Cysts and Tuberculosis of the Iris. 403 



of intra-ocular pressure, followed later by its diminution, and a 

 cloudiness of the anterior portion of the vitreous humor. This 

 last condition can only be detected by a full illumination of the 

 vitreous, and its examination with the ophthalmoscope. It is 

 quite hable to be complicated by suppuration and to go on to 

 panophthalmitis. 



The treatment does not materially differ from that of iritis, yet 

 atropia must be used with caution as it is hable to increase the 

 suffering. The preparations of mercury have been especially 

 recommended. 



CYSTS OF THE IRIS AND CORPORA NIGRA. 



Mayer speaks of these lesions in horses, but it is very difficult 

 to diagnose them correctly, even with the aid of the ophthalmo- 

 scope. The very manifest bulging at the part may be due to ex- 

 cess of pigment, especially in the corpora nigra, and an explora- 

 tory puncture would only be warranted when the protrusion be- 

 came excessive and injurious. One such puncture by Eversbusch 

 led to infection and loss of the eye. 



TUBERCUIyOSIS OF THE IRIS. 



This has occurred as the result of inoculation of the aqueous 

 humor in the smaller animals, and as a spontaneous localization 

 of the disease in cattle (Hess, Roder, Fischoder, etc. ) . In Hess's 

 case, the left eye was shrunken to half the size of the sound right 

 eye, and small caseated tubercles -were present in both iris and 

 choroid. There are usually coincident tubercles in other organs, 

 and these with the nodular appearance of the iris swellings, if 

 visible in life, may assist in diagnosis. (See Symptomatic Iritis 

 and Tuberculosis.^ 



