Study of Enhanced Depth Imaging Optical Coherence Tomography in Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy

Background: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary small artery disease caused by NOTCH3 gene mutation. We performed enhanced depth imaging optical coherence tomography (EDI-OCT) to evaluate the retinal vessel changes in CADASIL patients and assessed their consonance with brain magnetic resonance imaging (MRI) findings. Methods: Of 27 genetically confirmed patients and an equal number of controls were recruited at the Peking University First Hospital from January 2015 to August 2016. All patients underwent 7T-MRI of the brain. Fazekas score, number of small infarcts and microbleeds were evaluated. All patients and controls underwent EDI-OCT to measure subfoveal choroidal thickness (SFCT), inner and outer diameters as well as arterial and venous wall thickness, and arterial venous ratio of the inner (AVR(in)) and outer diameters (AVR(out)). The relation between retinal vessel changes and Fazekas scores, numbers of small infarcts, or microbleeds was analyzed. Paired t-test was used to compare the SFCT and retinal vessel measurement data between patients and controls. Spearman's correlation was used to investigate the correlation between retinal vessel changes and MRI lesions. Results: In CADASIL patients, mean SFCT (268.37 +/- 46.50 mu m) and mean arterial inner diameter (93.46 +/- 9.70 mu m) were significantly lower than that in controls (P < 0.001, P = 0.048, respectively). Mean arterial outer diameter (131.74 +/- 10.87 mu m), venous inner (128.99 +/- 13.62 mu m) and outer diameter (164.82 +/- 14.77 mu m), and mean arterial (19.13 +/- 1.85 mu m) and venous (17.91 +/- 2.76 mu m) wall thickness were significantly higher than that in controls (P = 0.023, P = 0.004, P < 0.001, P < 0.001, respectively). Arterial inner diameter (r(epsilon) = -0.39, P = 0.044), AVRin (r = 0.65, P < 0.001), and AVR(out) (r(s) = 0.56, P = 0.002) showed a negative correlation with the number of small infarcts. Venous inner diameter (r = 0.46, P = 0.016) showed a positive correlation with the number of small infarcts. Venous inner diameter (r(s)= 0.59, P= 0.002), outer diameter (r(s) = 0.47, P= 0.017), showed a positive correlation with the number of cerebral microbleeds (CMBs). AVR(in) (r(s) = -0.52, P = 0.007) and AVR(out) (r(s) = -0.40, P = 0.048) showed a negative correlation with the number of CMBs. Conclusions: Measurement of retinal vessels using EDI-OCT correlates moderately well with MRI parameters. EDI-OCT might be a useful evaluation tool for CADASIL patients.