Acute and chronic orbital myositis

Ocular muscle diseases fall into two distinct groups: acute or subacute exophthalmic myositis and chronic oligosymptomatic myositis. The diagnosis can only be established with certainty by means of B-scan sonography and CT scanning; these examinations demonstrate the irregular thickening of one or several eye muscles. The disease is apparently primitive; in some cases concomitant autoimmune factors may be found. The course is spontaneous, with continual recurrence, and may have sequelae in the form of a definitive exophthalmos or an acquired retraction syndrome. It responds remarkably well to corticotherapy and, if necessary, immunosuppressors; in general, these lead to rapid and - if treatment is started in time - total regression of the disease.