Preliminary study on the treatment of acute angle-closure glaucoma with high-intensity focused ultrasound cycloplasty

Preliminary study on the treatment of acute angle-closure glaucoma with high-intensity focused ultrasound cycloplasty | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Preliminary study on the treatment of acute angle-closure glaucoma with high-intensity focused ultrasound cycloplasty Wei Wang, Chunmiao Wang, Yi Zhou, Shuxi Yan, Xiangji Li, Lin Xie This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5675275/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 Sep, 2025 Read the published version in Scientific Reports → Version 1 posted 10 You are reading this latest preprint version Abstract High-intensity focused ultrasound cycloplasty (UCP) can effectively reduce intraocular pressure in glaucoma patients. This work aimed to analyze the efficacy, safety, and mechanism of UCP in treating acute angle-closure glaucoma. We collected and retrospectively analyzed the preoperative and postoperative clinical data of 16 cases (16 eyes) with acute angle-closure glaucoma, including the number of sectors activated, intraocular pressure (IOP), central anterior chamber depth (ACD), lens zonule length (LZL), ciliary muscle thickness (CMT), and trabecular-ciliary process angle (TCA). Of the 16 eyes, one received a single UCP procedure with 8 sectors and the others with 10 sectors. The mean IOP at follow-up time points after UCP was significantly lower than before UCP. The mean ACD at follow-up time points after UCP was significantly higher than before UCP. The mean LZL in the superior, inferior, nasal, and temporal quadrants on postoperative day 1, week 1, and month 1 was significantly shorter than those before UCP. The mean CMT in the superior, inferior, and nasal quadrants on postoperative day 1 and in the superior and inferior quadrants on postoperative week 1 were significantly larger than those before UCP. The mean TCA in the temporal quadrant on postoperative month 3 was significantly smaller than that before UCP. In conclusion, UCP is safe and effective in treating acute angle-closure glaucoma. The special mechanism of lowering IOP after UCP may be attributed to the increased depth of the central anterior chamber and the reopening of some non-adhesive closed angles. Health sciences/Diseases/Eye diseases Health sciences/Medical research/Study design Acute angle-closure glaucoma Ultrasound cycloplasty Intraocular pressure Anterior chamber depth Trabecular-ciliary process angle Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Acute angle-closure glaucoma (AACG), one of the ophthalmic emergencies, occurs after a rapid rise in intraocular pressure (IOP) due to a sudden occlusion of the anterior chamber angle 1 . This urgent condition warrants immediate treatments to reduce IOP and control inflammation, and the closed anterior chamber angle should be reopened through surgical intervention including laser treatment 1 , 2 . Theoretically, surgical intervention for AACG should be implemented after IOP is stabilized to normal, to reduce intraoperative and postoperative complications; however, clinically, the IOP of an AACG patient may not be controlled to normal after various anti-glaucoma medications, and surgical treatment must be given to reduce the persistent high IOP to avoid further damage to the optic nerve. Simple phacoemulsification alone or in combination with glaucoma surgery is strongly recommended for AACG patients over 50 years old according to the fifth-edition guidelines for glaucoma published by the European Glaucoma Society 2 . Phacoemulsification alone or in combination with goniosynechialysis was routinely chosen for AACG patients with cataracts 3 , 4 . However, AACG patients are prone to serious complications like expulsive suprachoroidal hemorrhage and corneal endothelial decompensation when phacoemulsification and glaucoma filtration surgery (also known as trabeculectomy) are performed for the condition of extremely high IOP 5 . If the condition is complicated with serious disorders like renal failure and severe corneal edema, AACG patients cannot receive intraocular phacoemulsification or goniosynechialysis. A safe and effective surgical approach is needed for such a case. Low-dose transscleral cyclophotocoagulation is used to reduce IOP in some AACG patients with uncontrollable IOP after anterior chamber paracentesis and medication 6 , 7 . Ultrasound cycloplasty (UCP) applies high-intensity focused ultrasound to work on the ciliary body to make partial destruction of the ciliary epithelium and decrease the generation of aqueous humor, thus reducing IOP 8 . As a non-invasive option, it operates on the ciliary body with a milder effect and lighter postoperative reaction than transscleral laser cyclophotocoagulation 9 . UCP is the first choice for treating open-angle glaucoma that occurs in some patients with exfoliation syndrome in some European countries 10 . There is no research on the application of UCP to reduce IOP for the common type of glaucoma, AACG, in China. Therefore, this retrospective study aims to explore the safety and effectiveness of UCP in the treatment of AACG and its mechanism of lowering IOP. Methods Patients This retrospective study included 16 patients (16 eyes; 10 females and 6 males) with AACG who underwent UCP in Chongqing Aier Eye Hospital (Chongqing, China) from January 2022 to January 2024. Before UCP, all included patients received systemic and local medication with intraocular pressure-lowering agents at their maximum tolerated dose and anterior chamber paracentesis, and their IOP still stayed at ≥ 35 mmHg (1 mmHg = 0.133 kPa) 24 hours after these treatments. Besides, the patients were in poor ocular and systemic conditions and had a higher risk of undergoing phacoemulsification surgery or glaucoma filtration surgery. Patients with intraocular diseases including secondary angle-closure glaucoma, endophthalmitis or uveitis within recent three months, eye trauma, and intraocular tumors, or who had a history of eye surgery or refused UCP were excluded. Ethics statement This study adhered to the Declaration of Helsinki and was approved by the Ethics Committee of Chongqing Aier Eye Hospital (approval No. IRB2020034). Trial registration: Chinese Clinical Trial Registry No. ChiCTR1900022880.All patients included signed the informed consent form for the UCP operation. Preoperative examinations All routine examinations including visual acuity test (naked vision; standard logarithmic/decimal visual acuity chart, China), slit-lamp biomicroscopy, fundoscopy (fundus examination), IOP measurement (iCare Pro Rebound Tonometer, Finland), corneal endothelial cell density detection (NIDEK CEM-530 Specular Microscope, Japan), axial length and white-to-white distance measurements (ZEISS IOLMaster 500 Optical Biometer, Germany), and ultrasonic biomicroscopy (UMB), were performed before UCP operation. Surgical procedures All patients underwent UCP (with the cyclocoagulation device EyeOP1 from EyeTechCare, Rillieux-la-Pape, France) by the same experienced ophthalmologist. The probe diameter (model) was determined according to the eye's biometric readings, and the number of treatment sectors activated was chosen according to IOP. The UCP instrument was turned on after routine disinfection, towel-laying preparation, and topical/retrobulbar anesthesia. After inputting the patient's basic information, the coupling cone for the probe was fixated on the eye by the vacuum suction ring with a negative pressure, and then the probe was put inside the cone. The negative pressure should be confirmed before UCP treatment. The activation of the transducers was started by constantly pressing the foot pedal until the UCP treatment was finished. Postoperative follow-ups After the UCP operation, prednisolone acetate eye drops (Allergan Pharmaceuticals Ireland) were administrated to the treated eyes four times a day (decreasing once a week and lasting for one month). IOP-lowering agents should be given if the IOP is greater than 21 mmHg. Follow-ups were scheduled on postoperative