The ophthalmoscopic appearances of the optic nerve in cases of cerebral tumour / by C.E. Fitzgerald.

  • Fitzgerald, Charles Edward.
Date:
1874
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Licence: Public Domain Mark

Credit: The ophthalmoscopic appearances of the optic nerve in cases of cerebral tumour / by C.E. Fitzgerald. 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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    This objection was first raised by Sesemann, who has written a very interesting paper on the orbital veins, in Du Bois Reymond’s Arcliives.* I shall merely quote one passage from it: ~ “ I am decidedly of the opinion,” he writes, “ as the result of my investigations, that in most cases the blood from the ophthalmic vein flows both into the sinus and into the facial; but, indeed, I think that by far the greater part empties itself into the latter. 1 arrived at this conclusion from the fact that the diameter of all the openings into the facial is greater than that into the sinus cavernosus, which is sometimes so small that only a very little of the blood can find its way through it. . . . In my opinion the inferior ophthalmica vein serves not only to carry away the blood out of the other orbital veins, but also serves as an outlet, a so-called ‘ emissary vein ’ of Santorini for the sinus cavernosus. All the other sinuses have such emissaries, why should not the ophthalmic have the same relation to the sinus cavernosus ? The emissaries, as a rule, empty themselves into the sinus, and it is only when the pressure in the latter is increased above what it is in the other veins connected with it, that the blood finds its way through them. This is what occurs in the ophthalmic, as much blood as can make its way through the narrow opening into the sinus does so, the rest flows into the anterior facial. But should the pressure in the sinus, through any circumstance, be increased, the ophthalmic not only discharges its contents into the facial, but, moreover, carries off the blood from the sinus.” If Sesemann’s investigations be accepted, they must prove fatal to the “ pressure theory,” as expounded by Von Graefe, and indeed they appear to be generally viewed in this light by most recent writers on the subject. To return to Dr. Pagenstecher’s objections. “ 3. Not every increase of cerebral pressure is followed by neuritis, and, undoubtedly, neuritis occurs when there is no such increased pressure. ‘‘ 4. Optic neuritis is sometimes one-sided, and, indeed, has been often observed on the side opposite to the cerebral lesion, whilst the eye on the same side has remained perfectly normal.” The latest theory is that advocated by Schmidt, and is based upon some experiments he has made (similar to Schwalbe’s) of injecting fluid into the arachnoid space.*’ He asserts that the injection fills the intra- vaginal space of the optic nerve, and that it “ then empties itself into a ‘ canal system ’ which ramifies in the lamina cribrosa. He concludes therefrom that the Stauungs Papilla arises from increased intra-ocular pressure, due to Stauung of the injected fluid in the canal system continuous with the arachnoid cavity.” ^ ^ Archiv. f. Anat. ii. Phys., 1869, No. 2, ^ Archiv. f. Oph., Vol. xv., Pt. ii., pp. 193, 197- * Allbutt. Op. cit., p. 57.