Clinical Study of Subretinal Transplantation of Human Embryo Stem Cell Derived Retinal Pigment Epitheliums in Treatment of Macular Degeneration Diseases

Inclusion Criteria: * Aging from 18 to 75 years * must have signed informed consent * At least one visually impaired eye caused by macular degeneration diseases * Can not be effectively treated with conventional therapies * Best corrected visual acuity scores between 19 and 73 letter in ETDRs (early treatment diabetic retinopathy ) eye chart , including 19 and 73 (or the equivalent of Snellen eyesight from 20/400 to 20/40) * Visual loss caused by macular degeneration diseases Exclusion Criteria: * Eyes with concomitant diseases which will interfere the visual improvement of the study * Active intraocular inflammation regardless of the grade of severity * Active infection (e.g. conjunctivitis, keratitis, scleritis, uveitis, ophthalmia) * History of uveitis * Severe cataract, glaucoma, retinal blood vessels occlusion, retinal detachment, macular hole, vitreous-macula traction * Iris neovascularization * Patients who have only one functioning eye, or the best corrected vision of untreated eye scores less than 24 letters in ETDRS chart(corresponding to 20/320 in Snellen chart) * History of intraocular surgery * Severe systemic diseases: Stroke, coronary heart disease, angina pectoris, renal insufficiency needing dialysis * Allergic to sodium fluorescein * Uncontrolled hypertension (systolic pressure\>140mmHg,or diastolic pressure\>90mmHg) * Coagulative function disorder * System administration of drugs that are toxic to lens, retina, or optic nerve like hydroxychloroquine, phenothiazine, ethambutol, tamoxifen, etc. * Involved in other clinical trials of any medicine within 1 month (or within 5 half-life periods) * Have maternity plan in 6 months * In pregnancy or lactation period.