At 12 weeks after treatment , VISA scores improved by a mean standard deviation of 5.2 12.5 points ( P = .20 ) in the DN group ( n = 12 ) and by 25.4 23.2 points ( P = .01 ) in the PRP group ( n = 9 ) ; at 26 weeks , the scores improved by 33.2 14.0 points ( P = .001 ) in the DN group ( n = 9 ) and by 28.9 25.2 points ( P = .01 ) in the PRP group ( n = 7 ) .