Trochleitis with Superior Oblique Myositis

Thirteen patients complained of recent fluctuating aching of one orbit, punctuated by stabbing pains. All had exquisite point tenderness over the trochlea and in half of the patients the pain was aggravated by eye movement. Standardized A-scan echography demonstrated swelling of the peritrochlear tissue and thickening of the superior oblique muscle with low internal acoustic reflectivity, typical of myositis. CT scan showed a soft tissue density in the region of the trochlea. Biopsy, performed on two patients, revealed peri-trochlear inflammation. In all patients the symptoms resolved within a period of weeks or months: indomethacin or naproxen were not effective, but oral or locally injected corticosteroids shortened the course compared to no treatment. None of the patients had ptosis, proptosis, Brown's syndrome, or a click, nor did they have echographic or radiographic signs of sinusitis or inflammation away from the trochlea. This probably represents a highly localized subtype of idiopathic orbital inflammation ('pseudotumor').