Walsh & Hoyt: Toxic and Difficiency Optic Neuropathies: Differential Diagnosis

When an individual complains of bilateral visual loss that refraction cannot correct, and has an otherwise normal examination, there are many diagnostic possibilities in addition to the toxic and nutritional optic neuropathies. Certain maculopathies can present in this guise. With time, the fundus will show abnormalities, but until then, fluorescein angiography or focal electroretinography may be the only means of establishing the nature of the lesion. Full field electroretinography may not reveal the defect.