Complete Text (Part 8)

terminal filaments of which, however, pass forward into the ciliary body, iris, and cornea. 62 THE EYE. What is the function of the tunica vasculosa ? It serves to form a dark chamber of the interior of the eye and to regulate the amount of light that enters that chamber. By its vascular supply it furnishes nutrition to the outer layers of the retina, to the vitreous, crystalline lens, and to the cornea. What are the general symptoms of iritis ? The mobility of the iris is always impaired. When light is reflected into the eye or a mydriatic instilled, the dilatation produced occurs slowly if posterior synechige have not formed. If they have formed, the dila- tation is also slow and the pupil assumes an irregular shape. The color of the iris is always changed from the normal, is darker, and presents a blurred or muddy appearance. The vision is more or less impaired accord- ing to the amount of exudation in the anterior chamber. There is marked injection of the pericorneal blood-vessels, and a ros}7 zone encircles the cornea, which usually presents a dark -red appearance. Pain is usually severe in acute cases, being most noticeable to the patient at night. The pain is referred to the temple or forehead, and is of a dull, constant character. What are the forms of iritis ? They may be divided, according to appearance, into .serous, spongy, and plastic ; according to cause, into rheumatic, syphilitic, traumatic, suppurative, and tubercular. Simple hyperemia of the iris sometimes occurs as an accompaniment of rheumatism or gout, without passing into the true inflammatory condition. What is serous iritis? This form of iritis has been termed descemetitis by older writers, but in fact has nothing to do with inflammations of Descemet's membrane. It consists in the throwing out of an exudation from the iris which has been termed serous. Deposits of a fibrinous nature also take place on the posterior surface of the cornea, forming in dots usually ranged in the shape of a pyramid, with the base at the lower part of the cornea, the apex reaching to the centre of the cornea. The aqueous is turbid, and vision impaired in proportion. Adhesion of the margin of the pupil to the anterior capsule of the lens occurs, and is sometimes very persistent. The pain accompanying this form of iritis may be comparatively mild or very severe. What are the causes of serous iritis ? Serous iritis may occur as a rheumatic or as a syphilitic iritis. The name has reference purely to the form of exudation observed. What is spongy iritis? This form of iritis also derives its name from the nature of the exuda- tion. The exudation from the iris into the anterior chamber consists of the plasma of the blood, which coagulates when it comes in contact with the THE IEIS, CILIARY BODY, AND CHOROID. 63 aqueous, and fills the whole anterior chamber with a spongy mass. The tendency to the formation of deposits on the posterior surface of the cornea and to permanent adhesions between iris and lens is not great. Pain accompanying this condition is usually pronounced, and the peri- corneal and conjunctival congestion is also very pronounced^ For the first few days the exudation remains unchanged. On cessation of the production of the exudation, that which occupies the anterior chamber begins to shrink and the shrinkage progresses. The mass gradually diminishes and disappears. What is plastic iritis? This form of iritis derives its name from the tendency which it pos- sesses to produce adhesions between iris and lens and of forming an oc- clusion of the pupil. The aqueous becomes cloudy, and vision is usually greatly impaired during the progress of the disease. The symptoms may at times be very severe. What are the causes of plastic iritis ? It may be from syphilis, rheumatism, traumatism, or from sympathy. What is rheumatic iritis ? It is any form of iritis which has rheumatism or gout as its cause. Rheumatism may produce serous, plastic, or spongy iritis according to the peculiarity of the individual. A form of rheumatic iritis not infre- quently met with is of the plastic variety ,_ progresses slowly, and is accom- panied with very little pain or local disturbance. Rheumatic iritis is very prone to relapses, and the so-called recurrent iritis is often of the rheumatic type. What is syphilitic iritis? Syphilitic iritis is any form of iritis which has syphilis as its cause. It may appear in the serous, spongy, or gummous form. It is sometimes difficult to determine the cause of iritis, particularly if of the syphilitic variety, and it becomes necessary, in the absence of the history of syphilis, accompanied by the absence of a history of gout or rheumatism, to deter- mine the diagnosis by the employment of antisyphilitic remedies. One form of syphilitic iritis is pathognomonic. This is the so-called gum- mous iritis. It consists in the formation of gummata in the substance of the iris. These are at first small, and appear in the inner zone of the iris about the margin of the pupil. At times the disease is not multiple, but one gumma appearing. This may attain to a large size and extend over the whole width of the iris. These small gummata which form in the inner zone are usually of a dusky-red color. They are slightly elevated. If the gumma attains to a large size, it becomes somewhat pale at its apex. There is but one form of iritis that might be confounded with the gummous form occurring in syphilis, and that is the tuberculous iritis. This form of iritis, however, is subacute. The elevations do not first appear at the margin of the pupil, are not so red, and are not accom- 64 THE EYE. panied with such marked congestion of the iris. In the syphilitic form the perivascular # injection is very pronounced. In the tuberculous but slight. Syphilitic iritis is usually accompanied with very great pain. What is suppurative iritis? A