COMPARISON OF THE OBLIQUE EXTRAOCULAR MUSCLES

The oblique muscles in many respects are the most interesting of all the extraocular muscles. They have been regarded by most authors as a pair, and emphasis is usually placed on their similarity to each other and to the rectus muscles. When the superior and the inferior oblique muscles are considered separately, however, and are compared one with the other, many significant contrasts are revealed. In presenting such a comparison, therefore, this paper expresses only in a rather unique form that of which most ophthalmologists are already cognizant. ANATOMIC RELATIONS Embryologically, the orbital muscles are said to be derived from the head, or cephalic, mesoblastic somites. The inferior oblique muscle, like all the muscles supplied by the third nerve, is derived from the first somite, while the superior oblique muscle originates from the second somite. The superior oblique muscle arises in the posterior part of the orbit from the mesial