Retinitis

RETINITIS (retinitis), inflammation of the retinal layer. Under the name R. are described various lesions of the retina, of which far from all are in reality inflammatory conditions. The first researchers of the fundus of the eye were inclined to consider most of the pathological changes they discovered ophthalmoscopically in the retina as manifestations of inflammation and accordingly described a number of pathological pictures under the name of various kinds of R. Subsequently, pathological-anatomical research either rejected or significantly shook the inflammatory nature of many of these diseases, but the originally introduced names, such as retinitis proliferans, retinitis pigmentosa, have taken strong root and are firmly held in medical nomenclature. Etiology and classification. Inflammation of the retinal layer can of course arise exogenously as a result of the introduction of infection through penetrating injuries to the eye, but in these cases the retinal layer is not affected in isolation, and changes in it recede to the background before the accompanying inflammatory phenomena in other layers of the eye. Lesions of the retina that are customarily called R. all have an endogenous origin, but their etiology is extremely diverse. Some R. develop by the metastatic route depending on the general infection of the body (syphilis, tbc, sepsis, etc.). Such kinds of R., caused by the penetration into the retina of pathogenic microbes or their toxins carried by the bloodstream, show clearly expressed inflammatory changes and from a pathological-anatomical point of view fully deserve the name inflammation of the retinal layer. A number of other R. are observed with various general ailments associated with changes in the conditions of blood circulation, metabolism, and blood composition (nephritis, diabetes, leukemia, etc.). The pathogenesis of these retinal lesions is not fully clarified. The pathological-anatomical process can only be considered inflammatory insofar as it is accompanied by hyperemia (predominantly however venous), exudation, edema, and subsequently proliferation of glia, but in general the changes found in the retina have a more degenerative than inflammatory character. Finally there are R. developing on a hereditary basis and from a pathological-anatomical point of view incorrectly classified as R., since they show exclusively phenomena of degeneration, not inflammation. Certain forms of R. are also described, the etiology of which remains unknown for now; with all probability they are also connected with general ailments of the body. The etiological sign is usually taken as the basis for the clinical classification of R., which according to the foregoing presentation appears in the following form. A. Retinitis on the basis of infectious diseases: 1) syphilitic, 2) tuberculous, 3) septic. B. Retinitis on the basis of other general ailments of the body: 1) albuminuric, 2) diabetic, 3) leukemic and others. C. Retinitis of unclear etiology: 1) exudative R. (Coats), 2) retinitis circinata. D. Retinitis on a hereditary basis: typical pigmentary R. and its varieties, which in essence belong to degenerations of the retina. Pathological anatomy. Corresponding to the heterogeneity of the pathological process in various forms of R., the anatomical changes have a different character and only brief general remarks can be made about them. First of all, it is important that the retina by its origin is an outlying part of the brain pushed to the periphery. Pathological changes in it in many respects resemble changes found in various lesions of the gray matter of the brain. True inflammatory infiltration is encountered only in R. of infectious origin; in other forms of R. phenomena of edema, fibrinous exudate between nerve cells and fibers, and various pictures of the death of the latter predominate. The participation of glia and the pigmentary epithelium in the pathological process is very characteristic. Their elements partly show destructive changes—disintegration, disappearance of pigment grains; but for the most part their reaction to pathological processes is expressed in the manifestation of phagocytic function and in proliferation, which serves to replace the dead nerve tissue. For an understanding of the pathological-anatomical changes in R., it is also important to keep in mind that the elements of the retina belong to 3 neurons located in three stories one above the other (see Retina). R. of various characters originate in one of the neurons or predominantly affect it. Recently Fuchs made an attempt to build a classification of R. on the basis of the localization of the process in one or another neuron. He divides