Standardizing optic nerve crushes with an aneurysm clip

Abstract

Objectives: Despite the widespread use of optic nerve injury models to simulate central nervous system injury, model protocols vary from laboratory to laboratory, making it difficult to directly compare findings between studies.

Methods: To standardize the optic nerve crush injury model, the commercially available Yasargil aneurysm clip, which provides a consistent clamping force, was used to produce a crush injury to the rat optic nerve. Histology was verified with hematoxylin-eosin. The number of retinal ganglion cells (RGCs) was counted by fluorescent gold dye labeling.

Results: Following nerve crush injury, the density of RGCs was substantially reduced in the aneurysm clip-operated group relative to the normal and sham-operated groups, and no discernable difference was noted between the latter two control groups.

Discussion: The present findings suggest that Yasargil aneurysm clip effectively produces permanent injury to the optic nerve with evidence from retrograde tracing of RGCs and may provide a standard technique for optic nerve crush studies.