Filtering Blebs
Filtering blebs fail for a variety of reasons. Only rarely is the blockage at the level of the internal ostium. Other identifiable locations for blockage to aqueous outflow include beneath the scleral flap, at the level of the episclera, and at the episclera-Tenon's fascia-conjunctiva interface. Precise localization of the site of blockage facilitates slit-lamp transconjunctival needle revision and restoration of flow in many eyes.
Normal Appearance
Click image to enlargeNormal ultrasound biomicroscopic appearance of a functioning filtering bleb. Clear fluid-filled spaces can be identified in the subconjunctival and sub-Tenon's spaces above the level of the episclera.
TOPBlockage at the level of the internal ostium
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Blockage at the level of the intrascleral pathway
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Blockage at the level of the episclera
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Click image to enlargeBlockage within Tenon's fascia and the subconjunctival space in this patient with an encapsulated filtering bleb.
Home > Patient Care & Services > Laboratories & Specialty Facilities > Ocular Imaging Center > UBM Clinical Database > FILTERING BLEBS
Main Number: 212-979-4000 • Physician Referral Line: 212-979-4472
