Introduction: This study aims to investigate retinal neuronal and vascular
structural alterations in Parkinson’s disease (PD) patients concerning
disease duration and severity, levodopa dosage, and stroke risk.
Materials and Methods: This retrospective study included 40 PD
patients and 40 age– and sex-matched controls. Retinal parameters,
including central foveal thickness (CFT), macular thickness (MT), retinal
nerve fiber layer (RNFL), and retinal vascular density, were measured
using optical coherence tomography (OCT) and optical coherence
tomography angiography (OCTA). Disease severity was assessed using
the Hoehn & Yahr (H&Y) scale, and stroke risk was evaluated using the
Stroke Risk Assessment (SRA) tool.
Results: PD patients demonstrated significantly reduced MT in the
temporal quadrant and reduced vascular density in both the superficial
(SCP) and deep (DCP) capillary plexuses compared to controls.
Additionally, the superficial and deep foveal avascular zone (FAZ) areas
showed notable enlargement. A negative correlation between disease
duration and both the temporal and nasal quadrants of the SCP and a
positive correlation between disease severity and deep FAZ area was
observed, while disease severity exhibited negative correlations with
temporal MT, average and superior quadrant RNFL. Levodopa dosage
was inversely correlated with inferior and temporal MT and temporal
SCP and DCP and positively correlated with the deep FAZ area. No
significant correlation was found between the SRA score and retinal
vascular changes.
Conclusion: This study is the first to evaluate retinal neuronal and
vascular changes in PD regarding stroke risk assessment. Our findings
suggest that retinal changes are associated with disease severity and
duration in PD patients. Further prospective studies with larger sample
sizes are needed to validate these findings and explore the potential role
of OCTA in early detection and stroke prevention in PD.
Keywords: Hoehn & Yahr scale, macular vascular density, optical
coherence tomography angiography, Parkinson’s disease, stroke risk
assessment score