A method of treating a detachment of a retina of an eye, the method including the steps of injecting a substance into a vitreous cavity of the eye, the substance slowing flow of fluid through the vitreous cavity into a subretinal space to reduce a rate of accumulation of a subretinal fluid in the subretinal space to below a rate of removal of the subretinal fluid from the subretinal space by retinal pigment epithelium and permitting the retinal pigment epithelium to reattach the retina. The invention also includes devices for practicing the method.