A treatment method is provided that includes an introduction step of introducing a transparent stent into a vitreous body of an eyeball, an expansion step of causing the stent to expansively deform inside the vitreous body to bring a retina into contact with a retinal pigment epithelium, and a placement step of placing the stent in the vitreous body with the stent keeping the retina in contact with the retinal pigment epithelium.
