Topical application of Cas9 ribonucleoproteins inhibits corneal neovascularization in a mouse model of alkali burn injury

Corneal neovascularization is a sight-threatening condition for which current treatments such as anti-VEGF agents are limited by invasiveness and side effects. We present the first non-viral, CRISPR/Cas9-based gene therapy delivered via topical eye drops that penetrates the cornea and inhibits pathological neovascularization. Cas9 ribonucleoproteins (RNPs) targeting the Vegfa gene were complexed with a liposomal carrier (lipofectamine) and administered to mice after alkali burn injury to the cornea. This approach achieved approximately 2% gene editing at the Vegfa locus in vivo, which significantly reduced local VEGF-A expression. Consequently, treated corneas showed markedly decreased macrophage infiltration and robust suppression of both hemangiogenesis and lymphangiogenesis compared to untreated controls. These findings demonstrate that even modest in vivo gene editing can yield a strong therapeutic effect, highlighting a clinically relevant strategy for controlling corneal angiogenesis. Our study introduces a feasible and safe topical CRISPR therapy for corneal diseases, offering a potential alternative to invasive or virus-based gene delivery methods.