EVALUATION OF LASER SCLEROSTOMY FISTULAS USING ULTRASOUND BIOMICROSCOPY

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.