Slowly progressive optic neuritis*

Abstract

Contemporary ophthalmologists caution against accepting a diagnosis of 'chronic optic neuritis' because of the possibility of overlooking a potentially curable expanding lesion compressing one or both optic nerves. We describe seven patients who experienced insidious onset of progressive monocular or binocular visual loss that we diagnosed as demyelinating optic neuritis after appropriate evaluation and follow-up. Several of these patients had time-varying visual symptoms, such as visual fatigue. statokinetic dissociation and temperature-dependent visual loss; all had reduced sensitivity to sinusoidal contrast. We suggest that awareness that demyelinating optic neuritis may present insidiously combined with increasingly accurate radiography should further reduce the occasional indications for diagnostic surgical exploration of the region of the optic nerve.