Isolated extraocular muscle involvement as the ophthalmic manifestation of leukaemia

P>Background: Clinical and imaging features of patients with orbital leukaemia primarily involving extraocular muscles were evaluated. Methods: This retrospective case series includes patients with leukaemia whose only ophthalmic manifestation was extraocular muscle enlargement. Demographic data, clinical information on the systemic disease, prominent ocular signs and symptoms, computed tomography and magnetic resonance imaging characteristics, treatments applied and the outcomes were collected. Results: Five patients were diagnosed as leukaemic infiltration of extraocular muscle between 1995 and 2008. The age at presentation ranged between 3 and 61 years. Acute myeloid leukaemia was the diagnosis in two patients, and chronic lymphocytic leukaemia, chronic myeloid leukaemia and biphenotypic acute leukaemia were found in one patient each, respectively. One patient had bilateral involvement. The lateral rectus muscle was affected in four patients and the superior rectus muscle in one case. Restricted ocular motility was the most common finding. In one patient who had no prior history of leukaemia, an incisional biopsy established the diagnosis. All patients received multi-agent chemotherapy. Four patients expired after a rapid decline of the systemic status within a mean period of 7 months. Conclusions: Leukaemic infiltration of extraocular muscles is a rare and late manifestation of the advanced disease associated with relapse and there seems to be a predilection for the lateral rectus muscle. Systemic prognosis remains dismal despite intensive chemotherapy.