A treatise on the diseases of the eye . ornea ; the laceration of the capsule ; and the removal of the lens throughthe openings made in the capsule and cornea. The division of the cornea must be ample enough, that the lens mayescape readily through it; we divide, therefore, a certain portion of thecircumference, carrying the section along the edge of the cornea, as nearas may be to the sclerotic coat. There are various reasons for making thesection at the margin of the cornea, and the principal of these is, that weshall not otherwise have sufficient room for the passage of the is th
A treatise on the diseases of the eye . ornea ; the laceration of the capsule ; and the removal of the lens throughthe openings made in the capsule and cornea. The division of the cornea must be ample enough, that the lens mayescape readily through it; we divide, therefore, a certain portion of thecircumference, carrying the section along the edge of the cornea, as nearas may be to the sclerotic coat. There are various reasons for making thesection at the margin of the cornea, and the principal of these is, that weshall not otherwise have sufficient room for the passage of the is the further advantage that the subsequent cicatrix will not inter-fere with vision. The section of the cornea must embrace an extent cor-responding to the transverse diameter of the lens, and that is nearly equalto the diameter of the cornea itself, so that the section of one half of thecornea is required to allow the lens to escape. We must puncture thecornea on the temporal side of the eye, [fig. 103,] carry the knife across Fisr. 640 EXTRACTION OF THE CATARACT. the anterior chamber, bring it out at the nasal side opposite to its entrance, [fig. 104,] and then continue the incision, so that the knife may cut itself out. The chief difficulty in the sec-tion of the cornea arises from theiris getting in the way of the the anterior chamber is pene-trated, the aqueous humor readilyescapes, and then the iris conies im-mediately against the knife, so thatwe cannot carry it on without wound-ing that part. In order to preventthe escape of the aqueous humor,the cornea knives are so shaped asto fill up the wound ; that is, they increase in thickness gradually from the point to the handle. The cornea may be divided in its upper [fig. 105], or lower half, [fig. 106,] or in its lower and outer portion. [Fig. 107.] The lower section is
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Keywords: ., boo, bookcentury1800, bookdecade1840, booksubjecteye, bookyear1847
