Long-term surgical outcomes of Ex-PRESS glaucoma filtration surgery: a 10-year follow-up study

Long-term surgical outcomes of Ex-PRESS glaucoma filtration surgery: a 10-year follow-up study | 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 Research Article Long-term surgical outcomes of Ex-PRESS glaucoma filtration surgery: a 10-year follow-up study Hiroshi Katayama, Naoki Tojo, Mitsuya Otuska, Atsushi Hayashi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9372905/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 6 You are reading this latest preprint version Abstract Purpose To evaluate the long-term outcomes of Ex-PRESS glaucoma filtration surgery and identify risk factors for surgical failure. Patients and Methods: This retrospective single-center study included 139 patients (171 eyes) who underwent Ex-PRESS surgery and were followed for at least 1 year. Surgical success was evaluated using two criteria. Criterion A was defined as a post-operative intraocular pressure (IOP) reduction of ≥ 20% from the preoperative IOP and an IOP of 5–18 mmHg. Criterion B was defined as a post-operative IOP reduction of ≥ 20% from the preoperative IOP and an IOP of 5–15 mmHg. The use of additional glaucoma medications was not considered in the definition of surgical success. The following six potential risk factors were evaluated using a Cox proportional hazards model: (1) age, (2) central corneal thickness, (3) preoperative IOP, (4) glaucoma type (primary open-angle glaucoma or pseudo-exfoliation glaucoma), (5) surgical methods (Ex-PRESS surgery alone or combined with cataract surgery), and (6) history of trabeculotomy. Results Ex-PRESS surgery significantly reduced IOP. The mean preoperative IOP was 24.4 ± 8.9 mmHg. The mean postoperative IOP was 11.3 ± 4.3 mmHg at 5 years and 10.4 ± 4.4 mmHg at 10 years. The 5-year and 10-year surgical success rates were 75.7% and 45.4%, respectively, for criterion A, and 67.8% and 44.1%, respectively, for criterion B. Pseudoexfoliation glaucoma (p = 0.045) and higher preoperative IOP (p = 0.046) were significant risk factors for surgical failure. Conclusions Ex-PRESS surgery requires long-term follow-up, as IOP increased in some patients even after 5 years. Ex-PRESS glaucoma risk factor surgical outcomes 10 years Figures Figure 1 INTRODUCTION Conventional trabeculectomy requires removal of the trabecular meshwork, which carries a high risk of hypotony during and immediately after surgery. Peripheral iridectomy, which carries a high risk of bleeding and vitreous prolapse, is also required. Many new devices have been introduced to reduce the risk of these complications associated with glaucoma filtration surgery. The Ex-PRESS filtration device (Alcon Laboratories, Fort Worth, TX, USA) was approved in Japan in December 2011. Made of stainless steel, it allows aqueous humor to flow into the filtering bleb without requiring trabecular meshwork resection or peripheral iridectomy [ 1 ]. Compared to conventional trabeculectomy, Ex-PRESS glaucoma filtration surgery has a lower risk of complications such as hyphema and suprachoroidal hemorrhage [ 2 , 3 ]. Several studies have reported comparable outcomes between the two approaches [ 2 – 5 ]. However, there have been very few reports of long-term surgical outcomes beyond 5 years, and no reports of outcomes beyond 10 years.In Japan, where life expectancy has increased markedly over the past decades [ 6 ], the long-term durability of glaucoma surgery, particularly sustained intraocular pressure (IOP) control, is increasingly important. [ 6 ]. Therefore, in this retrospective study, we investigated the long-term outcomes of Ex-PRESS glaucoma filtration surgery and identified risk factors for surgical failure. PATIENTS AND METHODS Patients This retrospective single-center study included consecutive patients who underwent Ex-PRESS surgery at Toyama University Hospital between April 2013 and May 2018. Surgical indications were determined by a single glaucoma specialist (N.T.). Patients were required to have at least 1 year of follow-up. A total of 139 patients (171 eyes) were included; in 32 patients who underwent bilateral surgery, both eyes were analyzed. We included patients who underwent Ex-PRESS surgery alone or combined with cataract surgery, as well as those with a history of trabeculotomy. Patients with a history of filtration surgery or tube shunt surgery were excluded. Since Ex-PRESS is not approved for use in Japan for secondary glaucoma or angle-closure glaucoma, only eyes with primary open angle glaucoma (POAG) or pseudo-exfoliation glaucoma (PEXG) were included. All patients had undergone ophthalmic examination including refraction, Goldmann gonioscopy, intraocular pressure (IOP) measurement, fundus examination, automated perimetry (Humphrey Field Analyzer; Carl Zeiss Meditec, Dublin, CA), optical coherence tomography (RS-3000; Nidek, Aichi, Japan), measurement of central corneal endothelial cell density using a specular microscope (EM-4000; Tomey, Nagoya, Japan), and measurement of central corneal thickness (CCT) using anterior segment optical coherence tomography (CASIA SS-1000; Tomey). IOP was measured in all patients by Goldmann applanation tonometry. IOP fluctuations were not considered, and the timing of IOP measurement was not fixed. This study adhered to the Declaration of Helsinki and was approved by the institutional review board of the University of Toyama (Approval No. R2026005). Surgical techniques All patients were performed by a single highly experienced glaucoma surgeon (N.T.). The Ex-PRESS surgical procedure was as follows. The conjunctival limbus was incised to expose the sclera. A square (3.5x3.5mm) single-layer scleral flap was created. Mitomycin C solution (0.04 mg/ml) was applied below the conjunctiva for 4 min and irrigated with 100 ml of balanced salt solution. In eyes undergoing combined cataract surgery, the cataract procedure was performed at this stage. All cataract surgery was performed using a temporal corneal incision with a WhiteStar Signature system (Johnson & Johnson Vision, Santa Ana, CA). The indication of cataract surgery was judged by one surgeon (N.T.). The intraocular lens was inserted through an incision in the temporal cornea. The scleral flap was lifted, and a 25-gauge guide needle was inserted into the anterior chamber at the TM. The Ex-Press device (model P50; Alcon Laboratories, Fort Worth, TX) was inserted into the anterior chamber along the guide needle. The scleral flap was sutured in two places with 10 − 0 nylon. The conjunctiva was tightly sutured with 10 − 0 nylon