LINEZOLID-INDUCED MITOCHONDRIAL TOXICITY PRESENTING AS RETINAL NERVE FIBER LAYER MICROCYSTS AND OPTIC AND PERIPHERAL NEUROPATHY IN A PATIENT WITH CHRONIC GRANULOMATOUS DISEASE.

ABSTRACT

PURPOSE: To report a case with unique changes in the retinal nerve fiber layer observed on optical coherence tomography in a 22-year-old patient on chronic linezolid therapy for recurrent pyogenic liver abscesses with underlying chronic granulomatous disease. METHODS: History and clinical examination, laboratory evaluation, fluorescein angiography, and optical coherence tomography. RESULTS: The patient presented with best-corrected visual acuity of 20/200 in the right eye and 20/125 in the left eye. He had moderate optic disk edema and superotemporal field defects bilaterally. Swept-source optical coherence tomography revealed the presence of retinal nerve fiber layer microcystic spaces. Laboratory tests showed no positive findings except for an elevated lactic acid level. Linezolid-induced optic neuropathy was suspected, and the drug was discontinued. Six weeks after termination of oral linezolid therapy, the optic disk edema and the microcystic spaces in the retinal nerve fiber layer resolved, and the best-corrected visual acuity improved to 20/50 in the right and 20/40 in the left eye, respectively. CONCLUSION: Linezolid is a widely used antibiotic with broad-spectrum action. However, chronic use can lead to mitochondrial toxicity that may have protean manifestations. Ocular examination, particularly of the optic nerve and nerve fiber layer using multimodal imaging, is critical in diagnosing such toxicity.