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.

Alaghband P, Galvis E, Ramirez A, et al. The effect of high intensity focused ultrasound on aqueous humor dynamics in glaucoma patients. Ophthalmology Glaucoma. December 12, 2019. [Epub ahead of print].