Xanthopsia

XANTHOPSIA, xanthopsia, xanthopia (from the Greek xanthos - yellow and opsis - vision), the perception of objects in a yellow light. Xanthopsia, which appears in jaundice, was known even to the ancient Greeks and Indians (Hirschberg). In addition to jaundice, it is observed in poisoning with picric acid (trinitrophenol) and santonin (C₁₅H₁₈O₃). With the latter, xanthopsia occurs shortly after taking a therapeutic dose and lasts from 10 minutes to 2 hours (Uhthoff). In such cases, violet vision is also sometimes observed. Xanthopsia caused by picric acid and santonin can also be produced experimentally. In amyl nitrite poisoning (C₅H₁₁ONO), a yellow ring is observed at the point of fixation (Uhthoff). Aside from intoxication, xanthopsia occurs in a whole series of diseases: for example, in Hilbert's summary (1908), out of 21 cases of xanthopsia, it was present 3 times on the basis of neurasthenia, 1 in epilepsy, 2 in helminthiasis, 2 in jaundice, 1 in sunstroke, 1 in connection with the gynecological sphere, 3 in hemeralopia, 2 in influenza, 1 in diabetes, 1 in concussion of the brain, 1 in typhus, 1 in otitis media, 1 in Weil's disease, and 1 in arteriosclerosis. Recently, Giesler described a case of xanthopsia caused by digitalis intoxication, and Yamaguchi described xanthopsia that arose during the nephritis of a pregnant woman and disappeared after an abortion was performed. Regarding the section of the visual organ and visual pathways in which the lesion causing xanthopsia occurs, there are three assumptions: one attributes it to a functional disorder of central origin, another to a retrobulbar peripheral lesion, and the third to the coloration of the refractive media. The first of these is admitted by Hilbert in his case of self-poisoning with the ingestion of 0.3 g of picric acid. Most authors are inclined to explain xanthopsia by a retrobulbar peripheral lesion. In jaundice, the transition of bile coloring matters into the tissues of the transparent media is assumed. Retinal origin of xanthopsia is especially probable in those cases where objects visible in the light in a yellow coloration become violet with the onset of darkness; a similar phenomenon occurs in erythropsia, in which objects in the shade appear green. Xanthopsia is not accompanied by organic changes in the fundus, and only certain authors, such as Rose and Koenigsberg, occasionally saw a yellow tint of the optic disc and fundus in jaundice. Rose, who was the first to subject a case of xanthopsia to physical investigation, found a shortening of the spectrum in its green part. Thus, the cause of the origin of xanthopsia still remains unclarified. The prognosis is favorable; treatment is based on the therapy of the underlying disease.