Walsh & Hoyt: Visual Recovery Following Decompression

In 1915, Cushing and Walker analyzed 81 cases of chiasmal compression and showed that restoration of visual function was not only possible following surgical decompression but it began within days after surgery. Pennybacker also described a dramatic response to surgical treatment in patients with loss of vision from pituitary adenoma and commented on the possibility of full recovery within a few days postoperatively. In a recent series of 27 patients undergoing decompression of the optic nerve, 47% showed improvement which, in two-thirds of the patients happened almost immediately. Zevgaridis and associates reported on 65 patients with meningiomas in the sellar region, and found that 39 (65%) of patients had improved vision after surgery on long-term follow-up (average 5 years). Favorable prognostic indicators included younger age, shorter duration of symptoms and an intact arachnoid membrane around the lesion. Li et al. reported on 30 patients with biopsy proven tumors and optic nerve compression that underwent optic canal decompression via an external ethmoidectomy approach, with 20 (67%) demonstrating improved visual function. Medical decompression of the optic nerve with bromocriptine in patients with prolactinsecreting pituitary tumors has yielded similar improvements in visual function. On the other hand, patients undergoing surgery for aneurysms involving the anterior visual pathways may experience sudden and severe vision loss presumed secondary to either optic nerve manipulation or ischemia.