A handbook of local therapeutics / edited by Harrison Allen.

Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: A handbook of local therapeutics / edited by Harrison Allen. Source: Wellcome Collection.

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    muscles introduces an unknown and varying factor, which is liable to vitiate the most careful calculations, and in joung subjects no certainty can be reached while this muscle is allowed full play. Patients are occasionally met with in whom the application of atropine produces a peculiar form of conjunctivitis. The conjunctiva is congested and the eye is irritable and watery, and the follicles in the conjunctival folds are sometimes enlarged. There is usually, also, erythematous in- flammation of the skin of the lids and cheek. This form of conjunctivitis is, in very rare cases, produced by a single instillation, and results from a too prolonged use of the drug, perhaps more frequently than is generally supposed. Kroener {Oph. Rev., Jan., 1882) thinks that atropine conjunc- tivitis is of septic origin, and is due to the Fungoid Growths found in solutions that have stood for some time, and recommends the addition of carbolic acid (i to 1000) to keep the solution clear. This view is not generally adopted. A more serious danger is the tendency of atropine to induce Glaucoma, This it is thought to do by increasing the thickness of the iris and crowd- ing its periphery into the angle of the anterior chamber, thus impeding the escape of fluids by way of the space of Fontana. The irritation of excessive ligiit through the dilated pupil, when the eye is not protected, may be another cause. Atropine should never be applied when there is suspicion of glaucoma, and its use in the case of old people should be cautious, and at first tentative, in weak solutions, except when iritis makes an immediate and decided effect imperative. The now universally ad- mitted fact that atropine may increase intraocular tension is in apparent contradiction to the opinion of the earlier observers that it reduces it by contracting the blood-vessels and diminishing secretion. It seems prob- able, however, that it diminishes pressure in the healthy eye, but, by the mechanical effect of the dilated pupil, increases it in the eye predisposed to glaucoma, because the angle of the anterior chamber is already dan- gerously narrow (Priestly Smith). Stocker, of Lucerne i^Oph. Rev., vol. VI, p. 359) states positively, as the result of numerous experiments with the manometer on curarized cats, that under physiological conditions atropine always produces a decided fall in the intraocular pressure, thus confirming the viewof Graefe, Wegner, Adamiick, Griinhagen, and Pfliiger. Homatropine. Hydrobromate of homatropine, a derivative of atropine, has of late years been extensively used as a means of suspending the accommoda- tion. It is likely, to a great extent, to supplant all other mydriatics in ordinary refraction work ; as while equally efficient its effects last less than one-fourth as long as those of atropine, and about half as long as those of duboisine, and the danger of inconvenience from constitutional poison-