Immediate visual deterioration after attempts at radical excision of pituitary adenomas.

Thirty cases of pituitary tumour have been operated on in the last five years by a transfrontal approach, using microsurgical technique. Three cases of postoperative blindness are described, with an analysis of possible contributory factors and causative mechanisms, prognosis, and measures to lessen the risk of this complication. The possibility of an impairment in the chiasma blood supply is discussed. Although the use of the microscope makes the removal of the so-called capsule an easier surgical task, it is recommended that this structure should be left undisturbed.