day 1 (POD1), week 1 (POW1), month 1 (POM1), and month 3 (POM3). The primary observation indexes were naked vision, IOP, the number of IOP-lowering agents used, central anterior chamber depth (ACD), lens zonule length (LZL), ciliary muscle thickness (CMT), and trabecular-ciliary process angle (TCA). The secondary observation indexes included the occurrence of complications including subconjunctival hemorrhage. ACD was defined as the vertical distance from the central anterior corneal epithelium to the anterior lens capsule (Fig. 1 A). LZL was defined as the midpoint of the ciliary process to the midpoint of the anterior aspects of the equatorial lens capsule (Fig. 1 B), and its mean value was taken from three measurements. CMT was defined as the line segment being perpendicular to the upper boundary of ciliary muscle and crossing the horizontal ciliary muscle apex at coronal section (Fig. 1 C). TCA was defined as the angle formed by the tangent of the inner corneal surface near the scleral spur and the connecting line between the scleral spur and the most anterior surface of the ciliary body with the scleral spur as the apex (Fig. 1 D). Statistical analysis The visual acuity values were converted into LogMAR visual acuities for statistical analysis, with the finger counting, hand motion, light perception, and no light perception recorded as 2.6, 2.7, 2.8, and 2.9, respectively 11 . Statistical software SPSS24.0 was used to process the data. The paired samples t -test was used to compare the measurement data that met the normal distribution, and the paired Wilcoxon rank sum test was used to compare the measurement data that did not meet the normal distribution (IOP before and after operation, the number of IOP-lowering agents used, etc. ). P -values < 0.05 were considered statistically significant. Results Patient information and operation parameters All the patients collected in this study were treated with anterior chamber paracentesis and IOP-lowering agents at the maximum tolerated dose, and the IOP still stayed at ≥ 35 mmHg. Their corneal thickness was thickened at different degrees due to corneal edema caused by high IOP. The density of corneal endothelial cells could not be measured in 9 cases because of severe corneal edema. The probe size was calculated according to the white-to-white distance, and the probe diameter was 11 mm for one case and 12 mm for the rest. According to the preoperative IOP, 8 sectors were selected for one case with a preoperative IOP of 30–40 mmHg, and 10 sectors were selected for 15 cases with a preoperative IOP greater than 40 mmHg for UCP operation. The details of patients' basic information and UCP parameters are shown in Table 1 . Table 1 The patients' basic information and ultrasound cycloplasty parameters. Term n = 16 Age (years) (median (range)) 65 (55–83) Number of patients (female/male) 10/6 Number of eyes (right/left) 12/4 Corneal thickness (µm) (median (range)) 648 (569–1190) Corneal endothelial cell density (cells/mm 2 ) (median (range)) 0 (0–3237) Axial length (mm) (median (range)) 22.35 (21.42–22.92) White-to-white distance (mm) (median (range)) 11.2 (10.6–11.8) Probe size (11/12/13 mm) ( n ) 1/15/0 Treatment sectors (6/8/10) ( n ) 0/1/15 Changes in IOP and the use of IOP-lowering agents The mean preoperative IOP was 52.31 ± 4.21 mmHg and significantly decreased to 13.00 ± 4.87 mmHg, 10.25 ± 2.35 mmHg, 11.06 ± 1.57 mmHg, and 14.75 ± 2.08 mmHg on POD1, POW1, POM1, and POM3, respectively (all p < 0.05; Fig. 2 A). The patients were administrated with 3 or 4 IOP-lowering agents before UCP operation. No IOP-lowering agents were used on POD1 and POW1; one eye was given one agent on POM1; two eyes were given one agent and one eye was given two agents on POM3. The mean number of IOP-lowering agents used significantly decreased from preoperative records ( p < 0.05; Table 2 ). Table 2 The use of intraocular pressure-lowering agents before and after operation (cases (%)). Cases 0 agent 1 agent 2 agents 3 agents 4 agents Before operation 16 0 0 0 2(12.5%) 14 (87.55%) Postoperative day 1 16 16 (100%) 0 0 0 0 Postoperative week 1 16 16 (100%) 0 0 0 0 Postoperative month 1 16 15 (93.8%) 1 (6.2%) 0 0 0 Postoperative month 3 16 13 (81.3%) 2 (12.5%) 1 (6.2%) 0 0 Changes in ACD, LZL, CMT, and TCA The mean ACD was 1.72 ± 0.21 mm, 1.61 ± 0.14 mm, 1.61 ± 0.14 mm, and 1.61 ± 0.14 mm on POD1, POW1, POM1, and POM3, respectively, which were significantly higher than that before operation (1.41 ± 0.24 mm) ( p < 0.05; Fig. 2 B). The mean LZL in the superior, inferior, nasal, and temporal quadrants on POD1, POW1, and POM1 was significantly shorter than those before operation ( p < 0.05; Fig. 3 A). No significant differences were found between the mean LZL in the superior, inferior, nasal, and temporal quadrants before operation and those on POM3. The mean preoperative CMT in the superior, inferior, nasal, and temporal quadrants was 0.5913 ± 0.05 mm, 0.6456 ± 0.06 mm, 0.6225 ± 0.057 mm, and 0.6181 ± 0.86 mm, respectively. Only the mean CMT in the superior, inferior, and nasal quadrants on POD1 and in the superior and inferior quadrants on POW1 were significantly larger than those before operation ( p < 0.05; Fig. 3 B). The TCA in the temporal quadrant on POM3 was significantly smaller than that before operation ( p < 0.05; Fig. 3 C). Changes in visual acuity and postoperative complications The mean postoperative LogMAR visual acuity showed a significant upward trend on POD1, POW1, and POM1 compared with that before operation ( p < 0.05), but there was no significant difference in LogMAR visual acuity between before operation and on POM3 (Table 3 ). No serious complications such as eyeball atrophy and hyphema occurred in all 16 patients. Conjunctival congestion in different degrees and subconjunctival hemorrhage were present in 16 cases and 14 cases respectively on POD1 (Fig. 4 ). All these conditions recovered on POM1. Eight patients suffered from ciliary body detachment on POD1, and all recovered on POM1. Table 3 The preoperative and postoperative visual acuities. Visual acuity p Before operation 2.30(1.34–2.9) Postoperative day 1 2.00 (1.00–2.9) 0.014 Postoperative week 1 1.70 (0.82–2.9) 0.006 Postoperative month 1 1.85 (0.94–2.9) 0.009 Postoperative month 3 2.30 (1.60–2.9) 0.182 Discussion AACG can cause blindness if not timely treated or immediate IOP control is not achieved, and the treatment time window of its attack is 4.6 hours as reported 12 . Quick IOP stabilization is the key to treating AACG, but it often cannot be achieved by IOP-lowering agents alone; laser cannot be applied in the presence of corneal edema, and anterior chamber paracentesis is an invasive operation that could increase the risk of intraocular infection and cannot relieve the cause; the risk of intraocular surgery for the case of extremely high IOP is high, for example, phacoemulsification is easy to cause serious complications such as malignant glaucoma 13 , and glaucoma filtration surgery, also named as trabeculectomy, is easy to cause explosive choroidal hemorrhage and decompression choroidopathy 14 , 15 . Therefore, a safe and effective surgical approach is needed to reduce IOP when AACG continues to go with high IOP. At present, in Europe and America, UCP has shown a good effect on primary open-angle glaucoma 16 , 17 , and its effectiveness in treating primary angle-closure glaucoma is also reported 18 . However, there is no report on the treatment of AACG with persistent high IOP. Before UCP operation, the appropriate size of the surgical ultrasound probe and positioning ring (vacuum suction ring) should be selected according to the eye biometric parameters, such as white-to-white distance, axial length, and ciliary sulcus diameter. The axial length and white-to-white distance of angle-closure glaucoma patients are short. In our study, the probe diameter was 11 mm for one case and 12 mm for the rest (15 eyes), consistent with the report for Chinese patients undergoing UCP 19 . The appropriate number of treatment sectors activated (6/8/10 sectors) is usually selected according to the IOP