Abstract
In the continuation of the study of ephedrine as a mydriatic, 1 it was found that in Caucasians a 10% solution uniformly produces mydriasis by local application, and that its mydriatic action is further strengthened if it contains, in addition, 0.1% of homatropine hydrobromide, or 1.0% of euphthalmine hydrochloride. These solutions are useful in ophthalmoscopic examination, especially from the patients' point of view, because they cause almost no change in accommodation. There were no untoward symptoms or signs noted. Only in iritis and uveitis do they fail to dilate the pupil.
Ephedrine is, however, much less certain as a mydriatic in Chinese and Negroes. Not infrequently does it fail to produce any appreciable mydriasis. It was also found that pseudo-ephedrine, synthetic ephedrine, cocaine, and euphthalmine, are less powerful in dilating the pupil of the colored races. The results observed in diffuse daylight are summarized in Table I.
Further observations are being made under controlled illumination by accurately measuring the image of the pupil with a filar micrometer attachment in a telescope. These data corroborate the above preliminary measurements and will appear at a later date.
Howard and Lee of Peking 2 reported that ephedrine is more effective as a mydriatic in individuals with light irides than in those with dark. Their results are on the same line with ours.
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