Extra-papillary colobomata / by G. Lindsay Johnson.

  • Johnson, G. Lindsay (George Lindsay), 1853-1943.
Date:
[1890]
Catalogue details

Licence: Public Domain Mark

Credit: Extra-papillary colobomata / by G. Lindsay Johnson. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    remarkable, as the coloboma encroached on the fovea itself, while in the case of Sarah S the coloboma were very- near the fovea. I think such cases would argue strongly in favor of a congenital defect, as I have never known of a case of choroiditis close to the macula in which the vision was at or above normal.' I have not noticed any alteration in vision unless the colobomaactuallycoveredthemacularegion. I might supplement my remarks under this heading of diagnosis by a reminder that, although we must not expect to find any pathological changes in a coloboma, yet the mere fact of the presence of a defect is sufificient to render the particular portion of the fundus more liable to be attacked by disease. To illustrate this I have inserted two drawings (Plate VII., 5 and 6), in which pathological changes in the neighborhood of the colobomata are present. Pigment and Ncevi.—We find in extra-papillary colobo- mata, as in many other cases in which the retina and choroid are atrophied, an agglomeration of pigment round the mar- gin, and this pigment, moreover, is frequently distributed over the coloboma in the form of a veil or network which lies above the retinal vessels. In some cases the pig- ment merely forms a single ring bordering the coloboma; in others it forms a double contour or crescent, separated by an intermediate zone of thinned or atrophied choroid (see Figs, i, 4, 6, 7, 8, 14). In others, again, the marginal pigment passes in the form of trabeculae towards the centre of the coloboma, where it forms a fine veil or network. In many cases these trabeculae are wanting, but their course can still be indicated by a few short processes or threads, as if the trabeculae had been broken off and absorbed (see Figs. 9 and 14). These remains can be detected in nearly all cases in which the central network is absent, and I have seen them in many of the drawings made by previous writers, although their import has, to my knowledge, never been pointed out. ' Mr. Nettleship, however, describes and figures a case of severe central choroiditis with a vision of f§ nearly. But he adds : '' Such changes involv- ing, as they appear to do in this case, the fovea centralis, would be incompat- ible with such excellent vision as this eye possesses.—Trans. Oph. Soc, vol. v., p. 147.