Visual failure more often than not is due to a disorder of the globe and falls within the realm of the ophthalmologist. However, a lesion that involves the optic pathways may occasionally be responsible for acute loss of vision and at times is overlooked because a thorough medical examination was not conducted when the patient first consulted his physician.1-3 Ideally, if irreparaable visual loss is to be prevented, the cause should be determined. This requires a thorough medical examination, which should include ophthalmologic investigation, the plotting of accurate visual fields, roentgenographic examination of the skull, and a complete neurologic examination. In the more difficult diagnostic problems, ancillary tests may be required if the condition of the patient can tolerate these procedures.
The records of 310 patients who came to the Mayo Clinic because of unilateral loss of vision were studied in 1953.4 Lesions involving the retrobulbar portion of