Chronic carbon disulphide poisoning: a 4 year follow-up study of the ophthalmological signs

Thirty workers of a viscose rayon industry had a complete eye examination in 1979 including visual acuity, perimetry, colour vision testing, fluorescein angiography, ERG and EOG, for possible signs of chronic carbon disulphide poisoning. They were divided into two groups, group A included workers exposed to relatively high CS2 levels (at least 50 mg/m3), group B working in the relatively safe bleaching division. In both groups fundus anomalies and abnormal EOG's en ERG's were found. Twenty-nine of these thirty workers were reexamined in 1983. A number of them were no longer exposed to CS2 for a period varying between 1 and 43 months. The fundus signs (pigmentary changes and vascular lesions) increased in frequency, even if the patient was no longer exposed. The light/dark ratio of the EOG after 4 years was decreased in comparison with the first EOG, although this was not statistically significant. The ERG improved on follow-up. This could be related either to a shift to supranormal amplitudes or to recovery from subnormal amplitudes after the patient was no longer exposed.