the diseases of the retina into diseases of the 1st, 2nd, and 3rd neuron and in each of these groups distinguishes congenital and acquired diseases. Symptomatology. Objective signs of R. are discovered exclusively when examining the fundus of the eye with the help of an ophthalmoscope; in diagnosing the initial degree of changes, ophthalmoscopy in red-free light renders great service. In R. first of all the normal transparency of the retina is disturbed to varying degrees. In some cases the resulting cloudiness of the retina has a diffuse character, and the red reflex from the vascular membrane over a considerable space is weakened. If the cloudiness of the retina occupies the circumference of the optic nerve head, then the boundaries of the latter become indistinct. The choroidal and scleral rings around the head, usually visible through the retina, become unnoticeable. In other forms of R. the cloudiness of the retina has not a diffuse but a limited character, appearing in the ophthalmoscopic picture in the form of various kinds of spots, also called nests or foci. The shape and size of these foci are extremely varied, just as the location of the foci in the retina varies greatly: in some cases they are located mainly along the periphery of the fundus, in others they concentrate at the posterior pole of the eye, in the area of the yellow spot and around the optic nerve head. In some diseases of the retina, foci of cloudiness are located in a more or less definite order, forming typical characteristic figures. In structure the spots of the retina are of several kinds. They include first of all the so-called white spots, which represent foci of degeneration predominantly of the inner layers of the retina. No less often than white spots, dark red hemorrhages are encountered in the retina, having somewhat different appearance depending on their position in one or another layer of the retinal membrane. In the layer of nerve fibers they consist of thin strips with a direction radial to the optic nerve head; in the outer layers of the retina they are solid, of small size, and of round shape. In addition, in the later stages of R. brownish-black pigment spots often appear in the retinal membrane, located sometimes in the area of the yellow spot but more often along the periphery of the fundus. In the ophthalmoscopic picture of R. the different relationship of white and pigmentary foci to the blood vessels deserves attention. Since the larger, visible with the help of an ophthalmoscope vessels lie anatomically only in the anterior layers of the retina (not deeper than the inner plexiform layer), depending on whether the vessel passes under the focus or is covered by it, one can judge the location of the focus in the anterior or posterior layers. In addition to changes in the retina itself, deviations from the norm are often noticeable in the fundus of the eye in R. also on the part of the optic nerve head. It has already been pointed out above that its boundaries are obscured with diffuse cloudiness of the retina. In the late stages of R. as a result of the destruction of nerve cells, ascending degeneration of the fibers of the optic nerve occurs, ophthalmoscopically discovered by the characteristic picture of retinal atrophy of it. From other parts of the eye in some forms of R. the vitreous body undergoes change, in which cloudiness appears as a result of inflammatory exudate or hemorrhage from the vessels of the retina. Subjective disorders in R. come down to a decrease in vision to one degree or another. The latter is determined mainly by the localization of the process in the retinal membrane: changes in the area of the yellow spot entail a decrease in central visual acuity, usually very significant, while peripheral vision does not suffer from this; conversely, with lesions of the peripheral parts of the retina, the field of vision is greatly limited, while central vision can be preserved in full measure. Of the individual forms of R. only the pigmentary one is accompanied by a typical disturbance of vision (ring scotoma and concentric narrowing of the field of vision); in other forms the decrease in vision does not show any characteristic features. Complete blindness in R. is encountered extremely rarely and only in very late stages of the disease. The development of complete blindness in the early stage of R. either indicates a complication in the eye (detachment of the retina) or is explained by cerebral causes (uremic amaurosis). Individual forms of retinitis. A. Inflammations of the retina of infectious origin. Syphilitic R. The picture of the disease varies depending on whether it is caused by acquired or congenital syphilis.

