This study provides further theoretical guidance for clinical application of FCVB through observing and collecting various indicators before and after surgical treatment of the FCVB in the real world.

1. Research purpose: Collect and analyze the medical data in clinical work, in order to provide further theoretical guidance for the clinical application of FCVB.

2. Inclusion criteria: 1) Patients with severe retinal detachment, cannot be cured with existing vitreous substitutes, and are scheduled for FCVB implantation surgery; 2) Patients with silicone oil dependent eye, silicone oil emulsification, and chooses FCVB surgery; 3) Patients whose eyeball Atrophy, and strongly demand eye protection.

3. Exclusion criteria: 1) Patients with positive urine pregnancy test; 2) Patients with FCVB removed and switched to other alternative treatments; 3) Patients the investigator consider are not suitable for this clinical trial.

4. Endpoint Primary endpoint: Changes in corneal transverse diameter and ocular protrusion after 1 year of FCVB implantation.

   Secondary endpoints: visual acuity and intraocular pressure; local inflammatory response and complications evaluation; satisfaction investigated by questionnaire survey.

5. Process Before surgery, collecting the patient's medical history and pre-operative related specialist examination data and subjective opinions of doctors on surgical indications. Recording the surgical procedure, intraoperative complications. After surgery (3 days, 1 week, 2 weeks, 4 weeks, 3 months, 6 months after surgery, 1 year and 1 year follow-up every year), using visual acuity chart, slit lamp microscope, ophthalmoscope, intraocular pressure, Hertel exophthalmometer, vernier caliper to observe the patient's visual acuity, local inflammatory reaction, intraocular pressure and eyeball atrophy changes.

6. Efficacy evaluation Main indicators: the changes of corneal transverse diameter and ocular protrusion were observed 1 year after FCVB implantation.

   Secondary indicators: visual acuity and intraocular pressure; local inflammatory response and complications evaluation; satisfaction investigated through questionnaire survey.

7. Safety evaluation Adverse events that occurred during all studies.

8. Termination criteria During the clinical trial, the clinical trial shall be terminated in any of the following cases; (1) FCVB cannot be implanted (2) Subjects who fail to comply with the program requirements (including loss of follow-up) are subject to termination by the study physician; (3) a female patient who is intentionally pregnant or a female subject who has been confirmed to have been pregnant; (4) Participated in other clinical trials after participating in this clinical trial; (5) Adverse events or serious adverse events occurred during the trial and were unable to continue participating in the study; (6) The subject withdraws the informed consent or requests termination of the trial for some objective reason.

Inclusion Criteria:

1. Patients with the diagnose that severe retinal detachment and cannot be cured with existing vitreous substitutes, or silicone oil dependent eye accompanied with silicone oil emulsification, or eyeball atrophy meanwhile patients strongly demand keeping eyeball.
2. Patients agree to receive FCVB implantation surgery.

Exclusion Criteria:

1. Patients whose urine pregnancy test are positive.
2. Patients whose FCVB have been removed and switched to other alternative treatments.
3. Patients whom the investigator consider are not suitable for this clinical trial.

patients are scheduled for FCVB implantation surgery