To evaluate the clinical features and treatment outcomes of steroid therapy for orbital inflammatory pseudotumor.

Sixty-four patients diagnosed with orbital inflammatory pseudotumor were reviewed retrospectively. Patients with a follow-up period of less than 6 months were excluded from the study. The pseudotumor was classified into myositic, lacrimal, anterior, diffuse, or apical type according to orbital computed tomography findings. All patients were initially treated with systemic corticosteroids and evaluated for response to the treatment. Treatment outcome was considered a "success" if the patient had complete relief of symptoms with no recurrence, and a "failure" if the patient had no or only partial relief of symptoms or showed relapse. Factors affecting the treatment outcome were analyzed.

The most frequent lesion subtype was myositis. Periorbital edema was the most common symptom and was evident in 53.1% of the patients. Thirty-eight patients (59.4%) showed treatment success. Age, sex, bilaterality, and mean follow-up length did not correlate with the treatment outcome. A short interval from symptom onset to treatment time and apical subtype were significantly associated with good steroid response ( p < 0.05).

In orbital inflammatory pseudotumor, myositis was the most common subtype. A short interval from symptom onset to treatment time and apical subtype were associated with good steroid response.