AIM:To evaluate the efficacy of fluorescein sodium on dyeing residual vitreous during the vitrectomy.To discuss the effect of fluorescein sodium which can demarcate the residue vitreous on vitrectomy and whether there are statistical significance on postoperative intraocular pressure(IOP) and visual acuity with comparison group and whether it can decrease the complications or not during vitrectomy.To investigate whether the fluorescein sodium can produce retinal toxicity or not through clinical study.METHODS:The study included 60 cases (60 eyes) who underwent vitrectomy in the first clinical hospital of Harbin medical university from September,2009 to September,2010.The 60 cases were proliferative vitreous retinopathy or detachment of retina,without operation experience of posterior segment in the past.There were not any condition affecting the ocular disease.All the patients could endure the vitrectomy,and they had had common body examination and ocular examination.All eyes were examined by slit-lamp biomicroscopy,binocular indirect ophthalmoscopy,B-scan and electroretinography before operation.The condition of cornea,anterior chamber,lens,vitreous body,retina,etc.were learned about.60 cases with vitrectomy were divided into study group and control group.Fluorescein sodium injection was taken orally in 30 eyes of study group before the surgery.Fluorescein sodium was not used in the 30 eyes of control group.All eyes were examined by slit-lamp biomicroscopy,binocular indirect ophthalmoscopy,B-scan after operation.The mean follow-up was 1 month after operation,visual acuity and IOP of the two groups were compared and analyzed.RESULTS:The location and coverage of the residual vitreous cortex were clearly shown by fluorescein sodium and the residual vitreous cortex was conveniently to be recognized and removed There was neither difference in visual acuity,IOP before and after operation nor obvious ocular complications related to fluorescein sodium,and no evident differences in comparison between the two groups.CONCLUSION:Location and coverage of the residual vitreous cortex were clearly shown by fluorescein sodium.It has the surgery safety,without obvious adverse reactions,and decreases the complicating diseases such as incidence of iatrogenic retinal break.It is profitable to protect and recover visual function without intraocular toxicity.