Abducens Nerve Palsy and Optic Perineuritis Caused by Fungal Sphenoidal Sinusitis

ABSTRACT

PURPOSE: To report a case of abducens nerve palsy and optic perineuritis caused by fungal sphenoidal sinusitis. CASE SUMMARY: A 48-year-old male visited emergency department for retrobulbar pain, decreased vision, and horizontal diplopia for 3 days. He reported that previous medical history was non-specific, however, blood glucose level was 328 mg/dL (70–110). He had experienced severe headache for 7 days. The best corrected visual acuity was 20/20 at right eye and 20/25 at left eye. The pupil of left eye did not have relative afferent pupillary defect. Left mild proptosis was noted. The extraocular examination showed 30 prism diopters left esotropia at primary gaze and −4 abduction limitation of left eye. The left eye showed mild optic disc swelling and inferior field defect by field test. Brain magnetic resonance imaging showed enhancement of sphenoidal sinus, ethmoidal sinus, and around optic nerve at left eye. Three days after antibiotics treatment, the vision of left eye deteriorated to 20/40 and periorbital pain developed. The drainage and biopsy of sphenoidal sinus were performed. The histopathologic examination showed hyphae consistent with aspergillosis. The ocular symptoms were improved with anti-fungal treatment. Follow-up magnetic resonance imaging performed 1 month after treatment showed improvement of lesion at left orbit. Five months after surgery, the visual acuity of left eye was improved to 20/25. The patient showed orthotropia at primary gaze without limitation. CONCLUSIONS: The abducens nerve palsy and optic perineuritis can be caused by fungal sphenoidal sinusitis. The early diagnosis and appropriate treatment can lead to favorable outcome.