The influence of changes in the intraocular circulation on the intraocular pressure / by E.E. Henderson and E.H. Starling.

  • Henderson, Edward Erskine, 1870-1929.
Date:
1904
Catalogue details

Licence: In copyright

Credit: The influence of changes in the intraocular circulation on the intraocular pressure / by E.E. Henderson and E.H. Starling. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    packed into the cranial cavity by means of modelling wax, which held them in position. The anterior chamber of the eye was then connected with a recording apparatus, and the effect of exciting the Gasserian ganglion noted. In all cases the results obtained were identical. The blood-pressure remained, as was to be expected, unaltered, unless there had been insufficient division of the nerve. The intraocular pressure rose directly the nerve was stimulated, remained constant for a time, and then fell slowly, but remained above the base line during the whole period of stimulation. On ceasing the stimulation the intraocular pressure fell to normal (see Fig. 7). Thus, in one typical experiment the blood-pressure was 60 throughout the observation. The intraocular pressure, which was 10 to commence with, rose immediately on stimulation to 13- Thirty seconds later it began to fall, but did not reach its former level until the stimulus was discontinued 30 seconds later. On observation of the eyeball it was seen that stimulation of the 5th nerve caused retraction of the nictitating membrane and contraction of the orbital muscle, in addition to the well-known dilator effects on the pupil. The question at once arose whether the rise of intraocular pressure observed was to be ascribed to these effects, which are associated with the stimulation of sympathetic fibres passing through the ganglion, or whether, as has been so often imagined, they are due to a direct stimu- lation of vasodilator fibres, or of secretory fibres running in the 5th nerve itself. To decide this point it was necessary to eliminate any possible action of sympathetic nerve fibres. In three cats, therefore, the superior cervical sympathetic ganglion was excised on one side under antiseptic precautions. The animals were allowed to recover, and were kept alive for 3 to 4 weeks in order to allow time for the sympathetic fibres which run to the Gasserian ganglion from the superior cervical sympathetic ganglion to degenerate. At the end of this time the animals were again anaesthetised, and the 5th nerve divided, provided with electrodes, and the effect of stimulation of the 5th nerve on intraocular pressure recorded in the usual way. Stimulation of the 5th nerve was absolutely without effect on the intraocular pressure. Observation of the eyeball showed that the sympathetic fibres had degenerated, as was proved by the absence of any contraction of the orbital muscle or nictitating membrane, or any movement in the pupil. We may therefore conclude that the 5th nerve contains no secretory or vasodilator fibres to the eye, at any rate no fibres which can be stimulated by electrical excitation of the Gasserian ganglion. All the