At @ weeks after treatment , VISA scores improved by a mean standard deviation of @ @ points ( P = @ ) in the DN group ( n = @ ) and by @ @ points ( P = @ ) in the PRP group ( n = @ ) ; at @ weeks , the scores improved by @ @ points ( P = @ ) in the DN group ( n = @ ) and by @ @ points ( P = @ ) in the PRP group ( n = @ ) .