to prevent leakage of aqueous humor. Postoperative medication The postoperative treatments consisted of topical steroids, antibiotics, and non-steroidal anti-inflammatory drugs (NSAIDs). The antibiotics were applied for 4–8 weeks after the surgery. The steroid and non-steroidal anti-inflammatory drugs (NSAIDs) were reduced over a 12-week period after the interventions. After the surgeries, the patients' glaucoma medications were stopped in all cases. Glaucoma medications were added when judged necessary by the patient’s physician. Definitions of success We defined two success criteria. Criterion A was defined as a postoperative IOP value of ≤ 18 mmHg and post-operative IOP reduction ratio of ≥ 20% from the preoperative IOP. Criterion B was a postoperative IOP value of ≤ 15 mmHg and a post-operative IOP reduction ratio of ≥ 20% from the preoperative IOP. We defined a trial as unsuccessful if any of the following conditions were met: (1) Criterion A or Criterion B was not met on two consecutive visits; (2) postoperative IOP was < 5 mmHg on two consecutive visits; (3) additional glaucoma surgery was required; or (4) phthisis or loss of light perception occurred. The addition of glaucoma medications was not considered in the definition of surgical success. Needling procedures were not treated as additional glaucoma surgery. Evaluation of factors The following six risk factors potentially related to poor surgical outcome were evaluated: (1) age, (2) CCT, (3) preoperative IOP, (4) glaucoma type (POAG or PEXG), (5) surgical methods (Ex-PRESS surgery alone or combined with cataract surgery), and (6) history of trabeculotomy. Statistical analyses Preoperative and postoperative IOP values were compared using the paired t-test. Surgical success was evaluated using Kaplan–Meier survival curves. Cox regression analysis was performed to identify factors predictive of Ex-PRESS surgical failure. All statistical analyses were performed using JMP Pro 16 software (SAS, Cary, NC). RESULTS Postoperative IOP Ex-PRESS insertion was judged to be difficult in 5 cases, and the procedure was converted to conventional trabeculectomy; these cases were excluded. No cases of expulsive hemorrhage occurred intraoperatively. The final study group therefore consisted of 139 patients (171 eyes), all of whom were Japanese. Their ophthalmic characteristics are summarized in Table 1 . The mean postoperative IOP and the number of glaucoma medications are shown in Table 2 ; both were significantly lower than the corresponding preoperative values at all time points (p < 0.001). For patients who underwent additional glaucoma surgery, data obtained before the additional surgery were used. Table 1 Ophthalmic data No. of eyes 171 Age, years 70.7 ± 10.1 Gender (male/female) 98/73 Type of glaucoma (POAG/ PEXG) 79/92 Follow-up, months 70.7 ± 42.6 CCT, µm 527 ± 36 Pre IOP, mmHg 24.4 ± 8.9 No. of pre-medications 4.0 ± 0.9 Simultaneous cataract surgery 50/171 (29.2%) History of trabeculotomy 42/171 (24.6%) POAG: primary open angle glaucoma; PEX: pseudo-exfoliation; CCT: central corneal thickness; IOP: intraocular pressure. Table 2 Postoperative IOP Pre-ope IOP, mmHg Number of medications Number of eyes 24.4 ± 8.9 4.0 ± 0.9 171 1 year 11.0 ± 4.0 1.3 ± 1.6 157 2 years 11.3 ± 3.8 1.9 ± 1.7 147 3 years 11.5 ± 3.8 2.3 ± 1.5 118 4 years 11.4 ± 4.1 2.3 ± 1.6 99 5 years 11.3 ± 4.3 2.4 ± 1.6 77 6 years 11.3 ± 4.8 2.5 ± 1.6 42 7 years 10.3 ± 3.5 2.4 ± 1.6 35 8 years 10.8 ± 3.7 2.6 ± 1.5 32 9 years 10.9 ± 4.5 2.6 ± 1.4 22 10 years 10.0 ± 4.4 2.8 ± 1.4 16 Success ratio of Ex-PRESS surgeries The results of Ex-PRESS surgery are shown in Fig. 1 using Kaplan-Meier survival curve. The success rates for criteria A and B at 110 years are shown in Table 3 . The success rate at 10 years was 45.4% in criterion A and 44.1% in criterion B. Surgical failure occurred in 55 (32.2%) out of 171 eyes in criterion B. The reasons for failure were as follows: additional glaucoma surgery (44 eyes), insufficient reduction of IOP (7 eyes), hypotony < 5 mmHg (0 eyes), and loss of light perception (4 eyes). Table 3 Survival ratio Pre Criterion A 5 < IOP≤18mmHg Criterion B 5 < IOP≤15mmHg 24.4 ± 8.9 4.0 ± 0.9 1 year 90.5% 88.8% 2 years 87.5% 85.7% 3 years 84.6% 82.1% 4 years 82.1% 75.3% 5 years 75.7% 67.8% 6 years 67.7% 64.5% 7 years 62.0% 57.1% 8 years 56.0% 49.3% 9 years 45.4% 44.1% 10 years 45.4% 44.1% Postoperative complications Postoperative complications are summarized in Table 4 . A shallow anterior chamber was defined as contact between the posterior cornea and the iris. Hyphema was defined as bleeding forming a niveau in the anterior chamber. Bullous keratopathy was defined as the presence of corneal stromal opacity and the inability to measure corneal endothelial cells with a specular microscope (EM-4000). Four cases developed bullous keratopathy, but none required corneal transplantation. In one case, the Ex-PRESS device prolapsed and was therefore removed and resutured; this was considered additional glaucoma surgery and categorized as surgical failure. Table 4 Complications Complication Ratio (%) Choroidal detachment 42/171 (24.6%) Shallow anterior chamber 8/171 (4.7%) Hyphema 10/171 (5.8%) Bullous keratopathy 4/171 (2.3%) Endophthalmitis 1/171 (0.006%) Hypotony maculopathy 0/171 (0%) Prolapse of Ex-PRESS device 1/171(0.006%) Risk factors for Ex-PRESS surgery failure We investigated potential risk factors for failure to meet criterion A. The results of the Cox regression analysis are shown in Table 5 . Two factors significantly were significantly associated with Ex-PRESS surgical failure: PEXG (p = 0.045) and higher preoperative IOP (p = 0.046). Although not statistically significant, greater CCT (p = 0.138) and a history of trabeculotomy (p = 0.089) may also have contributed to poorer surgical outcomes. Table 5 Results of risk factors Risk factor Hazard ratio 95% lower Cl 95% upper Cl p value Age 0.989 0.954 1.022 0.473 CCT 1.006 0.998 1.015 0.138 Pre IOP 1.032 1.001 1.065 0.046 Type of glaucoma 3.238 1.027 10.212 0.045 Simultaneous cataract 1.546 0.473 5.058 0.471 History of trabeculotomy 3.061 0.844 11.109 0.089 CI: Confidence interval; CCT: central corneal thickness. Discussion Our study evaluated the long-term outcomes of Ex-PRESS surgery. The mean postoperative IOP was 11.3 ± 4.3 (77 eyes) at 5 years and 10.0 ± 4.4 (16 eyes) at 10 years. The postoperative IOP at 5 years was comparable to that reported in previous studies of Ex-PRESS surgery [ 4 , 7 ]. A substantial number of eyes (44 eyes) developed elevated IOP and underwent additional glaucoma surgery. Since data from these