Recent Progress in Ophthalmology

MYLES STANDISH, WM. DUDLEY HALL
1907 Boston Medical and Surgical Journal  
pan osomes have probably been the favorite subject of study. Although the first of this group was described by Valentine more than sixty years ago, who found it in the blood of a salmon, and, although from time to time allied organisms have been identified, sustained work in this direction was not begun until some years later. When Evans in 1880 demonstrated that a disease of camels and horses, known as surra, was dependent upon the presence in the blood of the animal, of a protozoal organism,
more » ... rotozoal organism, there was quickly instituted a series of experiments which had, as a result, an appreciation of the proper relation which should exist between plant and animal life as an exciter of infectious diseases. This organism, the trypanosome, may be briefly considered as a fusiform, more or less elongated body, about the length of the diameter of a blood corpuscle, possessed of a fin-like membrane, longitudinally, ¡nid a terminal fiagellum. It was soon found that other diseases of animals as, nagana, mal de caderas, dourine, etc., might be ascribed to other members of this group. These discoveries attracted but little notice in the medical world until Dutton identified a trypanosome in the blood of a European, who had resided in the Gambia region, and Castellaiii showed the significance of its presence in the cephalo-rachidian fluid of negroes who were suffering from the disease known as " sleeping sickness." Thus far the conditions set up by the parasite have been met with, for the most part, in Africa, Asia, and South America; but Morax, in a recent paper,1 has published the results of his work in the experimental pathology of the disease, paying especial regard to the ocular manifestations. He was struck by resemblances between certain corneal appearances in dourine and the well known lesions of interstitial keratitis observed in syphilis. Nagana, the tsetse-fly disease, affects all domestic animals and many that are wild, and is invariably fatal to the horse and dog, although a certain percentage of cattle recover. The duration may be several weeks or several months, and in case of recovery a certain immunity seems to be established in the animal in question for this particular form, but not for others of the group, thereby suggesting a certain specific character. Man is naturally immune, probably through some peculiar property of his blood plasma. Symptomatically there is noticed fever, lymph infiltration of subcutaneous tissues of neck, abdomen and extremities, destruction of red blood corpuscles, 1 Ann. d'Ooulist., Doc, 190(1. extreme emaciation, blindness and the constant presence in the blood of a parasite which was identified by Bruce in 1894 and which bearskins name.
doi:10.1056/nejm190710101571505 fatcat:qungrcwdazhhbpqtlkwhlgcezu