French researchers examining the reduction in intraocular pressure (IOP) and adverse events in patients with refractory glaucoma who underwent at least 1 round of ultrasound cycloplasty concluded that the treatment is a safe and effective alternative to other IOP-lowering therapies. Their findings were published in the Journal of Glaucoma.
A standard method of treating refractory glaucoma is to reduce the secretion of aqueous humor secretion by destroying the ciliary processes. This is typically performed either through necrosis using a thermal technique (laser and ultrasound) or through cryotherapy. However, earlier cyclodestructive methods were inconsistent and increased the risk of complications, according to researchers. Studies have found a “significant” risk of vision-threatening complications such as hypotony and phthisis. Further, several rounds of treatment may be necessary to maintain IOP reduction, the investigators note. Ultrasound cycloplasty, a newer technology, uses the thermal effect of high-intensity focused ultrasound to attain selective coagulation that is focused on the ciliary processes.
To evaluate the 3-year efficacy and safety of ultrasound cycloplasty, researchers recruited 104 patients with refractory glaucoma who underwent ultrasound cycloplasty. Examinations were performed 7 days, 1 week, 1 month, 3 months, 6 months, 12 months, 24 months, and 36 months after the procedure. Primary outcomes were therapeutic success at 3 years (IOP reduction from baseline ≥20% and IOP >5 mm Hg without other surgical procedure) and vision-threatening complications. The team also looked at mean IOP change from baseline at each follow-up visit, medication use, complications, and subsequent ultrasound cycloplasty or other postsurgical interventions.
They found that 3 years after ultrasound cycloplasty, the therapeutic success rate was 55%. For 75% of patients in the study, only 1 procedure was needed to achieve the targeted results. In this group, the effect was rapid (from the first month) and lasted throughout the 3-year follow-up period. For the study population as a whole, IOP was reduced significantly (P <.005) from 27.6 mm Hg ± 8.9 mm Hg (n=3 topical hypotensive medication) to 17.0 mm Hg ± 6.8 mmHg at 36 months (n=2.8 topical hypotensive medication, a 33% reduction). For successful patients, the IOP was initially 29.3 mm Hg ± 8.8 mm Hg (n=3 topical hypotensive medication) and was reduced to 15.6 mm Hg ± 4.3 mm Hg at 36 months (n=2.8 topical hypotensive medication, a43% reduction). The rate of complications was low, and researchers reported no cases of phthisis.
Rouland JF, Aptel F. Efficacy and safety of ultrasound cycloplasty for refractory glaucoma – a 3 year study. J Glaucoma. February 1, 2021. doi:10.1097/IJG.0000000000001796