Since spirochetes are carried to the eye by blood through the a. ophthalmica, and from there they can just as easily enter both the central artery of the retina and the posterior ciliary arteries, inflammatory changes often form simultaneously in both the retina and the choroid, and usually the disease is described as syphilitic chorioretinitis. Predominant involvement of the retina, especially at the beginning of the disease, apparently occurs in R. on the basis of acquired syphilis; here R. manifests in a diffuse form, first described in detail by Forster. The disease develops in the secondary period of syphilis and is initially characterized by diffuse whitish clouding of the retina in the posterior pole of the eye, especially around the optic nerve head. The latter in turn shows signs of hyperemia and edema. The intensity of retinal clouding gradually weakens toward the periphery of the fundus. In the very first stage of the disease, abundant fine dust-like opacities appear in the vitreous body; they are not very easily detected by the ophthalmoscope and are not extremely characteristic of syphilitic R. Subjective disturbances are expressed in a decrease in central vision to */z-^lli of normal, often even lower, in defects of the visual field, often of a ring-like nature, and in a significant weakening of light sensation, accompanied by impaired adaptation. Patho-anatomical changes in the initial period of the disease are little clarified. In the belief that the layers of ganglion cells and nerve fibers are most severely affected, Heine calls this disease R. of the inner layers. The disease more often develops in both eyes. The course in general is prolonged; the opacities of the retina and vitreous body, having reached a certain maximum, then begin to decrease, rarely disappearing completely. With the passage of time, pigmentary and atrophic foci are found in the fundus, indicating* the involvement of the posterior layers of the retina, possibly also the choroid. Visual impairment, especially under the influence of treatment, can improve significantly, but the disease has a great tendency to relapse and to complications, and for this reason the fate of such eyes b. ch. develops unfavorably. Changes in the fundus on the basis of congenital syphilis are usually described under the name of chorioretinitis, since both clinically and anatomically here lesions of both the middle and inner coats of the eye are confirmed. It has not yet been definitely established to what point the beginning of the disease refers. It is possible that the inflammatory process develops already in the fetal period. Sidler-Huguenin noted atrophic changes in infants at 4 weeks, 6 and 9 months of age. Schieck considers it more probable that the disease always begins after birth, based on the fact that in newborns corresponding changes in the fundus have not yet been found by anyone. Thus, in Igersheimer's observation in a child at 6 months of age, the fundus with artificially dilated pupil was found to be normal, the first signs of the disease were detected at 15 months in the form of densely arranged whitish spots on the periphery of the fundus, and by 2 years not only on the periphery but also near the optic nerve there were numerous foci containing pigment. The ophthalmoscopic changes found in congenital syphilis consist mainly of foci of yellow or yellowish-white color with clusters of pigment of various sizes between them. Depending on the size of individual nests, their location and the degree of pigment abundance, the ophthalmoscopic picture can vary considerably. According to Sidler-Huguenin, this variety of pictures can be reduced to 4 basic types. Type I is characterized by small reddish-yellow spots along with the smallest barely visible brownish grains of pigment ('Pfeffer und Salz' Retinitis—pepper and salt fundus). In pronounced cases, the changes are scattered throughout the fundus, reaching the optic nerve. The latter appears whitish, the retinal vessels are narrowed. In the peripheral parts of the retina, the reddish-yellow spots are somewhat larger in size, but white nests are not visible. Vision is not impaired only in mild cases, in more pronounced cases visual acuity and light sensation are weakened, the boundaries of the visual field are narrowed. Type II is characterized by large pigment spots located mainly on the periphery, between which white atrophic nests are barely visible. In type III, on the contrary, large white foci predominate with less numerous pigment accumulations between them and with localization mainly on the periphery. Finally, the changes in type IV extremely resemble the picture of pigmentary degeneration of the retina (retinitis pigmentosa). In type II and III, the optic nerve usually does not suffer and central vision is often not impaired; in type IV there is always involvement of the optic nerve and retinal vessels with impairment of eye function. Patho-anatomical changes in type I consist mainly of uneven pigmentation of the cells of the pigment epithelium: some of its cells are poor in pigment or completely devoid of it, others are pigmented more strongly than usual. In the other types, the changes are more significant. Judging by the duration of the process, here inflammatory or atrophic foci are found in the vascular and choroidal coats; degenerative changes in the latter are concentrated mainly in the outer layers with significant penetration of pigment into the atrophic retina. The frequency of the described eye lesions in congenital syphilis is apparently quite large. Arkhangel'sky and Feldman in 270 children from mothers with syphilis found chorioretinal changes in 60 cases. Specific therapy gives noticeable results in R. on the basis of acquired syphilis and proves to be little effective in chorioretinitis in congenital syphilitics. Tuberculous retinitis. Tuberculous involvement of the retinal coat according to modern views is most often detected by the ophthalmoscopic picture of tuberculous periphlebitis. In 1909, Axenfeld and Stock clarified that the recurrent hemorrhages into