[Idiopathic non-specific orbital inflammation: anatomic classification and treatment options]

The aim of this study was to identify the clinical presentation of idiopathic non-specific orbital inflammations (NSI) in relation to the anatomic pattern of involvement in the orbit and to evaluate the treatment options.

35 cases of patients with NSI were retrospectively reviewed. In all cases the diagnosis was confirmed by biopsy of the lesion. 10 patients exhibited a severe amount of fibrosis in biopsy specimens in terms of an idiopathic sclerosing non-specific orbital inflammation (SNSI). The patients were treated with corticosteroids, radiotherapy or surgery (en-block excision or orbital decompression/debulking). Follow-up data were available for 27 / 35 patients for a period of 2 to 24 months after initial diagnosis.

The anatomic pattern of involvement was anterior in 7 / 35, intraconal in 5 / 35, diffuse in 1 / 35, apical in 2 / 35, and lacrimal in 20 / 35 patients. 16 patients with NSI were initially treated with systemic corticosteroids. 12 / 16 patients had a complete regression of symptoms, 1 / 16 patients had partial regression and 3 / 16 patients had no improvement. 4 patients with SNSI were initially treated with systemic corticosteroids. 3 / 4 patients with SNSI had no improvement under steroid therapy. 1 patient with SNSI received no treatment and no progression was observed on follow-up. 7 patients (3 with NSI and 4 with SNSI) were treated surgically. In 5 / 7 (2 with NSI and 3 with SNSI) surgical therapy was the initial treatment due to well-circumscribed lesions in orbital imaging, whereas in 2 / 7 orbital decompression with debulking was performed after failure of systemic corticosteroids. 5 / 7 patients had a complete resolution of symptoms, whereas 2 / 7 had a partial resolution with persistent postoperative diplopia. 3 patients were treated with radiotherapy. In 2 / 3 previous steroid therapy was unsuccessful in controlling the disease. 2 / 3 of these patients had complete regression and 1 / 3 partial regression of symptoms.

Classification of NSI according to their anatomic pattern of involvement provides a useful framework for the clinical evaluation of these patients. Systemic steroids should be the first-line therapy in cases with NSI. However, if severe fibrosis in terms of SNSI is present, corticosteroid therapy is very likely to fail, so that surgical therapy should be considered early, especially in cases of relatively well-circumscribed lesions.