An unusual presentation of extraocular muscle pyomyositis as orbital apex syndrome leading to secondary endogenous endophthalmitis and review of literature

Abstract

Pyomyositis of extraocular muscle is an infrequent entity. We herein report the case of a 19-year-old male who presented with reduced vision in the left eye (LE), which was associated with pain since last month followed by double vision and drooping of the lid over the last 10 days. On examination, LE had lid edema, proptosis, ophthalmoplegia, conjunctival hyperemia, and chemosis. Imaging showed well-defined, peripheral rim-enhancing lesion along the inferior rectus (IR), suggestive of abscess. It was aspirated under intravenous antibiotic coverage. Postoperative day 1 showed exudates near the optic disc, and swept-source optical computed tomography (SS-OCT) showed focal area of retinitis suggestive of early endogenous endophthalmitis. A vitreous biopsy was performed with no growth. Intravitreal clindamycin and dexamethasone were injected, and the patient was discharged on oral steroids. Three-month follow-up showed clinical and symptomatic improvement. We hereby conclude that the diagnosis of orbital apex syndrome (OAS) with pyomyositis is based on careful history taking, clinical examination, and imaging, and it can lead to endogenous endophthalmitis.