Acquired dyschromatopsia in combined exposure to solvents and alcohol.

HYPOTHESIS

Does occupational exposure to solvents in combination with alcohol intake give rise to acquired color vision defects?

METHOD

A total of 138 individuals exposed to solvents (toluene, xylene, trichloroethylene, tetrachloroethylene) were examined using Lanthony's D-15 test and compared with 100 nonexposed controls. The extent of color vision loss was quantitatively assessed based on Bowman's color confusion index (CCI). A cumulative exposure index was calculated from the hours of exposure per day and the years of exposure. In 30 persons who were exposed to trichloroethylene and tetrachloroethylene, urinary trichloroacetic acid was assessed as a parameter of exposure. Alcohol intake was calculated as based on interviews of patients in grams of ethyl alcohol per week.

RESULTS

Individuals who consumed more than 250 g alcohol/week and were simultaneously exposed to solvents showed a significantly elevated CCI (P = 0.0044). No significant correlation emerged between trichloroacetic acid excretion in the urine or the cumulative exposure index and the CCI.

CONCLUSION

The combination of alcohol intake and occupational exposure to solvents discloses the risk of acquired subclinical color vision defects.