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

Date:
1890
Catalogue details

Licence: Public Domain Mark

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

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    most convenient place for the light being on the pillow above the patient's head. Even in daylight little difficulty is experienced unless the pupil is small, but the examination is facilitated by a screen of some kind, even by the shade of an umbrella. The direct method presents more difficulty; a convenient position is at right angles to the patient, with the lamp on the opposite side of the patient's head. All who have employed the ophthalmoscope in medical practice will agree with Hughlings-Jackson in urging the routine use of the instrument in all diseases in which ophthalmoscopic changes are, even occasionally, met with. It often happens that unexpected information is gained regard- ing the nature of the disease, or its probable consequences. It has been remarked that the medical ophthahnoscopist should possess familiarity with those changes in the eye which are of purely ocular significance. It is of equal importance that he should be familiar with those con- genital changes in the eye which are of no significance. Many of these will be alluded to in describing the morbid appearances with which they are most liable to be confounded. One or two, which give rise to special trouble to the beginner, may be here briefly mentioned. One of these is the variation in the colour of the optic disc. It has been well remarked that the tint of the optic disc may vary as much as the tint of the cheek. It is always redder in the young than in the old. In the latter the redness has often a grey tint mingled with it. In the young the tint may even be scarcely or not at all paler than that of the adjacent choroid. When the choroid is bright in tint, the apparent redness of the disc is increased by indirect examination T\dth a wide pupil and a bright light, and is a very frequent source not only of error in diagnosis but of scientific mis- takes. It is the sharpness of the edge of the disc to which attention should be especially dii-ected. When the physiological cup is very large, the vasculai- portion of the disc is confined to a narrow rim at the side, often much narroAver than that shown in PI. III. 1, which represents a large but not very large cup. When the part of