312 BACTERIOLOGY OF THE EYE 



found by Morax and Axenfeld in a case of ring abscess in a metastatic 

 ophthalmia, so that from a bacterial point of view a ' ring abscess ' is 

 not a definite infection. Stower 1 found a Gram-negative bacillus of 

 the Proteus type, which did not form pigment ; an exact cultural 

 determination was not carried out. 



In diphtheria the suppuration of the cornea is principally due to the 

 pyogenic organisms ; the diphtheria toxin prepares the way for their 

 action (Coppez). The diphtheria bacilli can cause a necrosis, but not 

 a suppuration, in the cornea. 2 Similarly, secondary infections play an 

 important part in gonorrhoeal affections of the cornea, though the 

 Gonococci can cause a suppurative destruction of the cornea, and even 

 find their way into the iris (Dinkier, Morax). The exceptional severity 

 of gonorrhoeal infections of the cornea is emphasized by Butler 

 (Palestine). 



Augstein has undertaken a systematic examination of simple infil- 

 trates of the cornea occurring in cases of trachoma. In the large and 

 small grey infiltrates he almost always obtained a negative result. 

 Thirty-five ulcers were examined ; Pncumococci were found in abun- 

 dance in four cases which were not ulcera serpentia, and which soon 

 healed with the customary treatment for granular ophthalmia. In 

 one case DiplobaciUi were found, and in ten the Bacillus xcrosis ; in 

 eighteen cases the findings were negative, though the ulcers were 

 deep and severe. The negative cases, amongst which those with 

 the xerosis were included, were considered to be due to the action 

 of the trachoma virus. The fact that the Pncumococci in these 

 four cases did not cause any difference in the appearance of the 

 ulcers is due to the increased resistance of the cornea in this disease. 

 Amongst the rare cases of ulcus serpens in trachomatous patients, 

 some were very mild in their course, even when there was no pannus. 



Infection of the cornea with the Koch-Weeks bacillus, fully de- 

 scribed in the monograph by Petit, occurring in cases of conjunctivitis 

 due to this organism, does not, as a rule, take on a purulent form ; it 

 remains superficial. 3 It is very rare to find these organisms alone in 

 a severe corneal suppuration. A few such cases are given by Petit 

 and by Butler. The infiltrates are most commonly found near the 

 periphery (catarrhal ulcers), and they produce an appearance which 

 resembles the ' infectious ulcer ' of Zur Nedden. Zur Nedden himself 

 admits that such an appearance is not necessarily caused by his 



1 Stower, K. M. f. A., March and April, 1907, xlv. 1. 



2 On this subject Tschirkowsky contributes an important article in A. f. 0., Ixviii., 

 i., 1908. 



3 See the chapter on ' Conjunctivitis.' 



