Encapsulated filtering bleb. A selective review--new deductions

Filtering bleb encapsulation may, in some cases, be a severe complication following filtering surgery. The cause and mechanism of its development are not known. A selective review of data that might shed some light on these dilemmas, is presented. Based on these data, it is suggested that: (a) non-contractile collagen-producing fibroblasts play a major role in the process of bleb encapsulation, while in wound healing following filtering surgery, contractile fibroblasts are the major components; (b) the process of bleb encapsulation is less sensitive to the toxic effect of 5-Fluorouracil than would healing; (c) collagen-producing fibroblasts may be less sensitive to the destructive effect of 5-Fluorouracil than contractile fibroblasts; (d) inflammatory mediators are important triggers of bleb encapsulation.