For open-angle glaucoma patients with uncontrolled IOP despite maximum medical therapy, high-intensity focused ultrasound may be a viable option. A study published in Ophthalmology Glaucoma found patients who underwent the ultrasound treatment had a 16% reduction in IOP and an aqueous flow rate decrease of 15% at three months.

The study enrolled 30 adult patients with either open-angle glaucoma or ocular hypertension who did not have adequate IOP control despite maximum medical treatment.

Patients underwent a comprehensive ophthalmic exam followed by fluorophotometry and tonography measurements of the aqueous humor. Patients then received six seconds of high-intensity focused ultrasound therapy. Aqueous humor dynamic measurements were repeated three months after the treatment.

Patients had a four-week washout from their glaucoma medication prior to their aqueous humor measurements at baseline and the three-month visit, the researchers noted.

At the three-month follow up visit, the approximate post-washout IOP was reduced by 16% (31.7±5.3mmHg vs. 26.6±4.8mmHg) while the aqueous flow rate was decreased by 15% (2.07±0.73μl/min vs. 1.77±0.55μl/min) from baseline without any significant effect on tonographic outflow facility and uveoscleral outflow.

The researchers noted a 20% risk of treatment failure, with six patients needing further surgical intervention within one month after a single ultrasound treatment.  Additionally, 80% of patients were able to undergo post-treatment washout measurements, and 26.6% of eyes achieved a greater than 20% IOP reduction at three months compared with baseline.

This is the first study that investigated aqueous humor dynamic effects using high-intensity focused ultrasound in patients with uncontrolled open-angle glaucoma on maximum tolerated medical therapy, the researchers said.