Clinical differentiation between a large intracranial aneurysm and an expanding brain tumor is difficult since both can produce pressure on adjacent structures.1 Because of inconstant patterns of enlargement, it has been suggested that aneurysm and tumor cannot be distinguished by examination of visual fields.1 In 1937, Jefferson2 predicted that the field defect most characteristic of internal carotid supraclinoid aneurysms would probably show "a scotomatous or rapidly failing eye" on the side of the aneurysm, "with a definitely homonymous hemianopic overlay in the field of both eyes." On the basis of Wildbrand and Saenger's work on the crossed fibers in the chiasm, Jefferson2 asserted that the "temporal defect in the opposite eye should be chiefly in the upper quadrant." However, neither Jefferson's patients nor the cases he quoted revealed any characteristic field defect or angiographic picture.
This study presents three cases of large (2 to 3 cm)
BERSON EL, FREEMAN MI, GAY AJ. Visual Field Defects in Giant Suprasellar Aneurysms of Internal CarotidReport of Three Cases. Arch Ophthalmol. 1966;76(1):52-58. doi:10.1001/archopht.1966.03850010054012