By far the best method of operating is the one proposed and practised by Mr. Critchett.
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Fig. xv. [92] |
Fig. xvi. [93] |
The object of it is to remove an elliptical portion of the front of the staphyloma, or the whole staphyloma, when it is possible, and at the same time to prevent as far as possible the escape of the vitreous.
Operation.—Three, four, or five small curved needles armed with thread are passed through the staphyloma from above downwards, being each entered a little above the line of the intended upper incision, and brought out a little below the line of the intended lower one (Fig. xv.)
To remove the included elliptical portion, Mr. Critchett pierces the sclerotic with a Beer's knife, just in front of the tendinous insertion of the external rectus. Through this incision a pair of probe-pointed scissors is introduced, and the piece cut just within the points of the needles. On the removal, the needles, which have retained the vitreous by their pressure, are drawn through and the threads cautiously tied.
Union by first intention very often occurs, and an excellent stump is left with a narrow depressed transverse cicatrix[94] (Fig. xvi.)
Extirpation of the Eyeball.—1. Of the Eyeball only.—A circular incision should be made with curved scissors through the conjunctiva, a little beyond the corneal margin, then, beginning with the external rectus, muscle after muscle should be raised with the forceps, and divided, after which the optic nerve is cut through with the scissors. A slight preliminary extension outwards of the optic commissure will facilitate the dissection, and must be secured with metallic sutures; any vessels should be tied, and the orbit filled up with a light compress of charpie secured with a bandage.
2. Of the contents of the Orbit.—This may be required for malignant disease, but with a very poor prognosis. The optic commissure should be freely divided, and then, by bold strokes of curved scissors, or curved probe-pointed bistoury, the orbit may be fairly emptied by scooping out its contents. Even the periosteum may require to be scraped off, and the optic nerve divided as far back as possible. The hæmorrhage may be pretty smart, but can generally be easily checked by compresses; if necessary, these can be soaked in the solution of the perchloride of iron.
The author has done this operation many times, in cases extensive and of old standing, for malignant disease, melanotic and encephaloid. All have recovered, and in no instance has there been any trouble in stopping the bleeding.