The fact that an intra-ocular new growth may spread into the optic nerve is well known. For this reason, one is led to secure a long portion of the nerve at enucleation. The following presentation deals with the results of examining globes enucleated for glioma, with the idea of determining the frequency of nerve invasion, the frequency with which the nerves are severed at operation distal to this invasion and the frequency of extra-ocular extensions. For the purpose of comparison, a small series of cases of sarcoma of the choroid is given.
The microscopic examination of 119 eyes enucleated for glioma with no extra-ocular extension showed that in 63, or 52 per cent, the gliomatous tissue had invaded the optic nerve posterior to the lamina cribrosa. Of these 63 cases, 51, or 81 per cent, showed that the optic nerve had not been severed distal to the extension