High-intensity focused ultrasound cycloplasty (UCP), a non-incisional, cyclodestructive procedure that reduces aqueous humor production has been examined in several countries for approximately 10 years, and is the topic of an analysis at an academic hospital in China — this new study also includes a set of patients with vision better than that typically displayed in end-stage glaucoma, as reported in BMC Ophthalmology.
Researchers evaluated records for 61 eyes of 58 patients (mean age, 62.0±13.04 years; 67.24% men, 32.76% women). This cohort represented all individuals who received UCP at the hospital’s ophthalmology department between March 2020 and August 2021. Diagnoses included primary open angle glaucoma (POAG), primary angle closure glaucoma (PACG), neovascular glaucoma, and various secondary glaucoma types. The analysis addressed visual function and pain, as well as qualified success rate, which was defined as intraocular pressure (IOP) decreasing 20% or more from baseline, absence of less than 5 mm Hg hypotony, and no further interventions.
The qualified success rate proved greater than 60% at 7 follow-ups that took place from postoperative day 1 until 18 months. At the 7-day check, and until the final visit, median IOP remained lower than 21 mm Hg.
Before the procedure, best-corrected visual acuity (BCVA) ranged from 20/20 to 20/800 in 20 eyes — the “vision group” — to no light perception in 15 eyes. Between these groups, 9 eyes displayed light perception, 15 detected hand motion, and 2 counted fingers. After UCP, participants with 20/800 or better did not show significant BCVA loss except at 1-day postoperative, but some lost 2 or more lines during follow-up, mostly from existing disorders such as cataract or diabetic retinopathy.
In many prior studies, BCVA remained consistent at 18 months after UCP in an average of 40% to 60% of patients, but 33% to 60% experienced loss of 2 lines or more. “The most common cause of vision loss was pre-existing cataracts or other fundus disease progression, which alerts us that regular follow-up visits and positive treatment for primary manifestations are necessary after UCP,” according to the study.
No severe adverse events occurred. One eye developed a choroidal detachment that resolved with medical therapy. Similar to the most frequent complication found in previous trials, all eyes of the current cohort showed slight conjunctival hyperemia for a few days to 1 month. Two eyes had 2- to 3-month scleral impressions, 21 exhibited minor anterior chamber inflammation for 1 to 2 weeks, and 3 developed short-lived hypotony of 5 mm Hg, as well as 2 eyes with mydriasis or astigmatism.
Several papers have demonstrated the greatest IOP decrease happens early during follow-up, as did the current work. The highest success rate of 94.55% was reached at 1 week post-UCP. Overall, this study’s 18-month 60% success rate was similar in previous research, although a few reported lower percentages. The analysis noted that success rate diminishes with time.
Limiting this investigation was the increased loss to follow-up sometimes inherent to a retrospective design, compared with prospective studies. In this case, greater dropout may have been caused by patients whose primary concern was eye pain rather than acuity, or subsequent visits made to a clinic closer to home due to the COVID-19 pandemic.
Chen D, Guo X-J, Luo S-K, et al. Efficacy and safety of high-intensity focused ultrasound cyclo-plasty in glaucoma. BMC Ophthalmol. Published online on October 7, 2022. doi:10.1186/s12886-022-02622-5