Vitreous Mediators after Intravitreal Bevacizumab or Triamcinolone Acetonide in Eyes with Proliferative Diabetic Retinopathy

Purpose: To evaluate vitreous vascular endothelial growth factor (VEGF), stromal cell-derived factor 1α (SDF-1α), interleukins (ILs), and tumor necrosis factor-α (TNF-α) after intravitreal bevacizumab or triamcinolone acetonide (TA) in eyes with proliferative diabetic retinopathy (PDR). Design: Interventional, consecutive, retrospective, comparative study with a historical control. Participants: Forty-seven eyes of 47 patients affected by active PDR were investigated. Bevacizumab (1.25 mg; 19 eyes; bevacizumab group) or TA (4 mg; 10 eyes; TA group) was injected into the vitreous cavity as preoperative adjunctive therapy 7 days before vitrectomy. Eighteen eyes without injection served as controls (control group). Methods: The vitreous samples were obtained at vitrectomy and were analyzed for concentrations of total protein, VEGF, SDF-1α, IL-1β, IL-6, IL-8, IL-10, IL-12p70, and TNF-α. Main Outcome Measures: Vitreous concentrations of VEGF, SDF-1α, ILs, and TNF-α were compared among bevacizumab, TA, and control groups. Results: Vitreous concentrations of VEGF and SDF-1α were lower in bevacizumab and TA groups compared with the control group. The median VEGF level was 0 pg/ml (range, 0-79.2 pg/ml) in the bevacizumab group, 343.5 pg/ml (range, 0-1683.3 pg/ml) in the TA group, and 1202.5 pg/ml (range, 76-4213.9 pg/ml) in the control group. The median SDF-1α level was 149.2 pg/ml (range, 0-519.4 pg/ml) in the bevacizumab group, 87.5 pg/ml (range, 0-252.5 pg/ml) in the TA group, and 245.7 pg/ml (range, 0-856.8 pg/ml) in the control group. The differences in both vitreous VEGF and SDF-1α concentrations among 3 groups were statistically significant (P<0.001 and P = 0.010, respectively). The eyes with intravitreal bevacizumab demonstrated the lowest vitreous level of VEGF, and the level was statistically significant compared with the eyes with intravitreal TA and control eyes (P<0.001 and P<0.001, respectively). The control eyes had the highest vitreous level of SDF-1α, and the level was statistically significant compared with the eyes with intravitreal bevacizumab and TA (P = 0.015 and P = 0.009, respectively). There was no significant difference regarding ILs and TNF-α. Conclusions: Intravitreal injection of bevacizumab potentially diminishes not only VEGF but also SDF-1α. These findings suggest that intravitreal bevacizumab may influence intraocular mediators beyond VEGF. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.