IRITIS AND GLAUCOMA 819 1 per cent) instillations should be employed to prevent iritic adhesions, also yellow ointment in the eye in case of central phlyctanula of cornea. In syphilitic keratitis this treatment should be supplemented by antisyphilitic treatment. As a general rule constitutional treatment is necessary. Corneal inflammation frequently terminates by leaving opacities of the cornea. DISEASES OF THE SCLERA, CILIARY BODY, AND CHORIOID Gout, rheumatism, syphilis, and traumatism are the chief causes of the diseases in question. Episcleritis (scleritis) occurs in circumscribed, slightly nodular subconjunctival patches of a bluish pink color. It is not infrequently associated with chronic keratitis, iritis, or chorioiditis. Cyclitis is an inflammation of the ciliary body, and may occur as a serous or as a suppurative inflammation. It is manifested by deep circumcorneal injection, with pain, and by tenderness on pressure. In serous cyclitis oblique examination discloses haziness of the anterior portion of the vitreous as well as the aqueous; in the plastic form a grayish mass behind the lens often obscures vision. Suppurative cyclitis is usually associated with suppurative chorioiditis and iritis. Chorioiditis is characterized by a diffuse haziness of the vitreous, which contains minute floating opacities, hyperæmia, and serous or plastic exudation of the chorioid. After absorption of the exudation, atrophic patches are left behind which greatly impair vision. This is especially the case in the syphilitic and tuberculous varieties and in old myopic conditions. TREATMENT.-Iodides and tonics internally. Hot applications locally. IRITIS Iritis. Inflammation of the iris is characterized by contracted pupil, impaired mobility of the iris, and, in the presence of adhesions, irregular dilatation of the pupil if light is reflected into the eye or a mydriatic is instilled. There is also marked injection of the circumcorneal blood vessels, and a rosy zone encircles the cornea. Pain is severe in acute cases, and especially at night. Iritis may be caused by traumatism, syphilis, rheumatism, or tuberculosis. Syphilitic iritis may appear in the serous, spongy, or gummatous form. The formation of gummata in the substance of the iris is pathognomonic of syphilis. It is accompanied by very severe pain. Rheumatic iritis is very prone to relapses and runs a very slow course. The pain is moderate. TREATMENT.-Hot fomentations and atropine. Leeches if the congestion and pain are very pronounced. Constitutional remedies in the presence of syphilis, rheumatism, etc. Permanent adhesions (posterior synechia) may be treated by removal of a portion of the iris. GLAUCOMA Glaucoma sometimes comes on insidiously, with rapid increase in presbyopia, making frequent changes of glasses necessary for reading; iridescent vision, consisting of a halo around lights, the outer ring being red and the inner one bluish green; diminution in the field of vision, and increased tension of the eyeball. Gradually these symptoms become intensified, the cornea becomes steamy, like glass that has been breathed upon, the pupil dilated, and the increased tension of the globe becomes more pronounced, finally causing it to reach a stony hardness, and the pupil becomes partly or fully dilated. The acute form is characterized by intolerable pain in the eyeball and by pronounced increase of tension. There is conjunctivitis, the cornea is anæsthetic and steamy, the aqueous is turbid, the iris is discolored, and the pupil is dilated. An attack may end in blindness. There are frequent recurrences and in cases of glaucoma not subjected to operation blindness is the final result. Treatment. Early recognition and treatment are of great importance. Mild cases sometimes yield to warm local applications and to the instillation of solutions of eserine, gr. j to 3j (1: 500) or of pilocarpine in the strength of per cent. Severe cases require an immediate operation (iridectomy). DISEASES OF THE RETINA Affections of the retina usually form a symptom of constitutional diseases, and according to their cause they are divided into albuminuric, hæmorrhagic, and syphilitic retinitis. In albuminuric retinitis whitish patches appear in the retina in the vicinity of the fovea centralis. In hæmorrhagic retinitis, which usually occurs in old people and almost always accompanies chronic interstitial nephritis, the arterial walls become much thickened and, as the disease progresses, permit of the escape of blood. Syphilitic retinitis is characterized by excessive exudations and more or less profuse hæmorrhages in the retina. In all forms of retinitis there is marked disturbance of vision and in severe cases even complete blindness. Treatment.-Removal of the cause. DETACHMENT OF THE RETINA Detachment of the retina is due to an effusion of a serous liquid from the chorioid between it and the retina, and may be caused by a diseased vitreous, or chorioid, high myopia, a blow on the eye, etc. The subjective symptoms depend upon the degree and the amount of the detachment. The prognosis is highly unfavorable. DISEASES OF THE OPTIC NERVE Optic neuritis is generally caused by diseases of the brain or the meninges, syphilis, or lead poisoning. It manifests itself by haziness and swelling of the optic disc, gradual enlargement of the veins, and diminution in the size of the arteries. Hæmorrhages may appear both upon and around the disc. The extreme condition of optic neuritis is called "choked disc." Optic atrophy is characterized by paleness of the disc, which becomes more white as the disease progresses. There is gradual loss of vision, which progresses by concentric limitation of the field. Optic atrophy is EYESIGHT AND EYE STRAIN 821 caused by the same ætiological factors which are operative in the production of optic neuritis and also by diseased processes of the retina, by embolism of the arteria centralis retinæ, or by tabes dorsalis. TREATMENT.