Miniaturized High-Intensity Focused Ultrasound Device in Patients with Glaucoma: A Clinical Pilot Study

PURPOSE. To evaluate the relative safety and potential efficacy of high-intensity focused ultrasound cyclocoagulation by a miniaturized annular device containing six piezoceramic transducers in patients with refractory glaucoma. METHODS. This was a three-center prospective interventional pilot study. Twelve eyes of 12 patients with refractory glaucoma were insonified using a ring-shaped probe containing six miniaturized high-frequency transducers operating at 21 MHz. Ultrasound biomicroscopy (UBM) and a complete ophthalmic examination were performed before the procedure and at 1 day, 1 week, 1 month, and 3 months after the procedure. Additional visits were performed 6 and 12 months after the procedure. RESULTS. Intraocular pressure was significantly reduced (P < 0.01) from a mean preoperative value of 37.9 +/- 10.7 mm Hg to a mean postoperative value of 27.3 +/- 12.4, 25.2 +/- 11.3, 25.2 +/- 7.7, 24.8 +/- 9.8, and 26.3 +/- 5.1 mm Hg at 1 day, 1 week, 1 month, 3 months, and 6 months, respectively, and to a mean value of 24.7 +/- 8.5 at the last follow-up visit. No major intraoperative or postoperative complications occurred. Minor postoperative corneal complications developed in four patients with previous corneal abnormalities: superficial punctate keratitis (n = 3) and central superficial corneal ulceration (n = 1). UBM showed cystic involution of the ciliary body in 9 of the 12 eyes and a suprachoroidal fluid space in 8 of the 12 eyes. CONCLUSIONS. Ultrasonic circular cyclocoagulation using high-intensity focused ultrasound delivered by a circular miniaturized device containing six piezoceramic transducers seems to be an effective and well-tolerated method to reduce intraocular pressure in patients with refractory glaucoma. (Invest Ophthalmol Vis Sci. 2011;52:8747-8753) DOI:10.1167/iovs.11-8137