form of iritis in which the production of pus takes place. It is usually accompanied with suppuration of the whole uveal tract unless it is the result of traumatism, when only the iris and ciliary body need necessarily take part. Low conditions of the system predispose to this form of iritis. It is a very uncommon disease. What is recurrent iritis ? Recurrent iritis may be syphilitic or rheumatic. As its name implies, it affects the individual repeatedly. Unfavorable conditions of the system produce a recurrence. What is the treatment of iritis ? It is very necessary to prevent and to break up adhesions between the free margin of the iris and the anterior capsule of the lens. For this purpose mydriatics are employed, the one most commonly used being atropine. In certain cases this mydriatic produces a marked in- flammation of lids and conjunctiva, and will not be tolerated by the patient. In these cases it is found that duboisine will often be borne without the disagreeable results produced by solutions of atropine. Warm fomentations to the eye will also aid in promoting the action of the mydriatic in causing dilatation of the pupil. The use of atropine is frequently sufficient to allay the pain which is present. If this does not suffice, leeches should be applied to the temple in the form of the natural or artificial leech. Blisters may be used, but are not very efficient. Leeches are applied in the following manner : The skin on the temple immediately back of the angle of the eye is the place best suited for their application. The surface is cleansed with soap and water, and lastly with clean water, and the leech, contained in an ordi- nary leech-glass, is permitted to become attached to the skin. It is best to employ five or six, and to confine their operations to a space on the temple that could be covered with a silver quarter of a dollar. The leeches are permitted to remain until they have filled themselves and drop off. The surface should then be washed with an antiseptic solution and a warm, moist bandage applied to encourage the bleeding. Four to six ounces of blood should be removed. After leeching the patient usually experiences great comfort and enjoys a refreshing sleep. Photo- phobia usually exists, and the patient should be kept in a darkened room and should wear a shade or dark-blue glasses to protect the eye from the light. Frequent bathing in hot water will be found to give relief and to favor the absorption of the exudation from the anterior of the eye. What are the results of iritis ? The most frequent result is the formation of permanent bands of ad- THE IRIS, CILIARY BODY, AND CHOROID. 65 hesion between the iris and the anterior capsule of the crystalline lens. These are called posterior synechice. They may be partial or complete. When partial, the injury to the eye is comparatively slight. When com- plete, the condition is usually associated with the presence of an exuda- tion which occludes the pupillary space.^ In a short time the secretions from the posterior chamber cause the iris to bulge forward ; the pupil is sunken, producing a condition known as crater pupil This bulging for- ward of the iris indicates retention of the fluids secreted in the eye, the globe becomes hard, and a condition of glaucoma ensues. What is the treatment of this complication in iritis ? The treatment is principally operative, and is employed in those cases where total posterior synechia or occlusion of the pupil exists. It con- sists in removing a portion of the iris. In recurrent iritis it is sometimes advisable to perform iridectomy, which, in connection with internal medication, not infrequently suffices to cure the patient. What is cyclitis? It is an inflammation of the ciliary body, and may occur as a serous or as a suppurative inflammation. In cyclitis there is deep pericorneal in- jection, with pain referable to the temple and side of the head. On palpating the eye through the lids the patient experiences a tenderness of the parts. In serous cyclitis the anterior portion of the vitreous, as well as the aqueous, becomes hazy and the fundus is obscured. Suppu- rative cyclitis is usually associated with suppurative choroiditis and iritis. What is plastic cyclitis? This is a form of cyclitis by which an exudation of plastic lymph is thrown out, which usually forms a layer in the anterior portion of the vitreous behind the lens. This exudation becomes organized and takes on the form of cicatricial connective tissue. In certain cases this mem- brane forms a firm partition between the lens and the posterior parts of the eye. Examination with the oblique method discloses a grayish mass back of the lens, situated at its periphery when the membrane is not complete. This form of iritis is usually extremely slow in its progress and frequently compromises vision to an alarming extent. What are the causes of cyclitis ? Rheumatism and syphilis play a prominent role, but traumatism isby far the most frequent cause of its production. The entrance of a foreign body into the eye or a lacerated or punctured wound, carrying minute germs of infection, suffices to produce the disease. What is the treatment of cyclitis ? Removal of the cause if possible. If this cannot be done, atropine, hot applications, with internal medication directed to any systemic pre- disposing cause, should be employed. 