value. At present, the transducers are automatically activated with a duration of 8 seconds for each sector. Six-sector surgical treatment was most used abroad 20 – 22 because the mean baseline IOP of the reported cases is not high, mostly 21–30 mmHg, while the persistent high IOP of AACG is often greater than 35 mmHg. The mean baseline IOP in our study was 52.31 mmHg, so we chose 8- or 10-sector surgical treatment. In our study, the IOP of 16 patients was reduced after the first postoperative day, and the IOP was controlled below 21 mmHg 3 months after operation. The significantly less use of IOP-lowering drugs after versus before the operation supports the decision of the 8- or 10-sector surgical treatment for our patients. UCP is effective in treating AACG in our study, but the sample size is small. More data are needed to prove it and ethnic differences should be considered as well. The mechanism underlying the immediacy of lowering IOP through UCP within one day in AACGs needs further exploration. At present, relevant studies show that IOP reduction after UCP is mainly attributable to reshaped ciliary body and reduced generation of aqueous humor achieved by degeneration or necrosis of the ciliary epithelium and occlusion of the ciliary process vessels 23 . It is also speculated that the scleral scar generated by UCP can increase the distance between the ciliary process and the sclera, causing the increase of aqueous humor outflow through the ciliary body and suprachoroidal space, and therefore reducing IOP 24 . These two potential mechanisms cannot fully explain the immediacy of lowering IOP through UCP in AACG treatment. The pathogenesis of AACG is extremely complicated, and many factors including short axial length, shallow anterior chamber, and crowded anterior segment structure, can easily give rise to angle closure and subsequent high IOP 25 , 26 . In this study, 16 included patients had short axial lengths and shallow anterior chambers before the operation; a deeper anterior chamber was found after the operation and remained until 3 months after the operation. Besides, it was observed that the anterior chamber angle of patients in some quadrants was reopened to varying degrees after UCP operation (Fig. 4 B). The reasons why UCP can deepen the anterior chamber and reopen the anterior chamber angle in some quadrants warrant further exploration. In recent years, some scholars have suggested that the abnormal lens position caused by the relaxation of suspensory ligaments may be one of the risk factors leading to angle closure and angle-closure glaucoma 27 . Ultrasound biomicroscopy is used to image suspensory ligaments and ciliary muscles to observe the morphological changes after UCP 28 , 29 , and it was found in this study that the length of the lens suspensory ligaments of the 16 AACG patients was shortened on POD1, POW1, and POM1. Besides, our study showed that CMT in the superior, inferior, and nasal quadrants on POD1 and in the superior and inferior quadrants on POW1 became thicker. The ultrasonic energy of UCP acts on the ciliary body and the thermal effect will cause edema of the ciliary muscle tissue in the early stage after UCP operation; the UCP probe avoids the treatment to 3-o'clock and 9-o'clock positions and the morphological changes are mainly manifested in the superior and inferior ciliary muscles 23 . Therefore, we speculate that the ciliary muscle-suspensory ligament-lens is a linkage system of the anterior segment 30 . Relaxed ciliary muscles resulting from early ciliary muscle edema make the suspensory ligaments and increase their tension in a short time; the suspensory ligaments pull on the lens capsule at the equator and reduce the curvature radius of the central anterior and posterior surfaces of the lens; the lens is moved backward and thus the depth of the central anterior chamber (ACD) is elevated and some non-adhesive closed angles are reopened. This could be a possible special mechanism of UCP in the early phase of AACG treatment. Forward placement of the ciliary body may be an influencing factor in the pathogenesis of angle-closure glaucoma 31 . Anteriorly placed ciliary body may force the peripheral iris forward as a plateau to close the angle. UCP acts on the ciliary body and whether it can improve the ciliary body's forward placement to open the closed angle is worth observing. The angle between trabecular meshwork and ciliary process (TCA) is an index to reflect the ciliary body's position. The mean preoperative TCA in our 16 patients is smaller than the mean TCA of normal individuals in China as reported 32 , so the angle is more likely to suffer from angle-closure glaucoma. Although the angle in the temporal quadrant at postoperative month 3 was smaller than that before the UCP operation, the statistical difference is insufficient to prove UCP's effect in the alteration of the ciliary body's position. Therefore, the slight alteration of the ciliary body's position should not be taken as the mechanism of UCP in treating angle-closure glaucoma. UCP is more controllable, selective, and safer in destroying the ciliary body tissue, compared with ciliary body photocoagulation 33 , 34 . In this study, no serious complications in the 16 UCP-treated patients, and their postoperative vision was improved. UCP itself could not improve vision, and the vision improvement of our patients could be attributed to the relief and gradual transparency of corneal edema after IOP reduction. Eight patients suffered from ciliary body detachment and recovered within one postoperative month. This suggests that IOP reduction in the early phase after UCP for AACG treatment may be related to choroidal detachment. However, the incidence rate of ciliary body detachment (50%) in our study is much higher than current reports 35 , 36 , and the severe inflammation during the attack of AACG may explain the high rate. Besides, it is reported that patients with glaucoma had easier uveoscleral outflow of aqueous humor after UCP 37 , but the specific mechanism is not clear. UCP is safe and effective in treating AACG. UCP can be used as a brand-new surgical approach for AACG under continuous high IOP although there are few AACG patients in our clinic because of the strict inclusion criteria,it is a challenging caes in clinical practice. Deepening ACD and Reopening some non-adhesive closed angles in the early stage may contribute to UCP's role in lowering IOP. More samples are highly needed for further investigation. Declarations Competing interests The authors declare no competing interests. Funding This research was funded by the Aier Eye Hospital Group Scientific Research Fund (No. AGF2306D04). Author Contribution L.X. and X.J.L. contributed to the conception and design of the study. W.W. and S.X.Y. organized the original data. C.M.W. performed the statistical analysis. W.W. and Y.Z. prepared the tables and figures. W.W. and X.J.L. wrote the first draft of the manuscript. W.W. and C.M.W. wrote the final version of the manuscript. All authors reviewed the manuscript. 