Xerophthalmia

XSEROFTALMIA, xerophthalmia (from Greek xeros - dry and ophthalmos - eye; literally "dryness of the eye"), a peculiar change in the conjunctiva and cornea. In the classification of xerophthalmia forms, 1) a deep parenchymatous form of X. is distinguished, explained by deep lesions of the tunica fibrosa and cornea, and 2) an epithelial form - superficial. - Parenchymatous X. has among the most important local causes the cicatricial transformation of the conjunctiva in trachoma (especially in far-advanced cases), pemphigus, and rarely after burns and diphtheria. The clinical picture of the conjunctiva: the tunica fibrosa loses its mucous properties, dry spots appear in it, it becomes matte and as if smooth, greased with fat. In pronounced cases, this dryness spreads to the entire tunica fibrosa, and then shortening of the conjunctival sac occurs. The sensitivity of the conjunctiva, as well as the cornea, is usually sharply reduced. Subjectively, an unpleasant sensation of burning in the eyes is noted; when the cornea is involved in the process, a significant reduction in visual acuity inevitably occurs, which can bring the patient to complete blindness. In the main, parenchymatous X. is explained by the atrophy of the entire glandular apparatus of the conjunctiva with the stagnation of the excretory ducts, as well as the closure of the excretory ducts of the lacrimal gland. The X. Vas. xerosis (xerotic bacillus) found in smears in this disease belongs to the group of saprophytic bacteria and has nothing in common with X. in an etiological respect. This bacillus is generally devoid of any virulent properties for humans and animals. - Epithelial form of X. affects the conjunctiva and less often the cornea. Observations made long ago regarding X. and the mild, rapidly passing form of hemeralopia have shown a certain epidemicity in their occurrence. Such "epidemics" were observed in prisons, barracks, and on ships. Fuss and Bles-sig, studying this disease during long seminovember fasts in Russia, also admitted the influence of poor nutrition in the pathogenesis of these disorders at that time. Further research showed that here we are dealing with disorders associated with the absence in the diet of vitamin A, which is contained in milk, eggs, carrots, etc. Some old authors also attributed the occurrence of X. to alcoholism (Uhthoff) and even meteorological influences (Shchepotiev); but according to the current state of the question, a close connection between avitaminosis and such disorders of the visual organ as paratypic hemeralopia, X., and keratomalacia, which are different degrees of the same process (see Avitaminoses), is indisputably established. - According to observations by Birnbacher, the younger the organism, the more sensitive it is to the absence of vitamins and in particular vitamin A, due to which X. develops in children, especially at a young age. Thus, in children under 10 years of age suffering from hemeralopia, Birnbacher saw xerosis in 72.2%, in the second decade - 51.4%, in age over 20 years - in men 30.6%, and in women 18.5%. Most authors note that the disease occurs in spring. Patho-anatomical changes are reduced to the lesion of the epithelium, which thickens and takes on the character of the epidermis. Those places that are favorite for X. are those exposed to external influences, i.e., the conjunctiva and cornea in the area of the palpebral fissure. It is precisely in the triangle having its base at the limbal edge that special white dry spots, described by Bitot and bearing the name of Bitot's spots, are observed. The mucous membrane here is slightly thickened, matte in color, and as if covered with a white coating. The surface of the affected area is devoid of shine and moisture and, being washed by tears, seems not to be moistened by them anymore. Subjectively, the signs of this state are reduced to a sensation of slight burning. - Mostly X. manifests itself on both eyes. After several weeks or months these phenomena disappear, leaving no traces behind in some cases. In some cases, the process develops rapidly into a severe form. Thus, 2 forms are distinguished: in one the course of X. is benign, and in it no complications on the cornea occur, and the other has a malignant course. The latter form usually appears in cachectic children of early age and is often accompanied by corneal lesion. In high degrees of development, xerophthalmia leads to infantile keratomalacia (see). - Prevention - vitamin nutrition. The prognosis is always serious in the parenchymatous form of X. and less threatening in the epithelial form, especially with timely attention to the composition of the diet. - Treatment is different depending on the forms: in parenchymatous X. it is recommended to bandage the eye with a warm compress, repeated prolonged instillation of physiol. solution for moistening the conjunctiva and cornea; various oils (almond) and ointments are also recommended. Among operative interventions, transplantation of the mucous membrane of the lip to the area of the conjunctiva affected by xerosis is applied. In some cases, the application of the operation of Rudin, leaving only a small opening in the area of the cornea by suturing the eyelids, is expedient. In the epithelial form of X., it is necessary to direct treatment towards improving the general condition of the organism: intensified nutrition, rich mainly in vitamin A (cod liver oil, butter, etc.).