Trachoma

738 Statistics and geographical distribution . .

740 Trachoma as a socio-domestic disease ....

752 Trachoma (from Greek trachys - rough, uneven) (syn. conjunctivitis trachomatosa, s. granulosa), a chronic infectious disease of the conjunctiva of the eyes, manifesting in widespread infiltration of its adenoid tissue with the formation of follicles, their subsequent degeneration, decay, and scarring. Trachoma is at the same time a socio-domestic disease, in its origin and development connected with certain socio-domestic conditions, the elimination of which and the fight against which is the basis for the prevention of this process. Historical data. Trachoma has been known since ancient times. In Egypt, it existed many centuries before the Christian era and has had huge prevalence there to this day. Therefore, trachoma was also called Egyptian ophthalmia (ophthalmia aegyptica). The well-known historian of ophthalmology Hirschberg points out that from numerous literary sources of ancient times (Plato, Plutarch, Galen, etc.) it is evident that the Greeks were aware of the fact of the contagiousness of trachoma more than 2,000 years ago. The name 'trachoma' is first encountered in Dioscorides in the first century of the Christian era. In Japan, according to Miyashita, trachoma has been known for no less than 1,200 years. In Europe, its appearance is linked to Napoleon's campaign in Egypt in 1798, but it is more correct to consider that trachoma existed in Europe even before the Napoleonic wars and only received special spread in the Napoleonic era. The spread of trachoma among troops during the war gave rise to calling it ophthalmia bellica, s. militaris. There is reason to think that trachoma in Russia was present long before Napoleon's invasion. At least in some historical materials, indications of the existence of trachoma have been found as early as the 17th century. Etiology. Despite the centuries-old history of trachoma, its essence is still understood differently. There are two views, still opposing each other today, the so-called unitary and dualistic. Dualists view trachoma as a process of an infectious nature, differing from other follicular processes in its origin, course, and outcome. At the same time, unitarians, with all the diversity of shades of their views on trachoma, deny it a separate place among other follicular diseases of the conjunctiva, deny infection as the sole cause of trachoma. The disagreements are explained mainly by the fact that the etiology of trachoma has not yet been established, although attempts to find its causative agent have occupied the minds of researchers for a long time and continue to this day. The first bacteriological studies of trachoma date back to the 80s of the 19th century, and from then until the beginning of the 90s, the appearance of a number of discoveries of either the trachomatous coccus or the trachomatous bacillus (Trachomcoccus of Michel-Sattler, Trachombacillus of Muller, etc.) did not cease, but all these findings were short-lived; their etiological significance was quickly rejected. And only from 1907, from the time of the discovery by Prowazek and Halberstaedter of special intracellular inclusions in trachoma, did the question of etiology enter a new phase [Vol. VII (art. 303-304), fig. 6]. During a systematic examination of the conjunctiva of trachomatous patients, using Giemsa staining of scrapings from the surface of the conjunctiva, they were able to establish that blue non-homogeneous inclusions are observed inside epithelial cells near the nucleus in the light-blue protoplasm. Among the bluish content, red or violet small, barely discernible coccoid formations are visible, having a tendency to divide in two (see table to the article Blennorrhea). Prowazek and Halberstaedter consider these diplococcal bodies, no larger than 0.25 µ, to be parasites that have invaded the epithelial cell. They consider the irregular masses of the inclusion to be products of the cell's reaction (plastin) due to the penetration of the parasite. Prowazek and Halberstaedter classify the found formations into the group of so-called Chlamydozoa. The studies of these authors served as a starting point for numerous works on intracellular inclusions, and at the present time, there is already a huge literature devoted to clarifying the significance of these inclusions for trachoma. To the morphological characterization of the inclusions, or, as they are called, Prowazek-Halberstaedter trachomatous bodies, substantial data were added in subsequent studies. Lindner distinguishes in the inclusion so-called initial bodies and elementary bodies (Initialkörper, Elementarkörperchen), which, in his opinion, belong to different stages of the parasite's development. The finding of intracellular inclusions in trachoma was confirmed by the vast majority of researchers, but the very first observations showed that inclusions in trachoma are not a regular phenomenon—they are encountered most often in fresh cases of untreated trachoma. Axenfeld in his monograph (1914) on the etiology of trachoma believed that inclusions are found in fresh cases in 52%, and in late periods only in 12%. In recent years, with the refinement of the research methodology, their presence is noted by many with great consistency. There are authors (Taboriysky) who claim that inclusions can be found in every case of fresh trachoma. It is unanimously recognized that inclusions are encountered predominantly in the epithelium of the conjunctiva and there are only rare indications of their presence in the epithelium of the cornea in pannus. The etiological significance of inclusions for trachoma was seen by the first researchers primarily in the fact that they were not found in control studies of the normal conjunctiva during its various inflammations. A fact confirming the specificity of the inclusions was finding them in the initial stage in experimental trachoma of animals (monkeys) and humans. The recognition of the specificity of the inclusions, however, met with objections subsequently; besides trachoma, they were discovered in a special form of blennorrhea of newborns (see Blennorrhea), then in the so-called bath or swimming pool conjunctivitis (see), and in rare follicular lesions, similar in picture to trachoma and now combined by the Lindner school into a general group of conjunctival diseases with inclusions (Einschlusskrankheiten). The question of the nature of the inclusions and their role in trachoma has caused a lively discussion throughout the history of the inclusions and it cannot be considered solved at the present time. Despite a number of gaps in the doctrine of the nature of Prowazek-Halberstaedter bodies, many researchers still consider these formations to be the causative agent of trachoma, attributing a parasitic origin to them (Lindner, Loewenstein, Taboriysky, etc.). Direct evidence of this, however, is still not available. No one has yet managed to obtain a culture of these inclusions and the presumed causative agent within them. With the etiological role of the inclusions not clarified, they still have a certain differential-diagnostic value. Finding them in doubtful cases of follicular processes sometimes allows for distinguishing trachoma from ordinary follicular catarrh. In recent years, the attention of ophthalmologists has been drawn to a new, very important discovery by the bacteriologist Noguchi. In 1927, Noguchi managed to isolate from the conjunctiva of trachomatous patients a special type of bacillus, which he named Bact. granulosis. The Noguchi bacillus is characterized by the following morpho-biological features. It is from 0.8 µ to 1.4 µ long and 0.25-0.3 µ thick. It is Gram-negative, motile, and grows best on a semi-solid medium, the so-called medium for leptospira (Leptospira-medium), containing fresh blood serum and hemoglobin (8 parts 0.9% NaCl, 1 part fresh rabbit serum, 1 part 2% agar; to this is added 0.1 part laked rabbit red blood cells). On this medium, the Noguchi bacillus grows at 30°, but it also grows just as well up to 37°. Besides the medium for leptospira, the bacillus rarely grows on blood agar. The pathogenic significance of the isolated microbe was tested by Noguchi and many other researchers in relation to monkeys. A pure culture, inoculated into monkeys subconjunctivally or after scarification of the conjunctiva, in most cases caused the development of chronic granular conjunctivitis, slowly progressing and at the height of its development similar to human trachoma. Noguchi managed to obtain transmission of the bacillus from one monkey to another. Based on his observations, Noguchi considers the bacillus to be the causative agent of trachoma. However, numerous verification observations do not allow, even to this day, to come to a definite conclusion about the etiological significance of Bact. granulosis. Among researchers, there is a different interpretation of the clinical picture of experimentally induced trachoma in animals. Some, like Olitsky and his school, claim that a specific trachomatous disease is caused in monkeys by the culture of the Noguchi bacillus, while others, like Lindner, Wilson, Weiss, Finnoff, and Thygeson, etc. (Wilson, Weiss, Finnoff, Thygeson), with great categoricalness, deny the conclusiveness of inoculations of the bacillus onto the conjunctiva of animals. Undoubtedly, experiments with the inoculation of the culture into humans are of great importance for the recognition of the etiological significance of the bacillus.

