Tube-Shunt Bleb Pathophysiology, the Cytokine Story.

Purpose: To define tube bleb-pathophysiology, outlining factors that may play a major role in the ultimate success or failure of the bleb. Methods that may be used to advance success of these blebs are discussed.

Materials And Methods: The study describes the importance of tube shunt bleb pathophysiology, including the role of cytokines, relating to bleb failure or success. Methods to influence these outcomes, are outlined.

Results: Understanding the various parameters involved with the pathophysiology of tube shunt blebs, especially intraocular pressure (IOP), and cytokine content of aqueous. The production of cytokines by tube shunt blebs, and the possible adverse results of this action on a second tube shunt in a different quadrant of the eye.

Conclusions: Tube shunts are conduits transporting aqueous from within the eye to the subconjunctival space. The ultimate end result is to create a drainage bleb over the tube plate. The formation of the bleb is controlled by multifactorial components, including age of the patient, racial background, presurgical IOP, and thereby aqueous cytokine content, and patient's individual reaction to the presence of a foreign body beneath the conjunctiva. Prolonged IOP within the bleb results in cytokine production by the bleb lining. Occluding the tube of a failed implant can prevent damage to a new implant in a different eye quadrant.