A female, aged 52 years, underwent pituitary irradiation in 1969, with a total dose of 55.5 Gy given in 54 days, with an assumed daily dose 1 to 2 Gy, with 18 MV betatron photons and a seven-field technique for a GH-producing pituitary adenoma. At diagnosis of acromegaly and within the first ten years after radiation therapy no visual deficits were reported. In 1979 she suffered sudden visual loss in the left eye decreasing to light perception only. On fundoscopy of the left eye, the optic nerve was atrophic. Goldmann kinetic perimetry showed a central scotoma; the visual functions of the right eye were normal. A CT-scan of the pituitary fossa showed a residual intrasellar pituitary mass without suprasellar extension.
Subsequent CT-scans also did not reveal suprasellar mass; she declined to undergo an MRI.