Encapsulated Bleb

Encapsulated filtering bleb (Tenon's Cyst) with loculated thinning.
  • Also called a Tenon's capsule cyst.

Clinical Features

  • May be associated with progressive conjunctival hyperemia.
  • Signs:
    • Tense, elevated, smooth dome with a thick wall aqueous-filled cyst
    • Absence of conjunctival microcysts
  • Usually appears during the first postoperative month
  • Complications associated with encapsulated filtration blebs include elevated intraocular pressure, corneal dellen, and ocular discomfort.


  • Resumption of glaucoma medications (aqueous suppressants) to lower the IOP and to allow the remodeling of the cyst wall. The encapsulation gradually resolves after a period of 2-4 months.
  • Digital pressure and steroid therapy may be useful to reverse the encapsulation response and improve bleb function.
  • If medical therapy is insufficient to control IOP, a surgical approach (e.g. bleb needling, surgical revision) should be considered.
  • Repeated bleb needling at the slit-lamp can effectively puncture the fibrous tissue and encourage filtration.
  • When bleb needling is unsuccessful, a more invasive technique such as surgical excision of the fibrous capsule may be necessary