Correlation of Retinal Thickness and Visual Features in Patients With Parkinson's Disease

Aim Visual symptoms are a common non‐motor feature of patients with Parkinson's disease (PwPD). Optical coherence tomography (OCT) is a non‐invasive test for assessing retinal thickness and morphology. Reports have shown reduced retinal thickness from early illness in PwPD, but its relationship with visual symptoms/functions remains unclear. We aimed to investigate the correlation between retinal thickness and visual symptoms/functions in PwPD. Methods A single‐centered and cross‐sectional study was conducted with PwPD attending the neurology and ophthalmology outpatient departments. All patients underwent an OCT retinal thickness measurement. The presence/absence of visual symptoms and the visual perception test for agnosia (VPTA) were used to assess visual function. Results Fifty‐six PwPD were evaluated. We obtained significant correlations in color perception, symbol recognition, and visuospatial perception ( p < 0.05). Furthermore, PwPD with visual hallucinations had thinner than those without in the nasal region ( p < 0.05). Conclusion There were correlations between retinal thickness and some items of the VPTA, and between retinal thickness in the nasal visual field and visual hallucinations. These results suggest that impairment of visual input associated with retinal abnormalities may have a secondary effect on visual symptoms associated with PD.