Clinical characteristics of drug-induced optic neuropathy cases associated with voriconazole administration for chronic pulmonary aspergillosis

Background Visual abnormalities are relatively common side effects of voriconazole use, but optic neuropathy is rare and not well recognized. The aim of this study was to investigate the characteristics of patients diagnosed with optic neuropathy during voriconazole treatment. Methods We reviewed six patients who developed optic neuropathy during voriconazole treatment at our hospital. Visual acuity and critical flicker fusion frequency (CFF) tests were used to diagnose optic neuropathy. Results Voriconazole was used to treat chronic pulmonary aspergillosis in all patients. The median time to onset of optic neuropathy was 181 (72–292) days, the dose was 5.87 (5.55–10.36) mg/kg/day, and the trough value was 1.85 (0.59–2.37) µg/ml. One patient was not using any other drugs during voriconazole treatment, but the other five patients used ethambutol concomitantly. The median dose of ethambutol was 13.89 (12.93–15.63) mg/kg/day, which was within the optimal range, and the duration of use was 70 (22–104) months. The participants using ethambutol had been using the drug for a longer period than typically associated with ethambutol-induced optic neuropathy. Peripheral neuropathy of the lower extremities was observed in four of six cases, coinciding with the appearance of optic neuropathy. Conclusions Voriconazole-associated optic neuropathy may be more likely to occur in cases of concomitant ethambutol treatment or peripheral neuropathy. It is important to be aware of possible optic neuropathy during voriconazole treatment and to perform visual acuity examinations for early detection.