Retinal microvascular impairment in Parkinson's disease with cognitive dysfunction

Area of Science:

• Ophthalmology
• Neurology
• Medical Imaging

Background:

• Parkinson's disease (PD) is linked to retinal structural changes.
• The presence of these retinal changes in PD with mild cognitive impairment (MCI) is not well understood.
• Retinal microvascular alterations may offer insights into PD pathophysiology.

Purpose of the Study:

• To investigate retinal microvascular impairments in Parkinson's disease (PD) using optical coherence tomography angiography (OCTA).
• To assess if retinal microvascular changes are associated with mild cognitive impairment (MCI) in PD patients.
• To explore the correlation between retinal microvasculature and cognitive function in PD.

Main Methods:

• Evaluated 83 eyes from 45 PD patients and 83 eyes from 42 healthy controls.
• Utilized OCTA to analyze vessel density in the superficial capillary plexus (SRCP), deep capillary plexus (DRCP), and radial peripapillary capillaries (RPC).
• Assessed retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness, correlating vessel density with cognitive function in PD patients.

Main Results:

• PD patients exhibited significantly lower parafoveal vessel density in the SRCP and DRCP compared to controls.
• No significant differences were observed in RPC, RNFL, or GCC between PD patients and controls.
• Lower executive function scores in PD patients were associated with reduced vessel density in the DRCP.

Conclusions:

• OCTA demonstrates reduced macular microvascular density in PD patients.
• Microvascular impairments in the deep retinal capillary layer are linked to executive dysfunction in PD.
• These OCTA-derived parameters show potential as early diagnostic biomarkers for PD.