High-Intensity Focused Ultrasound Circular Cyclocoagulation in Glaucoma: A Step Forward for Cyclodestruction?

Uveoscleral Outflow Routes after MicroPulse Laser Therapy for Refractory Glaucoma: An Optical Coherence Tomography Study of the Sclera

To analyze in vivo scleral changes induced by MicroPulse transscleral laser therapy (MP-TLT) in refractory glaucoma using anterior segment-optical coherence tomography (AS-OCT). Forty-two candidate patients for MP-TLT were consecutively enrolled and underwent AS-OCT at baseline and after six months. MP-TLT success was defined as an intraocular pressure (IOP) reduction by one-third. The main outcome measures were the mean superior (S-), inferior (I-), and total (T-) intra-scleral hypo-reflective space area (MISHA: mm2) and scleral reflectivity (S-SR, I-SR, T-SR; arbitrary scale) as in vivo biomarkers of uveoscleral aqueous humor (AH) outflow. The IOP was the secondary outcome. The relations between the baseline-to-six months differences (D) of DS-MISHA, DI-MISHA, and DT-MISHA and DS-SR, DI-SR, DT-SR, and DIOP, were investigated. At 6 months, the median IOP reduction was 21% in the failures and 38% in the successes. The baseline S-MISHA, I-MISHA, and T-MISHA did not differ between the groups, while S-SR and T-SR were higher in the successes (p < 0.05). At six months, successful and failed MP-TLTs showed a 50% increase in S-MISHA (p < 0.001; p = 0.037), whereas I-SR and T-SR reduced only in the successes (p = 0.002; p = 0.001). When comparing DS-MISHA, DI-MISHA, and DT-MISHA and DS-SR, DI-SR, and DT-SR, there were no significant differences between the groups. In the successful procedures, DIOP was positively correlated with DT-MISHA and DI-MISHA (ρ = 0.438 and ρ = 0.490; p < 0.05). MP-TLT produced potentially advantageous modifications of the sclera in refractory glaucoma. Given the partial correlation between these modifications and post-treatment IOP reduction, our study confirmed that the activation of the uveoscleral AH outflow route could significantly contribute to the IOP lowering after MP-TLT.

Outcomes and Predictors of Failure of Ultrasound Cyclo Plasty for Primary Open-Angle Glaucoma

Aims: To evaluate the outcomes of ultrasound cyclo plasty (UCP) for primary open-angle glaucoma (POAG) and identify the predictors of failure. Methods: This retrospective cohort study included patients with POAG who underwent UCP at King Abdul Aziz University Hospital, Riyadh, Saudi Arabia, between 2016 and 2021. The main outcome measures were the intraocular pressure (IOP), the number of antiglaucoma medications, and the presence of vision-threatening complications. The surgical outcome of each eye was based on the main outcome measures. Cox proportional hazard regression analysis was performed to identify the possible predictors of UCP failure. Results: Sixty-six eyes of fifty-five patients were included herein. The mean follow-up period was 28.95 (±16.9) months. The mean IOP decreased significantly from 23.02 (±6.1) to 18.22 (±7.0) and 16.44 (±5.3) mm Hg on the 12th and 24th months, respectively; the mean number of antiglaucoma medications decreased significantly from 3.23 (±0.9) to 2.15 (±1.5) and 2.09 (±1.6), respectively. The cumulative probabilities of overall success were 71.2 ± 5.6% and 40.9 ± 6.1% on the 12th and 24th months, respectively. High baseline IOP and the number of antiglaucoma medications were associated with a higher risk of failure (hazard ratio = 1.10 and 3.01, p = 0.04 and p < 0.01, respectively). The most common complications were cataract development or progression (30.8%) and prolonged or rebound anterior chamber reaction (10.6%). Conclusions: UCP reasonably controls the IOP and reduces the antiglaucoma medication burden in eyes with POAG. Nevertheless, the success rate is modest, with a high baseline IOP and number of medications.

