56 Surgical Diseases and Surgery of the Dog 



the needle is withdrawn. It. should be borne in mind that the larger 

 the opening is made in the capsule, the more freely will the aqueous 

 humor produce the desired effect. Following the operation, the iris 

 must be kept well dilated with atropine (i :ioo) dropped in the eye 

 three times daily, until absorption of the lens is complete. This 

 takes place in varying periods, according to the density of the 

 cataract, three weeks being about the shortest time, the more pro- 

 tracted cases running into months. The operation should be re- 

 peated if absorption is slow or incomplete. 



EXTRACTION OP THE LENS. 



This operation is really an elaboration of the preceding one. 

 Ebctra instruments are necessary, namely, a Graefe cataract knife 

 and a Daviel spoon. The pupil being previously dilated with atro- 

 pine, and the speculum inserted, the eyeball is steadied by seizing a 

 fold of conjunctiva below the inferior border of the cornea with 

 the fixation forceps, and drawing it downward. The next step is 

 corneal section and the flap should embrace the upper half of 

 the diameter of the cornea. The point of the Graefe knife with the 

 edge directed upward is made to enter the anterior chamber at the 

 corneo-scleral junction and to emerge at a point exactly opposite 

 and the section completed with a gentle sawing movement. This 

 causes escape of the aqueous humor. The discission needle is next 

 introduced and with it the capsule is incised crucially as in the pre- 

 ceding operation. The back of the spoon is then laid against the 

 inferior portion of the cornea arid firm but gentle pressure exercised 

 with upward motion to coax out the cataract. During the operation 

 the iris sometimes prolapses, when it is to be carefully replaced, or 

 failing in this it may be snipped off with scissors close to the border 

 of the cornea. The after treatment is the same as for the preced- 

 ing operation, but in this case, to prevent injury to the eye by 

 scratching, it should be bandaged with a piece of lint soaked in bi- 

 chloride solution and changed twice daily. 



BIBLIOGBAPHT. 



Barrier— Bull, de la Soc. de Med. Veter. 1898, p. 4T6. 

 Cocteaa & Leroy — Joam. de Phy. Exper. et Pathol. 7, 30^44. 

 Contejean— Ck>mpte9 rendas de la Soc. de Biol. 1896. p. 10S2. 

 Fromarget— Rec. de M6d. V6t6r. 1898, p. 89. 

 Hobday — Joarn. Comp. Path. & Ther. 8, p. 250. 

 Moeller — Zeitschr. f. Tergleich. Angenhellk. 1885, p. 65. 

 Pisa— Schwelz. Archlv. 1897, p. 230. 

 Randolph — Johns Hopkins Hospital Bulletin. Feb., 1895. 

 Boasl — Tjdsch. Toor Veeartsenljknnde. Jan., 1895. 



