High-intensity focused ultrasound in the treatment of glaucoma: a narrative review

ABSTRACT

Introduction: Ultrasound Cyclo-Plasty (UCP) using High-Intensity Focused Ultrasound (HIFU) is a recently developed cyclodestructive procedure. It can be applied to the target area, avoiding any effect on surrounding tissues. This review aims to present the actual role of HIFU in the management of glaucoma patients.

Areas covered: The PubMed database was consulted in November2020. The search terms used were: ‘high intensity focused ultrasound treatment,’ ‘cyclo-ablation’‘cyclo-destruction’‘cyclo-plasty.’ Relevant aspects about UCP are discussed in this review, particularly the probe development, the histological effects, and the mechanism of action. Furthermore, UCP indications are reported. Besides, technical limitations are evident, such as mild adverse events, severe adverse events, and long-termoutcomes, including reducing hypotensive medications, additional glaucoma surgery, and comparison with other cyclodestructive techniques. Finally, future perspectives about HIFU applications and improvements are reported.

Expert opinion: Ultrasound Cyclo-Plasty(UCP) procedure is simple to perform and can be applied to almost all glaucoma types and eyes. It can be considered asafe and effective procedure. However, its mechanism of action is not entirely understood, resulting in different IOP lowering. Nevertheless, focalized and selective ciliary body coagulation with HIFU opened the possibility of anew therapeutic approach against glaucoma disease.

KEYWORDS:

• High-intensity focused ultrasound
• ultrasound cyclo-plasty
• ciliary body
• glaucoma
• intraocular pressure
• open-angle glaucoma
• angle-closure glaucoma

Article highlights

• Ultrasound Cyclo-Plasty (UCP) using High-Intensity Focused Ultrasound (HIFU) selectively coagulates the ciliary body, sparing adjacent structures, allowing the development of UCP.

• The reduced aqueous humor production seems the primary mechanism of action of UCP.

• UCP is indicated for refractory glaucoma who had previous surgery, naive open-angle glaucoma, and angle-closure glaucoma (ACG).

• IOP reduction ranges between 28.1% and 31% 24 months after the UCP procedure.

• The UCP procedure can be repeated once or twice, usually 3 to 12 months from the first application, if the IOP target is not reached at the first attempt.

• The UCP procedure is considered an overall safe treatment. Usually, mild adverse events like mild transient anterior chamber inflammation and conjunctival hyperemia resolve during the first month of follow-up.

Supplemental online material

The video of the Ultrasound Cyclo-Plasty performed with the second generation HIFU device.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose

Additional information

Funding

This manuscript was not funded