Ultrasound Cyclo Plasty After Failed Glaucoma Surgery: Outcomes and Complications

Introduction

The purpose of this study is to report the outcomes and complications of ultrasound cyclo plasty (UCP) after failed glaucoma surgery.

Methods

A retrospective case series included patients with previously failed glaucoma surgery who underwent UCP at King Abdul Aziz University Hospital, Riyadh, Saudi Arabia, between 2016 and 2021. The main outcome measures were: intraocular pressure (IOP), number of antiglaucoma medications and presence of vision-threatening complications. The surgical outcome of each eye was based on the main outcome measures.

Results

Seventy eyes of 70 patients were included in the study. The mean follow-up period was 31.89 months (± 17.5). The IOP and the number of antiglaucoma medications decreased significantly from a mean of 23.91 mmHg (± 6.3) and 3.43 (± 0.8) to 17.88 mmHg (± 8.1) and 2.48 (± 1.3) and of 16.74 (± 7.9) and 2.11 (± 1.3) at the 12th and 24th months postoperatively, respectively (p < 0.01 for both). The success rates were 77.1% (54/70) and 48.6% (34/70), while the failure rates were 22.9% (16/70) and 2.9% (2/70) at the 12th and 24th months postoperatively, respectively. The cumulative probabilities of success were 70.0% (± 5.5%) and 47.1% (± 6.0%) at the 12th and 24th months postoperatively, respectively. The most common complications were anterior chamber reaction (24.3%), cataract development/progression (18.6%), hypotony/choroidal detachment (4.3%), phthisis bulbi (1.4%) and aqueous misdirection (1.4%).

Conclusions

UCP is an effective treatment modality to control IOP and decrease the burden of antiglaucoma medications in eyes with previously failed glaucoma surgery. Monitoring and counseling of possible postoperative complications are needed.

Effect of high-intensity focused ultrasound (HiFU) treatment on intraocular pressure and aqueous humour dynamics: 12 -months results

PURPOSE

High intensity focused ultrasound (HiFU) is a cyclodestructive therapy for controlling intraocular pressure (IOP) in glaucoma. The mechanism of action is thought to be through destruction of the ciliary epithelium as well as increased uveoscleral outflow. We reviewed the change in aqueous humour dynamics parameters including aqueous humour flow rate, tonographic outflow facility (TOF) and uveoscleral outflow at 12 months.

PATIENTS AND METHODS

This is a prospective observational study. Consecutive patients with open angle glaucoma (OAG) or ocular hypertension (OHT) requiring further IOP lowering were enroled in the study between August 2016 and January 2017. Patients were commenced on medication washout period prior to baseline and twelve months' visit.

RESULTS

Sixteen patients (OAG) in the treatment group underwent assessment at twelve months follow up. Mean age was 63.1 ± 11 years. Eleven patients were African/Caribbean and 5 were Caucasian. Nine patients were female and 7 were male. Mean post-washout IOP was reduced by 21% (28.3 ± 5.7 at baseline vs 22.4 ± 8.4 mmHg at 12 months, p = 0.04). Aqueous humour flow rate was reduced by 16% at twelve months (2.40 ± 0.6 at baseline vs 2.02 ± 0.6 µl/min at 12 months, p = 0.0493). There was no statistically significant change in the TOF (0.12 ± 0.09 at baseline vs 0.08 ± 0.05 µl/min/mmHg at 12 months, p = 0.08) or uveoscleral outflow (0.6 ± 1.3 at baseline vs 1.3 ± 0.85 µl/min at 12 months, p = 0.15).

CONCLUSION

In this study, we demonstrated that the observed IOP reduction was likely due to aqueous humour flow rate reduction. The TOF and uveoscleral outflow were not detectibly changed.

Ultrasonic circular cyclocoagulation prospective safety and effectiveness study

PURPOSE

To evaluate the efficacy and safety of ultrasound cycloplasty procedures (UCP) in patients with uncontrolled glaucoma.

