262 



roid. Tho amouut of flocculent deposit in the chamber of the aqueous 

 humor is also iu direct ratio to the iuflammatiou of the iris. Perhaps 

 the most marked feature of internal ophthalmia is the extreme and 

 l^aiuful sensitiveness to light. On this account the lids are usually 

 closed, but when opened the pupil is seen to be narrowly closed even if 

 the animal has been kept iu an obscured stall. Exceptions to this are 

 seen when inflammatory effusion has overfilled the globe of the eye, and 

 by i)ressure on the retina has paralyzed it, or when the exudation into 

 the substance of the retina itself has similarly led to its paralysis. Then 

 the pupil may be dilated, and frequently its margin loses its regular 

 ovoid outline and becomes uneven by reason of the adhesions which it 

 has contracted with the capsule of the lens, through its inflammatory 

 exudations. In the case of excessive effusion into the globe of the eye 

 that is found to have become tense and hard so that it can not be in- 

 dented with the tip of the finger. With such paralysis of the retina, 

 vision is heavily clouded or entirely lost, hence in spite of the open 

 pupil the finger may be approached to the eye without tiie animal be- 

 coming conscious of it until it touches the surface, and if the nose on 

 the affected side is gently struck and a feint made to repeat the blow 

 the patient makes no effort to evade it. Sometimes the edges of the con- 

 tracted pupil become adherent to each other by an intervening plastic 

 exudation, and the opening becomes virtually abolished. In severe in. 

 flammations pus may form in the choroid or iris, and escaping into the 

 cavity of the aqueous humor show as a yellowish white stratum below. 

 In nearly all cases there is resulting exudation into the lens or its cap- 

 sule, constituting a cloudiness or opacity (cataract), which in severe 

 and old standing cases appears as a white fleecy mass behind a widely 

 dilated pupil. In the slighter cases cataract is to be recognized by ex- 

 amination of the eye in a dark chamber, with an oblique side light as 

 described in the introduction to this article. Cataracts that appear as 

 a simple haze or indefinite fleecy cloud are usually on the capsule (cap- 

 sular), while those that show a radiating arrangement are in the lens 

 (lenticular), the radiating fibers of which the exudate follows. Black 

 cataracts are formed by the adhesion of the pigment on the back of the 

 iris to the front of the lens, and by the subsequent tearing loose of the 

 iris, leaving a portion of its pigment adherent to the capsule of the lens. 

 If the pupil is so contracted that it is impossible to see the lens, it may 

 be dilated by applying to the front of the eye v> ith a feather some drops 

 of a solution of 4 grains of atropia in an ounce of water. 



The treatment of internal ophthalmia should embrace first the removal 

 of all existing causes, or sources of aggravation, of the disease, which 

 need not be here repeated. Si^ecial care to protect the patient against 

 cold, wet, strong light, and active exertion, must, however, be specially 

 insisted on. A dark stall, and a cloth hung over the eye, are important, 

 while cleanliness, warmth, dryness, and rest are equally' demanded. If 

 the patient is strong and vigorous a dose of i drams of iiarbadoes aloes 



