OCTA changes of retinal microvessels and thickness in moyamoya disease

Moyamoya disease (MMD) is a structural abnormality of the cerebral vasculature characterized by cerebral ischemia, and is rare but its incidence is increasing. Digital subtraction angiography (DSA) of the brain is the primary means of diagnosing and evaluating this disease. But its high price and invasiveness limit its use as a monitoring tool for disease progression. As a non-invasive test for ophthalmic disorders, the optical coherence tomography angiography (OCTA) is widely used. In addition to ophthalmic diseases, OCTA has also been used in some neurological diseases. The aim of this study was to assess fundus changes in patients with MMD by OCTA and to investigate whether these changes could be a diagnostic and assessment marker for MMD. This study evaluated cerebral vessels, superficial macular capillary vessel density (SMC-VD) and macular retinal thickness (MRT) in subjects in the non-operated group (nGO), operated group (OG) and healthy controls (HC) using DSA, OCTA and other techniques. Analyses of variance (ANOVA) and Bonferroni post hoc analysis were used to calculate statistical differences between the three groups. Correlations between SMC-VD and MRT were assessed using Pearson correlation analysis. In addition, the ability of the SMC-VD and the MRT to distinguish MMD from HC was analyzed using receiver operating characteristic (ROC) curves. We found that the SMC-VD and MRT in the nOG group were significantly lower than those in the HC group and had not returned to normal levels at one month postoperatively. In the nOG, the SMC-VD and MRT were positively correlated in the Full region (6*6 mm) and in the Inner region (3*3 mm), and in many subregions they showed high ability to distinguish MMD from HC. The above findings indicate significant reduction in the SMC-VD and the MRT in patients with MMD even in the absence of ocular clinical manifestation. Most importantly, SMC-VD and MRT have a strong ability to distinguish between MMD patients and HC, suggesting that OCTA, a relatively inexpensive and non-invasive method, is useful in assessing cerebrovascular changes in MMD patients.