ENDOGENOUS INFECTIONS 375 



was later confirmed by Lietro-Vollaro l that meningitis organisms generally were 

 unable to pass forward in the optic sheath, as their passage was early blocked 

 by the exudation into the optic canal. 



And even in those rare cases where the presence of Pneumococci could be demon- 

 strated in the sheath, their transference from thence into the interior of the eye 

 could not be established. De Lietro-Vollaro has shown the same to be the case in 

 a traumatic suppurative meningitis, where the Streptococci could be found in the 

 sheath of the nerve, but had not passed from there into the globe. 



We can conclude that the same is true in meningococcal meningitis and its com- 

 plications in the eye. Till now, at least, there is no certain case known of infection 

 of the interior of the eye from the optic sheath. 2 



The important question, In which part of the eye do the bacterial 

 mctastases occur } can only be answered by microscopical examination 

 of serial sections of the early stages, in which either the organisms 

 can be seen inside the vessels, or a particular part of the eye can be 

 found intensely or exclusively affected. At any later stage the point 

 of origin is lost in the suppurating mass, and the exudate invades 

 other parts of the eye. In the stage of panophthalmitis no such 

 determination is possible ; indeed, in many cases it is impossible even 

 at an early stage. 



Many infections spread rapidly into the vitreous. The resulting 

 exudate may so carry the bacteria into the interior that, when we 

 examine the eye, we find the vitreous almost or exclusively filled with 

 bacteria, which then and there develop into dense masses. Pure 

 cultures are often found in the anterior part behind the lens. Trans- 

 ference into the vitreous takes place with extreme rapidity when the 

 adjoining retina is infected, and those cases which Straub and 

 Vogelsang 3 called * metastatic hyalitis ' are chiefly the results of 

 bacterial metastatic retinitis. 



The favourable cases for early examination have shown that the 

 retina was usually the primary site of infection ; in many cases it 

 alone was infected, and in others it was so along with other parts of 

 the eye. This is the case to a special extent, though not quite in- 

 variably, for those common cases (one-third of all observed) in which 

 a metastasis occurred in both eyes. In the one-sided cases, however, 

 the uvea was generally the site of an embolic infection. 



In the material which I have collected and examined this preference for the 

 retina was very marked in the double-sided cases. I have illustrated this by sections 

 from two similarly (Gram-\Veigert) stained globes in a case of double metastatic 

 ophthalmia, where bacterial necrosis (streptococcal) is very clearly seen. 



1 K. M.f. A., 1903, Beilageheft (Festschrift f. JIam). 



- The cases Avhicli are so considered by Saltini (loc. cit.), Silcock, Treacher Collins 

 (T. O. S., 1900, xx. 121), and others, are capable of another interpretation. 

 3 Vogelsang, Dissertation, Amsterdam, 1907, p. 58. 



