A treatise on the diseases of the eye / By W. Lawrence.

  • Sir William Lawrence, 1st Baronet
Date:
1847
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on the diseases of the eye / By W. Lawrence. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    external orifice will now be reduced to a small round opening, through which a little mucous discharge may escape, and the style may be substi- tuted for the bougie. The patient soon learns to remove and replace the style; and he takes it out and cleans it, from time to time. It might be supposed that the passage of the tears would not be assisted by introducing a solid substance into the duct. Experience, however, shows us that the fluid takes its natural course, when a style is thus kept in the lachrymal passages, and the enlargement of the urethra round a catheter left in the canal affords an explanation of the circumstance. The style, indeed, be- comes so loose, that it sometimes falls out when the head is bent down- wards. As the presence of the instrument causes neither pain nor incon- venience, I recommend patients to wear it permanently. According to my experience, this method maintains the natural course of the tears with the least trouble to the patient. [Dr. Edward Lubbock describes, in the Edinburgh Med. and Surg. Journal for Oct., 1835, a knife [fig. 141] which he has devised for Fig. 141. opening the lachrymal sac and dividing the stricture in obstructions of this canal, which appears to possess advantages over the lancet or bis- touries ordinarily employed for that purpose. The blade of the knife is 2| inches long, including the shoulder, and less than ■§- of an inch broad. In shape it resembles a catling, and cuts upon both edges for the extent of half an inch from its point where the knife is thin; but as the thickness of the instrument increases towards the handle, the edges become too thick to cut easily; the groove extends exactly along the centre of the anterior surface; the posterior surface is slightly convex, in order that the groove may be made as deep as possible. When made according to this fashion, the length, together with the extreme narrowness of the knife, and its being precisely of the same width throughout, allow of its ready passage through the nasal canal, so that the point will fairly rest upon the inferior wall of the nostril, and the groove will be placed looking directly forwards, and most conveni- ently for the easy passage of the style, which, of course, is readily passed along it, every obstacle having been already overcome by the knife, the point of which has penetrated beyond the limits of the nasal canal into the inferior meatus of the nose. The operation is most easily performed whilst the patient is sitting on a chair, with his head leaning against the breast of the operator, who stands behind the chair, and directs the knife inwards, downwards, and a little back- wards [see fig. 142], whilst he keeps the lower eyelid stretched by the finger of the left hand applied upon the margin of the orbit [see fig. 140]. Should it be the right lachrymal sac, the correspond- ing eyelid is most readily kept tense by the aid of an assistant, provided that the surgeon is not ambidexter. When per- formed in this manner the whole opera-
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