Up to 1934, quite a lot of such experiments were conducted (over 30 published), and in the overwhelming majority, they had a negative result, and those cases which the authors accepted as positive, with the exception of a few, give rise to well-founded objections regarding the correctness of their interpretation. Some researchers, led by Lindner, having isolated a bacillus similar in its morpho-biological properties to Bact. granulosis from the conjunctiva in follicular catarrh, express the assumption that Noguchi's bacillus is the causative agent not of Trachoma, but of follicular catarrh. But even this view cannot be considered proven, since there are observations that reject Lindner's assumption (Finnoff and Thygeson). Among the proofs of the etiological significance of Noguchi's bacillus, observations regarding the filterability of the trachomatous virus and Noguchi's bacillus were not uninteresting. Until recently, the trachomatous virus was considered a filterable virus, since infection with filtrate from trachomatous material gives a positive result, but recent experiments by Trapezontsova, Olitsky, and others allow one to doubt the established view on the filterability of the trachomatous virus. The filterability of Noguchi's bacillus is also denied. There were attempts to find confirmation of the specificity of Bact. granulosis in serological and allergic skin reactions, but they also give contradictory results. Thus, the question of Noguchi's bacillus remains open to this day. Epidemiology. Trachoma does not belong to highly contagious infections; its transmission occurs through contact, and the infectious material is pus, mucus, and lacrimal fluid of the trachomatous eye. The relatively low resistance of the Trachoma virus to physical agents has been established. It is destroyed by heating to 50° for 1/2 hour; drying at 32° for 1/8 hour also deprives it of its infectious properties. But, on the other hand, it retains its infectivity after prolonged (7 days) stay at ice temperature. The infection is introduced by contaminated hands and objects that have come into contact with infectious material. It turned out, according to the experiments of Nicolle, that flies can also be transmitters of the infection. Coming into contact with the tear or pus of a trachomatous eye, flies carry the infection to a healthy eye, which is easily done during sleep, especially in children. The use of a common towel for wiping the face in a family, washing in a common basin, and using common bedding have special epidemiological significance. The role of a common towel in the infection and spread of Trachoma, especially among the peasant population, has long been known. In the past, it was usually a matter of using not a towel, but simply a rag of old linen, with which all members of the family wiped their faces, thanks to which discharge from diseased eyes got into healthy ones and infected them. And such a domestic feature as the use of a common washing basin has more than once manifested itself as an obvious cause of the spread of Trachoma, sometimes overshadowing immeasurably more powerful factors. Markov, having examined Trachoma among the Germans of the Volga region in 1911, could note that among the Germans, although economically stronger and undoubtedly more cultured compared to the surrounding Russian population, the percentage of trachomatous individuals is significantly higher, which is primarily connected with the application of the 'ancient German custom of washing the family from one and the same basin, and in a number of cases without changing the water.' Trachoma is a kind of 'family disease': when one family member is infected, it usually captures other members as well during their close interaction. The same happens under unsanitary conditions of the joint life of trachomatous individuals with healthy ones in dormitories, barracks, prisons, etc. The spread of Trachoma in schools is usually due to introduction from the family. Trachoma spares no age, sex, or nation. The most favored age for infection is childhood, and the frequency of infection drops at later ages. The following table of the spread of Trachoma by age and stages (in %) can serve as an illustration (the table was compiled on the basis of materials from a total examination in the former Kazan Governorate in 1913). Age Up to 10 years..... 10-20 » ..... 20-50 » ..... Over 50 years . . . For all ages Stages of trachoma 3S 16 £3 From this table, it is evident that the first stage of Trachoma, i.e., fresh Trachoma, is observed predominantly up to 20 years of age, and above 20 years, infections are rare. The reason for this, apparently, must be sought first of all in factors of an exogenous nature—in conditions of easier contact in childhood. There are no sufficient grounds to speak about a special susceptibility of children or immunity of later ages to Trachoma. The spread of Trachoma by sex is characterized by a predominance of Trachoma among women. Proof of this can be found in almost every total examination in areas affected by Trachoma. Thus, according to data from a total examination of the Udmurt Region in 1926 (Dymshits), out of 5,687 examined, 46.6% were men and 53.4% were women; many such examples can be cited. More frequent cases of Trachoma in women are easily explained by domestic factors. A woman in the conditions of peasant life, especially in the past, is exposed to the possibility of infection more often than a man. She is more closely connected with the family; in the past, she was less cultured, more often illiterate than a man. In any case, there is no data to consider sex a factor of an endogenous order for Trachoma infection. It is also necessary to consider as completely erroneous the assertion of researchers about so-called racial predisposition, resp. racial immunity. The fact of the more frequent spread of Trachoma among some nationalities compared to others finds its full explanation in the socio-domestic conditions of their historical life, and not in endogenous racial influences. In recent years, much attention has been paid, at the initiative of Brana and Angelucci, to the significance of constitution in Trachoma infection. They attribute a dominant influence to constitution in Trachoma, establishing a special type of 'pre-trachomatous constitution,' 'habitus trachomatosus,' etc. While not denying the significance of constitution for the onset of trachomatous infection, there is, however, no reason to consider the presence of a certain type of constitution a mandatory prerequisite for infection. Total examinations in areas of endemic spread of Trachoma clearly indicate that Trachoma affects persons of diverse constitutions, and there