait in Parkinson’s disease: A visuo-cognitive challenge

“…Declines with age • Common in the absence of ocular morbidity (Wright and Wormald, 1992) • Decline is marked in those >60 years old (Garnham and Sloper, 2006) Impaired • Common in drug naïve patients (Kim et al, 2011) • Linked to reduction in gray matter volume in the right extra-striate visual cortex (Koh et al, 2013) Some studies limited by not assessing for nor excluding patients with vision affecting eye conditions e.g. Goodale and Haffenden (1998).…”