Volume 1

A treatise on diseases of the eye, nose, throat, and ear : for students and practitioner ... / edited by William Campbell Posey and Jonathan Wright.

Date:
1903
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: A treatise on diseases of the eye, nose, throat, and ear : for students and practitioner ... / edited by William Campbell Posey and Jonathan Wright. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    the glass that corrects the manifest en-or. I at tlie same time test the patient's vision for near, and find the glass thjxt suits him for readmg. If, as in most instances, I wish to use a cycloplegic, I then \ instil homatropine, and, innnediately, before the drug has time to act, make the muscle tests. Later, when the cycloplegic action of the homatropine is complete, or nearly so, I determine the refraction with skiascopy. Then I confirm or modify this result with the trial case, and finally check off these last results again by skiascopy. In certain cases, as in children and in very nervous people, it saves time and is less tiresome to the patient to cut the subjective examina- tion short, and to proceed at once to the objective examination with the shadow test, making this as carefully as possible. Using the cor- rection thus found as a basis, I again make the test with the trial case, and now generally find that there is very little left to do in order to arrive at the final result, so that now I do not have to tax the patient's attention unduly nor make much demand upon his patience or judgmo!nt. The Use of Cycloplegics. As we have seen, the myope may invol- untarily exaggerate liis myopia, and the hyperope wholly or partly conceal his hypero]^ia by using his acconnnodation. Patients whom we examine for glasses are so apt to do this that, if we wish to find out the precise refractive state of the eye, it often becomes necessary to abolish the accommodative effort altogether. This we do with a cycloplegic. The one ordinarily used is homatropine, a 2 per cent, solution of which instilled every five or ten minutes for five times produces in general complete paralysis of the accommodation in from an hour to an hour and a half from the time of the first instillation. The effect soon begins to wear off, and disappears entirely in from twenty-four to thirty-six hours. In instilling the homatropine it is best, as Jackson suggests, to have the patient throw the head back and look down, so that we may drop the solution directly on the upper part of the cornea. The eye in which the instillation is made should be held open until the patient voluntarily opens the other eye. This prevents his squeezing the drop out of his eye. Homatropine is an irritant producing a moderate congestion of the eye, which, however, is transitory, and has no ill effects whatever. Sometimes scopolamine in 0.1 per cent, solution is used, but in my experience it has no advantage over homatropine. In cases where we wish to produce a very thorough and lasting effect—i. e., in spasm of accommodation—atropine may be used in 1 per cent., or in particularly obstinate cases 1.5 per cent, solution. This is instilled night and morning for one or two days before the ex- amination. The patient should be examined three hours after the last instillation. The paralysis of the accommodation in these cases lasts fully a week. \Vith the cycloplegic near vision for the hypermetrope and emmetrope is rendered impossible. Cycloplegics, besides abolishing accommodation, dilate the pupil. They lience render the vision