The objective of the study is to evaluate:

1. Safety and efficacy of a novel foldable capsular scleral buckle (FCSB) in scleral buckling for primary rhegmatogenous retinal detachment (RRD) of medium complexity.
2. Comparison between FCSB and pars plana vitrectomy in therapeutic effects and complications in the treatment of primary RRD of medium complexity.

Pars plana vitrectomy (PPV) and scleral buckling (SB) are major choices in treating rhegmatogenous retinal detachment (RRD) of medium complexity. PPV is more prevailed since it improved internal search for breaks and elimination of vitreous traction. SB has unmatched advantages over PPV such as earlier rehabilitation, free from prolonged positioning, less complicated cataract or glaucoma. The novel foldable capsular scleral buckle (FCSB) can create a big bulge by pressing on the sclera and seal the break in bullous RRD without scleral drainage. In the study, differences of anatomic and functional results between PPV and FCSB in treating primary RRD of medium complexity are evaluated.

Inclusion Criteria:

One or more retinal holes which cannot be treated sufficiently with a single silicon sponge or silicone band (e.g. large holes, multiple holes, multiple holes of varying anterior-posterior localisation, massive traction)

Exclusion Criteria

1. simple rhegmatogenous retinal detachment which can be treated with a single silicon sponge or silicone band (e.g. single holes, no traction, limit retinal detachment)
2. Complicated RRD, including macular hole within the arcade, PVR C or D, severe cataract, severe vitreous hemorrhage, unclear macular hole,
3. Combined with other eye diseases that affect vision prognosis.
4. History of other eye surgeries including cataract surgery.
5. Presence of systemic diseases that may affect postoperative observation and follow-up.