the retina and vitreous body, often encountered in young people, the etiology of which was not known until then, depend on the tuberculous process in the vicinity of the retinal veins (in the venous sheath). Such tuberculous periphlebitis is characterized by the appearance of whitish clouding, bordering the vein along its length to a greater or lesser extent. At the site of clouding, the vein sometimes has a normal caliber and is freely passable for blood, more often its lumen is narrowed here, which is accompanied by stagnation in the overlying segment of the vein, noticeable by its dilation and tortuosity and by surrounding hemorrhages into the retinal tissue. The white border around the vein may be weakly expressed and then it is difficult to detect it. Often not one venous branch is affected, and periphlebitic foci appear in multiple numbers, then located on the periphery of the fundus. The pathohistological study of Fleischer (1914), subsequently confirmed by a number of authors, proved that the ophthalmoscopically visible periphlebitic foci correspond to actual tuberculous nodules in the lymphatic spaces surrounding the vein. It is quite natural that the tuberculous process, passing to the wall of the vein and gradually corroding it, often causes its perforation, which gives rise to hemorrhages into the vitreous body, sometimes very abundant. These hemorrhages usually resolve well, but have a great tendency to recur. The disease affects almost exclusively men aged 20-30 years and often both eyes, has a very long course with the repeated appearance of new foci around the veins and fresh hemorrhages. The fate of these foci varies: some of them disappear without a trace, others gradually turn into connective tissue membranes (adhesions) lying on the outer or inner surface of the retina, and long strands protruding into the vitreous body. The formation of membranes and strands especially occurs after significant hemorrhages and gives a picture long described by Manz under the name retinitis proliferans, in which the ophthalmoscope detects white or bluish-white strands protruding into the vitreous body, often in connection with retinal vessels. The contraction of these strands often leads to detachment of the retina with complete loss of vision. At the present time it has been clarified that retinitis proliferans most often develops on the basis of tuberculous periphlebitis, but hemorrhages of other origin can also lead to the same picture. Tuberculous periphlebitis by no means always accompanies such severe consequences for the eye. In many cases it has a more benign course, since the foci around the veins often resolve and the process does not reach hemorrhage. Septic retinitis. Pyemic processes of various origins are often complicated by severe purulent inflammation of the eye, usually ending in its death and bearing the name of metastatic ophthalmia (see). Metastatic ophthalmia has prognostic significance in the course of pyemic diseases. Its appearance indicates a severe life-threatening nature of the disease.

Cases of bilateral ophthalmia during puerperal infection almost always end fatally. Besides the acutely developing septic retinitis during pyemic diseases, changes in the retina in the form of scattered hemorrhages and white spots, described for the first time by Roth, are observed, with the latter showing no tendency to spread. The vitreous body is not affected, the process in the eye is limited to the retina alone and has a relatively benign character. Changes in the retina may completely disappear over time without noticeable consequences. In terms of prognosis, such 'simple septic retinitis' does not have as poor a significance as metastatic ophthalmia; even with bilateral eye disease, complete recovery is observed. Roth, and after him Herrnheiser, believed that in such cases the cause of retinal changes is not bacterial emboli in its vessels, but the presence of toxins in the blood that affect the vascular walls and cause a degenerative rather than inflammatory process in the retina. Others consider the cause of the described changes to be emboli of bacteria of reduced virulence (Leber) or small numbers, even single cocci (Kruckmann). B. Retinitis on the basis of general body ailments. Retinitis in kidney disease (retinitis albuminurica). In 1855, A. v. Graefe described under the name of albuminuric retinitis the changes in the fundus of the eye in nephritis. The typical ophthalmoscopic picture, quickly confirmed by numerous observations by ophthalmologists from all countries, greatly contributed to the popularity of the ophthalmoscope and established its importance for recognizing internal diseases. The objective signs of albuminuric retinitis consist of changes in the retinal vessels with and without hemorrhages, of white foci and phenomena of retinal edema in the region of the posterior pole of the eye. As for the vessels, unevenness of their caliber is noted, narrowing of the arteries up to closure of their lumen, stagnation in the veins and various types of hemorrhages. The latter are more often of small size, streak-like or punctate, and in rare cases more significant hemorrhages occur. B.ch. they are located near or along the course of blood vessels, but sometimes this connection with vessels is not noticeable. White nests are especially typical for albuminuric retinitis. They are almost always present, appearing on the fundus in the form of small white or yellowish-white plaques or in the form of larger shiny-white foci. The relationship of the foci to blood vessels varies: large vessels usually pass over them, while smaller ones are covered by the foci. White nests are diffusely scattered in the posterior part of the retina; around the yellow spot they have a characteristic radial arrangement, forming a star figure. The latter is rarely fully expressed; often only a partial star figure is found in the nasal half of the area of the yellow spot. When examined with ophthalmoscopy under high magnification (in direct view), it can be seen that individual rays of the star consist in turn of