38 OPHTHALMOLOGY FOR VETERINARIANS 



subcutaneous tissue. It may be confined to one lid only 

 or both lids may be affected. It is often the result of 

 continued attacks of inflammation of these tissues. 



Blepharospasm is an involuntary contraction of the 

 lid. It may be clonic or tonic in character. It is usually 

 reflex, and is due to some irritation of the seventh nerve. 

 The lid is spasmodically contracted when a foreign body 

 is present and also in some diseases of the cornea. The 

 mild clonic type is often due to nervous diseases, chorea, 

 habit, etc. In these cases nerve tonics and rest are of 

 benefit. In the animal, more likely a foreign body is the 

 cause. Remove the cause. 



Ankyloblepharon is a condition in which the edges 

 of the lids have grown together. It is usually caused 

 from traumatism or disease, or may be due to a con- 

 genital defect, when the Hds fail to open, as is often 

 seen in kittens and other pets. An operation is the 

 only relief, though in congenital cases the lids will 

 usually separate if one will give nature sufficient time 

 to do its work. 



Blepharitis marginalis, an inflammation of the lid, 

 is known as blepharitis, but the former term designates 

 a local inflammation along the margin. There are two 

 principal types — the superficial and the ulcerative. The 

 superficial type is manifest by the presence of redness 

 and swelling, together with the formation of crusts, 

 which usually occur about the lashes, and frequently 

 cause them to fall out by slight friction. The hair- 



