Background: Shallow anterior chamber associated to external drainage of aqueous humor (positive Seidel test) is one of the undesirable complications of filtering surgeries.
Objective: To evaluate the frequency of persisting external drainage of aqueous humor after trabeculectomy, in a Brazilian university hospital.
Methods: Revision of clinical records of 73 patients (84 eyes), aged from 30 to 87 years (median = 65 years), submitted to trabeculectomy (Glaucoma Clinic, Hospital das Clнnicas da Faculdade de Medicina de Ribeirгo Preto, Universidade de Sгo Paulo, Brazil). The data analyzed were: values of intraocular pressure, obtained by Goldman tonometer, one day before surgery (with the maximally tolerated medical therapy) and in the post-operative period (1 day, 1 week, 1 month and 3 months, after trabeculectomy); medicines used in order to try the control of the intraocular pressure; and post-operative complications.
Results and Comments: The frequency of positive Seidel test was 21.0%. The patients or the eyes were classified in two groups, according the presence or not of external drainage of aqueous humor. Different parameters, as age, drugs used for the treatment of glaucoma, presence and number of other complications, and values of intraocular pressure with the maximally tolerated medical therapy were analyzed (Chi-square - Yates corrected or 2-tailed Fisher exact test). The only significant difference between groups detected was related to the pre-operative levels of intraocular pressure (p=0.01).