350 BACTERIOLOGY OF THE EYE 



Pigeons '), the wandering cells take a part later. (Regarding the 

 occurrence of the bacilli in primary tuberculosis of the cornea in man, 

 and for the literature, see J. Schmidt, Inaug. Dissert., Leipzig, 1903.) 

 Wehrl considers that the so-called ' Knotchenformige keratitis ' 

 (nodular opacity of the cornea) is tubercular. 



The experiments of Lagrange, 1 Friedrich, Xoeske, and particularly 

 Stock, show that, on injection of virulent bacilli into the jugular vein 

 of a rabbit, scattered haematogenous deposits occur in the choroid of 

 both eyes. In spite of the high susceptibility of the choroid, this 

 only leads to multiple healing nodules. In the iris and ciliary body 

 the lesions are more severe, and recurrences more readily occur, 

 although even here a very free resorption is possible. 



Stock showed by the positive results of inoculation that even in this stage of 

 remission and cicatrization bacilli were present in the iris tissues, and these, when 

 inoculated on another animal, could cause an inoculation tuberculosis. There was, 

 therefore, no attenuation, nor was there any destruction of the bacilli, but a resting 

 stage had been produced by encapsulation. 



These experimental results correspond to the clinical fact that the choroid is very 

 often affected in miliary tuberculosis. They also show to what an extent the uvea 

 is a site of election for tubercular deposits. They furnish a variety of clinical 

 pictures of those chronic deep inflammations of the uvea, sclera, and cornea so 

 freely corresponding to the obscure chronic inflammations of these structures, long 

 ago designated by Michel as tubercular, and which have such variable courses, 

 often being quite benign. 



Deyl (Akad. d. Wissensch., 1894, Prag) first demonstrated the action of dead 

 tubercle bacilli when directly introduced into the eye. 



Leber and Bruns (A.f. 0., 1904, Iviii., p. 439) produced endogenous inflammatory 

 nodules in the conjunctiva by the injection of dead bacilli. The nodules did not 

 resemble either true tubercles or phlyctenules. 



In Stock's experiments the lacrymal gland was often affected by endogenous 

 tuberculosis. This agrees with my own observation that in miliary tuberculosis in 

 man this gland may be the site of a fresh deposit of tubercle, although it is not 

 affected by ectogenous means, even though there may be a long-continued tubercu- 

 losis of the upper conjunctiva ; the infection seems unable to pass freely against 

 the stream. In tuberculosis of the gland the demonstration of the bacilli is usually 

 difficult, as they are very scanty (cf. Plitt, K. M.f. A., 1905, Beilageheft). It is 

 important that it should be carried out on account of the differentiation from many 

 lynaphoid processes. 



In spite of the accessibility of this mucous membrane to the air, the influence of 

 endogenous infection in the etiology of tuberculosis of the conjunctiva and lacrymal 

 sac is even greater than that which used to be attributed to external factors. 

 (Cf. Lafon, These de Bordeaux, 1904 ; Reis, K.M.f.A., February, 1907, xlv. both 

 papers on 'Tuberculosis of the Bulbar Conjunctiva'; also Axenfeld, Med. Klinik, 

 1904 ; and ' Le Catarrhe Printanier,' Paris, 1907 [Steinheil] ; and Wirtz, K. M.f. A., 

 April, 1907, xlv., on ' Tuberculosis of the Lacrymal Sac. 1 ) 



1 Bull, du Congres de la Soc. Fran<>. d'Ophth., 1898, p. 96. 



