The Significance of Enlargement of the Superior Orbital (Sphenoidal) Fissure

Abstract

The clinical features of 23 cases of infraclinoid aneurysm are discussed together with the radiological appearance. The high incidence (74 per cent) of erosion of the greater wing of the sphenoid in this condition is confirmed and some factors which contribute to this erosion are discussed. A comparison is made of the relative rarity with which pituitary tumours produce a similar change (4 per cent), but it must also be remembered that pituitary tumours are much commoner than infra-clinoid aneurysms. Sphenoidal wing and middle fossa meningiomata may also rarely produce widening of the superior orbital fissure (4 per cent), but associated bony sclerotic changes often enable a correct diagnosis to be made. Twenty per cent of cases presenting as “orbital tumours” showed widening of the sphenoidal fissure and this is held to provide good evidence of an intracranial extension of the disease process.