Non motor symptoms and signs in Parkinson's disease (PD) also include a series of visual deficits; deepening these aspects could be useful for a better management of symptoms, to standardize a specific protocol for the issues related to vision and also to understand how these aspects are important for the understanding of the mechanisms underlying the PD.

In Parkinson's disease (PD) several non-motor signs and symptoms already occur in the early stages of the disease; the symptoms are diverse and these also involve visual difficulties which commonly affect the majority of patients and which gradually worsen the quality of life.

The most common malfunction produced by PD is the dysfunction of dopaminergic pathways that may be responsible for a series of visual deficits too:

• decreased visual acuity and decreased sensibility to light and color,
• strabismus and forms of sensory and eye movement dysfunctions,
• eyelid dysfunctions and dry eye syndrome

Moreover, in patients affected by PD, typical retinal features were discovered for the first time in 2004 by the use of OCT (Optical Coherence Tomography) such as:

• the reduction of the retinal nerve fiber layer (RNFL)
• a typical thinning of the macular thickness, even if with different results. In the follow-up of the PD, these retinal features, verifiable by the use of OCT, could be considered as a marker of the pathology.

For these reasons it may be useful:

• quantify in an objective manner how much the visual aspects affect the overall deterioration of the quality of life in patients with PD
• demonstrate the validity of a specific and integrated outpatient diagnostic protocol for the study of visual and ophthalmological disorders in patients with PD
• demonstrate the diagnostic role of early changes in macular thickness and of the optic disc in subjects suffering from PD using the OCT
• establish orthoptic evidence in patients with PD

Inclusion Criteria:

• Patients aged ≥ 18 years
• Patients affected by Parkinson's disease (PD) according to the diagnostic criteria of the United Kingdom Brain Bank, in the ON phase of their usual treatment
• Hoehn-Yahr Stage from 1 to 3
• Signature of the Informed Consent and of the privacy form

Exclusion Criteria:

• Patients with symptoms and signs compatible with atypical parkinsonism
• PD patients treated with antagonist drugs for central dopaminergic receptors (first and second generation antipsychotics) in the last 6 months before enrollment
• Patients suffering from other neurological diseases
• Patients with evident cognitive impairment (MMSE <24/30)
• Patients with manifest eye movement disorders prior to the diagnosis of PD.
• Patients with daltonism
• Patients with amblyopia
• Patients suffering from high anisometropia
• Patients suffering from advanced cataracts
• Patients suffering from glaucoma
• Patients suffering from maculopathy
• Patients suffering from pathologies of the optic nerve
• Patients with severe visual field deficits
• Patients with refractive defects above 5 diopters

1. Patients affected by Parkinson's disease (PD) according to the diagnostic criteria of the United Kingdom Brain Bank, in the ON phase of their usual treatment (Hoehn-Yahr Stage from 1 to 3) coming from Parkinson's Center of Neuromed IRCCS Institute with signature of the Informed Consent and of the privacy form.
2. Health subjects coming from Neurological Department of Neuromed IRCCS Institute with signature of the Informed Consent and of the privacy form.