Risk factors for bleb-related infection following trabeculectomy surgery: ocular surface findings-a case-control study

Purpose Bleb-related infection (BRI) is a devastating complication of trabeculectomy surgery. The aim of this study was to identify ocular risk factors for BRI with specific emphasis on ocular surface parameters. It has been suggested that the frequency has increased since the introduction of antimetabolites, particularly mitomycin C. Design A case-control study. Method A clinical study of BRI following trabeculectomy surgery to investigate risk factors by documenting historical data review from patients records, self-reported questionnaire specific to ocular surface symptoms and a repeat detailed clinical examination of the lid, ocular surface and tear film. Results Twenty-eight cases and 31 controls were assessed. The overwhelming risk factor for development of BRI was chronic blepharitis (multivariate analysis OR 16.3 (1.687 to 157.44) p=0.016). No increased risk was identified with the antimetabolite used during trabeculectomy surgery (p=0.38) or the type of conjunctival reflection adopted for surgery (p=0.38). Neither age (p=0.32) nor dry eyes (p=0.13) were identified as risk factors. Conclusion An increased risk of BRI was identified in eyes with chronic blepharitis. To minimise the risk of infection following trabeculectomy surgery, it may be advisable to manage the lid disease in these patients prior to performing trabeculectomy surgery or offer an alternative treatment such as a shunt.