Ocular wall dimensions (axial eye length, anterior chamber depth, lens thickness, vitreous length, thickness and volume of the ocular wall) were determined by echobiometry on 10 eyes of 10 patients with glaucoma one day before and four days after trabeculectomy. The results showed significant differences: decreased axial eye length, and increased thickness and volume of the ocular wall were found after trabeculectomy. The observed changes in the ocular dimensions might be due to ocular hypotony and postoperative inflammation. Echographic follow-up of the changes in the ocular wall is a useful monitor to study alteration in eye dimensions after glaucoma surgery.