additional glaucoma surgeries were excluded, the long-term mean IOP may have been underestimated. The 5-year surgical success rates were 75.7% according to criterion A and 67.8% according to criterion B, which is consistent with previous reports [ 4 , 7 ]. Notably, some eyes developed elevated IOP or required additional glaucoma surgery even after 5 years. After 5 years, 17 eyes under criterion A and 18 eyes under criterion B were classified as failures, which is not negligible. Favorable IOP control at 5 years therefore does necessarily indicate long-term stability. These findings suggest that long-term follow-up is necessary after Ex-PRESS surgery. Although Ex-PRESS surgery is reported to have a low risk of complications due to hypotony, a high incidence of choroidal detachment was observed in this study [ 8 ]. Trabecular meshwork tears sometimes occurred during Ex-PRESS insertion, and some cases developed hypotony. All cases of choroidal detachment and shallow anterior chamber were improved spontaneously, and no cases developed hypotonic maculopathy, which results in permanent visual loss. Several previous studies have reported risk factors for the failure of filtration surgery: these include younger patient age [ 9 ], greater CCT [ 10 ], simultaneous cataract surgery [ 11 ], type of glaucoma [ 12 , 13 ], preoperative IOP [ 14 , 15 ], diabetes mellites (DM) [ 16 ] and non-Caucasian race [ 7 ]. Our results indicated that PEXG and preoperative high IOP were significant risk factors for failure. When the surgical success group and the unsuccessful group were compared using Student’s t-test, significant differences were observed in younger patients (p = 0.048) and in patients with greater CCT (p = 0.007), and higher preoperative IOP (p = 0.037). In this study, all patients were Japanese, and it was not possible to investigate racial risk factors. In all cases of diabetes, tests such as HbA1c measurement were not performed. Because blood glucose levels and blood pressure can change, it is difficult to investigate the effects of these on surgical outcomes in the long term. We previously reported that PEXG is a factor that tends to reduce the volume of the filtration bleb after Ex-PRESS surgery [ 17 ]. The reason is unclear, but there are reports that inflammatory cytokines might contribute to reducing the volume of the filtration bleb [ 18 ]. Nakakura et al. reported that high preoperative IOP was a risk factor for failure of Ex-PRESS surgery [ 14 ]. The Collaborative Bleb-related Infection Incidence and Treatment Study, which utilized a large data set, also reported higher preoperative IOP as a significant risk factor for failure of trabeculectomy surgery [ 15 ]. Since these factors are associated with failure in both trabeculectomy and Ex-PRESS surgery, it might be worthwhile to consider alternatives such as long tube surgery in patients with risks for surgical failure, such as PEXG or high preoperative IOP. There are some study limitations to address. This was a retrospective analysis. We did not consider IOP fluctuations. We did not define the indications for glaucoma surgery, cataract surgery, and additional glaucoma medications. The number of patients we were able to follow up for more than 10 years was small. Finally, although postoperative IOP remained stable for 5 years after Ex-PRESS surgery, it is not guaranteed to remain stable in the future. Therefore, long-term monitoring is necessary. Declarations Competing interests: The authors have no relevant financial or non-financial interests to disclose. Ethical approval: This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of Toyama University. Consent to participate: Informed consent was obtained from all individual participants included in the study. Funding statement: The authors declare that no funds, grants, or other support were received during the preparation of this manuscript. Employment: None of the authors is employed by an organization that may gain or lose financially through the publication of this manuscript. Financial interests: The authors have no relevant financial or non-financial interests to disclose. Author Contribution All authors made a significant contribution to the work reported, whether in the conception, study design, execution, acquisition of data, analysis and interpretation, or all of these areas; participated in drafting, revising or critically reviewing the article; gave final approval of the version to be published; agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.H.K, A.H. and N.T. wrote the main manuscript text , figure and tables and M.O. collected data and performed statistical analysis. All authors reviewed the manuscript. References Ishida K, Moroto N, Murata K, Yamamoto T. Effect of glaucoma implant surgery on intraocular pressure reduction, flare count, anterior chamber depth, and corneal endothelium in primary open-angle glaucoma. Japanese journal of ophthalmology. 2017;61(4):334–46. Good TJ, Kahook MY. Assessment of bleb morphologic features and postoperative outcomes after Ex-PRESS drainage device implantation versus trabeculectomy. American journal of ophthalmology. 2011;151(3):507–13 e1. Netland PA, Sarkisian SR, Jr., Moster MR, Ahmed, II, Condon G, Salim S, et al. Randomized, prospective, comparative trial of EX-PRESS glaucoma filtration device versus trabeculectomy (XVT study). American journal of ophthalmology. 2014;157(2):433–40 e3. de Jong L, Lafuma A, Aguade AS, Berdeaux G. Five-year extension of a clinical trial comparing the EX-PRESS glaucoma filtration device and trabeculectomy in primary open-angle glaucoma. Clinical ophthalmology. 2011;5:527–33. Gonzalez-Rodriguez JM, Trope GE, Drori-Wagschal L, Jinapriya D, Buys YM. Comparison of trabeculectomy versus Ex-PRESS: 3-year follow-up. The British journal of ophthalmology. 2016;100(9):1269–73. Tokudome S, Hashimoto S, Igata A. Life expectancy and healthy life expectancy of Japan: the fastest graying society in the world. BMC research notes. 2016;9(1):482. Mariotti C, Dahan E, Nicolai M, Levitz L, Bouee S. Long-term outcomes and risk factors for failure with the EX-press glaucoma drainage device. Eye. 2014;28(1):1–8. de Jong LA. The Ex-PRESS glaucoma shunt versus trabeculectomy in open-angle glaucoma: a prospective randomized study. Advances in therapy. 2009;26(3):336–45. Tojo N, Hayashi A, Otsuka M. Evaluation of Early Postoperative Intraocular Pressure for Success after Ex-Press Surgery. J Curr Glaucoma Pract. 2019;13(2):55–61. Otsuka M, Tojo N, Hayashi A. Risk factors for Ex-Press((R)) surgery failure. International ophthalmology. 