The absolute risk ratio (ARR) of NPTS for adverse event was 3.0%, (NNT=33.2), it costs additional RMB $116,100 for preventing one adverse event.

• 低眼压性黄斑水肿1只眼。 (6)成本效果分析:NPTS组对不良事件的绝对风险降低率(ARR)=3.；0%25；防止1例不良事件发生需治疗的病例数(NNT)=33