The calabar bean as a new agent in ophthalmic medicine / by D. A. Robertson, M.D.

  • Robertson, Douglas Argyll, 1837-1909.
Date:
1863
Catalogue details

Licence: Public Domain Mark

Credit: The calabar bean as a new agent in ophthalmic medicine / by D. A. Robertson, M.D. Source: Wellcome Collection.

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

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    determined, I introduced a drop of the weakest extract of the Cala- bar bean into my left eye, at 10 minutes past 12 o'clock. Its introduction occasioned no farther irritation than a drop of simple water would produce. No change was observed in the condition of the eyes until ten minutes thereafter, when, upon looking with the left eye, all objects beyond the distance of about a foot appeared dim and indistinct, but within that distance clear and well defined; while objects at all dis- tances appeared nearer and larger than natural. Vision in the right eye remained unaltered. No difference was visible in the size of either of the pupils. A feeling of straining and heaviness was felt in the left eye similar to that experienced after a prolonged inspection of fine objects near the eye. At 12.30, or 20 minutes after the introduction of the exti-act, a marked alteration in the size of the pupils was observable ; the left pupil being only 1 line in diameter, while the right measured fully two lines. Looking with the left eye, all objects beyond nine inches from the eye appeared very dim, and at all distances every- thing seemed about a half larger than natural, and nearer to the eye. Vision in the right eye was unaffected. At 12.40, the left pupil measured only f of a line, while that of the right eye had dilated to 2^ lines. The fiu'thest point of distinct vision with the left eye was 8 inches from the eye. In other respects no alteration was observable since last report. At 1.20, the pupils measured on the left side ^ a line, on the right 2 lines. With the left eye objects could with some effort be seen distinctly to the distance of about 10 yards, but, as before, larger and darker than with the other eye. When reading with both eyes, a sensation of heaviness and fatigue was soon felt in the left. Vision in the right eye continued unaltered. At 6 o'clock, the left pupil had dilated to 1 line, while the right had contracted to If line. Vision with the left was somewhat improved, and with an effort distant objects could be distinctly seen. Both pupils contracted under the influence of light, both singly and sympathetically. At 12 o'clock, tlie left pupil measured 1^ line, the right 2^ lines, and the same symptoms were present as at last report, only to a less marked degree. A dull aching and heaviness was experienced in the left eye consequent upon its exer- cise in reading and writing. On the following morning, there was still an appreciable differ- ence in the size of the pupils, and vision with the left eye was still slightly affected; but the symptoms gradually subsided, and in the afternoon completely disappeared. The results obtained from this experiment were, that the Calabar bean acted first on the accommodation of the eye, causing indistinct vision of distant objects to such an extent that all objects beyond 8 inches from the eye appeared dim and indistinct. The next marked effect produced was contraction of the pupil, its diameter being reduced from 2 lines to ^ a line. As a natural consequence