Non specific orbital inflammatory diseases.

The understanding of 'pseudotumors' has significantly changed with the advent of modern imaging techniques by which the tissues affected in the orbit can be identified, and nonspecific orbital inflammatory disease is classified according to the tissue involved. Twenty cases of nonspecific orbital inflammatory diseases were treated between July 1987 and September 1991. Eight patients had myositis, 6 had diffuse disease, 2 each had dacryoadenitis, periscleritis and perineuritis. Involvement of all four recti in one patient and isolated superior rectus and superior oblique each in 2 others are the unusual forms of myositis. Perineuritis presented as diffuse thickening of the optic nerve on CT scan with disc edema and normal vision in both patients with external ophthalmoplegia in one of them. All patients responded to oral steroids while the patient with myositis of all four recti required radiotherapy in addition. This series documents the spectrum of clinical presentation, diagnosis and management of nonspecific orbital inflammatory disease.