Retinal functional and structural changes in patients with Parkinson's disease

Area of Science:

• Ophthalmology
• Neurology
• Neuroscience

Background:

• Visual dysfunction is a common non-motor symptom in Parkinson's disease (PD).
• Retinal changes may serve as an indicator of neurodegeneration in PD.
• Understanding these changes can offer insights into disease progression.

Purpose of the Study:

• To assess functional and structural retinal alterations in PD patients.
• To investigate the correlation between retinal changes, disease duration, and motor impairment.
• To compare retinal parameters in PD patients with age- and sex-matched healthy controls.

Main Methods:

• A case-control study involving 50 idiopathic PD patients and 50 healthy controls (aged 50-80).
• Motor function assessed using Hoehn and Yahr staging and UPDRS.
• Retinal structure evaluated via Optical Coherence Tomography (OCT) and function via full-field electroretinogram (ff-ERG).

Main Results:

• PD patients exhibited significantly reduced peripapillary retinal nerve fiber layer (RNFL) thickness and macular ganglion cell complex (GCC) thickness compared to controls (P<0.05).
• ff-ERG revealed significantly delayed latencies and reduced amplitudes in both rod and cone responses in PD patients (P<0.001).
• Negative correlations found between disease duration and RNFL thickness, and between UPDRS scores and ff-ERG parameters.

Conclusions:

• Significant structural and functional retinal impairments are present in Parkinson's disease patients.
• Retinal thickness is significantly affected by disease duration.
• Motor dysfunction severity in PD correlates negatively with retinal function.