Background. Laser sclerostomy is a relatively new technique in glaucom
a surgery. Clinical examination, particularly of the intrascleral part
of laser sclerostomy fistulas, is difficult. We performed ultrasound
biomicroscopy (UBM) in order to determine, if it were possible to visu
alize fistulas. Moreover, it was the aim to investigate whether this i
maging technique could provide additional information on fistula morph
ology. Patients and methods. Ten eyes of eight patients with chronic o
pen angle glaucoma who had undergone erbium-YAG laser sclerostomy ab e
xterno were examined using a UBM-probe with a 20 MHz transducer provid
ing spatial resolution of approximately 80 mu m. Results. Radial scann
ing allowed visualization of the sclerostomy fistula in nine of ten ey
es. The different functional state of sclerostomy fistulas correlated
well to UBM findings. It was possible to image differences in the morp
hology of occluded and patent fistulas and to visualize the filtering
pathway in functioning blebs. Conclusions. Ultrasound biomicroscopy al
lows imaging of laser sclerostomy fistulas. UBM and clinical findings
correlated well in the majority of the patients we examined. The techn
ique supplements clinical examination and in some cases may provide ad
ditional information.