2023;43(5):1657–63. Inoue T, Kawaji T, Tanihara H. Monocyte chemotactic protein-1 level in the aqueous humour as a prognostic factor for the outcome of trabeculectomy. Clinical & experimental ophthalmology. 2014;42(4):334–41. Lim SH, Cha SC. Long-term Outcomes of Mitomycin-C Trabeculectomy in Exfoliative Glaucoma Versus Primary Open-Angle Glaucoma. Journal of glaucoma. 2017;26(4):303–10. Ehrnrooth P, Lehto I, Puska P, Laatikainen L. Long-term outcome of trabeculectomy in terms of intraocular pressure. Acta ophthalmologica Scandinavica. 2002;80(3):267–71. Nakakura S, Asaoka R. Comparison of surgical outcomes between initial trabeculectomy and Ex-PRESS in terms of achieving an intraocular pressure below 15 and 18 mmHg: a retrospective comparative study. Eye and vision. 2022;9(1):9. Sugimoto Y, Mochizuki H, Ohkubo S, Higashide T, Sugiyama K, Kiuchi Y. Intraocular Pressure Outcomes and Risk Factors for Failure in the Collaborative Bleb-Related Infection Incidence and Treatment Study. Ophthalmology. 2015;122(11):2223–33. Law SK, Hosseini H, Saidi E, Nassiri N, Neelakanta G, Giaconi JA, et al. Long-term outcomes of primary trabeculectomy in diabetic patients with primary open angle glaucoma. The British journal of ophthalmology. 2013;97(5):561–6. Tojo N, Hayashi A, Otsuka M. Factors influencing the filtration-bleb volume after Ex-PRESS((R)) surgery. Clinical ophthalmology. 2018;12:1675–83. Djordjevic-Jocic J, Zlatanovic G, Veselinovic D, Jovanovic P, Djordjevic V, Zvezdanovic L, et al. Transforming growth factor beta1, matrix-metalloproteinase-2 and its tissue inhibitor in patients with pseudoexfoliation glaucoma/syndrome. Vojnosanitetski pregled. 2012;69(3):231–6. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 15 May, 2026 Reviewers agreed at journal 18 Apr, 2026 Reviewers invited by journal 15 Apr, 2026 Editor assigned by journal 11 Apr, 2026 Submission checks completed at journal 11 Apr, 2026 First submitted to journal 09 Apr, 2026 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-9372905","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":625280928,"identity":"101a3ddc-aed0-4016-ae23-38afce1ee3e8","order_by":0,"name":"Hiroshi Katayama","email":"","orcid":"","institution":"University of Toyama","correspondingAuthor":false,"prefix":"","firstName":"Hiroshi","middleName":"","lastName":"Katayama","suffix":""},{"id":625280930,"identity":"992d174f-e439-41a8-9399-bc64e5f84623","order_by":1,"name":"Naoki Tojo","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+klEQVRIiWNgGAWjYHCCBIYPBhL1DAzMBxgYG6BiEnjU8wC1MM6osElgYGBLIFoLAzPPmTSgFh4DhBZ8wJ694eED3rbDeeZiZ75J/NxhI8fAfvgAg+UOPLbwHEg2kGw7XGw5O3ebZO+ZNGMGHqCVkmfwaJFISJMwbDvMuOF27jYJoHWJDRJAF0q2EdCSCNaS80zyL9FaDpxJSwRqYZMmzpYzB5INGypsjA1upxlby7alGbMB/XIAn1/Y23sSH/8xkJAzuJ388ObbNhs5fvbDBx9L4gkxoD0JMBYLOALZgPiwZAM+LewHYCzmDzAW40e8WkbBKBgFo2CEAQBjh1HsYPrNkgAAAABJRU5ErkJggg==","orcid":"","institution":"University of Toyama","correspondingAuthor":true,"prefix":"","firstName":"Naoki","middleName":"","lastName":"Tojo","suffix":""},{"id":625280935,"identity":"aa866f67-70c8-4540-8837-63acd3ed4315","order_by":2,"name":"Mitsuya Otuska","email":"","orcid":"","institution":"University of Toyama","correspondingAuthor":false,"prefix":"","firstName":"Mitsuya","middleName":"","lastName":"Otuska","suffix":""},{"id":625280938,"identity":"1654ce2c-5d6b-4ff1-aa6b-9c443bba035d","order_by":3,"name":"Atsushi Hayashi","email":"","orcid":"","institution":"University of Toyama","correspondingAuthor":false,"prefix":"","firstName":"Atsushi","middleName":"","lastName":"Hayashi","suffix":""}],"badges":[],"createdAt":"2026-04-09 23:53:15","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9372905/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9372905/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107675183,"identity":"c096ab1f-785a-468b-8340-97e2e40b8513","added_by":"auto","created_at":"2026-04-24 00:41:23","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":42410,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSurvival ratio of Ex-PRESS surgery\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe solid line shows the survival curve under criterion A. The dot line shows the survival curve under criterion B.\u003c/p\u003e","description":"","filename":"Fig1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9372905/v1/0ff76c4d8c0e18a296e8dee2.jpg"},{"id":107707774,"identity":"0d937e53-182c-426c-b456-69dffd2ba3e7","added_by":"auto","created_at":"2026-04-24 09:21:08","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":292825,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9372905/v1/4ade8372-6ec9-4a60-8822-a9f5dd226eae.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Long-term surgical outcomes of Ex-PRESS glaucoma filtration surgery: a 10-year follow-up study","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eConventional trabeculectomy requires removal of the trabecular meshwork, which carries a high risk of hypotony during and immediately after surgery. Peripheral iridectomy, which carries a high risk of bleeding and vitreous prolapse, is also required. Many new devices have been introduced to reduce the risk of these complications associated with glaucoma filtration surgery. The Ex-PRESS filtration device (Alcon Laboratories, Fort Worth, TX, USA) was approved in Japan in December 2011. Made of stainless steel, it allows aqueous humor to flow into the filtering bleb without requiring trabecular meshwork resection or peripheral iridectomy [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eCompared to conventional trabeculectomy, Ex-PRESS glaucoma filtration surgery has a lower risk of complications such as hyphema and suprachoroidal hemorrhage [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Several studies have reported comparable outcomes between the two approaches [\u003cspan additionalcitationids=\"CR3 CR4\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, there have been very few reports of long-term surgical outcomes beyond 5 years, and no reports of outcomes beyond 10 years.In Japan, where life expectancy has increased markedly over the past decades [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], the long-term durability of glaucoma surgery, particularly sustained intraocular pressure (IOP) control, is increasingly important. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Therefore, in this retrospective study, we investigated the long-term outcomes of Ex-PRESS glaucoma filtration surgery and identified risk factors for surgical failure.