This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1894 Excerpt: ... as previously stated, is roughly speaking to be regarded as a loss of transparency in the crystalline lens. Since the opacity lies directly in the line of sight it must of necessity cause great interference with vision. No medicine is known by the internal use of which the opacity can be resolved; accordingly the ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1894 Excerpt: ... as previously stated, is roughly speaking to be regarded as a loss of transparency in the crystalline lens. Since the opacity lies directly in the line of sight it must of necessity cause great interference with vision. No medicine is known by the internal use of which the opacity can be resolved; accordingly the oculist removes the dim lens by a surgical operation. When dealing with cataract in old persons, or senile cataract, as it is called, the operator cuts through the cornea, thus opening the anterior chamber of the eye. Next, he sometimes removes a piece of iris, which he has previously withdrawn by the aid of a delicate pair of forceps; he performs in fact an iridectomy. The thin enclosing capsule of the lens is then scratched through by means of an instrument called a cystitome (Fig. 52). Lastly, by gentle pressure on the cornea, the opaque lens is made to leave its natural position, and come altogether outside the eye. The operation thus described is spoken of as "extraction of senile cataract." Cataract may be met with, however, in the eyes of young persons, when a different operation is employed. A fine needle is thrust through the cornea, and the capsule of the lens opened with its point. The aqueous is thus brought into actual contact with the lens, which is gradually dissolved by that fluid. This operation has received various names, viz., discission, the needle operation, or solution of the cataract. But the action of the aqueous upon the lens is slow, and the needle operation may have to be repeated at intervals of a few weeks. Hence some surgeons hasten matters by introducing a hollow nozzle (Fig. 57), into the anterior chamber, and suck out the broken-up lens matter. This is called the suction operation. Sometimes the linear op...
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