-Removal of the cause whenever possible. Attention to the general condition of the patient. Strychnine internally; this remedy is especially valuable in diseases of the optic nerve due to poisoning by alcohol, tobacco, etc. CATARACT AND OPACITIES Cataract is an opacity of the crystalline lens. Opacities occurring in the lens usually have a whitish appearance when examined by direct or oblique illumination. Certain forms of nuclear cataract give an amber tint, and in the exceptional cases of black cataract the color is deep brown. In lamellar cataract examination discloses a circular line of opacity which is most dense at its periphery. At first the patient usually experiences disturbance of vision in the form of dark lines or branching opacities, which are projected into space. The causes of cataract are old age, traumatism, exposure, privation, etc., i. e., interference with the nutrition of the lens. It not infrequently accompanies diabetes mellitus. The TREATMENT is surgical. SQUINT, STRABISMUS Strabismus (squint) is concomitant and paralytic. In order to ascertain the existence of strabismus, the patient is caused to fix the eyes on an object, and then they are alternately covered and uncovered. In order to distinguish concomitant from paralytic strabismus, the eyes are made to follow the movements of an object in various directions; in concomitant strabismus both eyes will move to the same extent and their movements will not be restricted in any direction; in paralytic strabismus the movement of the affected eye will be restricted in the direction of the action of the paralyzed muscle. TREATMENT.-In concomitant strabismus errors of refraction should be corrected, and if the affection persists after the tenth year of age, tenotomy should be performed. In paralytic strabismus attention should be directed to the cause, such as syphilis and diphtheria. About 25 per cent of cases of strabismus may be overcome by non-operative treatment. EYESIGHT AND EYE STRAIN Emmetropia is the normal condition of the refracting media of the eye, in which the anteroposterior diameter is of the right length so that the rays of light from distant objects come to a focus upon the retina. Eye Strain. The symptoms of eye strain are multiple, and their origin in the eyes is often overlooked. The eyeballs ache. There is supraorbital pain or a pressure back of the eyes; letters on the page run together if one persists in using the eyes, and black spots dance about in the field of vision. Hypermetropia (far-sightedness) is a condition in which the anteroposterior diameter is too short; the parallel rays come to a focus behind the retina. Myopia (near-sightedness) is that form of error of refraction in which the anteroposterior diameter is elongated; parallel rays are thus brought to a focus in front of the retina. This condition may be congenital or acquired. Astigmatism is a condition of the refraction of the eye in which rays of light passing through one of the principal meridians are refracted differently from those passing through the other meridians. It is produced by a difference in the curve of different parts of the cornea or, sometimes, of the crystalline lens. Presbyopia is the natural change in the eyesight, viz.: the diminution of the power of accommodation, accompanying advancing years. TREATMENT.-Correction of refraction. Hypermetropia is corrected by means of a convex (x) lens; myopia by the use of a concave (-) or dispersing lens; astigmatism by the use of cylindrical glasses so adjusted as to correct the difference between the refraction of the principal meridians in addition to correction of other errors of refraction if present. CHAPTER XXXI ANESTHESIA, INTOXICATIONS, MISCELLANEOUS AILMENTS, KEEPING CASE RECORDS AND ACCOUNTS SYNOPSIS: Remarks on General and Local Anæsthesia.-List of Poisons and Antidotes.Gas Poisoning.-Ptomaine Poisoning.-Grain Poisoning.-Poisoning by Pigments and Preservatives. Snake Bites.-Insect Bites.-Drug Habits and Alcoholism.-Seasickness and Mountain Sickness.-Hydrophobia.-Traumatic Tetanus.-Case Records and Accounts. ANESTHESIA REMARKS ON LOCAL AND GENERAL ANESTHESIA General Anæsthesia THIS is employed to relieve pain in surgical and obstetrical manipulations. It is employed in severe eclampsia, in setting fractured and dislocated bones, in making important x ray exposures, in the case of children who would not be apt to hold still, and for facilitating painful examinations for diagnostic purposes. The risk of artificial sleep must be assumed by the person who is to be benefited, with the understanding that the anesthetizer shall be qualified by actual practical experience and shall use all rational precautions and safeguards. When anesthesia is induced for diagnostic purposes, the patient has a right to expect that the information thus elicited shall be final. Chloroform is about ten times as dangerous as ether, but is to be preferred in the presence of renal insufficiency and in obstetrical practice. It is contraindicated in myocardial weakness and in very prolonged operations, but is again indicated in cases in which complete relaxation cannot be obtained from ether. It is administered by dropping it upon a mask or napkin from a drop bottle. Chloroform is not inflammable. When chloroform kills, the patient dies quickly. Chloroform anæsthesia can be made more safe by combining oxygen and chloroform by means of a special inhaler. Ether is the safer anæsthetic in unskilled hands, but it may cause death some time after its administration, yet it is to be preferred as a rule in the presence of cardiac insufficiency. Its administration is accomplished by means of a cone made out of paper and a towel. Ether is highly inflammable. Nitrous oxide and ethyl bromide are used for anæsthesia of short duration. The latter is administered by means of a napkin or chloroform mask. |