OPHTHALMO REACTION 53 



f erred into the cylinder. Boiled water or sterile saline is added to the i, 

 2 or 4 per cent, dilution mark. The pipette is washed clean in the solution 

 by successive aspiration and expulsion in order to free it completely of the 

 remaining concentrated tuberculin, and can now be employed as the eye 

 dropper. 



The solution should be used only on the day it is prepared. The tuber- 

 culin in the sealed tube can be kept indefinitely. The pipette and graduate 

 are sterilized by dry heat, boiling or by thorough washing in boiling water. 



One drop of the tuberculin dilution is deposited in the inner angle of 

 the eye, and care should be taken that the drop is not immediately expelled, 

 but evenly distributed in the conjunctival sac. 



In tuberculous individuals the reaction appears in twelve to 



Gradation twenty-four hours, and according to its intensity can be 

 of the Oph- ,. . , , . A ^, , 



thalmoRe- dlvlded mto three S rades ' 

 action. First Grade. Reddening of the caruncle and inner side of 



the lower lid (+) (see Fig. 2, Plate I). 



Second Grade. Same as above but additional involvement of the con- 

 junctiva of the eyeball (++) 



Third Grade. Conjunctivitis purulenta, phlyctenulae and other such 

 severe manifestations (+ + +). 



The reactions of the first and second degree occur most frequently. 

 The manifestations associated with the former of these are so mild that the 

 patient himself does not usually notice them. If the proper dilution is 

 used and the contraindications of this test are observed, a reaction of the 

 third degree is obtained only in exceptional cases. Fever never occurs. 

 The other eye serves as a control. It is advisable therefore before under- 

 taking the reaction, to note carefully any differences that may exist in the 

 conjunctive on both sides. It must be remembered that 

 Selection i- The greater the dilution, the more specific is the reaction, 

 of Correct 2. The test should not be repeated upon the same eye, even 

 Dilution, jf there was no reaction at all at the first instillation. 



The following procedure should be adopted. A drop of the 

 2 per cent, tuberculin dilution is placed in the left eye. If a positive 

 reaction takes place, it is of great probability that the patient is suffering 

 from an active tuberculous process and thus the diagnosis is established. 

 If, however, that proves doubtful, and further corroboration is required, 

 the patient should receive, after the first reaction has entirely subsided, one 

 drop cf a i per cent, tuberculin dilution in the right eye. 



If a negative reaction is obtained at the instillation of the 2 per cent, 

 dilution, one drop of the 4 per cent, dilution is placed in the right eye. A 

 negative reaction with the 4 per cent, mixture speaks almost conclusively 

 for the absence of tuberculosis except in far advanced cachectic condi- 

 tions. A positive result does not, on the other hand, indicate the presence 