METHODS

Prospective longitudinal study with UCP was performed by EyeOP1© probe with 8 s duration on 6 or 8 sectors, according to baseline intraocular pressure (IOP). Complete ophthalmic examination was performed pre- and post-operatively at 1st day, 1st week, 1st, 3rd, 6th, 9th and 12th months. UCP was repeated beyond 3rd month if IOP was > 21 mmHg, under maximum therapy, without major complications. Primary outcomes were complete (IOP reduction ≥ 20% or reduction in number of antiglaucomatous drugs and IOP ≥ 5 mmHg without occurrence of major complications) and qualified (IOP reduction ≥ 20% or reduction in number of antiglaucomatous drugs and IOP ≥ 5 mmHg) surgical success rates at 12 months. Secondary outcomes were mean IOP reduction, mean number of drugs reduction, rates of failure, number of repeated procedures, mean time to failure and occurrence of complications.

RESULTS

Fourteen eyes of 13 patients (11 male) with advanced glaucoma (Hoddap classification) were included. Six were surgically naïve. Mean age was 68.29 ± 10.66 years. Four eyes were treated in 8 sectors (28.5%). Patients were followed for 12 months after first UCP procedure. Overall surgical success was achieved in 92.9% at 6 months and in 100% of cases at 12 months. Mean IOP significantly reduced from 28.50 ± 7.61 mmHg to 13.79 ± 6.97 at 1 month, 17.36 ± 8.58 at 3 months, 17.79 ± 6.29 at 6 months, 16.3 ± 4.6 at 9 months and to 15.23 ± 5.09 at 12 months (p < 0.01). Mean number of drugs reduced from 3.71 ± 0.61 to 2.43 ± 1.51 at 3 months, 2.86 ± 1.1 at 6 months, 2.64 ± 0.93 at 9 months and to 2.92 ± 0.86 at 12 months (p < 0.05). Major reversible complications included choroidal detachment in 2 (14.29%) and corneal edema in 1 eye (7.14%), without permanent visual acuity reduction. Minor reversible complications included anterior chamber reaction (92.25%), conjunctival hyperemia (71.43%) and superficial keratitis (57.4%). Four eyes (28.57%) had indication for repeating UCP, with mean period to failure of 8.1 ± 3.95 months.

CONCLUSION

UCP procedures are effective in reducing IOP in severe glaucoma. Its application and repetition seem to be a medium-long term acceptable alternative to cyclodestructive surgery. However, long-term efficacy and safety require yet further investigation.

Efficacy and safety of single Ultrasound Cyclo-Plasty to treat refractory glaucoma: Results at 1 year

PURPOSE

To evaluate clinical efficacy and safety of single Ultrasound Cyclo-Plasty (UCP) in the treatment of advanced refractory glaucoma.

METHODS

From January 2018 to August 2018, 25 patients (25 eyes) with refractory glaucoma and intraocular pressure (IOP) not controlled by drugs or conventional filtering surgery were included in the study. All subjects (neovascular glaucoma [n = 12], secondary glaucoma [n = 6], angle closure glaucoma [n = 6], and primary open angle glaucoma [n = 1]) underwent 8-sector Ultrasound Cyclo-Plasty. Patients were followed-up at Day 1, Week 1, and at 1, 3, 6, and 12 months, during which the IOP, the number of IOP lowering drugs and the occurrence of ocular complications were recorded. Clinical outcomes were IOP reduction, success rate, and ocular complications. According to the glaucoma type, patients were divided into a neovascular group (NVG) and a non-NVG group for sub-analysis.

RESULTS

All patients underwent a single UCP procedure and mean IOP reduced significantly from 39.7 ± 6.1 mmHg before UCP to 27.1 ± 11.0 mmHg at 1 year (p < 0.01) corresponding to a mean IOP reduction of 29.6%. The mean number of IOP-lowering drugs used was 2.4 ± 1.2 at baseline and 2.3 ± 1.0 at 12 months. Success rate after a single UCP procedure was achieved in 41.7% patients at 1 year, with a higher success rate in non-NVG than in the NVG group. No major postoperative complications were reported. The main complication was conjunctival congestion, anterior chamber inflammation, scleral ring congestion, and scleral inprint. Of these, scleral ring congestion and scleral imprint are relatively rare complications, which can still be observed 12 months after UCP treatment.

