Postvitrectomy diabetic vitreous hemorrhage in proliferative diabetic retinopathy

To investigate the reasons for postvitrectomy diabetic vitreous hemorrhage (PDVH), and to analyze the time of PDVH onset, the treatment of PDVH, the visual outcome of the treatment, and factors that affect visual acuity after treatment. Materials and Methods: Overall, 292 eyes from 236 patients with proliferative diabetic retinopathy (PDR) underwent vitrectomy from 2006 to 2010. Fifty eyes out of 43 patients had severe postoperative vitreous hemorrhage. The average follow-up duration was 6.8 ± 3.8 months (range, 2-12 months). Results: Recurrent vitreous hemorrhage (VH) after primary vitrectomy occurred in 40 eyes (80%) with an average time of VH onset of 62.5 ± 32.8 days (range, 3-170 days). VH occurred after silicone oil removal occurred in 10 eyes (20%), with an average time of VH onset of 27.4 ± 20.3 days (range, 1-60 days). The reasons for PDVH included chronic errhysis from retinal neovessels (47.1% of the eyes), residual fibrous vascular membrane (12.8% of the eyes), fibrovascular ingrowth at sclerotomy sites (4.3% of the eyes), iris neovessels and neovascular glaucoma (4.3% of the eyes), retinal vein occlusion (2.8% of the eyes), retinal tears (8.1% of the eyes), retinotomy (1.4% of the eyes), epichoroidal bleeding (1.4% of the eyes), polycythemia rubra vera (1.4% of the eyes), hypoperfusional retinopathy (4.3% of the eyes), and unknown reasons (12.8% of the eyes). Visual acuity increased in 43 eyes (86%) after surgical or nonsurgical treatment. The improvement in visual acuity after treatment was not affected by age, sex, duration of diabetes, time of PDVH onset, frequency of surgery, or treatment methods. Conclusion: Postvitrectomy diabetic vitreous hemorrhage commonly occurs two months after vitrectomy. Residual epiretinal neovascularization is the most common cause of PDVH. Active surgical or nonsurgical treatment for severe vitreous hemorrhage can obviously improve the patients’ visual prognosis.