Optic nerve sheath decompression. Review of 17 cases.

Seventeen patients (19 eyes) with progressive visual loss associated with retrobulbar optic nerve and/or sheath enlargement were treated by surgical nerve sheath decompression at the Bascom Palmer Eye Institute, Miami, from 1969 through 1984. A decision to intervene was based on progressive visual loss unresponsive to other modes of therapy and accompanied by retrobulbar optic nerve sheath enlargement as determined by computed tomography, contrast orbitography, or orbital echography. Follow-up ranged from three months to nine years, with an average of 17 months. Visual function improvement was noted within one month after operation in seven of 19 eyes. The other 12 eyes showed no improvement or continued to worsen. Postoperative complications were infrequent, with motility disturbances being the most common. Optic nerve sheath decompression via the medial orbital approach has a low operative morbidity and may improve visual function in patients with progressive visual loss associated with the accumulation of compressible fluids in the retro-orbital optic nerve sheaths. This relatively safe surgical approach to the retrobulbar optic nerve may also be of future use in the retrieval of optic nerve tissue and fluid for chemical and cytologic analysis.