EEMAEKS ON TECHNIQUE 3 



many earlier writers often failed to find the cause of hypopyon-keratitis 

 and ulcus serpens. 



It is important in deciding the diagnosis to obtain material from the 

 actual infiltrated tissue. This must be done with the greatest of 

 caution, as the scraping can loosen the tissues and result in a further 

 spread of the infection. In deeply-placed infiltrates this examination 

 should not be insisted upon, especially when the lesion is central. 

 A movement of the patient's eye may cause the point of the instrument 

 which is in contact with the infected focus to penetrate and infect the 

 cornea more deeply. I can remember several cases which have thus 

 been made worse ; and it is a rule in my clinic that, immediately after 

 the bacteriological examination has been made, the requisite treatment 

 should at once be applied (e.rj., in diplobacillary cases zinc freely, 

 in pneumococcal cases the cautery, etc.). This is naturally most 

 important in purulent processes. 



The point of a sterile Graefe knife or needle carefully used is very 

 suitable for removing the material. The cocained eye must be 

 absolutely steady. For this purpose the speculum and forceps are 

 often necessary, and have the added advantage of preventing con- 

 tamination by the lid margins. In the case of ulcus serpens we must 

 go carefully along the progressive margin. For this purpose Eomer 

 uses a platinum needle. A small amount of material is obtained, and 

 from it a culture should first be made, and then the rest rubbed out 

 on a slide. If nothing can be found in the film, some more material 

 must be taken. Cultures are often the more delicate test, especially 

 when the organisms are experimentally increased, as, for instance, 

 Pneumococci in glycerine and rabbit-serum bouillon (Eomer). In every 

 case well-tried and susceptible media must be used for all corneal 

 work. 



In many cases an examination of a Gram-stained preparation 

 settles the question at once ; this is especially the case in deciding 

 between diplobacillary and pneumococcal infections of the cornea a 

 most important diagnosis and one which is almost always thus decided. 

 Sometimes we find cases where the slide preparation gives a positive 

 result, but cultures are negative ; this is probably due to the scanty 

 numbers of the organisms. 



This bacteriological examination is especially desirous in purulent 

 affections of the cornea; it is also valuable in many simple infiltrates, 

 and can be recommended in every stubborn case. Peripherally situated 

 infiltrations will be more readily tested thus, as the pupillary area of 

 the cornea should not be interfered with unless absolutely necessary. 



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