Abstract
Purpose :
Ultrasound cycloplasty (UCP) utilises High Intensity Focused Ultrasound (HiFU) to treat glaucoma. This prospective study explores the effect of HiFU on aqueous humour dynamics in glaucomatous eyes.
Methods :
All patients with primary open angle glaucoma (POAG) with uncontrolled intraocular pressure (IOP) despite treatment were recruited from the glaucoma clinic and offered UCP as treatment. Peribulbar anaesthesia was used for all cases and postoperative treatment involved four weeks of topical corticosteroids. A washout of glaucoma medications was performed prior to the baseline and the 12-month postoperative aqueous dynamic measurement visits.
Inclusion Criteria: Patients >18 years of age with uncontrolled POAG
Exclusion Criteria: Other forms of glaucoma, systemic beta blocker use, a history of allergy to fluorescein and previous intraocular surgery not including SLT/ALT
Outcome measures: IOP (Goldmann tonometry), Outflow facility (Schiotz tonography), Aqueous flow rate (fluorophotometry), and Uveoscleral outflow (calculated using Goldmann’s equation).
Results :
32 patients were recruited onto the study with 16 completing 12 months follow up. IOP reduction of 20.9% was achieved (p=0.005) with a 15.7% reduction in aqueous flow rate(p=0.05). There was no significant difference in the outflow facility or calculated uveoscleral outflow.
Table1: Table shows aqueous humor dynamics at baseline and at 12 months postoperatively
Conclusions :
Aqueous humour dynamics and intraocular pressure are significantly affected following successful treatment with HiFU in patients with glaucoma. A reduction in aqueous outflow corresponds with a significant reduction in IOP up to 12 months post-operatively. This is in keeping with similar results at 3 months postoperatively and shows a sustained effect of HiFU.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.