\u003c/p\u003e"},{"header":"PATIENTS AND METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePatients\u003c/h2\u003e \u003cp\u003eThis retrospective single-center study included consecutive patients who underwent Ex-PRESS surgery at Toyama University Hospital between April 2013 and May 2018. Surgical indications were determined by a single glaucoma specialist (N.T.). Patients were required to have at least 1 year of follow-up. A total of 139 patients (171 eyes) were included; in 32 patients who underwent bilateral surgery, both eyes were analyzed. We included patients who underwent Ex-PRESS surgery alone or combined with cataract surgery, as well as those with a history of trabeculotomy. Patients with a history of filtration surgery or tube shunt surgery were excluded. Since Ex-PRESS is not approved for use in Japan for secondary glaucoma or angle-closure glaucoma, only eyes with primary open angle glaucoma (POAG) or pseudo-exfoliation glaucoma (PEXG) were included.\u003c/p\u003e \u003cp\u003eAll patients had undergone ophthalmic examination including refraction, Goldmann gonioscopy, intraocular pressure (IOP) measurement, fundus examination, automated perimetry (Humphrey Field Analyzer; Carl Zeiss Meditec, Dublin, CA), optical coherence tomography (RS-3000; Nidek, Aichi, Japan), measurement of central corneal endothelial cell density using a specular microscope (EM-4000; Tomey, Nagoya, Japan), and measurement of central corneal thickness (CCT) using anterior segment optical coherence tomography (CASIA SS-1000; Tomey). IOP was measured in all patients by Goldmann applanation tonometry. IOP fluctuations were not considered, and the timing of IOP measurement was not fixed.\u003c/p\u003e \u003cp\u003e This study adhered to the Declaration of Helsinki and was approved by the institutional review board of the University of Toyama (Approval No. R2026005).\u003c/p\u003e \u003cp\u003eSurgical techniques\u003c/p\u003e \u003cp\u003eAll patients were performed by a single highly experienced glaucoma surgeon (N.T.). The Ex-PRESS surgical procedure was as follows. The conjunctival limbus was incised to expose the sclera. A square (3.5x3.5mm) single-layer scleral flap was created. Mitomycin C solution (0.04 mg/ml) was applied below the conjunctiva for 4 min and irrigated with 100 ml of balanced salt solution. In eyes undergoing combined cataract surgery, the cataract procedure was performed at this stage. All cataract surgery was performed using a temporal corneal incision with a WhiteStar Signature system (Johnson \u0026amp; Johnson Vision, Santa Ana, CA). The indication of cataract surgery was judged by one surgeon (N.T.). The intraocular lens was inserted through an incision in the temporal cornea. The scleral flap was lifted, and a 25-gauge guide needle was inserted into the anterior chamber at the TM. The Ex-Press device (model P50; Alcon Laboratories, Fort Worth, TX) was inserted into the anterior chamber along the guide needle. The scleral flap was sutured in two places with 10\u0026thinsp;\u0026minus;\u0026thinsp;0 nylon. The conjunctiva was tightly sutured with 10\u0026thinsp;\u0026minus;\u0026thinsp;0 nylon to prevent leakage of aqueous humor.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003ePostoperative medication\u003c/h3\u003e\n\u003cp\u003eThe postoperative treatments consisted of topical steroids, antibiotics, and non-steroidal anti-inflammatory drugs (NSAIDs). The antibiotics were applied for 4\u0026ndash;8 weeks after the surgery. The steroid and non-steroidal anti-inflammatory drugs (NSAIDs) were reduced over a 12-week period after the interventions. After the surgeries, the patients' glaucoma medications were stopped in all cases. Glaucoma medications were added when judged necessary by the patient\u0026rsquo;s physician.\u003c/p\u003e\n\u003ch3\u003eDefinitions of success\u003c/h3\u003e\n\u003cp\u003eWe defined two success criteria. Criterion A was defined as a postoperative IOP value of \u0026le;\u0026thinsp;18 mmHg and post-operative IOP reduction ratio of \u0026ge;\u0026thinsp;20% from the preoperative IOP. Criterion B was a postoperative IOP value of \u0026le;\u0026thinsp;15 mmHg and a post-operative IOP reduction ratio of \u0026ge;\u0026thinsp;20% from the preoperative IOP. We defined a trial as unsuccessful if any of the following conditions were met: (1) Criterion A or Criterion B was not met on two consecutive visits; (2) postoperative IOP was \u0026lt;\u0026thinsp;5 mmHg on two consecutive visits; (3) additional glaucoma surgery was required; or (4) phthisis or loss of light perception occurred. The addition of glaucoma medications was not considered in the definition of surgical success. Needling procedures were not treated as additional glaucoma surgery.\u003c/p\u003e\n\u003ch3\u003eEvaluation of factors\u003c/h3\u003e\n\u003cp\u003eThe following six risk factors potentially related to poor surgical outcome were evaluated: (1) age, (2) CCT, (3) preoperative IOP, (4) glaucoma type (POAG or PEXG), (5) surgical methods (Ex-PRESS surgery alone or combined with cataract surgery), and (6) history of trabeculotomy.\u003c/p\u003e\n\u003ch3\u003eStatistical analyses\u003c/h3\u003e\n\u003cp\u003ePreoperative and postoperative IOP values were compared using the paired t-test. Surgical success was evaluated using Kaplan\u0026ndash;Meier survival curves. Cox regression analysis was performed to identify factors predictive of Ex-PRESS surgical failure. All statistical analyses were performed using JMP Pro 16 software (SAS, Cary, NC).\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003ePostoperative IOP\u003c/h2\u003e \u003cp\u003eEx-PRESS insertion was judged to be difficult in 5 cases, and the procedure was converted to conventional trabeculectomy; these cases were excluded. No cases of expulsive hemorrhage occurred intraoperatively. The final study group therefore consisted of 139 patients (171 eyes), all of whom were Japanese. Their ophthalmic characteristics are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The mean postoperative IOP and the number of glaucoma medications are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e; both were significantly lower than the corresponding preoperative values at all time points (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). For patients who underwent additional glaucoma surgery, data obtained before the additional surgery were used.\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\u003eOphthalmic data\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\u003eNo. of eyes\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e171\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\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e70.7\u0026thinsp;\u0026plusmn;\u0026thinsp;10.