DISEASES OF THE EYE. 351 



a probe after the abscess is open we find the bone rough and brittle 

 at the point of disease. The discharge has a peculiar fetid odor, 

 and is often mixed with blood. 



Treatment. — The aflPected bone must be laid bare and all diseased 

 portions removed by scraping or, if necessary, with saw or chisel, 

 disregarding the extent of the injury or the size of the wound neces- 

 sary to be inflicted. A large portion of the bony orbit may be re- 

 moved without serious danger to the eye, provided the eyeball itself 

 has not been previously affected by the disease or involved in the 

 original injury. 



TUMORS OF THE ORBIT. 



A fungous tumor of the eyeball or orbit occasionally appears, which 

 is designated fungus hsematodes. This may arise without any appre- 

 ciable cause, or as the result of a wound. It frequently commences 

 within the eyeball as a small, red mass, eventually bursts through, 

 and pushes its way outside the orbit as a large, dark-red mass, bleed- 

 ing at the slightest touch. It has a peculiar, fetid odor, and early in 

 its appearance destroys sight, involving all the contents of the orbit, 

 not infrequently the bony wall itself. 



Unless the tumor is totally removed in its early stage of growth, 

 together with the eyeball, the disease will eventually cause emaciation 

 and death of the animal. The enucleation of the eyeball should not be 

 undertaken by anyone unacquainted with the anatomical structures 

 involved in such an operation. When the operation is performed 

 early enough the result is generally satisfactory. 



Bony tumors of the orbit, the result of bruises, fractures, etc., are 

 occasionally present in cattle. They may encroach upon the contents 

 of the orbit, causing paralj^sis of the optic nerve — the condition 

 known as amaurosis — or by pressure upon the posterior surface of the 

 eyeball force it forward, or produce atrophy (shrinking). They may 

 displace the eye in any direction, with or without disturbing vision. 



Fibrous tumors growing within the orbit will produce symptoms 

 similar to those of bony tumors. 



Treatment. — When the outlines of the tumor, whether fungoid, 

 bony, or fibrous, can be detected, an operation for its removal should 

 be undertaken as soon as the sight of the eye is in any manner dis- 

 turbed. 



DISLOCATION OF THE EYEBALL. 



The eyeball may be torn out of its socket by the horns of another 

 animal, or it may be crowded out with the blunt end of a club, cane, 

 or probe in the hands of a brutal attendant. 



Treatment. — When the optic nei^^e is not lacerated and the retrac- 

 tor muscles at the back of the eye are intact, an attempt at reduction 



