Objective: To determine whether ultrasound biomicroscopic (UBM) appearance can predict successful lowering of the intraocular pressure following trabeculectomy.
Design: Blinded prospective study.
Setting: Glaucoma 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 discomfort, and five studies were excluded because the clinical information became known to the ultrasonographer. A total of 44 studies from 46 patients were analysed.
Outcome measures: Intraocular pressure and need for medication, UBM appearance.
Results: In 38 (86%) of the 44 studies there was a positive association between the UBM grade and the clinical findings. UBM had a sensitivity of 91% in predicting a functioning bleb and a specificity of 70% in predicting a nonfunctioning bleb.
Conclusions: UBM is a useful adjunct to the glaucoma surgeon in the management of certain patients following trabeculectomy.