5— Eye 66 THE EYE. What is the appearance of the normal choroid ? In the living subject the choroid must be studied by use of the oph- thalmoscope. When examined in this way the fundus of the eye pre- sents a reddish reflex when light is thrown upon it. This reddish reflex is produced by the reflection of light from the choriocapillaris of the choroid, the pigment-layer of the retina, and the pigment-cells distrib- uted throughout the choroid. The reddish background is complete throughout the fundus of the globe, except at the point of the entrance of the optic nerve, where there is a pale pink circular disk from which the nerve-fibres pass and are distributed on the surface of the retina, and the blood-vessels of the retina emerge, divide, and pass to the vari- ous parts of the retina. The fundus usually presents a mottled appear- Fig. 10. Ophthalmoscopic Appearance of Healthy Fundus in a Person of very Fair Complexion. Scleral ring well marked. Left eye, inverted image (Wecker and Jaeger). ance, which is more marked in the brunette than in the blonde. This mottled appearance is due to the presence of pigment in the spaces be- tween choroidal vessels. In the blonde the large vessels of the lamina suprachoroidae are visible, and the fundus is of a pale-pink hue. In the brunette the color is deeper, and in the negro it becomes very dark and in some cases is of a slate color. In the albino the blood-vessels of the choroid can be distinctly seen, and the shining through of the white sclerotic gives the fundus a very light pink tone. The blood-vessels of the retina course over all parts of the fundus, except at a point near the posterior pole of the globe known as the macula lutea, where the surface 67 is free from blood-vessels and the fundus presents an even tone. The fundus of the_ eye appears lighter in proportion to the light that is re- flected on to it. Consequently, examinations made when the pupil is small or illumination weak give a darker background than is the case in the same eye when the pupil is large or the illumination intense. What forms of inflammation is the choroid subject to ? Serous, plastic, purulent, tubercular, and syphilitic. What is serous choroiditis? This form of choroiditis is characterized by a diffuse haziness of the vitreous, which contains minute floating opacities. It is usually accom- panied with slight episcleral congestion and with slight pain. On look- ing into the eye the fundus is obscured and minute floating bodies may be discerned. Increase of the tension of the eye is sometimes notice- able. What is plastic choroiditis? It consists in an inflammatory process which occasions the throwing out of an exudation which unites the choroid and retina, and eventuates in the destruction more or less of the outer layers of the retina. What are the causes of serous and plastic choroiditis ? In many cases it is difficult to determine, but that syphilis plays a role in a very large number of cases is not to be doubted. Rheumatism and gout are the causes in some cases. What is the treatment of plastic choroiditis ? Nothing can be done to prevent changes that must necessarily take place in the percipient layer of the retina from its participation in the plastic process. The internal administration of the iodide of potash and of mercury in syphilitic cases will often produce very excellent results and will stop the progress of the disease. Where syphilis is not the causative agent tonic remedies and measures to improve the general con- dition of the patient are advisable. What is disseminated choroiditis? It is one form of plastic choroiditis, and it is distinguished by the gen- eral character and distribution of the atrophic patches produced by plastic choroiditis. These are distributed throughout the fundus, and are usually irrregular in size, some of the patches being very small and some very large. They are also irregular in shape. The atrophic patches are the result of the exudation which is thrown out in plastic choroiditis. These spots of exudation appear first as pale, ill-defined, irregular patches. The exudation gradually absorbs, carrying with it the pigment laj^er of the retina and of the choroid, causing a heaping up of pigment at the margins of the patch and permitting the white sclerotic to show through. 68 THE EYE. What is chorioretinitis centralis ? This is a form of plastic choroiditis which attacks only the posterior pole of the globe, producing its greatest ravages in the vicinity of the macula lutea, the area of most distinct vision. It may produce great impairment of vision. What is choroiditis syphilitica ? A form of plastic choroiditis characterized by a peculiar formation of the patches. These are circular in shape, usually small, and more or less widely distributed throughout the entire fundus. This form of choroiditis has also been termed choroiditis guttata, because of the drop- like appearance of the patches. What is suppurative choroiditis? As the name implies, it consists in the suppurative process taking place in the choroid. It is usually the result of traumatism or of meta- stasis from similar processes taking place in the membranes of the brain, in the genital tract, or in other parts of the system. Suppurative cho- roiditis is in the greater number of cases associated with suppurative cyclitis and iritis. The entrance of foreign bodies into the eye, infectious wounds, and suppurative processes affecting the cornea not infrequently produce suppurative choroiditis. What are the symptoms of suppurative choroiditis ? Occurring as the result of traumatism, it is usually rapid in its progress ; the ocular conjunctiva becomes much congested and oedematous, pro- ducing a raised border about the cornea — the condition known as chemosis. A reflected light into the eye gives back a yellowish reflex. The pain is intense until the eye has opened and the pus permitted to escape. Suppurative choroiditis of the above type is termed panoph- thalmitis. Occurring in children and in adults as a result of metastasis, it first produces redness and swelling of the ocular conjunctiva ; the globe becomes slightly harder than the normal and apparently slightly enlarged. The tension is somewhat increased. Some pain is experienced by the patient, but usually this is not intense. If the globe does not rupture, the inflammatory reaction gradually subsides, the globe becomes