AUTHOR=Rascunà Cristina , Russo Andrea , Terravecchia Claudio , Castellino Niccolò , Avitabile Teresio , Bonfiglio Vincenza , Fallico Matteo , Chisari Clara Grazia , Cicero Calogero Edoardo , Grillo Marco , Longo Antonio , Luca Antonina , Mostile Giovanni , Zappia Mario , Reibaldi Michele , Nicoletti Alessandra 

TITLE=Retinal Thickness and Microvascular Pattern in Early Parkinson's Disease

JOURNAL=Frontiers in Neurology

VOLUME=Volume 11 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2020.533375

DOI=10.3389/fneur.2020.533375

ISSN=1664-2295

ABSTRACT=Abstract 
A thinning of intraretinal layers has previously described in Parkinson’s disease (PD) patients compared to healthy controls (HCs). Few studies evaluated the possible correlation between retinal thickness and retinal microvascularization.  Thus, here we assessed the thickness of retinal layers and microvascular pattern in early PD patients and HCs, using, respectively, Spectral-domain optical coherence tomography (SD-OCT) and  SD-OCT-Angiography (SD-OCT-A) and, more interestingly, we evaluated a possible correlation between retinal thickness and microvascular pattern. Patients fulfilling criteria for clinically established/clinically probable PD and HCs were enrolled. Exclusion criteria were any ocular, retinal and systemic disease impairing visual system. Retinal vascularization was analysed using SD-OCT-A and retinal layers thickness was assessed using SD-OCT. Forty-one eyes from 21 PD patients and 33 eyes from 17 HCs were evaluated. Peripapillary Retinal Nerve Fiber Layer (RNFL) and macular RNFL, Ganglionic Cell Layer (GCL), Inner Plexiform Layer (IPL) and Inner Nuclear Layer (INL), resulted to be thinner in PD compared to HCs. Among PD patients a positive correlation between RNFL, GCL and IPL thickness and microvascular density was found in the foveal region, also adjusting by age, sex and, especially, hypertension. Such findings were already present in the early stage of disease and were irrespective of dopaminergic treatment. Thus, retina might be considered as biomarker of PD and could be a useful instrument for onset and disease progression.