A technique for excisional optic nerve biopsy.

PURPOSE: To describe a transconjunctival technique for full-thickness (excisional) optic nerve biopsy. METHOD: A medial transconjunctival approach to the optic nerve with disinsertion of the medial rectus is used. A small right-angle Mixter forcep is used to clamp the optic nerve far posteriorly, and then a microscalpel is directed metal-on-metal to cut the posterior optic nerve. The cut nerve is then rotated anteriorly to complete the proximal nerve cut. RESULT: A full-thickness specimen of 11 mm of more can be obtained without undue traction on the globe. The globe remains viable. CONCLUSION: A long length, excisional optic nerve biopsy can be readily and safely performed without endoscopic techniques.