He holds that excision of the superior cervical ganglion destroys all vasoconstrictor fibers of the eye. The arteries relax, the blood pressure is lowered, and extravasation is reduced. This operation destroys the excito-secretory fibers, thus limiting the amount of aqueous produced. The fibers which dilate the iris are destroyed, hence the contraction of the pupil reopens the iris-angle and removes the obstacle to the outflow of aqueous. The nerve-fibers supplying the unstriped muscular apparatus contained in Tenon’s capsule are destroyed, hence the pressure on the efferent veins is removed and ocular circulation is reestablished.
Jonnesco believes that the starting-point of the nervous derangement producing glaucoma is central: “When one removes the ganglion the point of origin of the influence will not be removed, but the communication between this center and the eyeball is destroyed.”
Regardless of the differing views of physiologists concerning the mechanism of the reduction of ocular tension, based on experiments made on the lower animals, there can be no difference of opinion concerning the effect of excision of the superior cervical ganglion in the human subject. The operations made by Jonnesco and others on the Continent, and by myself in America, prove that removal of the superior cervical ganglion causes a marked reduction of intra-ocular tension in glaucomatous cases. That the same effect occurs in eyes with normal tension is evident from my third operation—that done for optic-nerve atrophy.
EXTENT OF SYMPATHECTOMY IN DIFFERENT DISEASES.
Up to the present time excision of the cervical sympathetic has been performed for the following diseases: epilepsy, exophthalmic goiter, glaucoma, and optic-nerve atrophy. The question naturally arises: How extensive an operation is necessary in these affections? This I will attempt to answer:
In epilepsy it is necessary to excise the entire cervical chain on both sides for the reason that, according to Jonnesco’s theory, it is necessary to convert a state of cerebral anæmia—which he assumes is the condition in epilepsy—into one of cerebral hyperæmia. Since the carotid plexus is formed by branches from the superior ganglion, and the vertebral plexus arises from branches which have their origin in the inferior cervical ganglion, it is evident that the entire cervical sympathetic must be removed.