is no particularly selective tendency of the trachomatous process toward a certain constitution (Mikaelyan, Kruglov, and Tarnopolsky). Statistics and geographical distribution. Trachoma in capitalist countries. Trachoma is one of the most widespread diseases of humanity, but determining the exact degree of its spread presents enormous difficulties. The materials available so far allow us to speak only approximately about the number of trachomatous individuals in bourgeois countries. A general approximate count of Trachoma in any case gives huge figures. Thus, Morax and Petit believe that no less than 90–100 million people are affected by Trachoma, i.e., about 1/16 of all humanity suffers from this disease. Recently, Wibaut (1929) compiled a map of the global spread of Trachoma, from which one can get an idea of the wide coverage of various countries by Trachoma. In relation to individual countries, first of all, Egypt can be defined as the most affected by Trachoma. Trachoma has long been exceptionally widespread in Egypt. According to all available data, even now in Egypt, up to 85–90% of the entire population is affected by Trachoma. The spread of Trachoma is especially great in childhood. According to MacCallan, from 91.3% to 98.2% of those affected by Trachoma were found in schools. Trachoma has a huge spread in Tripolitania and Cyrenaica, where the number of trachomatous individuals also reaches 85% (Parascandolo). The African colonies of France are also extremely affected: Tunisia, Algeria, Morocco. In the south of Tunisia, for example, Petit found up to 90% of those affected by Trachoma among the natives, in Gafsa, in Tozeur—96%, and in Nefta even 98%. In Morocco (Casablanca), up to 70% of trachomatous individuals were found among eye patients. In Asia, it should be noted that Trachoma is widely spread in China. Morax and Petit believe that about 30% of the entire population of this huge country is affected by Trachoma. In some regions, the percentage of trachomatous individuals reaches 90. Japan has known Trachoma for over 1,000 years, and according to Miyashita, about 20% of the population suffers from Trachoma. In British India, Trachoma also has a wide spread. According to data from recent years, it reaches 96% in schools, and up to 78% among the military. In Asia Minor, Trachoma is strongly spread in Palestine, where, according to Ticho, 27.9% of the school population of Jerusalem is affected by Trachoma, and, according to Shimkin, in Jaffa, the percentage of trachomatous schoolchildren reaches 37; the total number of trachomatous individuals, according to Ticho, is 400,000. In Turkey, according to van Mellingen, trachomatous individuals make up 15.6% of eye patients. In America, in general, Trachoma does not have a wide spread, but still, a fairly high percentage of population affection is noted in places. In the USA, areas along the Atlantic coast are affected. According to Davies' statistics, in New York, among a million eye diseases, before the introduction of measures against immigrants, there was about 4% Trachoma. In subsequent years, Trachoma fell to 2%.

American authors, as is known, denied the infection of Negroes with Trachoma. Swan Burnett, on the basis of an examination of 13 regions of the USA, speaks of the relative immunity of Negroes. At the present time, a number of researchers have established that Negroes do not possess racial immunity, and among them in some localities, quite a few trachomatous individuals are encountered. There are many trachomatous individuals among the Indians in Minnesota, and especially in Oklahoma (up to 68%). Trachoma is also widely spread in New Mexico. In Canada, 3.6% of eye patients are noted as trachomatous. Trachoma is somewhat more widespread in Cuba. Among the school population, for example, in Havana, out of 3,000 children, Trachoma was found in 700. In South America, Trachoma is encountered more frequently in Brazil and Argentina. In Europe, Trachoma is distributed unevenly. In capitalist countries, the metropolises, unlike their colonies, as a rule have a relatively small number of Trachoma cases. In England, it is encountered only sporadically; in Ireland, it accounts for up to 2.3% of eye patients; in Scotland, only 0.8%. In France, Trachoma is encountered mainly in coastal cities; thus, in Marseille, 15% of all eye patients are trachomatous, and in Montpellier, 1.5–2.9%. In industrial cities, its percentage is very insignificant, according to Petit, 1.46. In Italy, Trachoma is endemic in all provinces. According to an approximate count, there are about 3,000 trachomatous individuals in the country. In Spain, high figures for Trachoma are also noted; in Madrid, for example, Trachoma accounts for 25% of all eye diseases, and in some other cities, such as Barcelona and Cadiz, even more. In total, out of 22 million inhabitants, there are 50,000 trachomatous individuals. In Holland, Trachoma is concentrated primarily in Amsterdam, mainly among the poor, crowded Jewish population. Among schoolchildren in 1923, it was detected in 3.9%. In Portugal, they count up to 13% of trachomatous individuals among eye patients (Gama Pinto). In Germany, the most affected region is East Prussia, where the incidence of Trachoma, according to 1925 statistics, reaches over 4% of the entire population. In Hungary, which is one of the old foci of Trachoma in Europe, the spread of Trachoma at the present time is small. In 1928, upon examination of the population, 10,830 trachomatous individuals were found out of 8.5 million of the population, and in schools, only 0.39% were trachomatous. In Yugoslavia, there are approximately 0.5% trachomatous individuals among the population. In Bulgaria, it is considered that there are up to 5,000 trachomatous individuals throughout the country. In individual districts, 10–20% of the inhabitants are affected by Trachoma. In Czechoslovakia, out of 13.7 million people, there are 61,000 trachomatous individuals. Sweden, Denmark, Norway, Iceland, and Greenland have negligible percentages of Trachoma. Of interest is the spread of Trachoma in countries bordering the USSR. Lithuania has 10% trachomatous individuals, Latvia 5%, Estonia 4%, and Finland, according to the latest information (1929), has 2% of the population affected by Trachoma. In Poland, Trachoma is especially widely spread among the child population. In children's homes, the percentage of trachomatous individuals reaches 20–30%. In 1924, in Poland, trachomatous individuals accounted for up to 7.2% of all eye patients, and in all of Poland, there were up to 300,000 of them (Zaehert). In Romania, Trachoma increased strongly after the war. In Bucharest, for example, instead of 10% of all eye