Primary open angle glaucoma treated by high intensity focused ultrasound (HIFU): results at 18 months of a prospective pilot study on patients treated with the 2nd generation probe

Purpose To assess the safety and efficacy of Ultrasound Ciliary Plasty (UCP procedure) using HIFU (high intensity focused ultrasound) with a second‐generation probe which increases the treatment surface area and the firing duration in patients with primary open angle glaucoma. Methods Prospective clinical series performed in two University Hospitals, on twenty eyes of twenty patients with primary open‐angle glaucoma, treated with the EyeOP1 medical device equipped with six miniaturized cylindrical piezoelectric transducers of a new generation with an increased lesion volume. All eyes were treated with an 8‐s exposure time per transducer. The main assessment criteria were safety and efficacy measured by the incidence of complications and IOP reduction. Ophthalmic examination and ultrasound biomicroscopy were performed before treatment and during clinical follow‐up at D7, M1, M3, M6, M12, M18 and M24. Results No major intra‐ or post‐operative complications were observed during follow‐up period. Clinical examination showed no lesions of ocular structures other than the ciliary body and no or few signs of intraocular inflammation after treatment. The mean intraocular pressure was significantly reduced from 29.1 ± 5.4 mmHg before treatment to 17.8 ± 6.2 mmHg at last follow‐up. Five patients have needed a second ultrasound procedure and two patients a third procedure. With a mean follow‐up of 18 months, success rate, as defined by an IOP reduction >20% after one or more UCP procedures was 67%. The mean IOP reduction achieved in responding patients was 44%. Conclusions Coagulation of the ciliary body using high intensity focused ultrasound carried out with the new‐generation of miniaturized transducers is a simple, well‐tolerated procedure which enables to significantly reduce the intraocular pressure in patients with Open Angle Glaucoma.