(P063) ORBITAL MYOSITIS AS AN EXTRAINTESTINAL MANIFESTATION OF IBD

Background

Orbital myositis (OM) is a rare extraintestinal manifestation (EIM) of inflammatory bowel disease (IBD) in which inflamed extraocular muscles cause severe eye pain. With fewer than thirty cases of OM described in the literature, its etiology remains largely unknown. We thus describe eleven cases of OM in patients diagnosed with IBD or microscopic colitis as well as prevalent comorbidities observed within this group.

Methods

Patients with known orbital myositis diagnosed by an ophthalmologist and documented IBD or microscopic colitis were included at this single center institution from 2012 to 2022.

Results

Of the eleven patients included in this study, six patients (55%) had Crohn’s disease, three patients (27%) had ulcerative colitis, one (9%) had indeterminate colitis, and one (9%) had lymphocytic colitis. All eleven patients were Caucasian and seven (64%) were female. The median age at OM presentation was 54 [47.5-60] years. On presentation, nine patients (82%) reported eye pain, seven (64%) reported blurry vision, four (36%) had headaches with concurrent photophobia, three (27%) had eye swelling, and three (27%) had diplopia. Six patients (55%) had unilateral OM and five (45%) had bilateral disease. Six OM cases were confirmed with ultrasound, two with MRI and three with clinical diagnoses.

The median age at IBD diagnosis was 43 [37-51.5] years. At the time of OM presentation, all patients were in clinical remission for their IBD (6/11 patients). Only five patients (45%) were on IBD medication at the time of diagnosis; three were on a biologic medication (infliximab, adalimumab, and ustekinumab), with the others on sulfasalazine and budesonide. Regarding EIMs, two patients (18%) had aphthous ulcers, and nine patients (82%) had a history of IBD-related arthropathy. There were no recorded instances of uveitis, or dermatologic EIMs. Eight patients (72%) had a history of cervical (n = 7) or lumbar (n = 5) spinal disease requiring at least one neurosurgical intervention. Three patients (27%) had a positive ANA titer. Five patients (45%) were given steroids on presentation. Two patients (18%) were initially treated with NSAIDs. One patient (9%) was treated with bromfenac ophthalmic solution. Only three patients (27%) had documented OM flares after treatment; one was initially treated with NSAIDs and two with steroids.

Conclusions 
Given its rarity, the true prevalence of OM is unknown. Our findings reaffirm prior studies’ observations about OM, including typical presentation and association with IBD. The number of patients in clinical remission for their IBD at the time of OM presentation may suggest a weaker correlation with underlying disease activity, in contrast to other EIMs. Additionally, the prevalence of cervical spinal disease among these patients, given their relatively younger age, warrants further investigation.