Occupational sunlight exposure, polymorphism of glutathione S-transferase M1, and senile cataract risk.

BACKGROUND

The pathogenesis of cataract is influenced by a number of factors including oxidative stress. Glutathione S-transferase (GST) catalyses the nucleophilic addition of the thiol of GST to electrophilic acceptors. It is important for detoxification of xenobiotics in order to protect tissues from oxidative damage.

OBJECTIVES

To examine whether the interaction of polymorphism of GSTM1 gene and occupational sunlight exposure modulate the risk of cataract.

METHODS

Blood samples from 95 subjects with cataract and 95 age and sex matched healthy persons were collected. The genotypes of GSTM1 were determined using PCR.

RESULTS

The null genotype of GSTM1 was associated with an increase in cataract risk in the indoor workplace, but this association was not significant in the outdoor subjects.

CONCLUSION

The active genotype of GSTM1 has lost its protective role in persons who work outdoors. It is suggested that activity of the GSTmu enzyme may be inhibited in the human lens after occupational exposure to UV light.