A membrane that supports the growth of retinal pigmented epithelial cells and comprises a porous non-biodegradable support layer having a pore density of between 1 x 10^7 and 3 x 10^8 pores per square cm. The pore density allows for the desired permeability levels and allows vascularisation. The pores can have a size of between 0.2 micron and 0.5 micron in diameter and the support layer can have a side coated with a glycoprotein. The support layer can be a hydrophilic polymer of a polyester, a polyurethane, a polyuria-urethane, a polyamide, a polyether-ester, a polycarbonate, a polyacrylate, poly(tetrafluroethene), a polysiloxane, a polyelfin and polyoxymethylene. The membrane can be used for the treatment of age related macular degeneration.
