ULTRASOUND BIOMICROSCOPIC EVALUATION OF F ILTERING BLEBS

Background Sometimes in glaucomatous patients treated with trabeculect omy there is not a correlation between bleb shape and intraocular pres sure. So we studied the functional anatomy of the filtering bleb by a ultrasound biomicroscope, using high frequency (50 Mhz) probe, which p rovides high resolution images of filtering blebs. Materials and Metho ds A total of 46 filtering blebs of 46 patients after trabeculectomy w ere analyzed by ultrasound biomicroscopy (50 Mhz). Dimensions, shapes and structure of blebs were evaluated in 2 groups of patients. Results It was possible to obtain longitudinal or transverse images of filter ing blebs, to measure the height, to evaluate the reflectivity inside and to follow the route under the scleral flap. Blebs with lower refle ctivity and a visible route under the scleral flap had a lower intraoc ular pressure while the height was not important for a good intraocula r pressure. Conclusions So ultrasound biomicroscopy can be a useful me thod to study filtering blebs and also to explain the mechanisms of fi ltering structures in patients who underwent trabeculectomy.