Anti-aquaporin-4 antibody-positive optic neuritis treated with double-filtration plasmapheresis.

PURPOSE: The anti-aquaporin-4 (AQP4) antibody was recently reported to be associated with neuromyelitis optica (NMO). Optic nerve involvements in many NMO cases are bilateral and the prognosis is poor. However, it has been suggested that plasma exchange is effective for those patients when steroid pulse therapy is ineffective. Herein, we report successful treatment of a patient with NMO using double-filtration plasmapheresis (DFPP). CASE: A 22-year-old woman consulted a neurologist for neck pain in March 2008. High-intensity lesions were shown in the cervical spinal cord by T2-weighted magnetic resonance imaging. On July 15, the patient was referred to our department for a headache and pain and blurred vision in the left eye. The best-corrected visual acuity was 20/50 and 20/500 in the right and left eyes, respectively, with visual field defects observed in both. After 3 courses of steroid pulse therapy, anti-AQP4 antibodies were positive. In November, the patient again noticed visual acuity loss in the left eye and was treated by additional steroid pulse therapy, which was not effective. Next, she underwent plasma exchange therapy, though it was stopped due to hypotension and dyspnea. The next day, the patient underwent DFPP treatment and visual function gradually recovered. CONCLUSION: It is important to consider NMO when steroid pulse therapy is not effective. We successfully and safely treated NMO in a young adult patient using DFPP.

Severe optic neuropathy caused by dichloromethane inhalation.

PURPOSE: In this paper, we report a case of severe optic neuropathy caused by dichloromethane inhalation. CASE: A 65-year-old man fell unconsciousness while cleaning a dichloromethane tank containing a small amount of dichloromethane (purity greater than 99%) and was transported to the emergency department of our hospital, after which he was treated with hyperbaric oxygen therapy. After 1 month, narrowing of the visual field in both eyes was noted and the patient was referred to our department for additional examinations. Visual acuity was 0.3 in both eyes, which demonstrated normal reactions to light, while the critical flicker frequency (CFF) values were 30 and 25 Hz in the right and left eye, respectively. There were no abnormal findings shown in slit-lamp and fundus examinations, except for a mild cataract. Concentric contractions of the visual field by 10 degrees in both eyes were shown by a Goldmann perimetry examination, while an electroretinogram (ERG) and visual evoked cortical potential (VECP) examination exhibited nearly normal results. We diagnosed the condition as optic neuropathy caused by organic solvent poisoning, based on the decreased visual acuity, decreased CFF values, and visual-field narrowing. Although the patient was treated with vitamin B(12), visual disturbance, optic nerve atrophy, and results of VECP examinations worsened in both eyes, whereas ERG examination results were normal. CONCLUSIONS: Based on our findings, we considered that the central nervous system, including the optic nerve, was more severely damaged than the retina due to the normal findings in the ocular fundus and ERG examinations. Since dichloromethane produces carbon monoxide when catabolized in the liver, carbon monoxide toxicity together with the direct toxic effect of dichloromethane were considered to contribute to optic neuropathy in this case. The outcome for the present patient was poor.