Impact of tobacco use on oxidative stress in cataract

Abstract

Even today, the leading cause of visual impairment is age related cataract. Among the risk factors for cataract, tobacco is one of the modifiable risk factors. Association between smoking and increased oxidative stress among cataract patients has been shown by some studies. But studies related to smokeless tobacco use are not done. The aim of the study was to estimate oxidative stress by markers like enzymatic antioxidant Superoxide Dismutase (SOD) and lipid peroxiation product Malondialdehyde (MDA) in tobacco user age related cataract (ARC) subjects and compare them with tobacco nonuser age related cataract (ARC) subjects. This cross sectional study was performed in 120 subjects divided into 2 groups – 60 tobacco nonuser age related cataract subjects and 60 tobacco user age related cataract subjects. 60 tobacco user cataract subjects divided into 5 groups - tobacco smokers, tobacco chewers, tobacco mishri users, dual tobacco chewers with mishri users and dual smokers with smokeless tobacco users. Oxidative stress was assessed by estimation of erythrocytic SOD and serum MDA. The study showed that in tobacco user group age of cataract patients was significantly less than tobacco nonuser cataract patients (P<0.05). Serum MDA levels were significantly high and erythrocytic SOD levels were significantly low in tobacco user cataract patients than tobacco nonuser cataract patients (P<0.001). Nuclear cataract was significantly more in tobacco user group (P<0.05). On comparison of subtypes of cataract in tobacco user subgroup, no significant difference was found. These results suggested that age related Cataract occurs at an earlier age in tobacco users due to increased oxidative stress. Also nuclear cataract was significantly associated with tobacco use.