Ultrasound cycloplasty delivers lasting pressure relief in glaucoma patients

Glaucoma remains the leading cause of irreversible blindness worldwide, and clinicians have long sought treatments that lower intraocular pressure without the invasiveness of conventional filtration surgery. A new one-year follow-up study from Northwest China now offers some of the most detailed long-term evidence yet for ultrasound cycloplasty, a minimally invasive procedure that uses focused sound waves to quiet the eye’s fluid-producing machinery. The results, published in Frontiers in Medicine, show that the technique cut intraocular pressure by nearly 60 percent at one year, stabilized dangerous day-night pressure swings, and did so with a safety profile free of the severe complications that have shadowed older cyclodestructive procedures.

The research team, led by ophthalmologists at the Second Affiliated Hospital of Xi’an Medical University, enrolled 24 patients with 30 affected eyes covering the full spectrum of glaucoma subtypes: primary angle-closure glaucoma, primary open-angle glaucoma, neovascular glaucoma, and secondary glaucoma arising from other ocular diseases. Every patient had failed to achieve adequate pressure control despite maximal medical therapy. The investigators tracked outcomes at six postoperative time points—one day, one week, one month, three months, six months, and one year—measuring not only pressure itself but also 24-hour pressure fluctuation, pain scores, medication burden, and complications.

Ultrasound cycloplasty works through high-intensity focused ultrasound, the same physical principle that underlies therapeutic ultrasound in other fields of medicine. A probe coupled to the eye delivers precisely quantified acoustic energy through the sclera to the ciliary body, the ring of tissue that secretes aqueous humor, the fluid that fills the eye and determines its pressure. The energy induces controlled coagulative necrosis of the ciliary epithelium, reducing fluid production at its source. Because the energy delivery is quantifiable and the probe geometry is matched to each eye’s axial length and corneal diameter, the procedure offers a degree of targeting that older cyclodestructive techniques, such as cyclocryotherapy, never achieved.

The surgical protocol in the study reflected this precision. Each treatment sector received a fixed sonication of 22 seconds at 2.3 watts, delivering 50.65 joules per sector, with the number of sectors scaled to baseline pressure—six sectors for pressures below 30 mmHg, eight for 30 mmHg or above, and ten for 40 mmHg or higher. The nasal and temporal quadrants were deliberately left untreated to avoid the long ciliary nerves, a refinement that significantly reduces postoperative pain. The entire treatment typically lasted three to five minutes.

The efficacy results were striking. Median preoperative pressure across all 30 eyes was 40.5 mmHg; by one year it had fallen to 12 mmHg, a 59.91 percent reduction that represented the largest decrease at any time point. Primary angle-closure glaucoma patients fared best, achieving a 66.12 percent reduction at one year and a surgical success rate that reached 96.67 percent overall at final follow-up. Patients with secondary glaucoma and neovascular glaucoma also showed substantial long-term reductions, though their responses emerged more slowly, with the most pronounced decreases appearing at six months to one year rather than in the first week.

One of the study’s most clinically valuable findings was a strong positive correlation between baseline pressure and the magnitude of pressure reduction at one year, with a Spearman coefficient of 0.641. In practical terms, the higher the starting pressure, the more pronounced the lowering effect. The authors propose a mechanistic explanation: congestion and edema of the ciliary processes under high-pressure conditions may increase the sensitivity of ciliary epithelial cells to ultrasonic energy, amplifying the suppression of aqueous production. They caution, however, that a ceiling effect could exist at extreme pressures, where the compensatory imbalance between fluid production and outflow might blunt the treatment’s effectiveness.

Perhaps the most innovative contribution of the study was its use of the mean amplitude of intraocular pressure excursion, or MAPE, as a dynamic efficacy indicator. Unlike single-timepoint measurements, MAPE captures clinically meaningful pressure drift over a full 24-hour cycle by filtering out minor physiological variations below a standard-deviation threshold. Before surgery, the mean MAPE was 10.6; one day after treatment it had halved to 5.3, a statistically significant improvement. The authors interpret this as evidence that ultrasound cycloplasty stabilizes pressure through a dual mechanism: focused ultrasound thermocoagulation suppresses aqueous production, while collagen remodeling enhances the patency of outflow channels.

Safety outcomes were equally reassuring. Transient conjunctival hyperemia occurred in 86.7 percent of eyes within 24 hours but resolved within days, and anterior chamber inflammation appeared in 46.7 percent without fibrinous exudation or synechiae. Pupillary irregularities developed in 40 percent of cases but stabilized within two weeks, often with short-term miotic therapy. Critically, no cases of profound hypotony, choroidal detachment, macular edema, or phthisis bulbi were observed during the entire follow-up period—complications that have been reported with older cyclodestructive approaches. Pain scores, measured on a numerical rating scale, fell from a median of 5 preoperatively to 1 at one year, suggesting long-term relief of glaucoma-related discomfort.

The study’s authors conclude that postoperative pressure stabilizes by three months, allowing gradual withdrawal of medications, and they position ultrasound cycloplasty as a reliable option across glaucoma subtypes. They acknowledge limitations, including the modest sample size, the single-center design, and the lack of between-eye correlation adjustment in patients with both eyes enrolled. They call for multicenter trials with larger cohorts, particularly for neovascular and refractory glaucoma, and suggest extending dynamic monitoring beyond 24 hours in selected patients.

For a disease projected to affect more than 111.8 million people by 2040, the findings carry real weight. Ultrasound cycloplasty cannot restore vision already lost to glaucoma, but by offering a repeatable, precisely dosed, and well-tolerated way to bring pressure under control—even in eyes where filtration surgery has failed or is anatomically unsuitable—it adds a genuinely minimally invasive weapon to the ophthalmologist’s arsenal. The Northwest China data, with their unprecedented attention to 24-hour pressure dynamics and long-term safety, suggest that the technique deserves a place in precision treatment algorithms for glaucoma worldwide.

Subject of Research: Ophthalmology

Article Title: Ultrasound cycloplasty: dynamic efficacy and long-term safety in glaucoma patients from northwest China

Article References: Ge, P., Shi, R., Mu, Q.-Q., Zhang, R.-X., Yang, X.-X., & He, Y. (2026). Ultrasound cycloplasty: dynamic efficacy and long-term safety in glaucoma patients from northwest China. Frontiers in Medicine, 13, Article 1819637. https://doi.org/10.3389/fmed.2026.1819637

Image Credits: AI Generated

DOI: 10.3389/fmed.2026.1819637

Keywords: glaucoma, ultrasound cycloplasty, high-intensity focused ultrasound, intraocular pressure, minimally invasive surgery, ophthalmology, Frontiers in Medicine, Ultrasound, cycloplasty, dynamic, efficacy, long-term