Primary empty sella syndrome: the role of visual system herniation.

Background: It has been traditionally accepted that ophthalmologic alterations in cases of primary empty sella syndrome are caused by the herniation of the visual system in the pituitary fossa, but this cannot be stated categorically.

Methods: Two female patients with primary empty sella syndrome and visual field defects were included in this series. The peculiarity of these cases was that in neither of them was there an evident herniation of the visual system. In the absence of other causes that could explain the visual defects, the patients were operated on through a transsphenoidal approach.

Results: Both patients showed immediate improvement of their visual deficits without recurrence. Postoperative imaging studies have shown continuance of an adequate elevation of the sellar contents during the 5-year follow-up period.

Conclusions: Visual field defects in cases of primary empty sella syndrome may occur even without radiological evidence of herniation of the visual system. The fact that the two patients described in this paper improved after surgery supports other reports that in this syndrome traction on the infundibular stalk may cause some microscopic anatomic alteration in the visual system or in its vascular supply that is not evident on imaging studies.