AIMS:To investigate the etiological factors and various effects of severe vitreous hemorrhage(VH)in Northern China.

METHODS: Files on patients presenting with VH treated with vitrectomy between January 2011 and January 2014 were retrieved from medical records.

RESULTS:A total of 1 335 eyes of 1 275 patients(735 males, 540 females)presenting with VH were included in this study. Proliferative diabetic retinopathy(PDR), retinal vein occlusion(RVO), either retinal detachment or retinal hole(RD/RH), ocular trauma, Eales disease, and either age-related macular degeneration or polypoidal choroidal vasculopathy(AMD/PCV)constituted the etiology of VH in more than 90% of the patients. The most common causes of VH were ocular trauma(40%), PDR(19.5%), and Eales disease(19.1%)in the youth group, PDR(34.4%), RVO(30.8%), and RD/RH(12.2%)in the middle-aged group, and RVO(35.7%), PDR(26.6%), RD/RH(14.6%), and AMD/PCV(8%)in the elder group.

CONCLUSION:PDR, RVO, and ocular trauma are usually the main causes of VH. Within each group, the most common causes of VH were ocular trauma and Eales disease in the youth group, PDR, RVO, and RD/RH in the middle-aged group, and RVO, PDR, RD/RH, and AMD/PCV in the elder group. In addition, we found that males with ocular trauma are at high risk for VH, PDR and Eales disease often present bilateral VHs, and PDR and RVO have a high risk of recurrence.