CONCLUSION

UCP for refractory glaucoma is effective in reducing IOP and has a good safety profile. Success rate is lower after a single UCP in NVG than for other types of glaucoma.

Comparison of ultrasound cycloplasty and transscleral cyclophotocoagulation for refractory glaucoma in Chinese population

Background

To compare the efficacy and safety of focused ultrasound cycloplasty (UCP) and transscleral cyclophotocoagulation (TSCP) in the treatment of refractory glaucoma in a Chinese population.

Methods

We retrospectively compared twenty-eight eligible patients with refractory glaucoma, who were divided into the UCP group and TSCP group. Patients in these two groups underwent a corresponding procedure from June 2018 to February 2019. The intraocular pressure (IOP), visual acuity, the number of anti-glaucoma agents used and complications were reviewed and compared between groups. Proper statistical methods were selected according to comparison models under IBM SPSS 25 software.

Results

After the 12-months follow-up, postoperative IOP and number of anti-glaucoma agents used in the two groups were both reduced than the baseline level, and the differences were statistically significant (P < 0.05). There were no significant differences in IOP, number of anti-glaucoma agents and the best-corrected visual acuity between the two groups at each follow-up time point (P>0.05). In terms of complications, the pain at 1 day after surgery in the UCP group was significantly milder than that in the TSCP group (P < 0.05). And there were no significant differences in other complications between the two groups (P > 0.05).

Conclusions

Both UCP and TSCP are safe and effective methods for the treatment of refractory glaucoma. Nevertheless, pain is less severe after UCP.

Efficacy and safety of high-dose ultrasound cyclo-plasty procedure in refractory glaucoma

AIM

To evaluate the efficacy and safety of high-dose ultrasound cyclo-plasty (UCP) for the treatment of refractory glaucoma in Chinese patients.

METHODS

In this 6-month retrospective study, 37 eyes of 37 patients suffering from severe glaucoma with uncontrolled intraocular pressure (IOP) of ≥21 mm Hg underwent 8-s ultrasonic cyclocoagulation with ten active piezoelectric elements. A complete ophthalmic examination was performed before and at 1d, 1, 3, 6mo after UCP. Therapeutic success was defined as IOP reduction from baseline ≥20% and IOP ≥5 mm Hg without adding new glaucoma medication compare to baseline at the 6-month follow-up visit. In addition to mean IOP at each follow-up visit, medications used and complications were also detected and compared to baseline.

RESULTS

After UCP procedure, the mean IOP was significantly reduced (P<0.01) from the preoperative 44.1±11.9 mm Hg to postoperative 26.7±11.8 mm Hg at 3mo, and 30.4±14.5 mm Hg at 6mo. The overall mean IOP reductions achieved at 3 and 6mo were 39% and 31% compared to baseline IOP. Sixty-one percent of patients responded well to UCP treatment with a mean IOP reduction of 48% at 3mo and 42% at 6mo. Ocular pain in most of patients were alleviated. No serious intraoperative or postoperative complications occurred.

CONCLUSION

High-dose UCP treatment is an effective and safe procedure to reduce IOP in Chinese patients with severe glaucoma.

Phacoemulsification Combined With Endoscopic Versus Transscleral Cyclophotocoagulation in Poorly Controlled Glaucoma: A Comparative Case Series

OBJECTIVE

The objective of this study was to report medium-term outcomes of a novel combination of phacoemulsification with transscleral cyclophotocoagulation (phaco-TCP) compared with combined phacoemulsification and endoscopic cyclophotocoagulation (phaco-ECP) in patients with uncontrolled or suboptimally controlled glaucoma and coexisting cataract.

