Combination of optical coherence tomography (OCT) and OCT angiography increases diagnostic efficacy of Parkinson’s disease

Abstract

Background: To assess the diagnostic efficacy of optical coherence tomography (OCT) and OCT angiography (OCTA) in Parkinson's disease (PD).Methods: OCT was used to obtain macular parameters and peripapillary retinal nerve fiber layer (RNFL) thickness. The macular superficial retinal vessel and foveal avascular zone (FAZ) were quantified with OCTA.The area under the receiver operating characteristic curve (AUC) indicated the diagnostic efficacy of the parameters.Results: Thirty-five eyes from 35 PD patients and 35 eyes from 35 age-matched healthy subjects who served as controls were evaluated. The mean RNFL thickness overall and the thicknesses of the other three quadrants were similar in PD patients compared with controls (P≥0.358). The RNFL thickness at the temporal quadrant, total macular volume (TMV), macular retinal thickness (MRT), and ganglion cell-inner plexiform layer complex (GCL-IPL) thickness were reduced in the eyes of PD patients (P≤0.046). There was no difference between the CMT of PD patients compared with control subjects (P=0.163). The vessel length density (VLD) in the central, inner and full regions; vessel perfusion density (VPD) in all regions; and the FAZ circularity index in PD patients were significantly lower than in controls (P≤0.049). The AUC of the VLD in PD in the central, inner and full regions were 0.712, 0.728, and 0.650, respectively; The VPD in the central, inner and full region were 0.711, 0.756, and 0.682, respectively. The mean RNFL thickness in the temporal quadrant, TMV and MRT revealed an AUC of 0.718, 0.693 and 0.699, respectively. The VPD in the outer region, FAZ circularity and GCL-IPL thickness did not have diagnostic ability in distinguishing PD from normal eyes (P≥0.05). The AUCs of a combination of the VLD in the inner region and TMV, the VLD in the inner region and MRT, the VPD in the inner region and TMV, and the VPD in the inner region and MRT, were 0.843, 0.849, 0.849, and 0.848, respectively (P≤0.001).Conclusions: Decreased OCT and OCTA parameters were detected in the eyes of PD patients. Combined non-invasive measurements of OCT and OCTA had better diagnostic ability than either alone, and may provide an additional biomarker for PD progression.

Foveal Remodeling of Retinal Microvasculature in Parkinson’s Disease

“…Furthermore, we found that the decrease in FAZ area was accompanied by an increase in microvascular parameters in the foveal zone, like skeleton and perfusion density, fractal dimension or lacunarity. This contrasts with the results of Zou et al who found less vessel length and perfusion in the central macula of PD patients and no changes in FAZ area ( Zou et al, 2020 ), and with the results of Rascunà et al who did not find vascular density changes in the foveal zone of early PD patients ( Rascunà et al, 2020 ). Some of these differences might be attributed to smaller sample sizes, differences in disease stage of patients and study design flaws of previous studies.…”

“…In this work, we showed that foveal lacunarity could be a promising biomarker for differentiating patients from controls, as a significantly greater AUC was achieved after adding this parameter to the null model that controlled for confounding variables like age, sex, and hypertension. In a previous study of Zou et al (2020) , similar AUCs were obtained after combining OCT-A and OCT parameters. However, these authors only accounted for capillary length and density, and no further microvascular parameters were considered.…”

“…Studying the morphometric variations of capillary networks in PD might provide key information about the regional neuronal structure, and the basis for investigating retinal vascular morphological features as potential biomarkers of cerebral microcirculation in PD. Although to date few studies have explored retinal vascular alterations in PD using OCT-A, the observations so far support the view that retinal vascular alterations are present in PD (Kromer et al, 2016;Kwapong et al, 2018;Rascunà et al, 2020;Shi et al, 2020;Zou et al, 2020;Robbins et al, 2021).…”

Visual Impairments Are Associated With Retinal Microvascular Density in Patients With Parkinson’s Disease

“…Optical coherence tomography angiography (OCTA) is a functional extension of optical coherence tomography (OCT) imaging that facilitates the visualization of microvascular and morphological structure non-invasively in the retina ( Spaide et al, 2018 ). Recently, several research findings described the decreased retinal microvascular density in patients with PD, which can serve as a surrogate biomarker for the diagnosis of PD ( Kwapong et al, 2018 ; Zou et al, 2020 ). However, studies focusing on whether altered retinal microvasculature affects visual function were scarce.…”

The Value of Optical Coherence Tomography Angiography (OCT-A) in Neurological Diseases

“…PD is related to the progressive loss of dopaminergic neurons as a consequence of α-synuclein accumulation within neuronal cytoplasm [ 7 ]. As a result, PD manifests with motor symptoms such as bradykinesia, resting tremor and rigidity [ 17 , 18 ]. Moreover, non-motor symptoms are also described, including sleep disorders, anosmia, depression, cognitive impairment and vision deficits [ 17 ].…”