Recent transplantation studies indicate that subretinal space is not always an immunologically privileged site and non-autologous cells may be rejected in patients with exudative age-related macular degeneration (AMD). We performed autologous iris pigment epithelial (IPE) cell transplantation by cell suspension after autologous IPE cell culture in 8 patients with AMD. These patients were followed without immunosuppression between 1.5 and 8 months and the retinal function was analyzed. No cystoid macular edema or fluorescein leakage was observed. Six of the 8 patients improved visual acuity of more than two lines and the other two patients retained preoperative visual acuity. Five patients had increased visual field sensitivity, one patient retained pretransplantation sensitivity, and one patient showed a gradual decrease in sensitivity (one patient was not examined). Although 2 of the 8 patients showed decreased amplitude of flicker electroretinography (ERG) (about 60 to 70% as that of preoperative level), the average improvement of each amplitude of a single white flash (a wave), photopic, or flicker ERG was 123, 102, and 107%, respectively. No proliferative change in the submacular lesion or vitreous cavity was observed after transplantation. From this functional analysis, transplanted autologous IPE may have, in part, an alternative function in regard to the retinal pigment epithelium in the subretinal space.