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Biol. 40 , 2096–2106 (2014). Additional Declarations No competing interests reported. Supplementary Files DATA.xlsx Cite Share Download PDF Status: Published Journal Publication published 29 Sep, 2025 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 02 Jun, 2025 Reviews received at journal 02 Jun, 2025 Reviewers agreed at journal 04 May, 2025 Reviews received at journal 10 Apr, 2025 Reviewers agreed at journal 06 Apr, 2025 Reviewers invited by journal 13 Jan, 2025 Editor assigned by journal 13 Jan, 2025 Editor invited by journal 31 Dec, 2024 Submission checks completed at journal 30 Dec, 2024 First submitted to journal 19 Dec, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5675275","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":396264517,"identity":"4b86a0f8-16f1-4163-a273-fbc14cd1f88c","order_by":0,"name":"Wei Wang","email":"","orcid":"","institution":"Department of Ophthalmology, the Third Affiliated Hospital of Chongqing Medical University","correspondingAuthor":false,"prefix":"","firstName":"Wei","middleName":"","lastName":"Wang","suffix":""},{"id":396264518,"identity":"d17879fc-d09b-4c9b-910d-165df04d5539","order_by":1,"name":"Chunmiao Wang","email":"","orcid":"","institution":"Chongqing Aier Eye Hospital","correspondingAuthor":false,"prefix":"","firstName":"Chunmiao","middleName":"","lastName":"Wang","suffix":""},{"id":396264519,"identity":"c32b53ed-7031-4f12-aa5c-3a98a5a091d8","order_by":2,"name":"Yi Zhou","email":"","orcid":"","institution":"Chongqing Aier Eye Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yi","middleName":"","lastName":"Zhou","suffix":""},{"id":396264520,"identity":"db123ecc-0679-48fa-919c-41f36331e271","order_by":3,"name":"Shuxi Yan","email":"","orcid":"","institution":"Chongqing Aier Eye Hospital","correspondingAuthor":false,"prefix":"","firstName":"Shuxi","middleName":"","lastName":"Yan","suffix":""},{"id":396264521,"identity":"74ac612d-be00-48b5-a0bd-3a3c9a754252","order_by":4,"name":"Xiangji Li","email":"","orcid":"","institution":"Department of Ophthalmology, the Third Affiliated Hospital of Chongqing Medical University","correspondingAuthor":false,"prefix":"","firstName":"Xiangji","middleName":"","lastName":"Li","suffix":""},{"id":396264522,"identity":"02abcf8e-c0ed-41cd-b46a-67bf4f1c2890","order_by":5,"name":"Lin Xie","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABE0lEQVRIie3PMWvCQBTA8SeBuBzc+hzaz3DQRVD6We4o6FDN0sXBIVA4t7rab5FSkI5PDuySNKvglA9QyFToIr00pnY4W0eH+xPCI9wvyQPw+c6xAFokoS+rmQC6h+d/ELBkUBMCPIHULzdyP51AxGtAVLzkEefZypRTBD67HSBMeipuZ+QinftQkkq3d51FJInWCJi+LxHSoYpZJF2EB0yQ0luVbOxAIYLA8RJb2qgYmXCRMOClJW8qyVNLdg3ZHSf2K2AJqYRGgla6IfFxYnepfuxGPVa7ZA/I7C7PXbkeXmk2chKRm6L41NdqzjNTTj76l3w2ftqU097FvJ06ya9Yc5ffF4T/nP8hUJ/3+Xw+36Ev+ONmc/gtc9MAAAAASUVORK5CYII=","orcid":"","institution":"Department of Ophthalmology, the Third Affiliated Hospital of Chongqing Medical University","correspondingAuthor":true,"prefix":"","firstName":"Lin","middleName":"","lastName":"Xie","suffix":""}],"badges":[],"createdAt":"2024-12-19 09:08:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5675275/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5675275/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-025-18675-7","type":"published","date":"2025-09-29T15:56:57+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":72754817,"identity":"b7969888-7bf7-4fbc-9159-be20dbf560ba","added_by":"auto","created_at":"2025-01-01 16:52:59","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":105526,"visible":true,"origin":"","legend":"\u003cp\u003eMeasurement of (A) anterior chamber depth (ACD), (B) lens zonule length (LZL), (C) ciliary muscle thickness (CMT), and (D) trabecular-ciliary process angle (TCA) with ultrasound biomicroscopy. These indexes are shown by red line segments and angle and pointed out by an arrow.\u003c/p\u003e","description":"","filename":"Figure1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-5675275/v1/e0e840911d2928c6f35de895.jpeg"},{"id":72756270,"identity":"ce4d0cea-9495-42ff-a3db-0dfe2f7f0176","added_by":"auto","created_at":"2025-01-01 17:08:59","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":52113,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative and postoperative (A) intraocular pressure (IOP) and (B) anterior chamber depth (ACD). POD1, postoperative day 1; POW1, postoperative week 1; POM1, postoperative month 1; POM3, postoperative month 3.\u003c/p\u003e","description":"","filename":"Figure2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-5675275/v1/08d0f22357b287db03c33684.jpeg"},{"id":72754824,"identity":"51d637e0-a1e0-4009-8cac-252abaaa2218","added_by":"auto","created_at":"2025-01-01 16:52:59","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":337296,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative and postoperative (A) lens zonule length (LZL), (B) ciliary muscle thickness (CMT), and (C) trabecular-ciliary process angle (TCA) in the superior, inferior, nasal, and temporal quadrants. POD1, postoperative day 1; POW1, postoperative week 1; POM1, postoperative month 1; POM3, postoperative month 3.\u003c/p\u003e","description":"","filename":"Figure3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-5675275/v1/a2a0f2e3a6d077db9fbb35e8.jpeg"},{"id":72754843,"identity":"cd74466c-a544-4128-963c-7b5865f54f8a","added_by":"auto","created_at":"2025-01-01 16:52:59","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":44653,"visible":true,"origin":"","legend":"\u003cp\u003eThe central anterior chamber depth and subconjunctival hemorrhage were observed by slit-lamp photography (A1) before operation and (A2) on postoperative day 1. Ultrasound biomicroscopy examination of trabecular-ciliary process angle at the 12-o'clock position (B1) before operation and (B2) after operation.\u003c/p\u003e","description":"","filename":"Figure4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-5675275/v1/dca33c04afba57073f8cbc21.jpeg"},{"id":92883932,"identity":"b6abafd0-0538-4afd-b531-ad504403c4bb","added_by":"auto","created_at":"2025-10-06 16:11:13","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1225555,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5675275/v1/70582d29-9248-43d3-b4df-d7c9fbd0cdbb.pdf"},{"id":72755963,"identity":"371f8fe2-3673-46dd-acbe-0025a68e3e20","added_by":"auto","created_at":"2025-01-01 17:00:59","extension":"xlsx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":21617,"visible":true,"origin":"","legend":"","description":"","filename":"DATA.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-5675275/v1/aae7c639a6b96f7062f209f2.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Preliminary study on the treatment of acute angle-closure glaucoma with high-intensity focused ultrasound cycloplasty","fulltext":[{"header":"Introduction","content":"\u003cp\u003eAcute angle-closure glaucoma (AACG), one of the ophthalmic emergencies, occurs after a rapid rise in intraocular pressure (IOP) due to a sudden occlusion of the anterior chamber angle\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. This urgent condition warrants immediate treatments to reduce IOP and control inflammation, and the closed anterior chamber angle should be reopened through surgical intervention including laser treatment\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. Theoretically, surgical intervention for AACG should be implemented after IOP is stabilized to normal, to reduce intraoperative and postoperative complications; however, clinically, the IOP of an AACG patient may not be controlled to normal after various anti-glaucoma medications, and surgical treatment must be given to reduce the persistent high IOP to avoid further damage to the optic nerve. Simple phacoemulsification alone or in combination with glaucoma surgery is strongly recommended for AACG patients over 50 years old according to the fifth-edition guidelines for glaucoma published by the European Glaucoma Society\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. Phacoemulsification alone or in combination with goniosynechialysis was routinely chosen for AACG patients with cataracts\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e,\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. However, AACG patients are prone to serious complications like expulsive suprachoroidal hemorrhage and corneal endothelial decompensation when phacoemulsification and glaucoma filtration surgery (also known as trabeculectomy) are performed for the condition of extremely high IOP\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. If the condition is complicated with serious disorders like renal failure and severe corneal edema, AACG patients cannot receive intraocular phacoemulsification or goniosynechialysis. A safe and effective surgical approach is needed for such a case.