AB0403 ORBITAL MYOSITIS: AN UNCOMMON OPHTHALMIC PRESENTATION IN RHEUMATIC DISEASES - CASE SERIES AND SYSTEMIC REVIEW OF CASE REPORTS
Authors: P. S. Wong, B. G. T. Coumbe, P. Mangat, H. Beynon, R. Stratton
Journal: Annals of the Rheumatic Diseases (2021)

Background: Ophthalmic conditions are common manifestations in patients with rheumatic diseases (RDs), orbital myositis (OM) remain rare. Only 1 case each for scleroderma and undifferentiated connective tissue disease (UCTD) reported. Objectives: Report frequency of Rheumatic Diseases with OM (RDs-OM), diagnosis and treatments. Methods: Patients database were obtained from trust electronic record and literature review of case reports were performed. Results: 4 out of 7 patients in our clinic with RDs-OM. Both Scleroderma-myositis (SCM) patients were positive for anti-PM/SCL antibody. All received glucocorticosteroid (GCS) and Mycophenolate as steroid-sparing or rescue therapy with good tolerance and outcome. One idiopathic OM has residual muscle paresis. Table 1. Case series of patients with Orbital Myositis Idiopathic OM (n=3 ) Rheumatology Diseases (n=4 ) p-value Age (years) 48 (27-72) 42.75 (21-60) P= 0.8571 Gender – Female (Male) 2 (1) 4(0) Median Period Of Follow Up (months) 24.60 (7-37) 47.25(1-120) Underlying RD I.UCTD - 1 II.Overlap Scleromyositis - 2 III.Behcet’s Disease - 1 Biopsy I.Pathological significant 1 1 II.Normal 1 1 III.Not done 1 2 Total 93 cases with RDs-OM reviewed and the characteristic of patients represented in Figure 1. Figure 1. Characteristics of orbital myositis in patients with rheumatic diseases. F: female, M:male, NS: not-specified, PrePD: onset before RD, AtD: onset with RD,PostPD: onset after RD, GCS 1 st : Glucocorticoid as first line treatment, GCS res: Glucocorticoid responder, BxEOM: biopsy of extra-ocular muscle, OtherTs: Other Biopsy A: Median age at diagnosis, Sarc: sarcoidosis, SLE: Lupus, EGPA: Eosinophilic Granulomatous Polyangitis, GPA: Granulomatous Polyangitis, RA: rheumaoid Arthritis, BD: Behcet;s Disease, RP: Relapsing Polychondritis, DM: Dermatomyositis, LoSSC: Localized Sclerderma, SPA: Spondyloarthropathy, ASOD: Adult Onset Still’s Disease, RPF: Retroperitoneal Fibrosis, GCOM: Giant Cell OM, SJS: Sjogren Syndrome, DL: Discoid Lupus, KD: Kawasaki Disease, SAPHO: Synovitis, acne, pustulosis, hyperostosis, and osteitis, APLS: Antiphospholipid Syndrome. OM although is rare but can present in most RDs. Our review showed OM commonest in patients with RA, GPA, EGPA and sarcoidosis. Only 1 each for SCM, APLS, UCTD, SAPHO and Kawasaki Disease. Most RDs-OM patients are female. 89.2% OM diagnosed concurrently with primary RD diagnosis. Majority RA, BD and GPA developed OM along the course of RDs (83%-90%). Except for routine RDs screening, thyroid eye disease, infections, malignancy (eg. lymphoma) and myasthenia gravis, atypical infective screenings include mycobacterium, fungal, Borrelia and spirochetes were excluded. Histopathological diagnosis is important diagnostic tool for IgG4 disease, neoplasm, sarcoidosis and vasculitis. 59% patients underwent tissue biopsy, 71% of these were sampled from EOM, some from involved organs. Orbital MRI or CT were the commonest diagnostic imaging, 5 reported had Ocular ultrasound as single or complementary imaging and 1 had PET-CT for exclusion of other diagnosis. Only 40% GPA and 20% of EGPA patients were positive for ANCA either c-ANCA, p-ANCA and MPO which is similar in other literatures. 97.8% (n=91) patients received GCS with 79% of these patients reported improvement or resolution of ocular symptom with or without steroid-sparing agents. Immunosuppressants used are those not foreign among rheumatologists while biologics prescribed for refractory cases were Rituximab(2), Infliximab(4), Adalimumab(2) and Tocilizumab(1). Orbital decompression and orbital radiation were other measures. 13 patients had residual EOM paresis. Conclusion: 1.RDs-OM is increasing recognized. 2.Most OM in RA, BD and GPA occurs along its primary RDs. 3.40% GPA and 20% of EGPA patients were ANCA positive. 4.GCS remain the primary treatment, three quarter patients responded. References: [1]Murray PI. The eye and inflammatory rheumatic diseases. Best Practice &amp; Research Clinical Rheumatology. 2016. Disclosure of Interests: None declared