Recurring ophthalmia, which is usually also an internal inflammation, appears more abruptly and often at first with greater severity, and accompanied by more hyperthermia. There is almost always a bluish white opacity around the margin of the cornea, the eye is retracted in its sheath so as to appear smaller, and the upper lid usually shows a marked angle between its inner and middle thirds in place of the evenly curved arch of the healthy palpebra. It usually appears for the first time in the young and in those that have inherited the susceptibility and have been kept on damp soils, in cloudy districts, or dark buildings.
Lesions. These are necessarily varied according as the inflammation is concentrated on particular parts of the interior of the eye. The secreting membrane of the aqueous humor is nearly always inflamed giving rise to an exudate and a milky opacity of the aqueous humor. The iris is the seat of congestion exudation, thickening, cell proliferation and investment by false membranes. The capsule of the lens is early clouded, may be covered by exudate and is rendered vascular in some cases. The choroid is also the seat of congestion, exudation and discoloration with the covering up at points of its pigmentary layer. The vitreous and lens finally become the seat of exudation and opacity which is liable to prove permanent.
Prognosis. The internal ophthalmias are always to be dreaded. In other organs exudates may take place and become organized as permanent structures without abolishing the function or rendering the organ physiologically useless, but in the delicate and transparent tissues of the eye, any such permanent product almost infallibly causes opacity and loss, or serious impairment of vision. In the retina the displacement, derangement, or covering up of the cones and rods necessarily interferes with or abolishes sight, the opacity of the cornea, lens, capsule, or vitreous interrupts the rays of light, and the destruction, or coating over of the pigment of the choroid leads to undue reflection and destroys vision. Beside this the destruction or impairment of one part of the eye, changes the refraction and blurs the vision, or interferes with accommodation and destroys the utility of the organ. Unless therefore the disease can be cut short in its early stages and a complete resolution effected it is likely to leave the patient very much deteriorated in value. Fortunately it is only in the most violent cases or in very susceptible animals that the disease in the one eye is transmitted to the other by sympathy and leads to destruction of that eye as well.
In the treatment of internal ophthalmia, rest in pure air and moderate warmth, away from a fierce glare of light is imperative. The causes should as far as possible be removed. Next, it is desirable to establish derivation. Leblanc and Trasbot attach great importance to phlebotomy from the jugular on the same side. A more direct local action with less loss of blood may be obtained from opening the angular vein of the eye or applying a leech beneath the lower lid. In most cases a sufficient derivative action can be secured by an active purgative which may be followed by daily doses of cooling diuretics. Locally astringent lotions (lead acetate or zinc sulphate 1 dr. to 1 qt. water; mercuric chloride, 1 ∶ 5000; boric acid, 2 ∶ 100; pyoktannin, 1 ∶ 1000) in combination with cocaine hydrochlorate, homatropin, atropia sulphate, duboisia or hyoscyamin (1 ∶ 1000) would be appropriate. These may be applied over the eye on a soft cloth, and in cases of infective inflammation the more antiseptic agents may be injected under the lids. When the inflammation is very severe the atropia or other sedative agent may be made of the strength of 1 ∶ 100 and a drop or two placed inside the lids with a dropper every two or three hours.
A blister of biniodide of mercury may be applied to a space the size of a dollar above the anterior end of the zygomatic ridge, or in dogs back of the ear on the side of the neck: or a seton may be passed through the skin in the same situation.
When the eyeball is unduly tense, puncture through the margin of the cornea with a fine aseptic lancet will relieve the tension and in some cases induce a more healthy action. Assiduous antisepsis is needful until the wound has healed.
In other cases benefit can be obtained from the use of an ointment of yellow oxide of mercury 1 part, in vaseline 10 parts, or of iodoform of the same strength. A small portion the size of a grain of wheat is put under the lid, and the latter manipulated with the finger to bring it in contact with all parts of the surface. In case of a rheumatic origin salicin and salicylate of soda are demanded.
SIMPLE IRITIS.
Causes. Symptoms: redness of sclera, in dogs, cats, birds, pigs, with a narrow zone of white next the cornea, red scleral vessels immovable, iris dull gray or brown, uneven, sluggish in response to light, synechia anterior or posterior, lens and capsule clouded or clear, pupillary margin uneven, myosis or midriasis, black cataract. Treatment: rest, dark stall or covering, head elevated, midriatics, cocaine, antiseptic puncture, purgation, leeches, seton, cooling astringent lotions, diuretics, for tension in convalescence iridectomy. In traumatic cases careful antisepsis.
This may come from any one or more of the causes of internal ophthalmia above named. The inflammation, however, concentrates itself on the iris so as to overshadow the disease in the adjacent organs.