Editor,—The pseudoexfoliation syndrome is characterised by the presence of light grey or white flakes on the pupillary margin and anterior lens capsule, the surfaces of the iris, zonules, ciliary body, hyaloid, trabecular meshwork, and the endothelial surface of the cornea. This syndrome is generally thought to be accompanied by open angle glaucoma. However, in some reports, the anterior chamber angle is narrow,1-3 and in other cases shown to be angle closure glaucoma.45 The relation between the pseudoexfoliation syndrome and angle closure glaucoma is unclear. We used the ultrasound biomicroscope to determine the pathogenesis of angle closure glaucoma in a patient with the pseudoexfoliation syndrome.