Little experimental work has been done on the rickettsias as related to ophthalmology. The inability to find any all-inclusive article on the subject prompted this paper, which is essentially a review of the literature. This topic is more important now, since the armed forces are engaged in combat in areas where rickettsial diseases are more frequent than in the United States.
Rickettsias are small, gram-negative, bacteria-like organisms, often pleomorphic, generally less than 0.5 micron in diameter, staining lightly with aniline dyes but well with Giemsa's stain, living and multiplying in arthropod tissues and acting as obligate intracellular parasites. Pinkerton1 stated that forty-two micro-organisms described as rickettsias, all of which are nonpathogenic for mammals, have been observed in thirty-seven species of arthropods. Only four pathogenic organisms at present can be classified with rickettsias on the basis of the definition given: 1. Rickettsia prowazeki is named in honor of the
H. P. VENABLE, F. J. POLLOCK. RICKETTSIAS IN OPHTHALMOLOGY. Arch Ophthalmol. 1943;30(3):362–370. doi:10.1001/archopht.1943.00880210086009