patients, trachomatous individuals now account for 20%, and the total number of Trachoma cases in the country reaches 80–90 thousand. Spread of Trachoma in the USSR. The total number of trachomatous patients in pre-revolutionary Russia in 1913, with a population of 178 million, was calculated at 1,029,333 people. The actual number of trachomatous patients in Tsarist Russia significantly exceeded this figure, since pre-revolutionary statistics did not cover all cases of Trachoma due to poor registration. An undoubted increase in the number of trachomatous individuals from year to year was noted, and the Trachoma index, i.e., the number of trachomatous individuals per 10,000 of the healthy population, was increasing, outpacing population growth. In 1902, the index was 36.2, and in 1913, it reached 63.3. The distribution of trachomatous patients in 1913 appeared as follows: in European Russia there were 885,789, in Asiatic Russia 144,094. The main material for these data was hospital statistics, which reflected primarily the population's seeking of hospital assistance, and did not express the true spread of Trachoma, which undoubtedly exceeded these official data. This situation is illustrated by some data from total population examinations for Trachoma. In 1913, an extensive total examination of the Kazan Governorate was carried out, which is now the territory of the national republics—the Tatar ASSR, the Chuvash ASSR, and the Mari Region. In 6 medical districts, out of 166,000 people, 42,616 trachomatous individuals were found, i.e., 25.5% of the entire population. In the years of the war and the first years of the revolution, the accounting of Trachoma in normal dimensions was not carried out, but from 1922, the registration of Trachoma was introduced, and with each year, the spread of Trachoma is being studied in more and more detail. When evaluating the data obtained, it is necessary to keep in mind that the comparison of figures with which we operate at the present time with the data of the past must be conducted with great reservations. The statistics of the past are based on a completely different healthcare system of Tsarist Russia and were compiled by other, far from perfect, methods of accounting. With a radically changed healthcare system, with significantly improved general hospital care, and with specialized eye care covering wider and wider masses of the working people, the accounting of Trachoma at the present time is being conducted with greater and greater accuracy and completeness of detection. In 1927, the total number of trachomatous individuals in the USSR was determined to be 846,750 people, i.e., a sharp decrease in the number of Trachoma patients (by 18%) is noted compared even with the underestimated figure of patients in Tsarist Russia (1913). In recent years, especially during the first five-year plan, huge shifts in the social and living conditions of the life of the Union's population, especially the collectivization of agriculture, and widely implemented measures by healthcare agencies to combat Trachoma, have yielded an even greater decrease in Trachoma during this short period. In this regard, the successes achieved in the national republics, which represented the group most affected by Trachoma, are especially significant. The Chuvash ASSR, which stood in one of the first places, has achieved the most indicative results during this time. According to materials from the Chuvash People's Commissariat of Health, based on data from total examinations, in 1932 compared to 1928, i.e., after 4 years of energetic struggle, Trachoma decreased by almost 20%. In the Mari Region, there is also a clear decrease in recent years. In the Udmurt Region, a decrease in Trachoma by 10% was noted during the 1st five-year plan. Trachoma as a social-living disease. When considering the causal moments of the spread of Trachoma, the outstanding role of factors of a social-living order is clear. It is difficult to find another eye disease which, throughout the entire history of its development, would present a more vivid example of the dependence of its spread on factors of an exogenous nature, primarily on the influence of the social environment. Trachoma, due to its exceptional spread among the most economically weak strata of the population, has long been known as a "disease of the poor." Numerous studies of the past and, in particular, observations of the revolutionary era have provided rich material that indisputably depicts the close connection in which the spread of Trachoma occurs among the working masses of those nationalities of the USSR that, in the era of Tsarism, stood at an extremely low level of culture, were economically weak, and lived in conditions of primitive daily life. The regions of our Union inhabited by various small nationalities present vivid illustrations in this regard. Take, for example, the Volga-Kama region, where the Chuvash, Mari, Udmurts, Tatars, Mordvins, and others, while having a high prevalence of Trachoma, were at the same time always significantly weaker than other nationalities of former Russia in economic and cultural respects. Against the background of economic backwardness, these nationalities always presented striking examples of their lack of culture as a whole and their exceptionally unsanitary living conditions. With the huge shifts of a social and cultural nature that have occurred in the USSR in recent years, living conditions are also changing sharply. Now, with the collectivization of agriculture, we are witnessing the breaking down of the old peasant way of life, and along with this, immeasurably better conditions are being created for the fight against the spread of Trachoma and its liquidation. Pathological anatomy. 75 years have already passed since Benz first established that in the conjunctiva during Trachoma, numerous limited accumulations of lymphoid cells—follicles—are observed. Starting from this time, we have a huge number of pathological-histological works devoted to the study of the trachomatous process. A special attention of researchers to the follicle as the most important element of the process runs like a red thread through the works of the past. At the present time, with the application of perfect methods of research, the significance of pathological-histological changes in Trachoma as a whole, in all manifestations of the process, is being brought to the fore, and the follicle is assigned a subordinate, secondary place. The basis of the histological picture must be recognized as inflammatory changes of the mucous and submucous connective membrane, which in severe cases lead to extreme hypertrophy of tissues and the development of cicatricial changes.

