DISEASES OF THE CORNEA 413 



"We must try to remove any spots on the sclerotic membrane l)y 

 means of irritants, such as the mihl chloride or oxide of mercury or 

 massage. According to Bayer, massage of the cornea has to be per- 

 formed in the following manner: The points of the fingers are placed on 

 the closed-up eyelids and by a constant circular or centrifugal friction 

 move the eyelid for sometime. In some cases we may also apply the 

 above-mentioned ointments and powders. The writer has obtained 

 far the liest results from calomel than anything else. He placed daily 

 a small amount of powder composed of equal parts of calomel and sugar 

 (grape sugar) on the cornea and massaged the eyelid for ten minutes. 

 Very good results by painting the enlargement several times daily with a 

 solution of pyoktanin (1 to 100). 



The following alterations are also seen in the cornea of the dog: 

 Dermoid of the Cornea. — This condition has already been de- 

 scribed under neoformation of the cornea. We find a peculiar ab- 

 normal collection of true epidermal tissue on the cornea Avhich is covered 

 with hair and interferes with the direct action of light, and also produces 



Fig. 140. — Dermoid of cornea. 



irritation in the cornea and conjunctiva (Fig. 140). The hair should 

 be cut off by means of scissors. Thierry observed the same a]3normality 

 on the sclerotic membrane of both eyes in a three months' old dog. 

 There was a slight swelling and enlargement above the surface of the 

 membrane which was covered with fine hair. 



The treatment consists in the removal of the almormality, the eye 

 is cocained, the dermoid is lifted with a pair of fine curved forceps and 

 removed by means of a pair of curved scissors. An opacity of the cornea 

 follows as a result; no attempt should be made to remove this for at 

 least two months, as any friction or manipulation shortly after the 

 operation is apt to set up great irritation. In removing the dermoid 

 great care must be exercised not to cut entirely through the cornea and 

 allow the escape of the contents of the anterior chamber; if any part of 

 the dermoid seems to involve the deep structure of the cornea, it had 

 better be left alone. French advises that during the operation a stream 



