Abstract
Idiopathic orbital inflammation (IOI) is a benign inflammatory condition usually confined to the orbit but extraorbital extension can also occur. IOI has been classified into categories including anterior, diffuse, posterior or apical, myositis, and dacryoadenitis. Other rare types of IOI include periscleritis, perineuritis, and focal mass. Diagnosis is based on careful history, clinical findings, computed tomography, and magnetic resonance imaging findings. An orbital biopsy is usually done for accessible orbital lesions such as dacryoadenitis. For other types such as myositis and apical IOI where surgery is difficult or dangerous, orbital biopsy is not initially considered. The mainstay of therapy consists of systemic corticosteroids, but other options including external beam radiotherapy, antimetabolites, alkylating agents, T-cell/calcineurin inhibitors, lymphocyte inhibitors, tumor necrosis factor-α inhibitors, and surgical debulking have also been used.