OBJECTIVE : To investigate the effect of trabeculectomy on corneal topography, corneal sensitivity and aberrations. METHODS : Twenty-four eyes of 24 subjects with open-angle glaucoma who required glaucoma filtration surgery were assessed. The evaluation of corneal topography, corneal sensitivity and aberrations were done before the trabeculectomy procedure, 1 week and 1 month after the trabeculectomy. RESULTS : There were significant differences in cylindrical power (P = 0.02), contrast sensitivity at 12 cycle/degree spatial frequency (P = 0.04) as well as high order aberration (P = 0.04) and high order without spherical component (P = 0.02) following trabeculectomy. However, significant differences were found for keratometric results and Fourier index in 3 and 6 mm pupil diameters between pre- and post-trabeculectomy (P > 0.05). CONCLUSIONS : According to the findings of the current study, trabeculectomy affects contrast sensitivity at 12 cycle/degree spatial frequency, higher-order aberration and higher order without spherical component aberration 1 month after trabeculectomy. Being knowledgeable about these changes may lead to some advancement in post-surgical management of patients particularly in early stages following trabeculectomy.