ABSTRACT
Background Age-related cataract is one of the common causes of blindness.Although the pathophysiology of age-related cataract is far from clearly understood,it is well accepted that DNA damage plays an important role in the disease pathogenesis.Objective The purpose of this study was to quantitatively evaluate the DNA damage in peripheral lymphocytes of age-related cataract.Methods A cross-sectional study was carried out.This study complied Declaration of Helsinki and approved by Ethic Committee of Affiliated Hospital of Nantong University.Written informed consent was obtained from each subject.Two hundred and eleven patients with agerelated cataract and 147 normal subjects were enrolled from a “ Jiangsu Eye Study:Funing 2011 Eye Disease Epidemic Survey”.All the subjects aged from 50 through 80 years with matched age and gender between the two groups.The percentage of tail DNA and Olive tail moment (OTM) were detected by comet assay to assess the extent of DNA damage in peripheral lymphocytes.Statistical analyses were performed with SPSS 17.0 software,and the differences of the percentage of tail DNA and OTM were compared between the age-related cataract group and normal control group by independent sample t test as well as among the 50-59 years group,60-69 years group and ≥70 years group by one-way analysis of variance.Results Comet assay showed a round lymph cell with the clear border in the normal group;while in the age-related cataract group,the cell was bigger with a comet-like tail.The percentage of tail DNA and OTM in peripheral lymphocytes were (21.75 ± 3.51) ％ and 6.54 ± 1.65 in the age-related cataract group,and those in the normal control group were (9.31 ±3.60)％ and 2.18 ± 1.10,respectively,with significant differences between them (t =32.67,P =0.00 ; t =28.02,P =O.00).In the 50-59 years subgroup of the age-related cataract group,the percentage of tail DNA and OTM in peripheral lymphocytes were (20.04±2.86) ％ and 5.92± 1.14,and in the 60-69 years subgroup of the age-related cataract group,the percentage of tail DNA and OTM in peripheral lymphocytes were (20.77 ±2.93) ％ and 6.13 ± 1.14,which were significantly reduced in comparison with (22.79 ± 3.67)％ and 6.95±1.91 of the ≥70years subgroup(TailDNA％:q=2.75,P=0.00; q=2.02,P=0.00;OTM:q=1.03,P =0.02 ; q =0.82,P =0.00).Conclusions The pathogenesis and development of age-related cataract probably is associated with DNA damage.