This inflammation has a chronic character with all the features inherent to it, wherein phenomena of proliferation, i.e., processes of inflammatory new growth, come to the fore. Characteristic of Trachoma is the simultaneous existence at the height of the process's development, alongside progressive signs of inflammation, of symptoms of degeneration, as well as proliferation of connective tissue. Infiltration processes, in accordance with the clinical picture, have extreme diversity in intensity and distribution in various sections of the conjunctiva. Where adenoid tissue is normally developed, the thickest layers of infiltration are observed—such are the transitional folds; the conjunctiva of the tarsi is affected less, and the conjunctiva of the eyeball is little involved in the infiltration. The cellular composition of the infiltration has been subjected to careful study more than once. A regular finding here is the presence of plasma cells. In weakly expressed forms of inflammation, they are encountered singly, but usually they are found in whole layers in the subepithelial tissue, sometimes extending into its deep layers. Plasma cells are encountered in all stages of Trachoma, and especially often in the stages of papillary hypertrophy. Another and most constant part of trachomatous infiltration is lymphocytes. They constitute the main part of the cellular infiltration in the initial stages of the process. Primary foci of inflammation consist predominantly of them, and they also provide the main mass of the cellular composition of the follicle. Besides these cells, histiocytes are observed with great constancy, and, what is especially emphasized by some, lymphoblasts are found in large quantities in the first and second stages of Trachoma. Neutrophilic leukocytes, mast cells, eosinophils, and histiocytes are encountered much less frequently. According to the research of the latest authors (Oguchi, Eleonskaya, and others), the latter are assigned a noticeable role in trachomatous infiltration. They are encountered both in the infiltration of the conjunctival stroma and in the follicles. Trachomatous follicles appear in the form of round formations, differing in their size and cellular composition, depending on the degree of development and location. A follicle consists of two sharply differing sections: a peripheral zone, consisting of strongly stained, densely arranged round cells, and a pale-stained center of large, weakly staining cells. The marginal zone consists of lymphocytes, arranged in fairly regular concentric rows and sharply delimiting the follicle from the surrounding more or less heavily infiltrated adenoid tissue. The main cellular mass of a mature follicle is formed by large or small lymphocytes. Among the lymphocytes, leukocytes (neutrophils, eosinophils, mast cells) are encountered. The central part, the so-called germinal center (Keimzentrum), is formed by epithelioid cells. A number of recent authors believe that there are two groups of cells in the cellular composition of the center—lymphoblasts and histiocytes (according to Oguchi and others), between which there also exist various transitional forms. Levkoeva and Dvizhkov consider lymphoblasts to be the dominant element of the first stages of Trachoma. They also classify the epithelioid cells of the follicle as lymphoblasts. As for the other elements of the follicle, it should be mentioned that the follicle consists of loose stroma, permeated by small vessels. The follicle has its own history of development. It basically breaks down into 3 stages: formation of the follicle, its degeneration, and cicatricial replacement, but it seems impossible to trace these stages in relation to each individual follicle. The conditions for the development of the follicle in different places of the conjunctiva and in different individuals are too different, the cellular composition of the follicle in different forms of Trachoma is too diverse, and the timing of the onset of degenerative and reparative processes in individual cases of trachomatous inflammation is different. The processes of degeneration observed in follicles usually proceed alongside the same processes in the inflammatory infiltration of the tissue and undoubtedly represent one of the characteristic phenomena of Trachoma. These processes are a regular consequence of trachomatous inflammation and occur at various times of its existence. Regressive phenomena will be revealed by noticeable cellular decay and the disappearance of cellular elements, loosening of tissues, etc. The decay of follicles of the subepithelial tissue is not the only type of its regressive metamorphosis. Sometimes follicles, undergoing processes of cellular necrosis, empty their contents outward after the rejection of the epithelium covering them (see figure). The process of follicle decay is very early accompanied by the new formation of connective tissue, which usually appears in the region of the follicle in connection with the adventitia of the vessels. Around the follicle and inside it, a new formation of fibroblasts occurs, which then causes the replacement of the follicle with cicatricial tissue. The same regressive changes in a certain period of Trachoma also occur in the area of inflammatory infiltration. As a final result, cicatricial tissue forms in place of the trachomatous infiltration of the follicles, the degree of development of which depends on the extent of the process. In addition to the general characterization of Trachoma from the pathological-anatomical side, it is necessary to point out the changes in the conjunctival epithelium. Already in the early stages of the development of inflammatory infiltration, the epithelium, especially that covering the follicles, is rarely normal. Usually, the epithelial cover thickens and gives tongue-like ingrowths into the underlying tissue. In the regressive, especially the cicatricial period, the process of epidermization of the epithelium occurs—flattening of the cells and their keratinization. In the clinical picture of Trachoma, the growth of papillary bodies is common. Pathological-anatomical papillae, especially strongly developed on the convex edge of the tarsus, represent elevations of the conjunctiva not only in places of the pre-existing system of its depressions and elevations in the normal state, but also where the normal conjunctiva has a smooth, evenly arranged epithelium. In the tarsus itself, diverse and deep changes often arise, similar in character to the changes in the mucous membrane itself. Inflammatory infiltration sometimes captures the deep parts of the tarsus, but the formation of typical follicles is observed rarely. The Meibomian glands of the tarsus undergo a series of degenerative changes leading to their destruction. Often, early hyalinization of the tarsal tissue is noted in the tarsus, and sometimes its fatty degeneration is also observed. The outcome of the lesion of the tarsus can be its cicatricial shrinkage—atrophy. Sometimes the tarsus, undergoing a widespread process of degeneration, becomes very thick and bumpy. Changes in the conjunctiva of the eyeball have been the subject of recent research. Contrary to clinical observations, histological studies by a number of authors (Pokrovsky, Eleonskaya, and others) indicate with certainty that the conjunctiva of the sclera is also often involved in the process. The character of the changes in the conjunctiva of the sclera is generally defined as chronic proliferative inflammation of the same type as in the conjunctiva of the eyelids. Mention should also be made of changes in the lacrimal and tear-conducting organs. Phenomena of diffuse inflammation in the region of the lacrimal gland with infiltration from plasma cells have been described. In the late periods of Trachoma, scarring appears in the region of the lacrimal gland with cystic dilation of its individual parts. Purely trachomatous lesions of the lacrimal sac, contrary to the indications of Kuhnt, cannot yet be considered proven. Thus, from all available data, it should be recognized that what is characteristic of the trachomatous process is not its histological components taken separately, such as the follicle or diffuse infiltration, but the totality of anatomical changes and their preferred localization. Difficulties arise when evaluating the histological picture of initial forms of Trachoma, when, from the pathological-anatomical side, there is not yet material that would allow one to definitely differentiate Trachoma in this stage of the process from follicular catarrh of the conjunctiva. The not-yet-sufficiently defined outline of the histological picture of Trachoma is one of the reasons for the existing disagreement in understanding its essence. Clinic. The clinical picture of Trachoma is extremely diverse both in the extent of the process and in the degree of development of follicles and infiltration, the degree of hypertrophy of the papillae, and the character of the complications encountered. The course of this disease is in the vast majority chronic, lasting for years, sometimes decades, and both eyes are usually affected. After an incubation period of 7-14 days, three main stages can be distinguished in the clinical course of the process, as was proposed by Rahlmann. 1st stage—trachoma I—progressive stage. It is characterized by the increasing development of inflammatory phenomena—hyperemia, thickening due to infiltration of the conjunctiva, the appearance of grains—follicles, and the growth of papillary bodies from the very initial signs of the process up to the picture of blooming Trachoma.

