Abstract
Purpose :
Diabetic Retinopathy (DR) is a microvascular disease with loss of pericytes and smooth muscle cells. Most state-of-the-art retinal imaging techniques provide only limited information on vascular substructures. Adaptive optics optical coherence tomography (AO-OCT) allows non-invasive 3D investigation of cellular vessel wall components in microscopic resolution.
Methods :
10 eyes of 7 patients (female n=2) with mild NPDR (n=3), moderate NPDR (n=4), severe NPDR (n=3) and 7 eyes of 7 healthy (female n=2) controls were investigated with a prototype pyramid wavefront sensor AO-OCT at the Medical University of Vienna. Single AO-OCT volumes were recorded at an extended field of view of 4°x4° at 5 adjacent locations along the vascular trajectories.
Results :
The vascular wall and the differentiation of outer and inner lumen can be visualized in single volume scans. Within the arterial wall, hyper-reflective structures in the order of 7µm can be observed, possibly corresponding to vascular smooth muscle cells (vSMCs). In venule walls, cellular hyper-reflective structures measuring 9µm in size are scattered along the vessel. Similar structures can be observed adjacent to capillaries and might correspond to pericytes. AO vascular biomarkers like parietal thickness (PT), inner and outer lumen diameter (ID and OD) can be measured. The quantification of mural cells for each vessel type in eyes with NPDR and healthy eyes is subject of ongoing work and will be reported.
Conclusions :
AO-OCT enables the investigation of morphological changes in the microvasculature and the quantitative assessment of cellular structures in healthy and diabetic eyes. Measurement of mural cell density may serve as a new quantitative biomarker for diabetic retinopathy. AO-OCT imaging represents a promising clinical tool for investigating cellular biomarkers in vascular diseases.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.