To report the case of an isolated abscess in an extraocular muscle.

We report a case of an isolated abscess in an extraocular muscle in a patient who was treated with systemic chemotherapy for precursor B lymphoblastic leukemia. A 54-year-old female who had undergone systemic chemotherapy for precursor B lymphoblastic leukemia presented with right ocular pain and limited eye movements. On ophthalmic examination, she had elevated intraocular pressure (IOP) and limited upward and downward gaze. MRI (magnetic resonance imaging) examination revealed an isolated abscess in right inferior rectus muscle. Although the patient was treated with empirical intravenous antibiotics and IOP-lowering agents, the size of the abscess increased, as confirmed by MRI findings. Therefore, we performed a pus drainage procedure by the transconjunctival approach. We were not able to find any residual abscess lesions on CT scans 3 months postoperatively. The patient's ocular pain disappeared and the limited eye movements improved significantly 6 months postoperatively.

There have been no case reports of an isolated abscess in an extraocular muscle in Korea. For immunocompromised patients unresponsive to systemic empirical antibiotic treatment, an early pus drainage procedure by the transconjunctival approach may be a useful and effective therapeutic method in the management of an idiopathic isolated abscess in an extraocular muscle.