\u003c/p\u003e \u003cp\u003eLow-dose transscleral cyclophotocoagulation is used to reduce IOP in some AACG patients with uncontrollable IOP after anterior chamber paracentesis and medication\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e,\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e. Ultrasound cycloplasty (UCP) applies high-intensity focused ultrasound to work on the ciliary body to make partial destruction of the ciliary epithelium and decrease the generation of aqueous humor, thus reducing IOP\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. As a non-invasive option, it operates on the ciliary body with a milder effect and lighter postoperative reaction than transscleral laser cyclophotocoagulation\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e. UCP is the first choice for treating open-angle glaucoma that occurs in some patients with exfoliation syndrome in some European countries\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. There is no research on the application of UCP to reduce IOP for the common type of glaucoma, AACG, in China. Therefore, this retrospective study aims to explore the safety and effectiveness of UCP in the treatment of AACG and its mechanism of lowering IOP.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePatients\u003c/h2\u003e \u003cp\u003eThis retrospective study included 16 patients (16 eyes; 10 females and 6 males) with AACG who underwent UCP in Chongqing Aier Eye Hospital (Chongqing, China) from January 2022 to January 2024. Before UCP, all included patients received systemic and local medication with intraocular pressure-lowering agents at their maximum tolerated dose and anterior chamber paracentesis, and their IOP still stayed at \u0026ge;\u0026thinsp;35 mmHg (1 mmHg\u0026thinsp;=\u0026thinsp;0.133 kPa) 24 hours after these treatments. Besides, the patients were in poor ocular and systemic conditions and had a higher risk of undergoing phacoemulsification surgery or glaucoma filtration surgery. Patients with intraocular diseases including secondary angle-closure glaucoma, endophthalmitis or uveitis within recent three months, eye trauma, and intraocular tumors, or who had a history of eye surgery or refused UCP were excluded.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eEthics statement\u003c/h3\u003e\n\u003cp\u003e This study adhered to the Declaration of Helsinki and was approved by the Ethics Committee of Chongqing Aier Eye Hospital (approval No. IRB2020034). Trial registration: Chinese Clinical Trial Registry No. ChiCTR1900022880.All patients included signed the informed consent form for the UCP operation.\u003c/p\u003e\n\u003ch3\u003ePreoperative examinations\u003c/h3\u003e\n\u003cp\u003eAll routine examinations including visual acuity test (naked vision; standard logarithmic/decimal visual acuity chart, China), slit-lamp biomicroscopy, fundoscopy (fundus examination), IOP measurement (iCare Pro Rebound Tonometer, Finland), corneal endothelial cell density detection (NIDEK CEM-530 Specular Microscope, Japan), axial length and white-to-white distance measurements (ZEISS IOLMaster 500 Optical Biometer, Germany), and ultrasonic biomicroscopy (UMB), were performed before UCP operation.\u003c/p\u003e\n\u003ch3\u003eSurgical procedures\u003c/h3\u003e\n\u003cp\u003eAll patients underwent UCP (with the cyclocoagulation device EyeOP1 from EyeTechCare, Rillieux-la-Pape, France) by the same experienced ophthalmologist. The probe diameter (model) was determined according to the eye's biometric readings, and the number of treatment sectors activated was chosen according to IOP. The UCP instrument was turned on after routine disinfection, towel-laying preparation, and topical/retrobulbar anesthesia. After inputting the patient's basic information, the coupling cone for the probe was fixated on the eye by the vacuum suction ring with a negative pressure, and then the probe was put inside the cone. The negative pressure should be confirmed before UCP treatment. The activation of the transducers was started by constantly pressing the foot pedal until the UCP treatment was finished.\u003c/p\u003e\n\u003ch3\u003ePostoperative follow-ups\u003c/h3\u003e\n\u003cp\u003eAfter the UCP operation, prednisolone acetate eye drops (Allergan Pharmaceuticals Ireland) were administrated to the treated eyes four times a day (decreasing once a week and lasting for one month). IOP-lowering agents should be given if the IOP is greater than 21 mmHg. Follow-ups were scheduled on postoperative day 1 (POD1), week 1 (POW1), month 1 (POM1), and month 3 (POM3). The primary observation indexes were naked vision, IOP, the number of IOP-lowering agents used, central anterior chamber depth (ACD), lens zonule length (LZL), ciliary muscle thickness (CMT), and trabecular-ciliary process angle (TCA). The secondary observation indexes included the occurrence of complications including subconjunctival hemorrhage. ACD was defined as the vertical distance from the central anterior corneal epithelium to the anterior lens capsule (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA). LZL was defined as the midpoint of the ciliary process to the midpoint of the anterior aspects of the equatorial lens capsule (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB), and its mean value was taken from three measurements. CMT was defined as the line segment being perpendicular to the upper boundary of ciliary muscle and crossing the horizontal ciliary muscle apex at coronal section (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eC). TCA was defined as the angle formed by the tangent of the inner corneal surface near the scleral spur and the connecting line between the scleral spur and the most anterior surface of the ciliary body with the scleral spur as the apex (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eD).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eThe visual acuity values were converted into LogMAR visual acuities for statistical analysis, with the finger counting, hand motion, light perception, and no light perception recorded as 2.6, 2.7, 2.8, and 2.9, respectively\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. Statistical software SPSS24.0 was used to process the data. The paired samples \u003cem\u003et\u003c/em\u003e-test was used to compare the measurement data that met the normal distribution, and the paired Wilcoxon rank sum test was used to compare the measurement data that did not meet the normal distribution (IOP before and after operation, the number of IOP-lowering agents used, \u003cem\u003eetc.\u003c/em\u003e). \u003cem\u003eP\u003c/em\u003e-values\u0026thinsp;\u0026lt;\u0026thinsp;0.05 were considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003ePatient information and operation parameters\u003c/h2\u003e \u003cp\u003eAll the patients collected in this study were treated with anterior chamber paracentesis and IOP-lowering agents at the maximum tolerated dose, and the IOP still stayed at \u0026ge;\u0026thinsp;35 mmHg. Their corneal thickness was thickened at different degrees due to corneal edema caused by high IOP. The density of corneal endothelial cells could not be measured in 9 cases because of severe corneal edema. The probe size was calculated according to the white-to-white distance, and the probe diameter was 11 mm for one case and 12 mm for the rest. According to the preoperative IOP, 8 sectors were selected for one case with a preoperative IOP of 30\u0026ndash;40 mmHg, and 10 sectors were selected for 15 cases with a preoperative IOP greater than 40 mmHg for UCP operation. The details of patients' basic information and UCP parameters are shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe patients' basic information and ultrasound cycloplasty parameters.