On the influence of the cervical portions of the sympathetic nerve and spinal cord upon the eye and its appendages, illustrated by clinical cases, with observations / by John W. Ogle.

Ogle, John W. (John William), 1824-1905.

Date:: 1858

Credit: On the influence of the cervical portions of the sympathetic nerve and spinal cord upon the eye and its appendages, illustrated by clinical cases, with observations / by John W. Ogle. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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$posed to the spinal which acts through the channels of the sympathetic, is greater than in the rabbit. It ought to be added, that Professor Reid found that pressure also upon the cervical part of the sympathetic pro- duced contraction of the pupil, which, on the removal of the pressure, completely regained its natural size. The above particulars comprehend, as I believe, the sum of our present information with regard to the peculiar de- pendency of the movements of the iris on certain branches of the sympathetic and that portion of the spinal cord from M'hich they emanate, as shown by experiment. The question is naturally suggested as regards the con- tracted state of the pupil in connexion with the ptosis and. strabismus which in so many cases followed division of the cer- vical sympathetic,—What is the signification or physiological purpose, of these changes in the eye and its appendages ? I believe these phenomena may be looked upon as having some final reference to the condition of the retina, just as we find that in early life the pupil is generally contracted, and thus adapted as a screen to the delicacy of this tender nervous expansion; or again, as in old age, when, as Bichat observes, the pupil is generally dilated in proportion to the insensibility of the retina or to the opacity of the originally transparent refracting media, by which the entrance of light is hindered. And why in these experiments the retina should require such careful protection, such a tendency to contraction of the pupil and closure of the eyelids in order to exclude a superabundance of light, may easily be conjectured when we call to remembrance the anatomical constitution of that structure, a most delicate nervous sheet, the integrity of whose capillary vessels as to tone, &c., is of the very utmost necessity to that of its function; and when we also bear in mind the numerous examples which we possess of disturbance to the capillary circulation produced by injury to the sympathetic, whose ultimate branches are distributed along with the vessels. A better instance of this capillary disturbance, by way of illustration, we cannot have than the distension of the$