Visual field defects during low-dose methotrexate therapy

A patient was treated with low-dose methotrexate because of psoriasis that did not respond to conventional therapy. During treatment, visual symptoms occurred; optic disc swelling was found, and later slight optic disc atrophy. Moreover, paracentral relative visual field defects showed fluctuations parallel to methotrexate dose changes. It seems likely that methotrexate affected optic nerve function.