Exophthalmos or proptosis is a common condition of the eye which is present in numerous general as well as in many local conditions, and its presence constitutes a valuable diagnostic sign. It requires careful study and serious consideration because it produces disturbing functional and organic changes and also a distressing cosmetic effect. Although much has been written on various special divisions of this subject, little attempt has been made to correlate the various types and to enumerate their essential differences.
The study of exophthalmos in a large number of patients with thyroid disease has given me a keen interest in the problems presented by this condition, and, in order to evaluate the findings, the entire subject has been reviewed. The following notes are the result of a study of the patients we have seen, plus a review of the literature.
The total volume of the orbit is approximately 30 cc. and the eyeball occupies one-fifth of the orbital space. The eye does not lie in the center of the orbit, but a little to the side of the midline and is near the base of the bony cone anteriorly-posteriorly. It does lie in the center of the vertical plane.
The eyeball moves in all directions and can be moved anteriorly, posteriorly, and, to a slight degree, vertically. Several instances of persons who have well established voluntary propulsion have been reported. The eye is raised, with the help of the superior rectus muscle, approximately 1 mm. on extreme elevation of the. . .