Electro-oculogram findings in patients treated with antimalarial drugs.

WITHIN the last few years it has become increasingly evident that the antimalarial drugs cause eye damage. First developed as a cure for malaria, these drugs are now widely used in the treatment of the chronic collagenoses for which the dosages are very large and may be prolonged for many years. In this time the drugs accumulate in the body and reach toxic levels. This often results in severe visual disturbances. Corneal deposits of the drugs may temporarily impair the optical properties of the eye, but are of minor importance as they are easily reversible when drug treatment ceases (Hobbs and Calnan, 1958; Zeller and Deering, 1958; Calkins, 1958; Hobbs and Calnan, 1959; Kersley and Palin, 1959; Pau, 1959; Rogers, 1959). However, in a small percentage of patients, permanent retinal damage may result. Many reports have appeared in the literature during the last 4 years describing the fundus appearance and visual defects associated with chloroquine retinopathy (Cambiaggi, 1957; Hobbs, Sorsby, and Freedman, 1959; Sternberg and Laden, 1959; Hobbs, Eadie, and Somerville, 1961; Ellsworth and Zeller, 1961; Rebello, 1961; Smith, 1962; Henkind and Rothfield, 1963). The earliest sign of a retinopathy is said to be a pigmentary disturbance of the macula advancing to give the "bulls-eye" appearance (Henkind and Rothfield, 1963). The retinal changes often progress after discontinuation of therapy and visual acuity drops and central scotomata result. In advanced cases the arteries are attenuated and there may be peripheral pigmentation and considerable areas of field loss. Examination of the fundus oculi gives no indication of the toxic effects of the drugs until irreversible damage has occurred. Also the earliest signs of the retinopathy are extremely difficult to assess. Animal experiments and histopathological examination of human eyes, after long-term antimalarial therapy, have indicated that the drugs selectively damage the pigment epithelium and receptor cells of the retina (Potts, 1963; Wetterholm and Winter, 1964; Bernstein and Ginsberg, 1964).