The vascular system in the orbit: spatial relationships

The relationships between blood vessels and orbital connective tissue, which forms an interindividually constant, bilateral symmetrical system of connective tissue septa bordering adipose tissue compartments, are characteristic and constant but essentially different for arteries and veins. The arteries run within the adipose tissue compartments only incidentally contacting the septa where they perforate them. The veins, in contrast to this, run within the septa, thus making up the walls of the adipose tissue compartments together with the septa. Resulting from this difference in histological relation to the connective tissue, arteries and veins show a different three-dimensional pattern. The arteries form a radiating system, whereas the veins form an anastomosing complex of venous rings which are arranged circularly inside as well as outside the muscle cone. The microvascular system has its own adaptation to the connective tissue system. It is predominantly confined to the adipose tissue compartments.