a large number of small spots. Edema of the retina, noticeable by its grayish, sometimes fine-streaky clouding, is detected mainly around the optic disc and at the posterior pole. Due to this edema, impregnation of the tissue of the disc with fluid, its boundaries become indistinct, sometimes to a very marked degree. T.k. simultaneously in connection with changes in the central vessels on the disc, hemorrhages may appear, the same picture is obtained as in inflammation of the optic nerve, which led to the introduction of the term neuroretinitis albuminurica. In some cases, edema of the disc is particularly pronounced, the picture of congestive discs is observed, apparently in connection with an increase in intracranial pressure due to congestive phenomena in the brain. Occasionally the picture of albuminuric retinitis is complicated by detachment of the retinal membrane due to the accumulation under it of a protein-rich transudate from the choroid. Combining the listed signs, each of which can be expressed to varying degrees, the ophthalmoscopic picture of albuminuric retinitis appears in different cases rather diverse, but in general it is so characteristic that usually at the first examination it leads to the correct diagnosis, which of course must be confirmed by the data of general examination and urine analysis. For a long time it was believed that in this picture the star figure around the yellow spot is the most pathognomonic for nephritis. But in fact the star figure is found far from in all cases of albuminuric retinitis, and in those cases where it is present, it is often only partially expressed. Schick is even inclined to think that a very sharply expressed star figure is not characteristic of albuminuric retinitis, but is found in some rare cases of tub. periphlebitis, as well as on the basis of other general body ailments, such as chlorosis, cancerous cachexia, etc. (retinitis pseudoalbuminurica). T.o. the greatest importance for diagnosis is not the star figure, but the white spots in the retina, especially in combination with hemorrhages and edema. It should be noted that during the course of the disease, the white spots and hemorrhages that have formed may disappear again, just as fresh ones may reappear. Visual impairment in albuminuric retinitis depends on the localization of changes in the retina. The latter themselves almost never cause complete blindness; the onset of such, usually sudden, indicates a complication by uremic amaurosis. Defects or limitations of the visual field are also not characteristic of albuminuric retinitis. Central vision is mainly affected due to the predominant damage to the central part of the retina. Weakening of vision is often the first symptom that makes the patient seek medical help; in such cases, the first assumption about the presence of nephritis is made by the eye doctor on the basis of ophthalmoscopic examination. For the pathological anatomy and pathogenesis of retinitis on the basis of kidney disease, see Nephrosclerosis, clinic. Some forms of diffuse glomerulonephritis, including scarlatinal, as well as nephritis of pregnancy, often have a favorable course and in connection with this, changes in the retina, initially reaching a very significant degree, subsequently undergo reverse development in these forms simultaneously with improvement of the renal process. Nephritis of pregnancy is particularly characteristic in this respect. Changes in the retina, if they develop in it, are usually very sharply expressed and relatively often complicated by detachment of the retina. But with timely termination of pregnancy, the retina quickly recovers, the phenomena of detachment disappear, white spots and hemorrhages resolve, and in their place remains either irregular pigmentation or single small atrophic nests. Of course, such a favorable outcome with complete or significant restoration of vision is possible only in cases where the process in the retina was not too prolonged and did not lead to the destruction of a significant number of nerve elements. In such far advanced cases, as a visible expression of the death of retinal nerve cells, atrophy of the optic disc develops and vision, despite the disappearance of the phenomena of retinitis, remains permanently severely reduced. Other forms of kidney diseases, especially nephrosclerosis and secondary shrunken kidney, as is known, have no tendency to improvement, and the albuminuric retinitis developing in them not only does not pass, but is in terms of prognosis a very ominous sign, indicating an extremely serious general condition of the body. The life expectancy of such patients after the detection of albuminuric retinitis in them usually does not exceed 1-2 years. Retinitis in diabetes. Changes in the retinal membrane occurring in diabetic patients are close in nature to albuminuric ones. In the ophthalmoscopic picture, hemorrhages and white spots are also present here. Nevertheless, some features are noted that distinguish diabetic retinitis from albuminuric: the optic disc here has a normal appearance, showing no signs of hyperemia or edema. White spots are sometimes completely absent, and if they are present, they are sharply defined and do not form a star figure. The most characteristic features of diabetic retinitis are hemorrhages of various sizes and shapes, including preretinal and into the vitreous body. Path-anatomically in diabetic retinitis, hemorrhages in the deep layers of the retina, sclerotic changes in the walls of blood vessels, deposits of fibrin around the vessels, accumulations of fat-granular cells and varicose hypertrophied nerve fibers have been found in the retina. It should however be borne in mind that all hitherto published studies have been made in cases complicated by kidney disease. Microscopic changes and the ophthalmoscopic picture of diabetic retinitis have so much in common with those in albuminuric retinitis that some authors deny the independent existence of diabetic retinitis and see the cause of the development of retinitis in the simultaneously existing kidney damage.

