Objective: To investigate the changes in macular vessel density (VD) of the superficial layer of retina (SLR) and deep layer of retina (DLR) in dysthyroid optic neuropathy (DON) after high-dose intravenous pulse methyl-prednisolone (IVMP). Materials and Methods: Eighteen DON patients (29 eyes) who completed high-dose IVMP and 16 healthy in-dividuals (32 eyes) were enrolled in this study. Optical coherence tomography angiography (OCTA) image analysis and comprehensive ophthalmic examinations were performed, including the SLR macular whole-image VD (SLR-mwiVD) and DLR-mwiVD, best-corrected visual acuity (BCVA), the mean deviation of visual field (VF-MD), pattern standard deviation of visual field (VF-PSD) and the other parameters.Results: The SLR-mwiVD (41.39 +/- 4.71 vs. 48.13 +/- 3.68, p < 0.001) and DLR-mwiVD (40.77 +/- 5.85 vs. 49.14 +/- 7.02, p < 0.001) were decreased in DON compared to control eyes. After IVMP, visual function parameters were improved, and SLR-mwiVD (49.41 +/- 3.18, p < 0.001) and DLR-mwiVD (50.41 +/- 4.04, p < 0.001) were increased in the DON group compared to pretreatment. The increased SLR-mwiVD and DLR-mwiVD were significantly correlated with improvements in BCVA (Log MAR: from 0.62 +/- 0.49 to-0.01 +/- 0.03, p < 0.001), VF-MD (from - 6.89 +/- 2.89 dB to - 1.75 +/- 1.29 dB, p < 0.001) and VF-PSD (from 4.38 +/- 2.52 dB to 2.32 +/- 1.64 dB, p < 0.001).Conclusion: The increase in macular VD was significantly correlated with the improvement in visual function in DON after IVMP. Macular VD changes on OCTA may be a useful indicator for the response in DON after IVMP.
