Anatomical Review of the Orbit and Cross Area in the Dog

Abstract

The orbit is a bony conic recess in the skull which contains the eyeball and its circumferential bulbar adnexa. The adnexa function in protection and maintenance of the eyeball integrity and hold the eyeball in situ. Orbital, ocular and optical axes are highly important to visual acuity. The orbital axis is on the middle line connecting between base to apex of the optical canal. The ocular axis (bulbar axis) passes from center of cranial to caudal aspect of the eyeball. The optical axis (axis opticus, visual axis) is a line drawn from center of cranial aspect to the fovea of the eyeball. These three axes do not completely overly on each other. Alittle medial deviation of the orbital axis from the optical axis is measurable. The afflicted and normal anatomy of the orbital cavity and its surrounding structures affecting function of the eyeball are described.