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender (male/female)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e98/73\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType of glaucoma (POAG/ PEXG)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e79/92\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFollow-up, months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e70.7\u0026thinsp;\u0026plusmn;\u0026thinsp;42.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCCT, \u0026micro;m\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e527\u0026thinsp;\u0026plusmn;\u0026thinsp;36\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePre IOP, mmHg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24.4\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo. of pre-medications\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSimultaneous cataract surgery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50/171 (29.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistory of trabeculotomy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42/171 (24.6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003ePOAG: primary open angle glaucoma; PEX: pseudo-exfoliation; CCT: central corneal thickness; IOP: intraocular pressure.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\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\u003ePostoperative IOP\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ePre-ope\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIOP, mmHg\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNumber of medications\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNumber of eyes\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24.4\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e171\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1 year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e11.0\u0026thinsp;\u0026plusmn;\u0026thinsp;4.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e1.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e157\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e11.3\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e1.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e147\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e11.5\u0026thinsp;\u0026plusmn;\u0026thinsp;3.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e118\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e11.4\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e11.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e77\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e11.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e42\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e10.3\u0026thinsp;\u0026plusmn;\u0026thinsp;3.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e35\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e10.8\u0026thinsp;\u0026plusmn;\u0026thinsp;3.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e32\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e9 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e10.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cp\u003e10.0\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e16\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\n\u003ch3\u003eSuccess ratio of Ex-PRESS surgeries\u003c/h3\u003e\n\u003cp\u003eThe results of Ex-PRESS surgery are shown in Fig.\u0026nbsp;1 using Kaplan-Meier survival curve. The success rates for criteria A and B at 110 years are shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. The success rate at 10 years was 45.4% in criterion A and 44.1% in criterion B. Surgical failure occurred in 55 (32.2%) out of 171 eyes in criterion B. The reasons for failure were as follows: additional glaucoma surgery (44 eyes), insufficient reduction of IOP (7 eyes), hypotony\u0026thinsp;\u0026lt;\u0026thinsp;5 mmHg (0 eyes), and loss of light perception (4 eyes).\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\u003eSurvival ratio\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\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003ePre\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCriterion A\u003c/p\u003e \u003cp\u003e5\u0026thinsp;\u0026lt;\u0026thinsp;IOP\u0026le;18mmHg\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCriterion B\u003c/p\u003e \u003cp\u003e5\u0026thinsp;\u0026lt;\u0026thinsp;IOP\u0026le;15mmHg\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24.4\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1 year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e90.5%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e88.8%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e87.5%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e85.7%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e84.6%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e82.1%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e82.1%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e75.3%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e75.7%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e67.8%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e67.7%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e64.5%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e62.0%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e57.1%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e56.0%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e49.3%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e9 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e45.4%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e44.1%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e45.4%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e44.1%\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003ePostoperative complications\u003c/h2\u003e \u003cp\u003ePostoperative complications are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. A shallow anterior chamber was defined as contact between the posterior cornea and the iris. Hyphema was defined as bleeding forming a niveau in the anterior chamber. Bullous keratopathy was defined as the presence of corneal stromal opacity and the inability to measure corneal endothelial cells with a specular microscope (EM-4000). Four cases developed bullous keratopathy, but none required corneal transplantation. In one case, the Ex-PRESS device prolapsed and was therefore removed and resutured; this was considered additional glaucoma surgery and categorized as surgical failure.