Optical coherence tomography angiography in non-alcoholic fatty liver disease: is it a disease affecting the microvascular system??

Purpose: To investigate retinal thickness and vascular structure in patients with non-alcoholic fatty liver disease (NAFLD) using optical coherence tomography (OCT) and OCT angiography (OCTA) and to compare the results with healthy controls. Method: The medical records of NAFLD patients were retrospectively reviewed. Macular thickness (MT) and peripapillary retinal nerve fibre layer (pRNFL) thickness were assessed. The vessel density (VD) of Superficial Capillary Plexus (SCP), Deep Capillary Plexus (DCP), foveal avascular zone (FAZ) area, FAZ circularity index (CI), and FAZ perimeter were also recorded. Results: The study included 64 patients with NAFLD and 64 healthy controls. Mean MT and pRNFLT were similar between groups. The study group showed a significant reduction in VD-DCP compared to the control group (36.0 ± 5.2 vs. 38.5 ± 4.1, p < 0.001). Total FAZ area was greater in the study group than in the control group (0.42 ± 0.10 vs. 0.33 ± 0.12mm2, p < 0.001). FAZ CI also differed between groups (0.47 ± 0.08 vs. 0.53 ± 0.08, p < 0.001). Enlarged FAZ area and decreased VD-DCP were significantly associated with NAFLD severity. Conclusion: Individuals with NAFLD have certain changes in the retinal microvasculature, including reduced VD-DCP, an increased FAZ area, and a decreased of FAZ CI. The variations in VD-DCP and FAZ area exhibit discrepancies according to the disease grade. There are some limitations, including its retrospective nature, the small number of participants, the lack of analysis of the peripapillary area, and the lack of examination of longitudinal changes. © The Author(s) 2025.