Others, on the contrary, defend the independence of diabetic retinitis, emphasizing the peculiarities of the ophthalmoscopic picture and relating the changes in the retina to disturbances in the chemical composition of the blood. In a prognostic sense, diabetic retinitis does not have such an unfavorable significance as albuminuric retinitis. The appearance of changes in the retina in diabetes does not yet mean that the main disease has taken on a character inevitably leading to a near fatal outcome. Leukemic retinitis is generally rare, developing only in severe cases of leukemia, especially in its myeloid form. The appearance of retinitis is preceded by the picture of the leukemic fundus: the fundus is much lighter than usual, having a light brick-red or orange-yellow color. The retinal vessels are dilated and tortuous and appear very lightly colored, especially the veins, as a result of which the difference between arteries and veins is smoothed out. On the optic disc, the vessels are almost invisible, barely standing out due to their light color against the surrounding tissue (Uthoff's phenomenon). In particularly severe cases, to these phenomena of the leukemic fundus are added the signs of so-called leukemic retinitis in the form of numerous light-brown hemorrhages and white spots. The latter partly have the character of similar areas of degeneration as in albuminuric retinitis, and partly represent formations of the lymphoma type and then protrude somewhat above the level of the fundus. To this group of retinal diseases also belong the lesions of the retina in various types of anemias (e.g., in pernicious anemia), in various forms of hemorrhagic diathesis, and in general cachexia due to cancer or other debilitating diseases. In such cases, changes in the retina usually develop in both eyes in the form of hemorrhages and white spots, to which, especially in pernicious anemia, signs of edema may be added. B. Diseases of the retina with unknown etiology. The concept of exudative retinitis was introduced into ophthalmology by Coats in 1908. As a characteristic feature of the condition, it is noted that it develops almost exclusively in only one eye and affects predominantly young men (up to 25 years of age). The ophthalmoscopic changes consist of the appearance of large white opacities in the retina, lying behind the retinal vessels. In the area of the opacities, the retina often protrudes forward, sometimes these white formations extend far into the vitreous body. In the arrangement of individual foci on the fundus, no regularity is observed, their color is often white, sometimes with a yellowish or grayish tint. To this are added changes in the vessels in the form of uneven caliber along the course of the vessel, encircling bands, aneurysmal dilations, significant tortuosity and anastomoses, taking on the character of a 'wonderful net'. The course of the disease is very protracted and sluggish. The white infiltrates that appear gradually increase, between them hemorrhages often appear, later detachment of the retina, partial or complete, joins. Since the disease develops only in one eye, it initially passes unnoticed for the patient. When seeking medical help, the changes are usually already sharply expressed and vision is greatly reduced. In rare cases, the changes in the retina undergo regression. In most of the described cases, the disease progressed with an outcome in retinal detachment, often with a clinical picture of pseudoglioma. In the patho-anatomical picture of the disease described by Coats, special importance was attached to the hemorrhages found in the outer layers of the retina, which often penetrate to the outer surface of the retina, here undergoing disintegration and through slow organization turning into scar adhesions. On this basis, Coats gave the disease an additional name-retinitis haemorrhagica externa. Further research, in particular by Leber, clarified the secondary nature of these hemorrhages, which merely accompany the main inflammatory and necrotic process in the retina. The etiology of the condition remains unclear for now; it is possible that the clinical picture of exudative retinitis develops under the influence of various pathogenic causes and that tuberculosis plays a certain role in some cases. Treatment usually gives no results. In many cases, the matter ends with enucleation of the eye due to suspicion of a tumor with the developed picture of pseudoglioma or due to the appearance of pain due to the onset of secondary glaucoma. Another type is the peculiar retinitis described by Fuchs-retinitis circinata. The disease is extremely rare and occurs mainly in old age, more often in women than in men. The ophthalmoscopic changes are very typical and consist in the fact that around the yellow spot a not quite closed ring often forms, consisting of small bright white spots, sometimes merging with each other. The retinal vessels pass over the spots. In addition, the area of the yellow spot itself shows opacification, sometimes very delicate, sometimes more intense with a gray or yellowish tint; in severe cases, the central opacification protrudes somewhat above