DISEASES OF THE CORNEA 93 



The pus in the anterior chamber does not come from the 

 cornea, but from the inflamed condition of the struc- 

 tures within the globe. When perforation takes place 

 the severity of the central portion subsides, though 

 destruction of the tissue may proceed along the borders 

 until the whole cornea has become destroyed. Per- 

 foration is followed with a prolapse of the posterior struc- 

 tures; the iris falls into the opening, or, if exactly central, 

 the lens capsule may fill the perforation and become 

 adherent. After perforation, healing takes place much 

 more quickly, though there is a scar left which is 

 opaque and interferes with vision. In extremely severe 

 types purulent inflammation of the uveal tract occurs, 

 the eye is lost, and shrinking of the globe follows. 



A purulent ulcer is any ulcer which rapidly or slowly 

 sloughs. It is due to the entrance of pyogenic bacteria 

 following an injury to the cornea. The progress invades 

 the deep corneal layers at the point of commencement 

 and a rapid destruction of the tissue follows. Early 

 treatment should be employed in order to save the eye. 

 Hypopyon is pus in the anterior chamber. It gravi- 

 tates to the lowest portion of the chamber; and if fluid 

 in character it changes its position upon movements 



of the head. 



Trealmenl of Corneal ?7fcm.-The treatment of all 

 ulcers of the cornea must be prompt, and energetic 

 measures employed. If the ulcer is a small one and 

 apparently clean, simple antiseptic washes maybe used, 



