DISEASES OF THE CRYSTALLIXE LENS 419 



(Fig. 143, a). The fluid in the anterior chamber causes a gradual break- 

 ing up and reabsorption of the lens. An assistant holds the eyelids open 

 and the operator seizes a fold of the conjunctiva with a small tenaculum, 

 holding the eye firmly with the left hand, while holding the needle in 

 the right hand, placed on the animal's head to steady it. The needle 

 is then introduced into the cornea, in the middle of the lower external 

 quadrant, in such a direction as to meet the ciliary insertion of the iris 

 and as far as the upper internal quadrant. Before the point of the 

 needle has reached this latter point, however, it is placed firmly on the 

 capsule of the lens, and this is cut through in a transverse direction with a 

 lever-like movement of the needle (Fig. 144) . The instrument must then 

 be removed in the same way that it was introduced in perforating the 

 cornea. After the operation the animal must be placed for some time 



b 

 a. 



Fig. 144. — Discission of the lens: a, Form and size of the cross-incisions; 6, method of insertion 



of the needle. 



in a dark place and the eye treated twice a day with atropine. We must 

 treat all irritating symptoms of the eye by means of cold compresses, 

 and sometimes we must use mild laxatives. After six or eight weeks 

 the reabsorption of the lens is complete. We generally perform dis- 

 cission in young animals affected with soft cataract. The result of this 

 operation, however, is not always satisfactory, as reabsorption is slow 

 and in many cases requires a second operation. Several months may 

 also elapse before the cataract is absorbed. Schlampp advises in such 

 cases puncturing the cornea, and by this means slowly allowing the 

 fluid of the anterior chamber to escape, leaving the lens untouched. 

 Anterior displacement of the lens enlarges or ruptures the opening 

 which has been made in the capsule. Reabsorption follows, as a rule, 

 more quickly when this is performed, probably due to the fact that the 

 fluid which contains the elements of the lens has been discharged and 

 replaced by fresh fluid. The process is not dangerous, and may be 

 repeated much oftener than discission. 



Linear Extraction. — This operation is used where there is complete 

 opacity of the lens and enlargement of the lens and contraction of the 



