ECTASIA OF THE CORNEA 537 



increased later if necessary. A severe reaction usually follows 

 the first treatments. This disappears later when the strength 

 of the solution can be increased. Red or yellow oxid of 

 mercury ointment has also been used with good results. 

 A small quantity is applied once daily. Silver nitrate 

 solution (4 per cent.), or protargol (10 per cent.) is used to 

 stimulate greater cellular activity in the region of the opacity. 

 Succus cineraria maritima compositus is also of value. To 

 obtain results treatment must be continued for a long time. 

 As a last resort, when medical treatment does not suffice, 

 iridectomy may be tried. The operation consists in making 

 an artificial pupil so situated that light may reach the 

 retina. 



ECTASIA OF THE CORNEA. 



Two types of ectasia are recognized: (a) Inflammatory 

 ectasia, and (b) non-inflammatory ectasia. 



Inflammatory Ectasia.— Two forms occur in animals, viz.. 

 Staphyloma, and keratectasia. 



Staphyloma.— Definition. —A protrusion of the cornea, the 

 result of inflammation (ulceration, perforation, prolapsus of 

 iris). Staphyloma may be partial or complete; in form 

 spherical or conical. In animals it is usually complete the 

 entire cornea protruding from the scleral margin. In color 

 it is blue or black due to cellular infiltration and pigment 

 deposit. The protrusion may interfere with the closing of 

 the lids. Lacrimation, photophobia and pain are prominent 

 symptoms. In the incomplete form (conical) only a portion 

 of the cornea protrudes. 



Treatment.— Treatment is usually unsatisfactory. The 

 cause should be removed if possible. Apply gentle pressure 

 to the eye through antiseptic packs retained with a head 

 bandage. When the intra-ocular pressure is too great, some 

 of the fluid from the anterior chamber may be aspirated 

 before applying the pack. Permanent satisfactory results 

 can hardly be hoped for. When other treatment fails the 

 affected eye should be enucleated. 



Keratectasia.— Definition.— Keratectasia involves only the 

 cornea which has become weakened at some point either from 



