DEPARTMENT OF SURGERY. 
923 
liininary operation, which is performed in order to get access to 
structures beyond the iris. 
2 . Glaucoma. —The name u glaucoma ” is applied to any 
condition of the eye characterized by an increased intraocular 
pressure or induration and hardening of the eyeball. For our 
purpose we will consider two forms :—i. Simple Glaucoma , 
which includes all glaucomatous conditions that seem to exist 
without inflammatory symptoms ; 2. Secondary Glaucoma, 
which includes glaucomatous conditions that are sequelae of other 
ocular diseases. Iridectomy has been considered a curative meas¬ 
ure for glaucoma since 1856, and is to-day receiving as much 
attention as ever. 
3. Cataract is a diminished transparency of the lens or its 
capsule, and is more commonly observed in old animals. It 
may be influenced by heredity, heat, trauma, internal ophthal¬ 
mitis, and disturbed nutrition. The operation in the treatment 
of cataract may be considered preliminary iridectomy. 
4. Prolapse of Iris. —The iris sometimes protrudes through 
openings in the cornea. Such perforations result from disease, 
traumatic or surgical wounds of the cornea. When the por¬ 
tion that protrudes through the corneal wound cannot be prop¬ 
erly replaced iridectomy is indicated. 
5. Iritis. —The causes of iritis are constitutional, local and 
metastatic. Constitutional iritis is not so common in domestic 
animals as local or metastatic, and either of these may be acute 
and chronic, or plastic and serous. I11 chronic plastic or serous 
iritis the intraocular pressure may be increased to such an ex¬ 
tent as to necessitate paracentesis and even removal of part of 
the iris; or the iris may adhere to surrounding structure and 
require it to be loosened and probably part of it resected. 
6. Tumors and foreign bodies hi the iris. —Tumors found in 
the iris are cysts, angioma granuloma, melanoma and sarcoma. 
These tumors when removed often require the resection of part 
of the body of the iris. Foreign bodies in the iris that require 
a removal of part of the iris is an indication for iridectomy. 
7. Preliminary operation. —Iridectomy is a preliminary op¬ 
eration when it is performed to enable the operator to get access 
to structures beyond the iris. 
SequelcE. —The operation, like all other ocular operations, is 
sometimes followed by undesirable conditions; among the most 
common sequelae are sympathetic ophthalmitis and intraocular 
haemorrhage. Sympathetic and internal ophthalmitis can be 
obviated to a certain extent by aseptic precautions ; but, intraoc- 
