Flexibility, Efficacy, and Safety of a Foldable Capsular Vitreous Body in the Treatment of Severe Retinal Detachment

Inclusion Criteria: 1. age range from 18 to 65, Refractive error less than ±3D 2. Corrected visual acuity less than 0.05 3. ocular axial length is 16 to 25mm 4. severe retinal detachment that can not be treated by current artificial vitreous body: 1. Severe unilateral ocular perforating injuries, compounded retinal or choroidal detachments resulted from retinal rupture or retinal choroidal hemorrhage. 2. Severe unilateral ocular rupture injuries result in retina or choroid defect. 3. Giant posterior scleral rupture injuries that can not be repaired. 4. Silicone oil can't be taken out for a long time with incomplete reattachment. 5. Participants have undergone retinal detachment surgery and silicone oil tamponade twice or more, however, retina is re-detachment after silicone oil removal. 5. Participants can understand the aim of this clinical trial and sign the informed consent form Exclusion Criteria: 1. Participants have a silica gel allergy or scar diathesis 2. entophthalmia 3. uveitis 4. The contralateral eye suffered from intraocular surgery 5. uncontrollable the other eye diseases 6. Corrected visual acuity of contralateral eye less than 0.4 7. Proliferative diabetic retinopathy 8. the lens of target eye is transparent 9. Serious heart, lung, liver and kidney dysfunction 10. pregnancy, preparation for pregnancy during clinical trial and breast-feeding female 11. drug abuse or alcoholism 12. participated the other drug or medical devices clinical trial before screening of this trial 13. Any research doctors consider that the condition of participants will hinder the clinical trial--Prone to mental stress, loss control of mood, depression etc. 14. Patient adherence is so poor that study procedures can not be finished