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Background: Increasing evidence has indicated that the entire visual pathway from retina to visual cortex may be involved in dysthyroid optic neuropathy (DON) pathological mechanisms. Purpose: To explore the functional and morphological brain characteristics in DON and their relationship with ophthalmologic performance. Study Type: Retrospective. Population: A total of 30 DON patients, 40 thyroid‐associated ophthalmopathy (TAO) without DON patients and 21 healthy‐controls (HCs). Field Strength/Sequence: A 3.0 T, 3D T1‐weighted spoiled gradient‐recalled echo and gradient‐recalled echo‐planar imaging. Assessment: Functional and structural alterations in brain regions were evaluated with fractional amplitude of low‐frequency fluctuations, degree centrality (DC), and gray matter volume (GMV). Clinical activity score (CAS) is assessed across patients. Statistical Test: One‐way analysis of variance with post hoc two sample t‐tests (GRF‐corrected, voxel level: P < 0.005, cluster level: P < 0.05) and correlation analysis (significance level: P < 0.05). Results: Compared to HCs, DON patients had significantly decreased DC values in the bilateral BA17 and BA18 regions. Compared to the TAO group, DON patients had decreased GMV in the left anterior cingulate cortex, left middle frontal gyrus, left lingual gyrus, left parietal gyrus, right Rolandic operculum, left supplementary motor area, and right middle temporal gyrus. In addition, GMV in the right Rolandic operculum was significantly positively correlated with CAS (correlation coefficient: r = 0.448). Data Conclusion: This study showed significant morphological and functional alterations in visual cortex and morphological alterations in partial default mode network regions of DON patients, which may provide insights into the mechanism of vision loss and may facilitate the diagnosis and treatment of DON. Evidence Level: 3. Technical Efficacy: Stage 3. [ABSTRACT FROM AUTHOR]

Background: The mechanism driving dysthyroid optic neuropathy (DON) is unclear. Diffusion‐tensor imaging (DTI) allows for noninvasively assessing the microstructure of the entire visual pathway and may facilitate a better understanding of the mechanism of DON. Purpose: To assess microstructural changes of the whole visual pathway and to investigate the potential mechanism of trans‐synaptic damage（TSD） pathogenesis in DON with DTI. Study Type: Cross‐sectional. Population: Sixty‐four patients with bilateral thyroid‐associated ophthalmopathy (TAO), 30 with and 34 without DON, and 30 age‐ and sex‐matched healthy controls (HCs). Field Strength/Sequence: 3 T/DTI (A single‐shot diffusion‐weighted echo‐planar imaging sequence). Assessment: Differences in DTI parameters including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) in each segment (optic nerve, tract, and radiation) of the entire visual pathway among the groups were compared. The parameters of visual evoked potentials (VEPs), visual field tests, and mean retinal nerve fiber layer (mRNFL) thickness on optical coherence tomography were also compared across patients. Statistical Tests: Student's t‐test, chi‐square test; ANOVA with post‐hoc testing, interclass correlation coefficient, and correlation analysis. Significance level: P < 0.05. Results: TAO patients with DON showed significantly reduced mRNFL thickness and abnormal VEPs. There was a tendency for gradually reduced FA and AD, and increased RD and MD from HCs, with non‐DON to with DON in optic nerve and tract, statistically. For radiation, the RD and MD showed statistical increase, the AD and FA just showed numerical decrease (P = 0.119 and 0.059, respectively). For DON, the FA and MD of visual pathway segments showed correlations with abnormal VEPs. Data Conclusion: DTI may be a useful tool for detecting microstructural changes in the entire visual pathway in DON. The changes in RNFL thickness and DTI parameters suggested TSD as a potential pathogenic mechanism of DON. Evidence Level: 4 Technical Efficacy: Stage 5 [ABSTRACT FROM AUTHOR]

To investigate the association between serum immunoglobulin G4 (IgG4) levels and laboratorial parameters. Moreover, the ocular manifestations were compared in Graves' ophthalmopathy (GO) patients. Fifty-seven GO patients and fifty sex- and age-matched euthyroid subjects were enrolled. Serum IgG4 and immunoglobulin G (IgG) levels, thyroid hormones and thyroid autoantibodies were measured in all participants. Ophthalmologic examinations were performed to GO patients. Serum IgG4 levels were increased in GO patients compared with euthyroid subjects (p<0.001). Multivariate analysis showed that TRAb levels were correlated with IgG4 levels in GO patients (β=1.45, p = 0.024). There were eight GO patients with IgG4 levels ≥ 135 mg/dL. They all had both eyelids swelling and the differences of HER were less than 2mm. Seven patients (7/8) showed bilateral symmetrical thickening of the extraocular muscles. Bilateral symmetry of ocular manifestation was observed in GO patients with IgG4 levels ≥135 mg/dL. IgG4 levels may be helpful in monitoring GO and diagnosing a new subtype of GO. [ABSTRACT FROM AUTHOR]

Background: With the extensive development of endoscopic sinus surgery, iatrogenic medial rectus muscle injury should be treated with caution. Traditional methods to repair a ruptured medial rectus need an anterior orbitotomy approach, with more injury and difficulty in finding the posterior end of the ruptured medial rectus. Objective: To explore a new method to repair a ruptured medial rectus. Methods: Eight cases of iatrogenic medial rectus rupture after endoscopic sinus surgery were reviewed from July 2015 to January 2019. Assisted by image-guided navigation, the ruptured medial rectus was sutured under an endoscopic endonasal orbital approach. Two methods were designed to suture the ruptured medial rectus. Optic nerve and orbital decompression were performed in 5 cases with visual impairment. The extent of exotropia and diplopia were followed up for 5 to 33 months after surgery. Results: With the help of image guidance, the posterior and anterior ends of the ruptured medial rectus of all patients were pinpointed, and operations using medial rectus anastomosis were successfully completed in 7 patients. The exotropia of these patients was corrected, and they have recovered. The vision of 2 patients recovered. There were no minor or major complications intraoperatively or postoperatively. Conclusion: Assisted by image-guided navigation, medial rectus anastomosis under an endoscopic endonasal orbital approach is a feasible method. The key to preventing orbital complications is strict professional training, including identification of the Onodi air cell and correct application of powered instrumentation. [ABSTRACT FROM AUTHOR]