(trachoma incipiens, recens, florescens). The 2nd stage is trachoma II—regressive, when phenomena of follicle degeneration, their disintegration, degeneration of inflammatory tissue, and the beginning of a reparative cicatricial process are observed—the appearance of individual scars; a widespread degenerative process in this stage is especially typical in the picture of the so-called gelatinous trachoma (sulziges Trachom of German authors). The 3rd stage is trachoma III—the terminal stage, when scarring processes predominate, replacing the inflammatory infiltration with follicles. Developing according to such a scheme, the trachomatous process is distinguished by the enormous diversity of its clinical picture. A common phenomenon in trachoma of long duration is the mixing of different stages at the same time. Trachoma begins in the vast majority of cases unnoticeably, and the disease is often determined during a random examination when it has already gone far or even finished completely. It must be especially emphasized that trachoma in childhood proceeds unnoticeably. This happens not only because the disorders of the state of the eyes caused by it are not noted by patients due to their age, but also because the trachomatous process in childhood very often proceeds not in as severe a form as in adults. Among children, there is no doubt that cases of spontaneous cure of the process without particularly sharp cicatricial changes in the conjunctiva of the eyes are encountered much more often. In its typical forms, trachoma begins with hyperemia, swelling of the transitional folds of the conjunctiva, and the appearance of follicles there, especially noticeable in the transitional fold of the upper eyelid. In the transitional folds, however, the trachomatous process does not linger for long, and soon it crosses the boundary that lies between the transitional fold and the upper edge of the tarsus, spreading to the area of the tarsal conjunctiva. The tarsal conjunctiva of the upper eyelid swells, thickens, and on the hyperemic, thickened conjunctiva, follicles appear in the form of small whitish, grayish spots, shining through from the depth of the tissue and sometimes rising above its surface. The spread of infiltration and follicles to the tarsal part of the conjunctiva makes the picture of the trachomatous process undeniable. With the progression of the process, the follicles developing in the transitional folds and in the area of the upper edge of the tarsus, in particular, increase more and more in their quantity. Due to diffuse infiltration and the development of a large number of follicles, the transitional fold, especially the upper one, protrudes from the palpebral fissure upon eversion of the eyelids in the form of folded, bumpy ridges, studded with grains of various sizes. The folding of the conjunctiva with follicles sitting in the tissue sometimes reaches such a degree that it takes on the appearance of a cockscomb, and the follicles themselves, with their abundant eruption, resemble frog spawn in their appearance. In addition to the transitional folds and the tarsus, the follicles very often also involve the semilunar fold of the conjunctiva—it appears thickened, studded with a row of usually large follicles protruding above the surface of the fold. In developed forms of trachoma, the spread of trachoma to the conjunctiva of the eyeball also occurs. Sometimes, very early, one can observe hyperemia, thickening of the conjunctiva of the eyeball near the transitional fold, especially of the upper eyelid, and the appearance of large, semi-translucent follicles there. Along with the development of thickening of the conjunctiva and follicles, an almost constant symptom of trachoma is the proliferation of papillary bodies. Velvety texture and often coarse irregularities, due to papillary hypertrophy, are observed in the developed form of trachoma both in the area of the tarsal conjunctiva and the transitional folds. Hypertrophy of the papillary bodies sometimes dominates the entire picture of trachomatous changes, obscuring the basic elements of the process—infiltration of the conjunctiva and follicles. The different state of the trachomatous conjunctiva in the progressive period allows some (Stellwag, Fuchs) to divide trachoma into separate forms: they call trachoma with the predominant development of follicles granular trachoma (t. granulosum), trachoma with the presence of noticeable papillary growths—papillary trachoma (t. papillare), and cases in which both follicles and papillary growths are observed are considered as a mixed form (t. papillo-granulosum). Trachoma of the first period in some cases proceeds without any noticeable discharge from the conjunctiva (some call such cases t. sicca—dry trachoma), but in many cases it is accompanied by the appearance of secretion—purulent or mucopurulent. The abundance of secretion usually characterizes faster-flowing forms of trachoma and, at the same time, more contagious ones, since with a significant amount of discharge, more favorable conditions for its transmission are created. After a more or less long existence of the first period of trachoma, symptoms of the 2nd period appear in the conjunctiva—phenomena of degeneration of inflammatory infiltration and follicles, their disintegration, and replacement by cicatricial connective tissue. Clinically, this is expressed in the developed form of trachoma by the fact that the follicles and the surrounding tissue become loosened, the follicles change in their color—their color becomes matte gray, gray-yellow, they become blurred at the contours; they are larger in size and greater in quantity. In this period, it is often visible how the follicles merge with each other; this is especially noticeable in the transitional folds and in the area of the upper edge of the tarsus of the eyelids, where the gelatinous degeneration of the conjunctiva, so characteristic of this period of trachoma, also stands out quite clearly. By the gelatinous form of trachoma, one understands such a state of the conjunctiva when the follicles, developing in an especially large quantity and having reached a large size, merge, degenerating, into one continuous gelatinous mass. The inflammatory infiltration also undergoes this same process, so that the entire conjunctiva of the transitional fold and the tarsus, especially in its upper section, takes on a glassy, gelatinous character. The clinical picture of the third period is also distinguished by diversity. Along with scars, phenomena of inflammatory infiltration, formation of follicles, etc., are also observed. Only in late periods, occurring in individual cases after varying amounts of time, do we have widespread cicatricial changes sometimes involving the entire conjunctiva of the eyelids. Such a state of complete cicatricial degeneration of the conjunctiva without the presence of infiltrate can be called the fourth period of trachoma (MacCallan, Chirkovsky, and others). Cicatricial changes in the transitional folds manifest themselves in the so-called smoothing of them, a decrease in their folding. Changes in the area of the tarsus are more noticeable. Here, in mild cases, individual thin, whitish streaks of cicatricial tissue arranged in a mesh are visible; in severe cases, the scars are coarse. With progressive shrinkage, the conjunctiva of the tarsus shortens significantly, pulling onto the area of the tarsal conjunctiva and the conjunctiva of the transitional fold; thereby, the entire area of the conjunctival sac narrows sharply. In mild cases, only single, barely noticeable small scars, often visible only under a magnifying glass, testify to the past process. Due to the strong shrinkage of the tarsal conjunctiva and due to regressive changes in the tarsus itself, a trough-like curvature of the tarsus, a change in the configuration of the eyelid, occurs, which is very characteristic of the cicatricial period of trachoma. With sharp cicatricial shrinkage of the conjunctiva, the so-called symblepharon post. (see Conjunctiva) develops. With further shrinkage of the conjunctiva of the eyelids, the curvature of the tarsus leads to one of the severe consequences of cicatricial trachoma—entropion of the eyelids, incorrect growth of eyelashes (trichiasis). In the outcome of the trachomatous process in its severe forms, along with widespread scarring of the conjunctiva, the development of xerosis or xerophthalmia (see) is sometimes observed. Acute Trachoma. In addition to the typical form of trachoma with its chronic course, an acute form of trachoma is occasionally encountered. The existence of such a form is disputed by some (Morax, Petit, MacCallan), but judging by the available data, it can be asserted that in rare cases, trachoma can arise acutely, manifesting itself in symptoms very similar to acute infectious conjunctivitis. According to Saemisch and Oguchi, such a form constitutes 6% of all trachomatous cases. The initial symptoms of acute catarrh in such a form of trachoma are soon replaced by signs of a follicular process. Among the edematous and hyperemic tissue, individual follicles begin to shine through, and papillary growths appear in the area of not only the transitional folds but also the tarsal conjunctiva. Along with this, the signs of the acute process gradually weaken, the hyperemia of the conjunctiva decreases, and the discharge decreases. The process usually passes into the picture of a typical, chronic form of trachoma. Unilateral Trachoma. As a deviation from the usual development, unilateral trachoma of long duration is sometimes encountered. This phenomenon is undoubtedly rare. There are only hypotheses to explain unilateral trachoma. They most often boil down to the assumption of a greater predisposition of one eye to trachomatous infection compared to the other or the presence of immunity of one eye to trachoma. Complications. Various complications are characteristic of trachoma.

