Long-term bleb-related infections: incidence, risk factors and influence of bleb revision

Abstract

Purpose: To report the incidence of late-onset bleb-related infection (BRI) and to identify risk factors for BRI.

Methods: BRI was defined as blebitis, endophthalmitis, or blebitis with endophthalmitis. A total of 1959 eyes of 1423 consecutive patients who underwent trabeculectomy and who were followed for ≥ 1 year were included.

Results: Twenty-four eyes were diagnosed with BRI; 15 eyes had blebitis and 9 eyes presented with endophthalmitis during a follow-up period of 5.4 ± 3.5 years (mean ± SD). Among 15 eyes with blebitis, 2 eyes developed endophthalmitis under treatment. The Kaplan-Meier estimated incidence of BRI was 2.0% ± 0.5% (mean ± SE) at 10 years. Multivariate analysis identified risk factors for BRI: a diagnosis of pigmentary glaucoma or juvenile glaucoma, history of bleb leak, intraocular pressure below the target pressure, chronic blepharitis, and presence of punctal plugs. Surgical bleb revision showed a protective effect against BRI (P<0.01) when risk factors were present (history of leak, hypotony, large or high blebs).

Conclusions: This case series demonstrates that the long-term incidence of BRI is less than 2%, and describes the risk factors associated with BRI. A protective effect of surgical bleb revision was demonstrated. Clinicians should be constantly vigilant for, and patients made aware of, the possibility of BRI long after trabeculectomy, especially in the presence of risk factors.