KERATITIS 529 



Keratitis Pigmentosa. — Pigmentary Keratitis. —Definition. 

 —A chronic disease of the cornea, either inflammatory or 

 degenerative, with which is associated pigment deposit. 

 It has been observed quite often in certain breeds of dogs 

 and cats. The poodle, small house spaniel, and other house 

 dogs are the most common sufferers. 



Etiology.— In most cases pigmentary keratitis is secondary 

 to ulceration of the cornea, other forms of keratitis and 

 corneal opacities. It may occur as a primary condition in 

 dogs having marked pigment deposits along the corneal 

 limbus. In these cases it affects usually only a portion of the 

 cornea, but may extend gradually to other portions. Occa- 

 sionally the pigmentation may be deposited around the 

 scleral corneal zone, extending toward the center of the 

 cornea. The causes of the primary form are unknown. 



Symptoms.— Pigmentary keratitis is characterized by 

 deposits of melanin or pigment in the cornea. It usually 

 begins as a fine, triangular network of small, dark lines 

 radiating from the limbus, the base of the formation being 

 at the limbus and the apex directed toward the center of the 

 cornea. The triangular pigment formation is often so dense 

 that the part of the cornea traversed by it is almost black. 

 Sometimes the pigmentation disappears to reappear later. 

 Continued recurrences eventually leave the cornea dull and 

 uneven on its surface. Lacrimation and photophobia are 

 little marked. 



Prognosis. — The prognosis is unfavorable. As a rule 

 following frequent recurrences permanent opacity of the 

 cornea results. 



Treatment.— Boric acid (2 per cent.), or ichthyol (2 per 

 cent.) is recommended. Pain may be arrested by stovain 

 (2 per cent.), or alypin (2 per cent.), combined with the 

 antiseptics. Internally potassium iodid (0.012-0.12) once 

 daily, or atoxyl in small doses has been used with apparent 

 success. The patient should be fed liberally and given good 

 care. 



Keratitis Punctata Superficialis. — Facetted Keratitis.— 

 Definition.— A chronic inflammation of the superficial layer 

 of the cornea causing opacity and the appearance of small 