the rest of the retinal surface. The disease affects first one eye, then both eyes, accompanied by a slowly developing but reaching a very significant degree of reduction in central vision. The latter does not improve even in those cases where the visible changes in the retina undergo regression. The etiology of the condition is definitely not known, the most probable connection is with arteriosclerosis. Treatment is ineffective. G. Retinitides of hereditary origin. Pigmentary retinitis (retinitis pigmentosa), more correctly pigmentary degeneration of the retina, is distinguished by its sharply expressed typicality and extreme characteristic nature of the symptoms. In the ophthalmoscopic picture, the most important signs of pigmentary retinitis are the pigmentation of the retina, the narrowing of its vessels, and the change in the optic disc. The pigment spots, from which the disease received its name, have a peculiar appearance, almost not found in other forms of retinitis: they are relatively small, of radial, star-shaped or spindle-shaped form, resembling bone corpuscles, often connected by their processes, forming circular-looped networks. They usually occupy the equatorial belt of the fundus at first, later the pigmentation spreads both toward the posterior pole of the eye and to the extreme periphery. The area of the yellow spot and the immediate vicinity of the disc usually remain free of pigment. In individual cases, the pigmentation belt is especially narrow, having a width of no more than two disc diameters, more often the area of pigmentation is much more extensive and gradually increases with the age of the patient. Pigment spots often clearly follow the vessels and partially cover them. The retinal vessels, especially the arteries, are markedly narrowed, as a result of which they are little or not at all visible at some distance from the disc and on the disc itself the number of visible vessels is less than normal. The optic disc only in the early stage of the disease has a normal color, later the disc shows the characteristic signs of so-called retinal atrophy: its color is yellowish-gray, with only a small admixture of a red tint and a waxy coating, the lighter color at the site of vessel exit is absent, the borders of the disc are visible but somewhat veiled. Quite often around the optic disc the pigment epithelium is discolored, as a result of which the choroidal vessels are clearly visible. In addition to the changes in the fundus, the objective signs of pigmentary retinitis also include lesions of the lens in the form of posterior cortical cataract. The latter does not always develop, but in any case so often that its finding in itself has diagnostic significance and requires a careful examination of the periphery of the fundus. The opacification of the lens is limited to the posterior cortical layer and very rarely extends to the entire lens.

* Among the subjective symptoms, the most constant are nyctalopia (see) and restriction of the visual field. The disturbance of the visual field usually begins with the appearance of the so-called ring scotoma (Ringskotoma), i.e., the disappearance of a circular belt from the visual field, the inner boundary of which corresponds to 20-40°, the outer to 45-70°, measured from the center. When compared with the ophthalmoscopic picture, it is found that the size and location of the scotoma coincide to a certain extent, but not completely, with the extent of pigmentation in the retina. In the further course of the disease, the defect in the visual field spreads, reaching on the one hand the periphery of the visual field, as a result of which instead of a ring-shaped scotoma a concentric narrowing of the visual field is obtained; on the other hand, due to the growth of the defect toward the center, the boundaries of the visual field become increasingly narrowed. It should be noted that the boundaries of the visual field are often considerably narrower in dim daylight or artificial light than in bright daylight. In far-advanced cases, the narrowing of the visual field reaches an extreme degree, only the central part of the retina functions, corresponding to the size of the visual field of 5-10° (tubular vision), and the orientation of the patient in space is severely impaired. Such a patient is practically blind (cannot walk without assistance) despite the fact that central vision is still largely preserved. But the latter also usually decreases sharply with time. The course of pigmentary R. is very prolonged. The disease begins in early childhood, with careful observation the first signs of nyctalopia are sometimes already detected at 2-3 years, ophthalmoscopic changes at 6-8 years; in some cases nyctalopia is detected later, at 12-15 years. In the further course, both objective changes and visual disturbances continuously progress; at 35-45 years the patient is usually unable to work, although the remainder of central vision can be preserved for a very long time and absolute blindness usually does not occur. There are, however, cases with a more severe course, when the decline in vision develops much faster, with the outcome of the process in