[Modifications in blood zinc and lead concentrations and ALA-dehydratase activity in optic neuropathy from alcohol and tobacco abuse].

Plasma red blood cell and total blood zinc levels were significantly decreased in 52 consecutives cases of bilateral, retrobulbar, axial optic neuropathy caused by chronic abuse of ordinary wine and/or beer and/or hard beverages and cigarette smoking principally in men in their forties [plasma zinc: 746 mg/l +/- 179 (n = 52), control 907 mg/l +/- 127; red blood cell zinc: 10,218 mg/l +/- 1,327 (n = 10), control 12,244 mg/l +/- 1,307; total blood zinc: 4,849 mg/l +/- 1,069 (n = 51), control 5,831 mg/l +/- 644]. In contrast, blood lead levels were increased in these cases - blood lead: 344 mg/l +/- 101 (n = 30), control 193 mg/l +/- 94. Activity of red blood cell delta-amino-levulinic acid dehydratase (ALA-dehydratase), a zinc dependent enzyme, was decreased [red blood cell ALA-dehydratase; 18,8 IU/l +/- 2,2 (n = 13), control 44,8 IU/l +/- 3,3]. Plasma magnesium was slightly decreased while serum copper was not significantly modified. Possible ophthalmological implication of these findings are discussed.