MATERIALS AND METHODS

Retrospective case series of 80 consecutive patients with a minimum of 12 months of follow-up. In total, 46 eyes underwent phaco-ECP and 34 phaco-TCP. Success was defined as intraocular pressure (IOP) between 6 and 21 mm Hg with ≥20% reduction from preoperative IOP (with no increase in ocular hypotensive medications or further glaucoma surgery). Secondary outcomes were change in IOP, number of ocular hypotensive medications and safety.

RESULTS

The mean follow-up was 32.6 ±10.3 months. Preoperative clinical characteristics were similar in both groups. At latest follow-up, success rate was greater with phaco-TCP than phaco-ECP (67.6% and 47.8%, P=0.037). IOP was also significantly lower after phaco-TCP (14.88±5.57 mm Hg, from 22.62±6.52 mm Hg) than phaco-ECP (18.07±6.72 mm Hg, from 22.83±7.88, P=0.0273). Ocular hypotensive medications required reduced similarly after phaco-TCP (from 3.38±0.88 to 2.65±1.04 medications, P=0.0012) and phaco-ECP (from 3.07±0.929 to 2.63±1.42 medications, P=0.0108). There were no cases of hypotony or reduction in vision related to glaucoma with either surgical intervention and a similar proportion required further glaucoma surgery (phaco-ECP 15.2%, phako-TCP 5.9%, P=0.2884).

CONCLUSIONS

Phaco-TCP appears more successful in controlling IOP than phaco-ECP with similar safety. Further investigation is warranted of this newly proposed combination which may be particularly useful where access or experience with ECP or other minimally invasive glaucoma surgery is limited.

High intensity focused ultrasound for glaucoma: 1-year results from a prospective pragmatic study

BACKGROUND

Ciclo plasty using high-intensity focused ultrasound (HIFU) technology acts through the selective coagulation of the ciliary body. Our aim was to evaluate the safety and efficacy profiles of 8-s probe HIFU cyclocoagulation using the EyeOP1 device.

METHODS

Prospective pragmatic trial.

INCLUSION CRITERIA

adult glaucoma patients with uncontrolled IOP despite optimised medical therapy, and/or intolerant to medical therapy required to achieve target IOP.

PRIMARY OUTCOME

surgical success defined as IOP reduction from baseline >20% with final IOP ≤21 mmHg, without adding any IOP-lowering drugs, and without loss of light perception; or decreased use of IOP-lowering drugs with stable/decreased IOP, without loss of light perception.

SECONDARY OUTCOMES

mean IOP, intra and postoperative complications, best-corrected visual acuity (BCVA) and number of IOP-lowering drugs at each visit. Outcome data were collected preoperatively and at postoperative day 1, and months 1, 3, 6 and 12.

RESULTS

Forty-nine eyes of forty-nine patients (28 male) with a mean age of 70 ± 14 years were enroled. Pre-operative IOP was 26.9 ± 7.4 mmHg under 2.8 ± 0.9 topical medications, decreasing to 17.8 ± 6.4 mmHg under 2.3 ± 1 drugs at 12 months (p < 0.01). One-year surgical success was achieved in 71.4% of patients (IOP-reduction criteria: 59.2%; decreased use of IOP-lowering drugs: 38.8%). Eight patients were ultimately submitted to other glaucoma surgical interventions. Five patients experienced serious adverse events (loss of light perception n = 5; hypotony n = 1).

CONCLUSIONS

This innovative non-invasive technology seems to be effective in decreasing IOP and/or the number of administered drops in patients with refractory glaucoma. It seems a valuable tool to delay or preclude the need for filtering procedures in the majority of the patients.

Efficacy and safety of ultrasonic circular cyclocoagulation with second-generation probe in glaucoma: A retrospective study

Background

To assess the efficacy and safety of the second-generation probe of ultrasonic circular cyclocoagulation (UC3) in naive or refractory glaucoma, with a 6-month follow-up.

