How to use the ophthalmoscope : being elementary instructions in ophthalmoscopy, arranged for the use of students / by Edgar A. Browne.

  • Browne, Edgar A. (Edgar Athelstane), 1841-1917.
Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: How to use the ophthalmoscope : being elementary instructions in ophthalmoscopy, arranged for the use of students / by Edgar A. Browne. Source: Wellcome Collection.

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    white opaque jDatclies absolutely hiding all beneath them. Haziness of the retina, due to slight infiltration accompanying hyperEemia or early inflammatory action, is recognised by impairment of the full red glow of the choroid. This is not easily de- scribed, except as what a painter would term a chalkiness in the red. It may easily escape observation in the indirect examination, or with too powerful illumination. If, therefore, in exa- mining an eye you do not perceive any obvious signs of disease, never rest satisfied that the retina is unaffected till you have explored it by the direct method, with a feeble illumination. Care is required to discriminate between haziness in the retina and that due to slight turbidity of lens or vitreous. The condition of the lens is ascertained by the oblique illumination. A diffuse haziness in the vitreous is generally uniform in distribution, and the reflex appears equally cloudy in whatever direction the eye is turned; but in retinitis you will almost always be able to make out certain parts of the retina to be more affected than others by carefully scrutinising the edges of the blood-vessels. In looking through a foggy vitreous, the amount of blurring is equal for vessels of equal size everywhere, and the obscurity