Surveillance of late-onset bleb leak, blebitis and bleb-related endophthalmitis - a UK incidence study

To determine the incidence of late-onset bleb leak (BL), blebitis (B) and bleb-related endophthalmitis (BRE) after trabeculectomy surgery, and report the management approaches employed by UK ophthalmologists. Prospective case ascertainment study reporting of incident cases fulfilling the study definitions of BL, B and BRE through the reporting mechanism provided by the British Ophthalmic Surveillance Unit (BOSU; United Kingdom) for the period July 2007 to August 2008 (13 months). Two questionnaires completed at initial reporting and 6 months later were used to collect clinical details related to presentation, early and late management and outcome. Ninety-eight cases were reported to the British Ophthalmic Surveillance Unit during the study period. Seventy-one first questionnaires were returned (response rate 72.4%). Of these, 11 were erroneous/duplicated. Sixty second questionnaires were sent out, and of these 37 fully completed questionnaires were returned. Analysis was, therefore, based upon 60 initial and 37 follow-up questionnaires. Overall incidences were estimated for isolated bleb leak (0.22%), blebitis without bleb leak (0.1%), blebitis with bleb leak (0.11%), and BRE with or without bleb leak (0.17%). Visual outcome in the BL group was good; however, in the BRE group half the patients ended with visions of perception of light or worse. There was a great variance in the initial and late management of these conditions. Surgical intervention for bleb leak seemed to result in the best chance of leak closure. These complications of trabeculectomy surgery are relatively low but potentially visually devastating. This study updates the knowledge of the incidence of these complications, and suggests that no consistent management approach to any of the reported conditions was practised. In view of the potentially catastrophic consequences of these complications, formal guidance as to best practice would be beneficial, and further research to establish this is required.