Methods

A retrospective consecutive case-series study included patients having a UC3 procedure with the second-generation probe of the EyeOP1 device, intraocular pressure (IOP) ≥ 21 mmHg and under maximum tolerated medical treatment, with or without previous glaucoma surgery. Surgical success was defined at the 6-month post-operative visit as IOP > 5 and ≤ 21 mmHg with IOP reduction ≥ 20% from baseline, without any reoperation, and visual acuity better than negative light perception.

Results

100 patients were included and 97 (97.0%; 97 eyes) attended the 6-month follow-up. At 6 months, surgical success was obtained in 48 eyes (49.5%). Intraocular pressure was reduced from a mean ± SD preoperative value of 28.0 ± 5.6 mmHg to 19.3 ± 7.1 mmHg at 6 months (p<0.0001). The proportion of eyes requiring oral acetazolamide decreased from 57.0% to 30.0% between baseline and 6 months after surgery (p = 0.0007). We observed 15 (15.0%) cases of postsurgical macular edema, 8 (8.0%) of hypotony, and 20 (20.0%) of visual acuity loss > 2 Snellen lines. Postsurgical macular edema was associated with a history of epiretinal membranes, uveitis or retinal detachment. Risk factors for hypotony were a history of diabetes or trabeculectomy.

Conclusions

The second-generation UC3 probe significantly reduced IOP in eyes with naive and refractory glaucoma but severe post-operative complications were often observed. Further studies are needed to better identify responders and decrease the high risk for complications associated with the procedure.

Transient choroidal detachment after ultrasonic circular cyclocoagulation

Two patients with refractory glaucoma followed in our ophthalmology department registered progression on left eyes (OS) despite best practice. Best corrected visual acuity (BCVA) was 9/10 and 8/10 and intraocular pressure (IOP) was above 20 mm Hg while under maximal hypotensive therapy. The procedure was performed under retrobulbar anaesthesia with second-generation EyeOp1probes. In follow-up, OS were hypotonic with registered IOP ≤5 mm Hg and revealed a 3/10 BCVA. The funduscopy showed one temporal and superior and another nasal and temporal choroidal detachments. The patients started oral steroids and interrupted all ocular hypotensive medication. After therapy, patients returned with normal rising OS IOPs and with totally reapplied choroids, accompanied by normalised BCVA. These two cases are proof of the possibility of transient choroidal detachment after a ultrasonic circular cyclocoagulation. While a very rare major vision-threatening complication, every ophthalmologist should remind it when sudden BCVA reductions occur after this procedure.

Safety and efficacy of ultrasound ciliary plasty as a primary intervention in glaucoma patients

AIM

To evaluate the safety and the efficacy of the ultrasound ciliary plasty (UCP) on the intraocular pressure (IOP) control in glaucomatous eyes without previous glaucoma surgery.

METHODS

A retrospective study included patients with primary and secondary glaucoma who underwent UCP in Dar AlShifa Hospital, Kuwait between January 2017 to June 2018. High-intensity focused ultrasound procedures were performed under peribulbar anesthesia using the 2^nd generation probe with 8s duration of each of the 6 shots. Complete ophthalmologic examinations were scheduled pre-treatment, and at 1d, 1wk, 1, 3, 6 and 12mo post-treatment. Primary outcomes were the IOP reduction and success rates at 12mo, while the secondary outcomes were the occurrence of vision threatening complications and visual acuity.

RESULTS

The records of 62 eyes of 62 patients were analyzed with mean age of 63.8y (67.7% males). There was statistically significant reduction in the mean IOP from 35.2±8.3 mm Hg before treatment to 20.6±8.7 mm Hg at 12^th month (P<0.0005) with a mean percentage IOP reduction of 42.3% with significant reduction in the mean number of antiglaucomatous drugs from 3.2±0.4 before treatment to 2.1±1.02 at 12mo (P<0.0005). Qualified success was achieved in 77.4% of eyes at 12mo. No major intra- or post-treatment complications were reported.

