THE CORNEA 305 



infected with Pueumococci. This would explain the origin at the margin ; the 

 immediate formation of vessels increases the resistance of the cornea ; the progress 

 is therefore centripetal and superficial. 



The bacteriological findings in cases of keratitis fasciculosa are not uniform, 

 Addario found Staphylococci a few times ; A. Macnab, Diplobacilli. Further 

 examinations are necessary, and for this we must take material from the very apex 

 of the creeping band, and it must be scraped out. or otherwise the contaminating 

 organisms which lie on the surface can easily cause confusion. 



In the literature there are a number of other atypical cases (not superficial) 

 described as due to the Pneumococcus (E. von Hippel, Doetsch, Petit, Hertel, 

 Holdeu, Bach, and Neumann). There are also those cases of perforative 

 keratomalacia in niarasmic children, in which Uhthoff and Axenfeld have found 

 Streptococci; Loeb, Pneumobacillij Frankel, Franke, and Schanz, Stapli. pyog. 

 aureuSj and Macnab, coll with Gonococci. 



In these children the rapid penetration of the cornea by the Pneumococcus can 

 be understood when we consider how the lowered general condition of the body 

 reacts on the resisting power of the tissues a reaction known to occur in diseases 

 of the cornea. Similar conditions obtain when infections of the cornea are added 

 to severe conjunctival affections (gonorrhcea, diphtheria). 



Since then further research (Secondi, Cuenod, Bach and Neumann, Panas, 

 Hertel, De Schweinitz, Vossius, Petit, Doetsch, Kibbe, Vallaude, Velhagen, Romer, 

 Horsmann MacNab, Angus Macnab, Pacerson, Calderero, Zur Nedden, Schmidt, 

 Salvaneschi, Tertsch, Morales J ) has shown that the ulcus serpens is pre-eminently 

 an infection with the Pneumococcus, and that an early infiltrate which contains 

 Pneumococci will, if it continues, develop into a serpiginous ulcer. 



There are exceptions to this rule. In three cases Petit found a peculiar bacillus 

 which closely resembles the Morax- Axenfeld bacillus, only differing from it in some 

 of its peculiarities of growth (vide infra). Since then Macnab and Agricola have 

 reported cases in my clinic, and Erdrnann, Eoehat, Paul, Augstein, Benedetti, and 

 McKee other cases, in which such bacilli were found ; in some of them the Morax- 

 Axenfeld bacillus, and in others the Petit type. After the Pneumococci the next 

 most frequent cause of an ulcus serpens is the Diplobacillus. On close examination 

 the majority of the cases which I have seen showed not only a serpiginous edge, 

 but also a marked and often deep infiltration of the base of the ulcer. 



In my last eighty cases of hypopyon-keratitis fifty-five were caused by Pneumo- 

 cocci, and these were all ulcera serpentia ; of the twenty-five caused by Diplcbacilli, 

 about half were serpiginous, and to some extent showed a definite infiltrated border. 



Gourfein records the occurrence of Friedlander's bacillus in typical hypopyon- 

 keratitis. In this connexion Gourfein holds the view that it is not because of any 

 special activity of the Pneumococcus that it is so often found in an ulcus serpens, 

 but from the coincidence that it is the most frequent organism in the vicinity of the 

 injured cornea, its frequent presence in the ulcer being due to its prevalence in the 

 pus from the lacrymal sac and on the normal conjunctiva. The Pneumobacilli 

 and the other suppurative organisms have the same relation to the clinical appear- 

 ances, only they do not occur so frequently in the immediate neighbourhood of the 

 cornea. 



This question is of vital importance. When we consider the available facts, it 

 appears that Gourfein's opinion is not justifiable, although it is quite true that the 



1 In Morales' case we find Streptococci very frequently recorded as occurring with 

 Pneumococci. It is not quite clear whether this is not merely a culture differential 

 diagnosis (cf. p. 183). It is questionable whether the Friedlander Diplobacillus which he 

 found in so many cases was not the Morax-Axenfeld or Petit bacillus, especially as diplo- 

 bacillary cases are not recorded to have occurred in the whole series. 



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