The positive rates of bacterial culture before conjunctival sac irrigation were 17.31 % ( 18 eyes ) in group A , 13.86 % ( 14 eyes ) in group B and 17.3 % ( 14 eyes ) in group C. Post irrigation , the positive rates in the three groups decreased to 5.76 % ( 6 eyes ) , 5.94 % ( 6 eyes ) and 7.22 % ( 7 eyes ) , respectively .