Abstract

Purpose: To describe clinico-radiological and histopathological features and outcomes of orbital immunoglobulin G4-related disease (IgG4-RD) and compare them to non-specific orbital-inflammatory disease (NSOID). Methods: Retrospective review of 84 patients histopathologically diagnosed with orbital inflammatory disease. Results: Mean age was 43 ± 16 years and 31 (57%) had IgG4-RD based on the comprehensive diagnostic criteria for IgG4-RD. Clinico-radiological features were comparable (IgG4-RD vs NSOID), however bilaterality (36% vs. 22%) and extra-ocular muscle involvement (74% vs. 61%) occurred more in IgG4 group. Storiform fibrosis (71% vs 17%, p< 0.001) and thrombophlebitis (55% vs. 13%, p< 0.006) were higher in IgG4-RD group. Complete response to pulse steroids tended to be better in NSOID group (16% vs 35%). Serum IgG4 levels did not correlate with outcome. Conclusion: Clinico-radiological features of IgG4-RD overlap with NSOID, but immunohistopathological features are distinct.