A compend of the diseases of the eye and refraction : including treatment and surgery / by George M. Gould and Walter L. Pyle.

  • Gould, George M. (George Milbry), 1848-1922.
Date:
[1914]
Catalogue details

Licence: In copyright

Credit: A compend of the diseases of the eye and refraction : including treatment and surgery / by George M. Gould and Walter L. Pyle. 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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    optic nerve. Externally it is connected by a fine cellular web (mem- brana fused) with the inner surface of the sclerotic. Internally it lies in contact with the basal membrane of the pigment-coat of the retina, as far forward as the ora serrata. The choroid is divided into two layers: an external, containing the larger vessels and the most pig- ment, and an internal. The external layer consists in part of the larger branches of the short ciliary arteries, which run forward be- tween the veins before they bend down to terminate in the capil- laries; but is principally formed by converging veins called vence vorticosce. The internal layer consists of an exceedingly fine capil- lary plexus, formed by the short ciliary vessels, and is known as the tunica ruyschiana. On the inner surface of this tunic is a very thin homogeneous membrane called lamina vitrea that separates it from the pigmentary layer of the retina. The pigment of the choroid consists of hexagonal cells, filled with dark-brown granules, and is scattered throughout both layers in sufficient quantity to absorb the light. CHOROIDITIS. Causes.—Inflammation of the choroid results from general diseases, such as syphilis, tuberculosis, scrofula, chlorosis, rheumatism, and gout. Senile choroiditis is probably preceded by choroidal apoplexy. Suppurative choroiditis is due to traumatism with infection ; to metas- tatic infarction, in pyemia and endocarditis ; and to severe infectious fevers. High myopia, by causing extreme stretching of the choroid, often gives rise to a local or diffuse inflammation. Choroiditis may be an accompaniment of inflammation of the iris and ciliary body. Varieties.—For convenience, choroiditis may be divided into the exudative and suppurative varieties, although many subdivisions, such as disseminated, syphilitic, areolar, central, guttate, etc., have been studied pathologically. exudative choroiditis is distinguished by the impairment of vision due to the simultaneous involvement of the retina, and the changes noticed by. the ophthalmoscope. The disease runs its course without pain and without external symptoms, and the patient is only aware of his trouble through the impairment of vision. It must be remembered that there is no definite relation between the amount of visual disturbance and the changes noted in the fundus.