Hyperglycemic hemianopia: a reversible complication of non-ketotic hyperglycemia.

Four patients each developed a reversible homonymous hemianopia caused by non-ketotic hyperglycemia. In two patients the homonymous hemianopia was the first manifestation of diabetes mellitus type 2. All four patients had abnormal MRI scans; in the three patients who had late follow-up scans the abnormalities resolved completely. In one patient the progressive visual field defect and unusual MRI findings initially caused concern for a tumor.