SYMPTOMS.-The subjective symptoms of this disease are not at all prominent or characteristic. They will simply complain that their eyes feel a little weak and that the vision does not seem quite as clear as formerly. Very frequently we find, upon ophthalmoscopic examination, extensive choroidal changes with little or no loss of the visual acuity. Randolph Archiv. Ophthal., vol. xviii., 4, 1889. reports two cases of very pronounced disseminate choroiditis with preservation of normal acuteness of vision. Often there is some night-blindness in those cases of marked choroidal changes, even when the vision is good. Slight scotomata are frequently complained of, especially in the later stages, and upon testing the field of vision we are apt to find it somewhat contracted. All the subjective symptoms are apt to be more marked during the stage of exudation than in the atrophic stages of the disease. The extent of the visual disturbances and the other symptoms depend, in a great measure, upon the location of the disease-if near the periphery, the effect is of course much less than when occurring at or near the macula. As the disease advances toward the macula the patient may complain that objects looked at appear distorted (metamorphopsia). This is due to the exudation causing a change in the relative position of the percipient elements of the retina. Again, all objects may appear diminished in size (micropsia) or unnaturally enlarged (macropsia). In micropsia there is, owing to a fresh exudation, a separation of the retinal elements at the point of such an exudation, and the image of any object falling on such a point affects a smaller number of retinal elements than normal and the object appears smaller. In macropsia, on the other hand, there is a greater approximation of the retinal elements, due to the contraction of an old exudation or some other atrophic change, and objects appear enlarged. Hyperaemia of the disc and haziness of the vitreous may sometimes be present when the disease has reached the neighborhood of the optic disc; or, on the other hand, if the disease extends far forward, it may result in some affection of the ciliary body or iris.
The most characteristic indications of choroiditis are, however, only to be determined by an ophthalmoscopic examination. In the early stages, if occurring in dark persons, it is difficult or impossible, owing to the greater amount of normal pigment, to recognize the first changes. If, however, the patient is a blonde, there is first seen a slight injection of the choroid in spots. Following this, in the stage of exudation, there may be seen numerous yellowish red nodules, of a more or less circular shape, varying in size, scattered about through the equator of the eye. When the disease is acute, there may be slight haziness of the retina around the optic nerve, and possibly slight haziness of the vitreous. After a longer or shorter period the color of these plaques of exudation changes to a yellow and later to a white, or a bluish-white appearance, and, owing to the pigment proliferation around their borders, become surrounded by black masses of pigment. (See Chromo-Lithograph, Plate 11 Fig.4). The stage of the disease is determined by the appearances of these patches, which are in the atrophic stages, white in color-due to the showing through of the sclera and to the cicatricial tissue itself, they have irregular margins, more or less surrounded by pigment, and choroidal vessels may be seen here and there passing through the white spot. In the stage of exudation the choroidal vessels are entirely hidden and the color of the patches are of a yellowish red, with no pigment. In atrophy there is a depression or sinking of the patch, while in exudation there is an elevation. Frequently there may be even in the same eye all stages of the disease.
Choroiditis Areolaris.-This is only a variety of the disseminate form just described, in which the nodules have more of an areolar structure and with great proliferation of the pigment over the nodule. The patches in areolar choroiditis are usually larger of a round or oval shape, and their location is especially around the optic nerve and the macula. the recent patches appear as very dark masses of pigment. As they grow older they gradually lose their dark color and finally appear white, surrounded by a black ring. In this form the pigment spots and exudation bear a certain relation to each other; the pigment spots are first noticed, and, as it progresses, the centre of the patch becomes lighter, of a yellowish white appearance, and gradually goes on to a clear white spot surrounded by pigment. The choroid between the patches remains perfectly healthy, and, although the location of the disease is all around the macula, it is usually last affected; but; when it is involved, it often becomes affected suddenly. this form is especially found in young persons and will exist for a long time with good vision-the macula rarely being involved before middle life.
Choroiditis Circumscripta, or Choroido-retinitis Centralis, is simply another form of disseminate choroiditis occurring in and near the macula. There is in this usually the development of a single nodule, but very rarely there may be two or three, consisting of a connective tissue frame-work, with cells and agglomerations of pigment. It arises in the choroid, but extends into the layers of the retina, which are raised at the point of the nodule, but are perfectly normal and healthy around it, thus proving the affection of the retina to be due merely to pressure and not to inflammation of its own tissue. It goes on to atrophy with shrinking of the cicatrix, which draws the retina back along with it.
(Fig.75 )
The disease is always uniform in that scattered nodules are never found, and, while there may be more than one nodule, they are always closely arranged around the macula. An ophthalmoscopic examination shows at first a reddish yellow, or later a bright yellow, round or oval spot at the macula. It is in the earlier stages elevated, well defined and may be vascular, while in the later stages it becomes whiter as it goes over into atrophy and then a depression occurs. This form of choroiditis affects vision by causing a very pronounced scotoma, which is persistent and especially annoying in the earlier stages; metamorphopsia is also usually complained of.
Choroiditis Syphilitica, or Choroido-retinitis Syphilitica, is still another form of plastic choroiditis, the pathological changes in which are the same in the late stages as already described under choroiditis disseminata and choroiditis circumscripta (Fig.75). In the first stage the disease attacks the epithelial layers, the retina and the vitreous. This form of choroidal affection, if not invariably, is, in a large majority of cases, a manifestation of syphilis, and generally appears in the late secondary or early tertiary stage of syphilis. It seems to be most apt to occur in cases where syphilis has been acquired late in life, is most frequently found affecting both eyes and is sometimes preceded by an attack of iritis.
SYMPTOMS.-The characteristic symptoms of this affection are the fine, dust like opacities of the vitreous, seen upon an examination by the direct method, with a weak illumination (after causing the eye to move rapidly upward and downward), to rise like dust before the wind. The opacities in some cases may form flakes or filaments, f which, however, are seen to float up and down in a medium full of the characteristic dust. In certain cases these coarser opacities may increase greatly in size, but the peculiar dust but appearance is always present and remains throughout the whole course of the disease. Another peculiarity of this dust-like haziness of the vitreous is that is varies considerably in amount from time to time during the course of the affection, and, owing to this, the vision will improve or diminish often within a few hours. When the vitreous dust is not sufficiently dense to obscure a view of the fundus, we will often see a hyperaemic condition of the disc, an indistinctness of its outlines and a slight haziness of the retina.
Hemeralopia, or night-blindness, is almost universally present among patient suffering from double specific choroiditis and in all cases where but one eye is affected, the size of objects seen with the diseased eye, when compared with the healthy, appear small (micropsia). Another characteristic sign is the subjective perception of luminosities (phosphenes), generally seen as sparkling scotoma and are always seen upon entering a bright light. The vision is always very much reduced in this form of choroiditis.
COURSE.-This form of choroiditis may run an acute course, recovering with nearly perfect vision and leaving no trace behind. More frequently, however, there remains some impairment of vision due to the persistence of vitreous opacities, which may be very dense, or to the changes in the choroid, similar to those in the disseminate form, which may develop gradually in the later stages of the disease.
Professor of Ophthalmology in the College of the New York Ophthalmic Hospital; Surgeon to the New York Ophthalmic Hospital. Visiting Oculist to the Laura Franklin Free Hospital for Children; Ex-President American Homoeopathic Ophthalmological, Otological and Laryngological Society. First Vice-President American Institute of Homoeopathy : President Homoeopathic Medical Society of the State of New York ; Editor Homoeopathic Eye. Ear and Throat Journal : Associate Editor. Department of Ophthalmology, North American Journal of Homoeopathy, etc.