Non penetrating deep scleroctomy (N.P.D.S.) with or without collagen device (C.D) in primary open-angle glaucoma: middle-term retrospective study

The purpose of this study is to evaluate the middle term tonometric results of a new filtering procedure, the non penetrating deep sclerectomy with or without collagen device, in primary open-angle glaucome. This technic aims to eliminate or minimize the complications of classical trabeculectomy