AIM:To observe the related factors that effected tear film functions due to pars plana vitrectomy (PPV).METHODS:Ninety eyes of participants who had received PPV were observed.The related factors (sex,age,IOP,diabetes mellitus (DM),the modus operandi,the period of surgery)were analyzed respectively,Logistic regression analytic manner in normal conditions was used to study all the related factors.RESULTS:The factors of age and the period of surgery effected tear film functions.There were not relationship between sex,IOP,DM,modus operandi and the dry eye.CONCLUSION:The age and the period of surgery are dangerous factors that effect tear film functions after PPV.