THE USE OF ULTRASOUND BIOMICROSCOPY FOLLOWING TRABECULECTOMY

Objective: To determine whether ultrasound biomicroscopic (UBM) appear ance can predict successful lowering of the intraocular pressure follo wing trabeculectomy. Design: Blinded prospective study. Setting: Glauc oma clinic at a tertiary care hospital in Calgary. Patients: Forty-six patients who had undergone trabeculectomy 1 week to 22 years earlier were recruited. In three cases UBM scanning was stopped because of dis comfort, and five studies were excluded because the clinical informati on became known to the ultrasonographer. A total of 44 studies from 46 patients were analysed. Outcome measures: Intraocular pressure and ne ed for medication, UBM appearance. Results: In 38 (86%) of the 44 stud ies there was a positive association between the UBM grade and the cli nical findings. UBM had a sensitivity of 91% in predicting a functioni ng bleb and a specificity of 70% in predicting a nonfunctioning bleb. Conclusions: UBM is a useful adjunct to the glaucoma surgeon in the ma nagement of certain patients following trabeculectomy.