Open AccessVISUAL DISTURBANCES IN PARKINSON’S DISEASE PATIENTS
Author(s) -
Nicoleta Tohănean,
Lucia Muntean,
Horea Demea,
Lăcrămioara PerjuDumbravă
Publication year - 2015
Publication title -
romanian journal of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.111
H-Index - 4
eISSN - 2069-6094
pISSN - 1843-8148
DOI - 10.37897/rjn.2015.4.2
Subject(s) - nerve fiber layer , parkinson's disease , photophobia , visual cortex , medicine , neuroscience , retina , retinal , visual processing , psychology , ophthalmology , disease , pathology , perception
Along with the motor symptoms, Parkinson’s disease (PD) patients experience a wide range of non-motor problems including visual disturbances. These are multifaceted, but often underreported as such. In a visual survey questionnaire, 78% PD patients reported at least one problem related to vision or visuospatial functioning. The most frequent encountered problems are impaired contrast sensitivity, color discrimination, visuospatial processing, ocular or eyelid movements and diplopia followed by visual misperceptions and hallucinations. Some patients report dry eyes, ocular pain or photophobia. The pathophysiological basis of the visual disturbances is not completely understood. Changes in the visual cortex were detected with functional MRI before the visual symptoms were clinically evident. Further studies are necessary to determine how these changes will contribute to development of visual symptoms in PD patients. Other authors consider a dopaminergic deficit in the retina to be responsible for some of these symptoms, being known that dopamine is the major neurotransmitter in the amacrine and interplexiform cells in the retina. Visual hallucinations are likely to be a result of disruption across related yet diverse neural circuitry. The therapy is only symptomatic and not always satisfactory. It includes ophthalmological treatment and specific treatment for hallucinations. Optical Coherence Tomography (OCT) is a new investigation method who offers quantitative morphology of gross retinal histology. The thinning of the peripapillary retinal nerve fiber layer was observed in PD. Some studies mentioned that macular thickness measured by the OCT could be a promising biomarker of PD. This work shows how complex the visual problems in PD patients can be and the importance of a thorough and multidisciplinary approach.