Alterations in optic canal following resection of nerve in rats

The authors have studied relations between bony optic canal and nerve eleme nts resulting from lesion in the optic nerve. Experimental animals were div ided in two groups: young adults and old adult rats; the non-operated sides of rat skulls were used as a control group At the same time in control sam ples the changes in osseous openings resulting from ageing were studied. Fo ur months after surgery the animals were sacrificed, their skulls macerated and morphometric measurements taken by photometric and planimetric techniq ues. The obtained results show no significant difference in size of bony opening s between the operated and non-operated sides. A significant difference has been found in the size of optic canal between the young and the old rats, regardless of the operated side. The authors have thus come to the conclusi on that the size of bony canals in adult animals depends on, their age in, the first place. Narrowing of bony canaliculi, observed in the course of ag eing, is most probably caused by primary osseous apposition, while atrophy of nerve elements may be considered as a secondary event.