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTerm\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;16\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (years) (median (range))\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e65 (55\u0026ndash;83)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNumber of patients (female/male)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10/6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNumber of eyes (right/left)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12/4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCorneal thickness (\u0026micro;m) (median (range))\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e648 (569\u0026ndash;1190)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCorneal endothelial cell density (cells/mm\u003csup\u003e2\u003c/sup\u003e) (median (range))\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0\u0026ndash;3237)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAxial length (mm) (median (range))\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22.35 (21.42\u0026ndash;22.92)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWhite-to-white distance (mm) (median (range))\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11.2 (10.6\u0026ndash;11.8)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProbe size (11/12/13 mm) (\u003cem\u003en\u003c/em\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1/15/0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTreatment sectors (6/8/10) (\u003cem\u003en\u003c/em\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0/1/15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eChanges in IOP and the use of IOP-lowering agents\u003c/h2\u003e \u003cp\u003eThe mean preoperative IOP was 52.31\u0026thinsp;\u0026plusmn;\u0026thinsp;4.21 mmHg and significantly decreased to 13.00\u0026thinsp;\u0026plusmn;\u0026thinsp;4.87 mmHg, 10.25\u0026thinsp;\u0026plusmn;\u0026thinsp;2.35 mmHg, 11.06\u0026thinsp;\u0026plusmn;\u0026thinsp;1.57 mmHg, and 14.75\u0026thinsp;\u0026plusmn;\u0026thinsp;2.08 mmHg on POD1, POW1, POM1, and POM3, respectively (all \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05; Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA). The patients were administrated with 3 or 4 IOP-lowering agents before UCP operation. No IOP-lowering agents were used on POD1 and POW1; one eye was given one agent on POM1; two eyes were given one agent and one eye was given two agents on POM3. The mean number of IOP-lowering agents used significantly decreased from preoperative records (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05; Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe use of intraocular pressure-lowering agents before and after operation (cases (%)).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCases\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 agent\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 agent\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2 agents\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3 agents\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e4 agents\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBefore operation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2(12.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e14 (87.55%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative day 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16 (100%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative week 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16 (100%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative month 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15 (93.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (6.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative month 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13 (81.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2 (12.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (6.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eChanges in ACD, LZL, CMT, and TCA\u003c/h2\u003e \u003cp\u003eThe mean ACD was 1.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21 mm, 1.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14 mm, 1.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14 mm, and 1.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14 mm on POD1, POW1, POM1, and POM3, respectively, which were significantly higher than that before operation (1.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.24 mm) (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05; Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eB). The mean LZL in the superior, inferior, nasal, and temporal quadrants on POD1, POW1, and POM1 was significantly shorter than those before operation (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05; Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA). No significant differences were found between the mean LZL in the superior, inferior, nasal, and temporal quadrants before operation and those on POM3. The mean preoperative CMT in the superior, inferior, nasal, and temporal quadrants was 0.5913\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 mm, 0.6456\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06 mm, 0.6225\u0026thinsp;\u0026plusmn;\u0026thinsp;0.057 mm, and 0.6181\u0026thinsp;\u0026plusmn;\u0026thinsp;0.86 mm, respectively. Only the mean CMT in the superior, inferior, and nasal quadrants on POD1 and in the superior and inferior quadrants on POW1 were significantly larger than those before operation (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05; Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eB). The TCA in the temporal quadrant on POM3 was significantly smaller than that before operation (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05; Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eC).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eChanges in visual acuity and postoperative complications\u003c/h2\u003e \u003cp\u003eThe mean postoperative LogMAR visual acuity showed a significant upward trend on POD1, POW1, and POM1 compared with that before operation (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05), but there was no significant difference in LogMAR visual acuity between before operation and on POM3 (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). No serious complications such as eyeball atrophy and hyphema occurred in all 16 patients. Conjunctival congestion in different degrees and subconjunctival hemorrhage were present in 16 cases and 14 cases respectively on POD1 (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). All these conditions recovered on POM1. Eight patients suffered from ciliary body detachment on POD1, and all recovered on POM1.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe preoperative and postoperative visual acuities.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVisual acuity\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBefore operation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.30(1.34\u0026ndash;2.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative day 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.00 (1.00\u0026ndash;2.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.014\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative week 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.70 (0.82\u0026ndash;2.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative month 1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.85 (0.94\u0026ndash;2.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.009\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative month 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.30 (1.60\u0026ndash;2.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.182\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eAACG can cause blindness if not timely treated or immediate IOP control is not achieved, and the treatment time window of its attack is 4.6 hours as reported\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e. Quick IOP stabilization is the key to treating AACG, but it often cannot be achieved by IOP-lowering agents alone; laser cannot be applied in the presence of corneal edema, and anterior chamber paracentesis is an invasive operation that could increase the risk of intraocular infection and cannot relieve the cause; the risk of intraocular surgery for the case of extremely high IOP is high, for example, phacoemulsification is easy to cause serious complications such as malignant glaucoma\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e, and glaucoma filtration surgery, also named as trabeculectomy, is easy to cause explosive choroidal hemorrhage and decompression choroidopathy\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e,\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e. Therefore, a safe and effective surgical approach is needed to reduce IOP when AACG continues to go with high IOP. At present, in Europe and America, UCP has shown a good effect on primary open-angle glaucoma\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e,\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e, and its effectiveness in treating primary angle-closure glaucoma is also reported\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. However, there is no report on the treatment of AACG with persistent high IOP.