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComplications\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\u003eComplication\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRatio (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChoroidal detachment\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42/171 (24.6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eShallow anterior chamber\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8/171 (4.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHyphema\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10/171 (5.8%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBullous keratopathy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4/171 (2.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEndophthalmitis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1/171 (0.006%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHypotony maculopathy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0/171 (0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProlapse of Ex-PRESS device\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1/171(0.006%)\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\u003eRisk factors for Ex-PRESS surgery failure\u003c/h2\u003e \u003cp\u003eWe investigated potential risk factors for failure to meet criterion A. The results of the Cox regression analysis are shown in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. Two factors significantly were significantly associated with Ex-PRESS surgical failure: PEXG (p\u0026thinsp;=\u0026thinsp;0.045) and higher preoperative IOP (p\u0026thinsp;=\u0026thinsp;0.046). Although not statistically significant, greater CCT (p\u0026thinsp;=\u0026thinsp;0.138) and a history of trabeculotomy (p\u0026thinsp;=\u0026thinsp;0.089) may also have contributed to poorer surgical outcomes.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e Results of risk factors\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\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 \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRisk factor\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHazard ratio\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e95% lower Cl\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e95% upper Cl\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ep value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.989\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.954\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.473\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCCT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.006\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.998\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.015\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.138\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePre IOP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.032\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.065\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.046\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType of glaucoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3.238\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.027\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10.212\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.045\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSimultaneous cataract\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.546\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.473\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.058\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.471\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHistory of trabeculotomy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3.061\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.844\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e11.109\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.089\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eCI: Confidence interval; CCT: central corneal thickness.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur study evaluated the long-term outcomes of Ex-PRESS surgery. The mean postoperative IOP was 11.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3 (77 eyes) at 5 years and 10.0\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4 (16 eyes) at 10 years. The postoperative IOP at 5 years was comparable to that reported in previous studies of Ex-PRESS surgery [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. A substantial number of eyes (44 eyes) developed elevated IOP and underwent additional glaucoma surgery. Since data from these additional glaucoma surgeries were excluded, the long-term mean IOP may have been underestimated. The 5-year surgical success rates were 75.7% according to criterion A and 67.8% according to criterion B, which is consistent with previous reports [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Notably, some eyes developed elevated IOP or required additional glaucoma surgery even after 5 years. After 5 years, 17 eyes under criterion A and 18 eyes under criterion B were classified as failures, which is not negligible. Favorable IOP control at 5 years therefore does necessarily indicate long-term stability. These findings suggest that long-term follow-up is necessary after Ex-PRESS surgery.\u003c/p\u003e \u003cp\u003eAlthough Ex-PRESS surgery is reported to have a low risk of complications due to hypotony, a high incidence of choroidal detachment was observed in this study [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Trabecular meshwork tears sometimes occurred during Ex-PRESS insertion, and some cases developed hypotony. All cases of choroidal detachment and shallow anterior chamber were improved spontaneously, and no cases developed hypotonic maculopathy, which results in permanent visual loss.