Ophthalmovascular choke / by George M. Gould.

  • Gould, George Milbrey, 1848-1922.
Date:
1908
Catalogue details

Licence: In copyright

Credit: Ophthalmovascular choke / by George M. Gould. 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.

    2/24 (page 2)
    [101] in nutrition, i. e., impaired visual functions, etc.? These and like questions were not asked. Another constant and daily revelation of the ophthalmo- scope has been crossings and pressures and windings of the retinal arteries and veins under, over, and about each other, and, more rarely, even of a single trunk about or across itself. In many, perhaps the majority of such crossings, twistings, etc., the lumen of the vessel may not be lessened and the flow of blood either to or from the capillaries may not be patently hindered. But in a certain number of cases the underlying vessel is plainly flattened, even closed, and the caliber and size of the whole tube after the crossing strikingly lessened or almost extinguished. There follows the inevitable diminu- tion of the amount of blood flowing by the constriction. Such phenomena, in default of a better name I have ventured to call “ Ophthalmovascular Choke.” It is of course a truism of physiology that perfection of physiologic function requires perfection of inflow and outflow of blood. The higher the function, the more complex the structure, the greater the necessity for a faultless blood-supply. In a noteworthy physiologic study, by Dodge, of Visual Fixation, there are manifold accurate proofs that, speaking absolutely, any exact or persisting macular response to the [102] image-stimulus hardly exists. The study takes no note of pathologic conditions, but every expert oculist knows how much more striking is the shortness and inconstancy of visual fixation with eye-strain, amblyopia, inflammations, etc. I have elsewhere made a study of over a dozen mechanisms pro- ducing shadings of the retina, and which help to reestablish the sensitiveness impaired by too much light, by the overlong or even by a short exposure of the retinal sensitive plate, etc. It goes without saying that this easily exhausted sensitiveness will give way quicker if the full supply of fresh blood is les- sened in any way. The false, blurred, or imperfect image of ametropia, of course, also increases the difficulty of the retinal labor. The sharp limits as regards the length of time of the response of the normal retinal function to the exposure of one image are quickly shortened or made morbid by many factors. The study and delimiting of these factors would, in truth,