Long-term bleb-related infections after trabeculectomy: Incidence, risk factors, and influence of bleb revision

Purpose To report the incidence of late-onset bleb-related infections and to identify risk factors for bleb-related infections after trabeculectomy for the treatment of glaucoma. Design Retrospective case series. Methods Bleb-related infections were defined as blebitis, endophthalmitis, or blebitis with endophthalmitis. A total of 1959 eyes of 1423 patients who underwent trabeculectomy and who were followed for 1 year were included. Results Twenty-four eyes were diagnosed with bleb-related infections; 15 eyes were found to have blebitis and 9 eyes presented with endophthalmitis during the follow-up period of 5.4 ± 3.5 years (mean ± standard deviation). Among 15 eyes with blebitis, 2 eyes developed endophthalmitis under treatment. The Kaplan-Meier estimated incidence of bleb-related infections was 2.0% ± 0.5% (mean ± standard error) at 10 years. A Cox multivariate analysis showed the significant risk factors for a bleb-related infection to be diagnoses of pigmentary glaucoma or juvenile glaucoma, history of bleb leak, intraocular pressure sustained below the target pressure, chronic blepharitis, and the presence of punctal plugs. Surgical bleb revision demonstrated a protective effect against bleb-related infections (P <.01) when risk factors were present. Conclusions This large case series with long-term follow-up demonstrates the incidence of bleb-related infections to be less than 2%, and describes the risk factors associated with bleb-related infections. A protective effect of surgical bleb revision was demonstrated. Clinicians should be constantly vigilant for, and patients made aware of, the possibility of bleb-related infections long after trabeculectomy, especially in the presence of identified risk factors.