Cataract extraction / by H. Herbert.

  • Herbert, H.
Date:
1908
Catalogue details

Licence: In copyright

Credit: Cataract extraction / by H. Herbert. 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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    the anterior chamber is shown by its bright appearance and by its mobility. If the anterior chamber happens to be very shallow, the point of the knife in passing slowly inwards has to be guided a little forward over the bulging iris ; and, finally, in attaining the transverse plane, which it must do to reach the site of counter-puncture, the blade may have to press against the iris, indenting it. In such a case the swing of the blade may tend to cause a slight leakage of aqueous through the puncture. Eyes which have been pulled inwards by the forceps, as above, are allowed to roll outwards again—at least, partly. This movement of the globe, while the knife is held stationary, takes the place of a portion of the movement of the blade ordinarily required as it crosses the chamber. The point engages in the posterior surface of the cornea at the nasal side about J millimetre before its disappear- ance behind the scleral boundary. This brings the knife to the surface barely within the sclerotic, and not at the greater distance from the cornea* which one might antici- pate. The site of this counter-puncture must be selected carefully, and corrected, if necessary, more than once by disengaging the point; but there must be no trace of hesitation on the completion of the counter-puncture, lest the aqueous begin to flow away. The knife must at once travel upwards with a steady, even, inward thrust, cutting equally on both sides of the cornea, to bring the blade well up in front of the iris, before the chamber can become emptied of fluid. Usually almost the whole of the blade is utilized in this first stroke ; but in operating upon eyes either insufficiently turned downwards or purposely still * The encroachment upon scleral tissue needs to be rather less at the inner end than at the outer end of the section, owing to the fact that the knife thrusting inwards tends to slip under the conjunctiva at the inner side of the globe.
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