Orbital myositis and scleritis after anti-SARS-CoV-2 mRNA vaccines: A report of three cases.

Purpose: To report three cases of ocular myositis and scleritis, bilateral scleritis and unilateral single muscle myositis after mRNA COVID-19 vaccination.

Methods: Case series of three patients who presented to the Orbit Outpatient Service of Fondazione Policlinico Universitario A. Gemelli with a history of unilateral proptosis, diplopia and pain, bilateral red eye and pain during eye movements and unilateral proptosis and inconstant diplopia respectively with onset 5-10 days after m-RNA COVID-19 vaccine. A thorough hematologic work up and orbital contrast enhanced magnetic resonance imaging (MRI) in patients with proptosis was performed.

Results: Patients were females, 64, 58 and 45 years old respectively. MRI showed enlargement of all right rectus muscles, with both muscle belly and insertion involvement in the first case associated to right scleritis. A bilateral scleritis was diagnosed in the second patient and a single muscle myositis in the third patient. Serological tests excluded thyroid diseases. The first and second patient were treated respectively with oral and topical glucorticoids with a complete clinical response. Two 2 cycles of oral non-steroidal anti-inflammatory drugs were administered to the third patient with a partial response.

Conclusion: As far as we know these are the first report of orbital myositis and scleritis presenting after mRNA BNT162b2 vaccine (Pfizer/BioNTech) and mRNA-1273-(Moderna) vaccine, an uncommon effect of a likely autoimmune reaction triggered by the virus antigen.