complete blindness. In the literature, a number of cases of complications of pigmentary R. with glaucoma are described; there are no sufficient data on the nature of the mutual connection of these processes. In addition, a significant part of patients with pigmentary R. (according to Leber, about 23%) simultaneously suffer from deafness or hardness of hearing, which, according to some studies, depends on the congenital hypoplasia of the organ of Corti. The pathological anatomy of pigmentary R. has been quite fully elucidated by the research of Gonin, Stock, and Ginsberg, dating from the first decade of the 20th century and showing that the basis of the disease is a degenerative process beginning in the first (outer) neuron of the retina. Of the two elements of the neuroepithelium, the rods are affected earlier, the cones later. The process begins in the periphery of the retina and gradually progresses toward the central parts; the neuroepithelium in the area of the macula lutea remains preserved the longest. The breakdown of the nerve elements of the retina is not limited to the first neuron; its inner layers gradually undergo the same process. The death of nerve elements is accompanied by proliferation of the supporting tissue of the retina-glia. Starting from the outer layers, glia containing nuclei proliferates abundantly in the retina, the fibers of which run in various directions, forming complex networks. Following the destruction of the rods and cones, changes occur in the pigment epithelium. On the one hand, in its cells the pigment partially or completely disappears, and on large areas its cells are found to be reduced in size and little or not at all pigmented. On the other hand, new formation of cells is observed in it; the latter are of irregular shape with processes and darker pigment grains. According to Leber, the proliferating cells of the pigment epithelium grow into the retina in solid strands, more rarely singly, and spread here along the course of the vessels, penetrating through all layers up to the inner limiting membrane. Krukman explains the picture of retinal pigmentation by the fact that during the breakdown of the pigment epithelium, pigment grains are actively captured by glial elements and spread along their processes. The vessels of the retina are in most cases greatly changed: their walls are thickened, the lumen is narrowed; in small vessels the thickened wall is significantly infiltrated with pigment and the lumen is often narrowed to complete obliteration. The choroid shows no noticeable changes, in particular the vessels of the choriocapillaris are found to be completely normal. The results of path-anatomical research lead to the conclusion that the basis of pigmentary R. is the insufficient viability of the light-perceiving apparatus-rods and cones, which from an early age gradually undergo breakdown. That this instability is congenital is proven by the hereditary nature of the disease, which repeatedly occurs in a series of generations and in many members of one family. The type of hereditary transmission is predominantly recessive, in accordance with which consanguinity of the parents plays a major role. On the basis of 297 pedigrees, Bell determines the frequency of consanguinity as 27.2%. But in some families the disease is inherited according to a dominant type. In the pedigrees published by Nettle-ship and Beckershaus, direct inheritance was observed over 6 generations. Fleischer suggests that there may be two different forms of pigmentary R., the distinctive features of which have not yet been clarified, one of which is transmitted by a recessive type, the other by a dominant type. In addition to the hereditary factor, numerous attempts have been made to establish a causal relationship between the development of pigmentary R. and general diseases (syphilis, typhus) or lesions of individual organs (liver, endocrine glands), but the case histories provided by the authors are not convincing. Syphilitic chorioretinitis can indeed in the late stage give a picture very similar to pigmentary R., but in the general course of these two diseases there is a significant difference. Serological reactions also do not confirm a connection between typical pigmentary R. and syphilis. - As related to pigmentary R., retinitis pigmentosa sine pigmento and retinitis punctata albescens are described. The subjective disorders and conditions of heredity in both these forms are the same as in pigmentary R., but in the pigment-free form no pigment is found in the retina. The independent significance of this form is doubtful. The disease is described mainly in young people, in whom the possibility of later appearance of pigmentation cannot be excluded. In the second form, the fundus of the eye is found to be studded not only at the periphery but also in the center with numerous small white foci, which are presumably drusen of the choroid. - The prognosis in pigmentary R. and its varieties is definitely unfavorable, since we have no means to stop the progressive course of the disease. The treatment with inhalations of amyl nitrite recently proposed by Imre requires further observation.