Currently the most widely applied use of therapeutic ultrasound in ophthalmology is for the treatment of refractory glaucoma. This new technique is described, histologic changes in experimental animals discussed, and mode of action postulated. The intraocular pressure (IOP) results obtained after treatment of 187 patient eyes are presented, with a review of complications and visual acuity changes. This study demonstrates that 70% of patients treated had an IOP reduction to 25 mm Hg or less one year after ultrasound therapy.