They give this infection an extremely severe character and are the cause of prolonged, sometimes multi-year visual disturbances and in a number of cases cause a terrible outcome: trachoma-blindness. Highly characteristic for the full picture of trachoma is the involvement of the cornea in the form of pannus (see). The emergence of this peculiar inflammation of the cornea, sometimes observed even in the early stages of trachoma, makes the diagnosis of trachoma especially reliable. Among other complications on the part of the cornea, one should keep in mind corneal ulcers that often arise during the trachomatous process, usually in the form of a deep, rapidly progressing infiltrate with the formation of an ulcer, which often has a tendency to destroy the cornea through its entire thickness (see Keratitis). Further, although rarely, changes in the configuration of the cornea are observed—its partial or complete protrusion. The latter is usually in the form of keratoglobus (see Staphyloma). A complication of the trachomatous process is often acute infectious conjunctivitis. Most often, this involves an infection of the conjunctiva superimposed on trachoma by the Koch-Weeks bacillus, pneumococcus, or gonococcus. Sometimes infections of a chronic character, such as diplobacillary (Diplobac. Morax-Axenfeld) conjunctivitis, also join trachoma, complicating its course. Infectious conjunctivitis can be a precursor to trachoma, creating favorable conditions for the introduction of the trachomatous virus. Superimposed on trachoma, these complications aggravate the course of the latter, in particular presenting a danger of corneal damage in the form of purulent keratitis. Further, it should be mentioned that in trachoma, diseases of the lacrimal passages, especially the lacrimal sac, are sometimes observed. The presence of dacryocystitis (see) of any origin is a factor complicating the course of trachoma. Impairment of lacrimal drainage, and especially pus with a huge number of microbes accumulating during dacryocystitis in the lacrimal sac, in itself causes persistent chronic conjunctivitis and naturally reflects unfavorably on the course of trachoma. Rare is the involvement of the lacrimal canaliculi in trachoma; it is attributed to a specific origin due to the spread of the trachomatous process to the mucosa of the canaliculi (Rubert). The diagnosis of trachoma presents difficulties at the beginning of the process, when there is not yet a picture of the full development of all symptoms of the disease, when the process is limited to the involvement of only the transitional folds. The basis of the diagnosis is not only the presence of follicles, but also the presence of infiltration of the conjunctival tissue, clinically expressed in its thickening. Extremely important for the diagnosis of trachoma is the localization of the process—the involvement in the process, besides the transitional folds, also of the conjunctiva of the cartilage of the upper eyelid. This was pointed out as early as the 1880s by Prof. E. V. Adamyuk. When the process is limited only to the transitional folds, a diagnosis of trachoma can be made only with their pronounced infiltration and the presence of many follicles. It must be remembered that the transitional folds are the initial site of localization of the infection, but they do not remain the only site of involvement for long. The process almost always, in its spontaneous development, spreads to the tarsal conjunctiva and other parts of it. At this time, the diagnosis becomes easy. Guided mainly by this for the diagnosis of the initial form of trachoma, one must, however, reckon with the difficulties that arise when follicles are located in the transitional folds or partially capture the conjunctiva of the cartilage as well, but are not accompanied by sharply pronounced deep infiltration of the tissue. Such cases give special cause for differential diagnosis with follicular catarrh and usually do not allow for an immediate diagnosis. Observation is required for diagnosis, and it would be more correct in such cases to limit oneself to a presumptive diagnosis (trachoma in suspectu, dubium). Observation, sometimes even for a short time, allows one to be convinced of the development of either a typical picture of trachoma or, conversely, a benign follicular process. Recently, Bonnet, Schousboe, and others have drawn attention to early changes in the corneal limbus in the initial periods of trachoma, considering them an important diagnostic sign. These changes are visible under a binocular loupe and especially with a slit lamp.

Prophylaxis of trachoma as a socio-living disease must proceed primarily along the path of improving economic and social conditions of the environment, i.e., along the path of further socialist construction. The enormous shifts in the social economy taking place in the USSR give every reason to believe that the conditions of this successful construction lie in the elimination of those age-old brakes that stood in the way of the correct organization of prophylaxis and the fight against trachoma in pre-revolutionary Russia. One of the main fundamental parts of the dispensary method in the fight against trachoma is the registration of the incidence of this infection, the identification of foci of the disease, and the study and improvement of general sanitary and specifically socio-living features of the life of the working and collective farm masses. In the registration of trachoma, until recently, a major obstacle was the absence of a unified trachoma registration card, which was reflected in the different form and content of the existing registration cards, and therefore studies conducted using diverse cards yielded low-value results. The introduction of a unified registration card of the People's Commissariat of Health of the RSFSR, built on a dualistic understanding of trachoma, eliminates the inconsistency in collecting information about trachoma. Special attention during all kinds of examinations is directed at identifying the socio-living conditions of the environment that influence the spread of trachoma, and at establishing the sources and mode of infection. The main organizational form in the fight against trachoma until now has been rural eye hospitals and departments of hospitals in cities. The direction of their activities towards the dispensary system of eye care in recent years has been indicated by a whole series of legislative decrees and instructions of the People's Commissariat of Health of the RSFSR. By a special decree of the All-Russian Central Executive Committee and the Council of People's Commissars of the RSFSR dated November 28, 1927, general directives were given for the fight against trachoma as a socio-living disease. The most important measure provided for by this decree of the All-Russian Central Executive Committee and the Council of People's Commissars was the decreeing of the right to compulsory examination of persons regarding whom there is reason to assume that they suffer from trachoma, as well as the right to compulsory treatment of certain categories of the population (students of the 1st and 2nd stage, organized childhood, university students living in dormitories, etc.), regarding whom the fact of having trachoma in its infectious period has been established, if these persons refuse voluntary examination and treatment. Subsequent instructions of the People's Commissariat of Health—March 15, 1928, and June 23, 1929—clarified in detail the plan for the fight against trachoma, but of especially great importance is the decree of the collegium of the People's Commissariat of Health of the RSFSR dated April 27, 1932, on the liquidation of trachoma in the RSFSR in the second five-year