A method of tightening inter-cellular junctions in retinal or choroidal vessel cells includes exposing the retinal or choroidal vessel cells to norrin and an anti-VEGF agent. Upon sufficient contact time, for norrin to selectively up-regulate gene expression of VE-cadherin or claudin-5 in the retinal or choroidal vessel cells, the inter-cellular junctions are tightened. The method is also suitable for treating retinal pigment epithelial cells in wet macular degeneration.
