Study design and participants
PDR
EYE
This is a single-center and retrospective study (registered at ClinicalTrials.gov: NCT05631054). It was approved by the Ethics Committee of Tianjin Medical University Eye Hospital (approval number: 2022KY-27) and was conducted in accordance with the Declaration of Helsinki. We included 186 PDR patients (250 eyes) who underwent primary vitrectomy in Tianjin Medical University Eye Hospital from January 2016 to October 2021. We defined 12 months postoperatively as a long-term period because previous studies have indicated that patients could gain stable visual acuity after this period of time (