\u003c/p\u003e \u003cp\u003eBefore UCP operation, the appropriate size of the surgical ultrasound probe and positioning ring (vacuum suction ring) should be selected according to the eye biometric parameters, such as white-to-white distance, axial length, and ciliary sulcus diameter. The axial length and white-to-white distance of angle-closure glaucoma patients are short. In our study, the probe diameter was 11 mm for one case and 12 mm for the rest (15 eyes), consistent with the report for Chinese patients undergoing UCP\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. The appropriate number of treatment sectors activated (6/8/10 sectors) is usually selected according to the IOP value. At present, the transducers are automatically activated with a duration of 8 seconds for each sector. Six-sector surgical treatment was most used abroad\u003csup\u003e\u003cspan additionalcitationids=\"CR21\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e because the mean baseline IOP of the reported cases is not high, mostly 21\u0026ndash;30 mmHg, while the persistent high IOP of AACG is often greater than 35 mmHg. The mean baseline IOP in our study was 52.31 mmHg, so we chose 8- or 10-sector surgical treatment. In our study, the IOP of 16 patients was reduced after the first postoperative day, and the IOP was controlled below 21 mmHg 3 months after operation. The significantly less use of IOP-lowering drugs after versus before the operation supports the decision of the 8- or 10-sector surgical treatment for our patients. UCP is effective in treating AACG in our study, but the sample size is small. More data are needed to prove it and ethnic differences should be considered as well.\u003c/p\u003e \u003cp\u003eThe mechanism underlying the immediacy of lowering IOP through UCP within one day in AACGs needs further exploration. At present, relevant studies show that IOP reduction after UCP is mainly attributable to reshaped ciliary body and reduced generation of aqueous humor achieved by degeneration or necrosis of the ciliary epithelium and occlusion of the ciliary process vessels\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. It is also speculated that the scleral scar generated by UCP can increase the distance between the ciliary process and the sclera, causing the increase of aqueous humor outflow through the ciliary body and suprachoroidal space, and therefore reducing IOP\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e. These two potential mechanisms cannot fully explain the immediacy of lowering IOP through UCP in AACG treatment. The pathogenesis of AACG is extremely complicated, and many factors including short axial length, shallow anterior chamber, and crowded anterior segment structure, can easily give rise to angle closure and subsequent high IOP\u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e,\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e. In this study, 16 included patients had short axial lengths and shallow anterior chambers before the operation; a deeper anterior chamber was found after the operation and remained until 3 months after the operation. Besides, it was observed that the anterior chamber angle of patients in some quadrants was reopened to varying degrees after UCP operation (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eB). The reasons why UCP can deepen the anterior chamber and reopen the anterior chamber angle in some quadrants warrant further exploration.\u003c/p\u003e \u003cp\u003eIn recent years, some scholars have suggested that the abnormal lens position caused by the relaxation of suspensory ligaments may be one of the risk factors leading to angle closure and angle-closure glaucoma\u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e. Ultrasound biomicroscopy is used to image suspensory ligaments and ciliary muscles to observe the morphological changes after UCP\u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e,\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u003c/sup\u003e, and it was found in this study that the length of the lens suspensory ligaments of the 16 AACG patients was shortened on POD1, POW1, and POM1. Besides, our study showed that CMT in the superior, inferior, and nasal quadrants on POD1 and in the superior and inferior quadrants on POW1 became thicker. The ultrasonic energy of UCP acts on the ciliary body and the thermal effect will cause edema of the ciliary muscle tissue in the early stage after UCP operation; the UCP probe avoids the treatment to 3-o'clock and 9-o'clock positions and the morphological changes are mainly manifested in the superior and inferior ciliary muscles\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. Therefore, we speculate that the ciliary muscle-suspensory ligament-lens is a linkage system of the anterior segment\u003csup\u003e\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e. Relaxed ciliary muscles resulting from early ciliary muscle edema make the suspensory ligaments and increase their tension in a short time; the suspensory ligaments pull on the lens capsule at the equator and reduce the curvature radius of the central anterior and posterior surfaces of the lens; the lens is moved backward and thus the depth of the central anterior chamber (ACD) is elevated and some non-adhesive closed angles are reopened. This could be a possible special mechanism of UCP in the early phase of AACG treatment.\u003c/p\u003e \u003cp\u003eForward placement of the ciliary body may be an influencing factor in the pathogenesis of angle-closure glaucoma\u003csup\u003e\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u003c/sup\u003e. Anteriorly placed ciliary body may force the peripheral iris forward as a plateau to close the angle. UCP acts on the ciliary body and whether it can improve the ciliary body's forward placement to open the closed angle is worth observing. The angle between trabecular meshwork and ciliary process (TCA) is an index to reflect the ciliary body's position. The mean preoperative TCA in our 16 patients is smaller than the mean TCA of normal individuals in China as reported\u003csup\u003e\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e, so the angle is more likely to suffer from angle-closure glaucoma. Although the angle in the temporal quadrant at postoperative month 3 was smaller than that before the UCP operation, the statistical difference is insufficient to prove UCP's effect in the alteration of the ciliary body's position. Therefore, the slight alteration of the ciliary body's position should not be taken as the mechanism of UCP in treating angle-closure glaucoma.\u003c/p\u003e \u003cp\u003eUCP is more controllable, selective, and safer in destroying the ciliary body tissue, compared with ciliary body photocoagulation\u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e,\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e. In this study, no serious complications in the 16 UCP-treated patients, and their postoperative vision was improved. UCP itself could not improve vision, and the vision improvement of our patients could be attributed to the relief and gradual transparency of corneal edema after IOP reduction. Eight patients suffered from ciliary body detachment and recovered within one postoperative month. This suggests that IOP reduction in the early phase after UCP for AACG treatment may be related to choroidal detachment. However, the incidence rate of ciliary body detachment (50%) in our study is much higher than current reports\u003csup\u003e\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e,\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u003c/sup\u003e, and the severe inflammation during the attack of AACG may explain the high rate. Besides, it is reported that patients with glaucoma had easier uveoscleral outflow of aqueous humor after UCP\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e, but the specific mechanism is not clear.