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.