CONCLUSION

Second-generation UCP prove to be effective in reducing IOP in naive glaucoma patients with lower success rates in cases of neovascular and uveitic glaucomas.

Short-Term Observation of Ultrasonic Cyclocoagulation in Chinese Patients with End-Stage Refractory Glaucoma: A Retrospective Study

Purpose

To assess the efficacy and safety of HIFU-based ultrasonic cyclocoagulation in Chinese patients with end-stage refractory glaucoma.

Method

Patients were recruited consecutively from May 2016 to May 2017 in the Zhongshan Ophthalmic Center. Ultrasonic cyclocoagulation was performed on every patient, using the EyeOP1 ultrasound emitting device. Return visits were set at 1 day, 7 days, 1 month, and 3 months after the treatment. An intraocular pressure (IOP) reduction of ≥20% while IOP ≥ 5 mmHg was deemed as success. Mean IOP change was assessed. Efficacy of two modes (6 sectors and 8 sectors) was also compared. Complications were recorded for safety evaluation.

Results

61 eyes were treated in this study. The baseline IOP (mean ± SD) was 41.11 ± 10.65 mmHg. The percentage of IOP reduction after treatment was 29.2%, 43.2%, 34.8%, and 23.1% at 1 day, 7 days, 1 month, and 3 months, respectively. Overall success rate at 3 months was 50.0% (26/52). No significant difference was found between the 6 sectors group and the 8 sectors group in terms of the success rate (48.6% vs. 52.9%, p=0.768) as well as IOP reduction (p=0.417) at 3 months. Primary angle-closure glaucoma (PACG) had the highest success rate (80.0%, 12/15). Scleral thinning existed in 12 eyes, among which 2 developed hypotony (2 mmHg and 3 mmHg). Average pain score decreased massively compared with baseline data.

Conclusion

With high percentage of IOP reduction and a good safety profile observed in our study, HIFU-based ultrasonic cyclocoagulation might become a promising alternative to cyclodestructive methods. Long-term efficacy and safety need further assessment. The study was registered with Chinese Clinical Trial Registry (http://www.chictr.org.cn; Registration number: ChiCTR-OOC-17014028).

Application of high intensity focused ultrasound for treatment of open-angle glaucoma in Indian patients

Purpose:

The aim of this study is to assess the efficacy of ultrasound cycloplasty (UCP) in Indian patients with open angle glaucoma (OAG).

Methods:

A prospective interventional study was designed to treat 73 eyes of 73 patients with OAG with the EyeOP1 device equipped with six miniaturized cylindrical piezoelectric transducers. Two treatment protocols of ultrasound delivery depending on exposure time (8 s and 10 s of shot per transducer) were used. Complete ophthalmic examination, ocular biometry and anterior segment optical coherence tomography were performed preoperatively and patients were followed up at day 1, day 7 and months 1, 2, 3, 6, and 12. The primary outcome measure was “successful” intraocular pressure (IOP) control defined as IOP reduction ≥20% from baseline and IOP value >5 mm Hg at the last follow-up visit. Secondary outcomes were the occurrence of complications and mean IOP during the follow-up period.

Results:

In all patients, the mean IOP reduced from 23.5 ± 3.0 mmHg before treatment to 15.7 ± 5.4 mmHg at 12 months (P < 0.05). Successful IOP control after a single procedure was 78.3% (79% and 78% in the 8 s and 10 s groups, respectively) at 12 months. Overall, the mean IOP reduction achieved in responding patients was 41% (standard deviation = 12%). Notwithstanding minor side effects such as transient pain, anterior chamber reaction, and refractive error changes, no major intraoperative or postoperative complications (severe hypotony or phthisis) were observed during the follow-up.

Conclusion:

Our short-term results reveal that UCP is a simple, safe, and noninvasive procedure which enables to significantly reduce the IOP in patients with OAG. The study results in Indian eyes corroborate findings in earlier studies on Caucasian eyes.