Visual loss two years after pituitary adenoma resection

Abstract

A72-year-oldmanpresentedwith ahistory of recent onset visual loss in his right eye, which had begun 1 week prior and had deteriorated rapidly over that time. His past history included resection of a large null-cell pituitary adenoma2 years previously that had eroded through to the clivus, extending superiorly to the suprasellar cisterns and anteriorly into the sphenoid sinus. Imaging at the time had shown chiasmal compression, but visual field testing and visual acuity had remained normal pre-operatively and post-operatively. The suprasella tumour was resected, but with incomplete excision of the extensive skull base component. MRI at 1 year post operation showed tumour progression at the skull base, and the patient was subsequently sent for radiotherapy. Conformal radiotherapy was delivered with a 3-point mask in 30 fractions at 1.8 Gy per fraction, for a total of 54 Gy. The final dose of radiotherapywas given approximately 15 months before the onset of visual loss. On examination, there was a relative afferent pupillary defect on the right,with corrected visual acuity of 6/9 on the left and6/60 on the right. Visual field testing showed dense visual loss in the temporal and superior fields. Visual fields from2 monthsprior to presentationhad