Idiopathic intracranial hypertension. Although the cause of IIH remains obscure, loss of visual function is common, and patients may progress to blindness. Diagnosis should adhere to the modified Dandy criteria. Recent case-control studies cast doubt on the validity of many frequently cited conditions associated with IIH. Valid associations include obesity, recent weight gain, female sex, vitamin A intoxication, and steroid withdrawal. Management should include serial perimetry using a sensitive disease-specific strategy so the proper therapy can be selected and visual loss prevented or reversed. 