The factors which determine the production of intraocular fluid / by E.E. Henderson and E.H. Starling.

  • Henderson, Edward Erskine, 1870-1929.
Date:
1906
Catalogue details

Licence: In copyright

Credit: The factors which determine the production of intraocular fluid / 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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    the end of the needle, this latter is thrust through the lateral part of the cornea, so as to lie in the middle of the anterior chamber. A bubble of air is introduced into the graduated tube by compression of one capsule, and brought to the middle of the tube by relaxing the clamp on the capsule at the end towards the eye. The reservoir is then rapidly adjusted to such a height that the bubble remains stationary. In some of the later experiments a platino-iridium cannula, with a solid steel point made slightly conical, was found to be an improvement, as, in the event of any leaking occurring, it could be pushed in further. In introducing the cannula great care must be used, as, should the needle catch in or tear the iris, or wound the lens, the eye would be rendered useless for the purposes of the experiment. The needle, being comparatively large and blunt, requires considerable force for its introduction. We have found it safer to make a small perforation with the point of a cataract knife and, without letting the aqueous humour escape, to introduce the cannula in the hole thus made. Should the exact spot be lost sight of, a little fluorescine will stain it, A fine silk thread passed through the episcleral tissue, as in the operation for advancement of a rectus tendon, gives a better hold than fixation forceps, and is somewhat less in the way. The fluid employed in the apparatus was usually Einger’s solution, in some cases normal saline. Whichever fluid was employed, it was filtered through a Berkefeld candle before the experiment, in order that no foreign body might be present which could lodge in and block the filtration channels. The intraocular fluid must play a twofold function in the eye. In the first place, by keeping up the intraocular pressure, it lends rigidity to the supporting structures of the eyeball, and furnishes therefore a fixed point for the intraocular muscles to contract against, besides maintaining the proper distances between the various refractive media. In the second place, it is the only source of nourishment to certain of the structures of the eye, namely, the middle and back part of the cornea, the lens and suspensory ligament, and the vitreous humour. The question that we have to decide is whether this fluid is formed by a process of secretion by the cells covering the ciliary processes, or whether it is a transudation similar to lymph. The question presents many analogies to that with regard to the secretion of urine. In each case we have a possible source of transudation in the capillary blood-vessel network and also an absorbing mechanism. We can only arrive at a conclusion by determining the physiological conditions under which we may alter either the production or the absorption of the intraocular fluid.
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