CATARACT 543 



Diabetic Cataract. Very rare in animals. A few cases have 

 been noted in dogs. 



Congenital Cataract. Quite common in young dogs. As 

 a rule, the lens only is involved. It is often bilateral. It 

 may be partial or complete. 



Symptoms. General. In animals cataract is usually over- 

 looked until it becomes so well marked as to be visible to the 

 ordinary observer. Partial cases are sometimes discovered 

 during an examination of the eye for some other disease. In 

 using the ophthalmoscope in cataract the light should not be 

 too strong. Under subdued light the opacity appears as a dark 

 spot, its color differentiating it from the tapetum lucidum or 

 the red papilla. Cataract should be distinguished from foreign 

 bodies on the cornea, corneal opacities and turbidity of the 

 vitreous humor. In most cases a careful examination with 

 an ophthalmoscope will suffice to differentiate between lens 

 opacities and those in other parts of the eye. When the 

 diagnosis cataract has been made, the form and cause 

 should be determined whenever possible. The history of 

 the case, the age and condition of the patient, and the 

 appearance of the opacity are indicative. 



Course. The course in cataract is chronic, usually lead- 

 ing to complete loss of vision. Occasionally a traumatic 

 cataract develops rapidly and undergoes a spontaneous 

 recovery within a short time. Such cases are rare. 



Prognosis. The prognosis is unfavorable. 



Treatment. The only treatment of value is an opera- 

 tion to remove the lens. In veterinary practice the diffi- 

 culty in keeping the parts aseptic, the dressings in place 

 and the patient- quiet, is so great that cataract operations 

 are seldom employed. There are two operations for cata- 

 ract: (a) A discission of the lens, and (6) extraction of the 

 lens. 



Discission. Discission is practised only in congenital 

 cataract, or when cataract appears early in life, is soft and 

 capable of absorption. The operation is performed under 

 complete anesthesia and strict asepsis. The eye to be 

 operated is flushed out with an antiseptic solution (boric 

 acid, 2 per cent.; bichlorid of mercury, l-5000) s followed 



