The Effect of Anti‐VEGF Treatment and Triamcinolone in Experimental Retinal Vein Occlusion

Abstract

AbstractPurpose We investigated the effect of intravitreal injection of anti‐VEGF antibodies and triamcinolone acetonide (TA) in a rat model of central retinal vein occlusion (CRVO).Methods In one eye of adult Brown Norway rats (n=81) CRVO was induced with laser photocoagulation. Animals were divided into 3 groups (each n=27): 1. CRVO only without any treatment; 2. CRVO with anti‐VEGF antibodies; and 3. CRVO with TA. The injection of anti‐VEGF antibodies or TA was performed 15 minutes after CRVO induction. The gene expression was investigated using RT‐PCR in the neural retina 1, 3 and 7 days after CRVO. We analyzed the expression of VEGF‐A, VEGF‐B, PEDF; of channels implicated in retinal osmohomeostasis (Kir4.1, AQP4, AQP1), and of inflammatory factors IL‐1ß and IL‐6.Results CRVO induced a rapid transient upregulation of Vegfa, and a delayed upregulation of Pedf. Further strong, downregulation of Kir4.1, Aqp4, and Aqp1, and striking rapid upregulation of Il1ß and Il6 was observed. Anti‐VEGF antibodies fully prevented the upregulation of Vegfa and of Pedf, and decreased the upregulation of Il1ß. This treatment had no effect on the expression of Kir4.1, Aqp4, Aqp1, and Il6. Intravitreal TA reversed the downregulation of Kir4.1 and accelerated the normalization of the upregulated expression of Il1ß and Il6, but had no significant effect on the expression of Vegfa.Conclusion The anti‐VEGF treatment inhibits strongly the upregulation of Vegfa but influences only marginally the water channels or inflammatory factors. TA inhibits the expression of IL‐1ß and IL‐6, and has neuroprotective effects via improvement of retinal potassium homeostasis.