Vascular morphometry and micrometry of the orbital region of the human optic nerve.

The study aims at providing data on the vascular morphometry and micrometry of the orbital region of the human optic nerve. The disposition of the microcirculatory trunk in the orbital region has been studied on 40 samples taken post-mortem, as well as on 10 pieces from subjects having undergone enucleation. Histological specimens were prepared from the optic nerves using eosinhematoxylin dye-staining, the Romhany-Bârzu staining and the Gomory trichromic staining. Functionally active capillaries make up 19.380 per cent (7-14 micro group), respectively 21.318 per cent (15-20 micro group) of the total vessels in the area, having an average diameter of 10.01 +/- 0.0826085 p, respectively 17.9272 +/- 0.0651995 micro, for P = 0.05. There are 169 reserve capillaries (with a diameter between 2-6 micron), representing 32.752 of the total of vessels counted. The existence of reserve capillaries allows, at a certain point, for the supplying of the obstruction or of the vasospasm on the territory of the functionally active capillary