A manual and atlas of medical ophthalmoscopy / by W.R. Gowers.

  • Gowers, W. R. (William Richard), 1845-1915.
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: A manual and atlas of medical ophthalmoscopy / by W.R. Gowers. Source: Wellcome Collection.

    27/392 (page 11)
    and relaining tlie cylindrical form. It may then have a more or less elliptical lumen (the same circumference enclosing a smaller area as an ellipse than as a circle), and in the retina, in consequence of the intra-ocular pressure, the flattening always takes place in the plane of the retina, at right angles to the Hne of vision, and the vein appears of undue width. At the same time the central reflection is altered, becoming commonly indistinct, hut sometimes unduly broad. This condition of the veins is seen especially in extreme ansemia, and in leucocythsemia, as in the accompanying figure (see also PL XI. 1 and 2). In these cases the arteries are usually smaller than normal, and so the contrast between the veins and arteries is enhanced. Diminution in the size of the veins is probably always the result of diminished supply of blood. The arteries may be diminished in size by causes similar to those which lead to increased width of the veins, such as local obstruction to the entrance of bloocl. The latter does Fm. 2.—Broad Retinal Veins and Narrow Arteriks. From a case of leucocytliDeniia.