period. Anti-trachoma measures have taken on a particularly wide scope in recent years in such national republics and regions as the Chuvash ASSR, the Mari, and Udmurt regions, with the Chuvash ASSR undoubtedly in first place in this regard. The national republics, former "non-Russian" regions that eked out a miserable existence in the era of the oppression of tsarist autocracy and feudal-landlord exploitation, were grandiose foci of trachoma. In pre-revolutionary times, in the "non-Russian" districts of the former Kazan and Vyatka provinces, populated by Chuvashes, Cheremis (Mari), Votyaks (Udmurts), and other national minorities, a huge incidence of trachoma was observed. Thus, during mass examinations in 1913 among the Chuvashes of the former Kazan province, in some places trachoma was detected in 50-70% of the entire Chuvash population; among the Votyaks, according to data from eye detachments, the percentage of trachomatous patients reached 72-80, etc. At the present time, in the national republics and regions, with enormous shifts of a socio-cultural character in the life of the population, a consistent and very successful fight against trachoma is underway, which has already yielded exceptional results. It was mentioned above that in the Chuvash ASSR, a decrease in trachoma is noted from year to year; the same is taking place in the Mari region, the Udmurt region, and other regions and republics previously terribly affected by trachoma. In the Chuvash Republic, mass dispensary registration of the trachomatous population is being successfully deployed. With great consistency, the so-called "nest treatment" of trachoma is being carried out, which consists of organizing, within medical districts, trachoma stations headed by a trachoma nurse, working under the guidance of doctors. At the present time, in the Chuvash Republic with its million-strong population, there are over 300 stations, and in the coming years, their number will be brought up to 700. According to approximately the same plan, the fight against trachoma is being deployed in other national republics, and there is every reason to believe that the task set by health authorities to liquidate trachoma as a mass disease in these regions will be successfully resolved in the coming years. The treatment of trachoma belongs to difficult tasks in view of the persistence of the process and the absence of specific remedies against it. Until now, the most widespread is medicinal therapy in the form of the century-old application of copper preparations (Cuprum sulfuricum).

Many currently use treatment with chaulmoogra oil (Ol. chaulmoograe) in the form of rubbing it into the conjunctiva every 2-3 days (Delanoe). Chaulmoogra oil is indicated in various stages of Trachoma where there are phenomena of infiltration and follicles. The best result from it is obtained when combined with the expression of follicles. Mercury cyanide is also used not without success, most often in the form of lotions and drops (in a solution of 1:3,000–1:5,000); in some cases, subconjunctival injections of mercury cyanide prove useful. Mechanical methods occupy a noticeable place in the treatment of Trachoma, most often in the form of medicinal massage (with solutions of sublimate, mercury cyanide, airol, etc.). Surgical methods for treating Trachoma are diverse. They are indicated especially in the first and second periods. The most common and effective is the expression of follicles (expressio folliculorum). Expression is performed with special forceps. Forceps by Belyarminov, Donberg, and Knapp are widely used. Expression is performed repeatedly at one interval or another depending on the severity of the process, and along with expression, various types of medicinal therapy are carried out. Recently, V. P. Filatov proposed performing repeated expression systematically, without conducting the usual intermediate treatment. French authors (Cuenod et Nataf) recommend the so-called xysis, which consists of scraping the surface of the conjunctiva with a special curette after anesthesia, destroying the follicles and adenoid tissue, followed by an injection of mercury cyanide into the tissue. Of the purely surgical techniques, the most commonly used are the operations developed by Kuhnt: simple excision of the transitional fold, combined excision of the transitional fold and cartilage, and enucleation of the cartilage. The first two operations are indicated in the progressive periods of Trachoma, the latter in the cicatricial period. A modification of the combined excision is the Pick operation, in which only part of the cartilage is removed, but the transitional folds are preserved. In addition to the indicated treatment methods, physiotherapy is also successfully used in some cases in the form of deep cauterization of the conjunctiva of the transitional folds with a thermocautery according to Abadie. Recently, the use of diathermy or diathermocoagulation (Worms, Bidault, and others) has attracted attention, sometimes having a pronounced and rapid effect. At one time, the use of radium (Kohn, Zelenkovsky, and others) raised many hopes. It is usually useful when combined with other treatment methods. X-ray therapy for Trachoma is gaining relatively wide distribution in our Union (Merkulov, Bykhovsky, Gasul, and Neminsky, and many others), but there is still no definite data to assert that this type of therapy gives a lasting result, especially in severe forms of Trachoma. Like radium, it is a good auxiliary agent in combination with other types of therapy. Besides local therapy, which does not have a specific character, attempts at specific treatment of Trachoma continue to this day. They have not yet yielded definite favorable data. Neither vaccine therapy nor serum therapy, when applied locally or generally, is accompanied by a noticeable effect in most cases. Non-specific therapy, most often in the form of autohemotherapy, gives a good result in some cases, especially with complications from the cornea. When treating Trachoma, one should not lose sight of the care for the general condition of patients, since clinical practice teaches that Trachoma proceeds especially severely in patients burdened with general suffering, such as tuberculosis, or scrofula, syphilis, etc. Therapy aimed at increasing the general resistance of the organism is fully indicated for Trachoma as well. A stay in good climatic conditions undoubtedly has a favorable influence on the course of trachoma. The beneficial effect of seaside mountainous areas with their dust-free air and ozonized atmosphere has long been pointed out.

V. Chirkovsky.

TREVIRANUS, Gottfried Reinhold (1776–1837), a German biologist who provided a summary of the knowledge and ideas of his time regarding the phenomena and laws of organic life in his works: Biologie oder Philosophie der lebenden Natur, für Naturforscher und Ärzte (Vol. I–VI, Göttingen, 1802–22) and Erscheinungen und Gesetze des organischen Lebens (Vol. I–II, Bremen, 1831–33). His natural philosophy represents a mixture of vitalistic ideas about a "vital plastic force" that has always existed on earth, the ideas of Leibniz and Fichte about the unity of the organization of an individual organism and the organization of the world, with phylogenetic thoughts about the primary generation of primary organic forms from the inorganic world (under the action of the vital force) and the gradual development of higher organisms from them in various directions. Treviranus imagined the system of organisms as a tree with leaves of common origin. In the opinion of Treviranus, each species has a period of growth, prosperity, and decline, transforming into other higher forms, and fossils are the remains of past stages of life.