[Appositional angle closure in narrow angle eyes].

Primary angle closure glaucoma (PACG) is a vision-threatening type of glaucoma. A high prevalence of PACG has been reported in the Asian region. In this review article, we would like to introduce novel findings on appositional angle closure, which plays an important role in the processes of PACG, based upon a new classification. Also, our studies of narrow angle eyes with the use of ultrasound biomicroscopy(UBM) revealed interesting features of appositional angle closure. Our studies showed that appositional angle closure was found frequently in dark conditions, and also that the width and location of the angles examined were significantly related to the presence of appositional angle closure. The use of UBM enabled us to observe physiologic changes in the angle structure in dark conditions, and provided us important information on the pathogenesis of PACG.