\u003c/p\u003e \u003cp\u003eUCP is safe and effective in treating AACG. UCP can be used as a brand-new surgical approach for AACG under continuous high IOP although there are few AACG patients in our clinic because of the strict inclusion criteria,it is a challenging caes in clinical practice. Deepening ACD and Reopening some non-adhesive closed angles in the early stage may contribute to UCP's role in lowering IOP. More samples are highly needed for further investigation.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis research was funded by the Aier Eye Hospital Group Scientific Research Fund (No. AGF2306D04).\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eL.X. and X.J.L. contributed to the conception and design of the study. W.W. and S.X.Y. organized the original data. C.M.W. performed the statistical analysis. W.W. and Y.Z. prepared the tables and figures. W.W. and X.J.L. wrote the first draft of the manuscript. W.W. and C.M.W. wrote the final version of the manuscript. All authors reviewed the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eWe highly thank all study subjects for their participation and cooperation, and Prof. Xiangge He for his scientific advice during this research.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eAll data supporting the findings of this study are available within the paper and Supplementary Information.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eOng, A. Y. et al. Lens extraction versus laser peripheral iridotomy for acute primary angle closure. \u003cem\u003eCochrane Database Syst. Rev.\u003c/em\u003e \u003cb\u003e3\u003c/b\u003e, CD015116 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEuropean Glaucoma Society. European Glaucoma Society Terminology and Guidelines for Glaucoma, 5th Edition. J. Ophthalmol. 105, 1-169. (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIijima, K., Kamiya, K., Iida, Y. \u0026amp; Shoji, N. Comparison of laser iridotomy and lensectomy outcomes for acute primary angle closure. \u003cem\u003eJ. Ophthalmol\u003c/em\u003e. 6959479 (2022). (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXuan, H. N., Nguyen Dinh, N. \u0026amp; Thu, N. Comparing the safety and efficacy of phacogoniosynechialysis with phacotrabeculectomy in the management of refractory acute primary closure angle glaucoma with cataract: A multicenter randomized trial. \u003cem\u003eJ. Glaucoma\u003c/em\u003e. \u003cb\u003e30\u003c/b\u003e, 552\u0026ndash;558 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFlores M\u0026aacute;rquez, A. et al. 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Management of delayed suprachoroidal hemorrhage after glaucoma surgery. \u003cem\u003eSemin Ophthalmol.\u003c/em\u003e \u003cb\u003e33\u003c/b\u003e, 59\u0026ndash;63 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMathur, G., Sindhu, N., Singh, D. V. \u0026amp; Garcha, G. S. Decompression retinochoroidopathy: a unique presentation post-trabeculectomy. \u003cem\u003eInt. Ophthalmol.\u003c/em\u003e \u003cb\u003e39\u003c/b\u003e, 927\u0026ndash;928 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFigus, M., Palma, A., Covello, G., Agnifili, L. \u0026amp; Posarelli, C. Ultrasound cyclo plasty in patients with open angle glaucoma and high myopia. \u003cem\u003eJ. Glaucoma\u003c/em\u003e. \u003cb\u003e32\u003c/b\u003e, 420\u0026ndash;425 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAptel, F., Dupuy, C. \u0026amp; Rouland, J. F. 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Biol.\u003c/em\u003e \u003cb\u003e40\u003c/b\u003e, 2096\u0026ndash;2106 (2014).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Acute angle-closure glaucoma, Ultrasound cycloplasty, Intraocular pressure, Anterior chamber depth, Trabecular-ciliary process angle","lastPublishedDoi":"10.21203/rs.3.rs-5675275/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5675275/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eHigh-intensity focused ultrasound cycloplasty (UCP) can effectively reduce intraocular pressure in glaucoma patients. This work aimed to analyze the efficacy, safety, and mechanism of UCP in treating acute angle-closure glaucoma. We collected and retrospectively analyzed the preoperative and postoperative clinical data of 16 cases (16 eyes) with acute angle-closure glaucoma, including the number of sectors activated, intraocular pressure (IOP), central anterior chamber depth (ACD), lens zonule length (LZL), ciliary muscle thickness (CMT), and trabecular-ciliary process angle (TCA). Of the 16 eyes, one received a single UCP procedure with 8 sectors and the others with 10 sectors. The mean IOP at follow-up time points after UCP was significantly lower than before UCP. The mean ACD at follow-up time points after UCP was significantly higher than before UCP. The mean LZL in the superior, inferior, nasal, and temporal quadrants on postoperative day 1, week 1, and month 1 was significantly shorter than those before UCP. The mean CMT in the superior, inferior, and nasal quadrants on postoperative day 1 and in the superior and inferior quadrants on postoperative week 1 were significantly larger than those before UCP. The mean TCA in the temporal quadrant on postoperative month 3 was significantly smaller than that before UCP. In conclusion, UCP is safe and effective in treating acute angle-closure glaucoma. The special mechanism of lowering IOP after UCP may be attributed to the increased depth of the central anterior chamber and the reopening of some non-adhesive closed angles.\u003c/p\u003e","manuscriptTitle":"Preliminary study on the treatment of acute angle-closure glaucoma with high-intensity focused ultrasound cycloplasty","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-01 16:52:54","doi":"10.21203/rs.3.rs-5675275/v1","editorialEvents":[{"type":"communityComments","content":1},{"type":"decision","content":"Revision requested","date":"2025-06-02T16:56:54+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-02T09:15:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"131846963087120132472257292152869488336","date":"2025-05-05T03:42:34+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-10T16:08:16+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"229188062223883078886568253194079024337","date":"2025-04-06T18:47:34+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-01-13T20:56:50+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-01-13T20:48:30+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-12-31T18:03:12+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-12-30T12:19:45+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2024-12-19T08:57:31+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"30b813ee-2b87-471c-baed-f4c201a00e24","owner":[],"postedDate":"January 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":42217852,"name":"Health sciences/Diseases/Eye diseases"},{"id":42217853,"name":"Health sciences/Medical research/Study design"}],"tags":[{"value":"featured","date":"2025-01-02 18:41:05"}],"updatedAt":"2025-10-06T16:05:30+00:00","versionOfRecord":{"articleIdentity":"rs-5675275","link":"https://doi.org/10.1038/s41598-025-18675-7","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2025-09-29 15:56:57","publishedOnDateReadable":"September 29th, 2025"},"versionCreatedAt":"2025-01-01 16:52:54","video":"","vorDoi":"10.1038/s41598-025-18675-7","vorDoiUrl":"https://doi.org/10.1038/s41598-025-18675-7","workflowStages":[]},"version":"v1","identity":"rs-5675275","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5675275","identity":"rs-5675275","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}