VEGF-A Antisense Oligonucleotide Therapy Inhibits Corneal Neovascularisation and Enhances Graft Survival in Murine High-Risk Corneal Transplantation.

BACKGROUND: To investigate, for the first time, whether an unconjugated VEGF-A antisense oligonucleotide (ASO) can inhibit corneal neovascularisation and improve graft survival in a murine high-risk corneal transplantation model. METHODS: A suture-induced corneal neovascularisation model was established in BALB/c mice, followed by high-risk corneal transplantation using C57BL/6 donor corneas. A VEGF-A RNase H-recruiting ASO (gapmer) was delivered via subconjunctival injection, topical eye drops, or ex vivo preincubation of donor corneas. Blood vessels (BVs) and lymphatic vessels (LVs) were quantified by immunohistochemistry, and Vegfa mRNA expression was measured by qPCR. Immune cell profiles in draining lymph nodes (dLNs), focusing on regulatory T cells (Tregs) and dendritic cells (DCs), were analysed by flow cytometry. Graft survival was monitored for 8 weeks using Kaplan-Meier analysis. RESULTS: Subconjunctival and topical VEGF-A ASO administration significantly suppressed corneal hemangiogenesis and lymphangiogenesis (p < 0.05). Subconjunctival injection also induced regression of established vessels (BVs -21.76%, p = 0.0039; LVs -49.75%, p = 0.0110). Graft survival improved significantly after subconjunctival treatment (p = 0.0438) and donor cornea preincubation (p = 0.0148). Flow cytometry showed increased Treg frequency in dLNs following subconjunctival ASO administration (p = 0.0293). Preincubation of donor corneas markedly reduced Vegfa mRNA levels (p < 0.0001). CONCLUSIONS: VEGF-A-targeting ASO effectively inhibits corneal neovascularisation and improves graft survival in high-risk transplantation. Local and ex vivo VEGF-A inhibition using ASO represents a promising therapeutic strategy for controlling ocular neovascularisation and enhancing corneal transplant outcomes.