Increased microRNA-155 and decreased microRNA-146a may promote ocular inflammation and proliferation in Graves' ophthalmopathy.

Graves' ophthalmopathy is an inflammatory autoimmune disease of the orbit, characterized by inflammation and proliferation of the orbital tissue caused by CD4+T cells and orbital fibroblasts. Despite recent substantial findings regarding its cellular and molecular foundations, the pathogenesis of Graves' ophthalmopathy remains unclear. Accumulating data suggest that microRNAs play important roles in the pathophysiology of autoimmunity and proliferation. Specifically, microRNA-155 (miR-155) can promote autoimmune inflammation by enhancing inflammatory T cell development. In contrast to miR-155, microRNA-146a (miR-146a) can inhibit the immune response by suppressing T cell activation. Furthermore, miR-155 and miR-146a are involved in cell proliferation, differentiation, and many other life processes. Thus, miR-155 and miR-146a, with opposite impacts on inflammatory responses carried out by T lymphocytes, appear to have multiple targets in the pathogenesis of Graves' ophthalmopathy. Our previous work showed that the expression of miR-146a was significantly decreased in peripheral blood mononuclear cells from Graves' ophthalmopathy patients compared with normal subjects. Accordingly, we proposed that the expression of miR-155 increased and the expression of miR-146a decreased in the target cells (CD4+T cells and orbital fibroblasts), thus promoting ocular inflammation and proliferation in Graves' ophthalmopathy. The proposed hypothesis warrants further investigation of the function of the differentially expressed microRNAs, which may shed new light on the pathogenesis of Graves' ophthalmopathy and lead to new strategies for its management.

Disc swelling and mild initial visual acuity loss predict a better short-term visual acuity outcome in bilateral acute optic neuritis.

Bilateral acute optic neuritis (AON) is rare in adults in Western countries, but is relatively common in Asian populations. We aimed to document clinical features in Chinese patients with bilateral AON, and to identify factors that are predictive of visual acuity outcome. We reviewed 41 patients (23 males, 18 females; age 18-74 years) diagnosed with bilateral AON from three centers between 2003 and 2009. Demographic and clinical data were compared to a group of patients with unilateral AON. Univariate analysis and multivariate linear regression were used to identify prognostic factors. We found that the median visual acuity (expressed as the logarithm of the minimal angle of resolution [LogMAR] scores) in our patients was 1.55 at presentation and 0.72 at discharge (p<0.001). There was a higher proportion of males (56% compared to 34%, p=0.015), a higher percentage with disc swelling (71% compared to 48%, p=0.014), and poorer visual acuity at presentation (median LogMAR scores: 1.55 compared to 1.70, p=0.001) in patients with bilateral AON than in those with unilateral AON. Both disc swelling (p=0.036) and visual acuity at presentation (p=0.023) were significantly associated with visual acuity at discharge. Our study suggests that bilateral AON has some clinical differences to unilateral AON, and that disc swelling and initial visual acuity may predict a short-term visual acuity outcome in bilateral AON.