santonin and Retinal-Diseases

Drug-induced dyschromatopsias are defined as functional or objective alterations of color sense following drug treatment. Drug induced chromatopsias are characterized by a perception of white surfaces as colored and occur following modifications of normally transparent structures or alterations of the chorioretina or higher centers. Digitalic intoxication is responsible for incorrect perception of yellow or blue; the retinal origin of the disorder is confirmed by electroretinograms and histologic modifications in the photoreceptor synapses. Santonin in doses exceeding 1 cg is associated with various color misperceptions due to injury to a peripheral neuron or problems of rhodopsin formation. Some sulfas and antibiotics may cause misperception of yellow, and the anticonvulsant drug Tridione may cause an almost complete disappearance of some colors. Chromotopsias of central origin due to direct action on cerebral neurons are rare but may follow use of phenacetine or atropine. Drug induced dyschromatopsias are more common and may be the initial symptoms of various kinds of drug intoxication. Various simple and reliable tests enable the practicing clinician to detect such disorders at an early stage. Synthetic antimalarial drugs derived from chloroquine and used in longterm treatment of rheumatism or during antimalarial prophylaxis, indomethacine, and the phenotiazins may cause dyschromatopsias due to retinal intoxication. Oral contraceptives diminish the chromatic perception in 20% of cases according to 1 author, and often cause deficits of blue-yellow perception. Disulfiram, certain antibiotics such as chloramphenicol, nystatin, isoniazide, and other drugs may cause dyschromatopsias due to alterations in the optical fibers. Ethambutol is the most harmful to color perception; its effects are usually but not always reversible on discontinuation of the drug. Systematic tests of color perception should be administered prior to and during treatment with any drug known to affect the color sense.

Topics: Antimalarials; Brain Diseases; Color Perception; Color Perception Tests; Contraceptives, Oral; Digitalis Glycosides; Disulfiram; Ethambutol; Female; Humans; Methods; Monoamine Oxidase Inhibitors; Phenothiazines; Retinal Diseases; Santonin; Vision Disorders; Visual Pathways