Purpose: To investigate whether vitreous and aqueous humor concentrations of vascular endothelial growth factor (VEGF) predict postoperative complications after vitrectomy for proliferative diabetic retinopathy (PDR).
Methods: Sixty eyes of 52 patients with PDR who underwent vitrectomy were enrolled. Vitreous and aqueous humor were obtained from eyes with PDR during primary vitrectomy and the levels of VEGF were measured using a commercial flow cytometer. Patients were followed for more than 6 months after surgery. Demographic data and both intraoperative and postoperative findings were recorded. The relationship between VEGF levels in ocular fluids and the main postoperative complications of early vitreous hemorrhage (VH) and neovascular glaucoma (NVG) occurring during follow-up was analyzed. Logistic regression analyses were performed to examine risk factors related to postoperative complications.
Results: Early VH occurred in 25%, and NVG occurred in 8% of 60 eyes. The vitreous levels of VEGF were significantly higher (P = 0.015) in eyes with early VH than in those without. The aqueous humor and vitreous levels of VEGF were significantly higher (P = 0.005 and P = 0.001, respectively) in eyes with NVG than in those without. Axial length was significantly shorter in eyes with early VH than in those without (P = 0.028). Multivariate logistic regression analysis showed that the higher vitreous VEGF level was associated with a risk of early VH after vitrectomy for PDR (odds ratio, 5.1; P = 0.020).
Conclusions: High intraocular VEGF level at the time of primary vitrectomy in patients with PDR was identified as a significant risk factor for postoperative early VH.