\u003c/p\u003e \u003cp\u003eSeveral previous studies have reported risk factors for the failure of filtration surgery: these include younger patient age [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], greater CCT [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], simultaneous cataract surgery [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], type of glaucoma [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], preoperative IOP [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], diabetes mellites (DM) [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] and non-Caucasian race [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Our results indicated that PEXG and preoperative high IOP were significant risk factors for failure. When the surgical success group and the unsuccessful group were compared using Student\u0026rsquo;s t-test, significant differences were observed in younger patients (p\u0026thinsp;=\u0026thinsp;0.048) and in patients with greater CCT (p\u0026thinsp;=\u0026thinsp;0.007), and higher preoperative IOP (p\u0026thinsp;=\u0026thinsp;0.037). In this study, all patients were Japanese, and it was not possible to investigate racial risk factors. In all cases of diabetes, tests such as HbA1c measurement were not performed. Because blood glucose levels and blood pressure can change, it is difficult to investigate the effects of these on surgical outcomes in the long term.\u003c/p\u003e \u003cp\u003eWe previously reported that PEXG is a factor that tends to reduce the volume of the filtration bleb after Ex-PRESS surgery [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. The reason is unclear, but there are reports that inflammatory cytokines might contribute to reducing the volume of the filtration bleb [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Nakakura et al. reported that high preoperative IOP was a risk factor for failure of Ex-PRESS surgery [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The Collaborative Bleb-related Infection Incidence and Treatment Study, which utilized a large data set, also reported higher preoperative IOP as a significant risk factor for failure of trabeculectomy surgery [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Since these factors are associated with failure in both trabeculectomy and Ex-PRESS surgery, it might be worthwhile to consider alternatives such as long tube surgery in patients with risks for surgical failure, such as PEXG or high preoperative IOP.\u003c/p\u003e \u003cp\u003eThere are some study limitations to address. This was a retrospective analysis. We did not consider IOP fluctuations. We did not define the indications for glaucoma surgery, cataract surgery, and additional glaucoma medications. The number of patients we were able to follow up for more than 10 years was small.\u003c/p\u003e \u003cp\u003eFinally, although postoperative IOP remained stable for 5 years after Ex-PRESS surgery, it is not guaranteed to remain stable in the future. Therefore, long-term monitoring is necessary.\u003c/p\u003e "},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eCompeting interests:\u003c/h2\u003e \u003cp\u003eThe authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eEthical approval:\u003c/h2\u003e \u003cp\u003e This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of Toyama University.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent to participate:\u003c/strong\u003e \u003cp\u003e Informed consent was obtained from all individual participants included in the study.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding statement:\u003c/h2\u003e \u003cp\u003eThe authors declare that no funds, grants, or other support were received during the preparation of this manuscript.\u003c/p\u003e \u003cp\u003eEmployment: None of the authors is employed by an organization that may gain or lose financially through the publication of this manuscript.\u003c/p\u003e \u003cp\u003eFinancial interests: The authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAll authors made a significant contribution to the work reported, whether in the conception, study design, execution, acquisition of data, analysis and interpretation, or all of these areas; participated in drafting, revising or critically reviewing the article; gave final approval of the version to be published; agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.H.K, A.H. and N.T. wrote the main manuscript text , figure and tables and M.O. collected data and performed statistical analysis. All authors reviewed the manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eIshida K, Moroto N, Murata K, Yamamoto T. Effect of glaucoma implant surgery on intraocular pressure reduction, flare count, anterior chamber depth, and corneal endothelium in primary open-angle glaucoma. Japanese journal of ophthalmology. 2017;61(4):334\u0026ndash;46.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGood TJ, Kahook MY. Assessment of bleb morphologic features and postoperative outcomes after Ex-PRESS drainage device implantation versus trabeculectomy. American journal of ophthalmology. 2011;151(3):507\u0026ndash;13 e1.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNetland PA, Sarkisian SR, Jr., Moster MR, Ahmed, II, Condon G, Salim S, et al. Randomized, prospective, comparative trial of EX-PRESS glaucoma filtration device versus trabeculectomy (XVT study). American journal of ophthalmology. 2014;157(2):433\u0026ndash;40 e3.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ede Jong L, Lafuma A, Aguade AS, Berdeaux G. Five-year extension of a clinical trial comparing the EX-PRESS glaucoma filtration device and trabeculectomy in primary open-angle glaucoma. Clinical ophthalmology. 2011;5:527\u0026ndash;33.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGonzalez-Rodriguez JM, Trope GE, Drori-Wagschal L, Jinapriya D, Buys YM. Comparison of trabeculectomy versus Ex-PRESS: 3-year follow-up. The British journal of ophthalmology. 2016;100(9):1269\u0026ndash;73.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTokudome S, Hashimoto S, Igata A. Life expectancy and healthy life expectancy of Japan: the fastest graying society in the world. BMC research notes. 2016;9(1):482.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMariotti C, Dahan E, Nicolai M, Levitz L, Bouee S. Long-term outcomes and risk factors for failure with the EX-press glaucoma drainage device. Eye. 2014;28(1):1\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ede Jong LA. The Ex-PRESS glaucoma shunt versus trabeculectomy in open-angle glaucoma: a prospective randomized study. Advances in therapy. 2009;26(3):336\u0026ndash;45.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTojo N, Hayashi A, Otsuka M. Evaluation of Early Postoperative Intraocular Pressure for Success after Ex-Press Surgery. J Curr Glaucoma Pract. 2019;13(2):55\u0026ndash;61.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOtsuka M, Tojo N, Hayashi A. Risk factors for Ex-Press((R)) surgery failure. International ophthalmology. 2023;43(5):1657\u0026ndash;63.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eInoue T, Kawaji T, Tanihara H. Monocyte chemotactic protein-1 level in the aqueous humour as a prognostic factor for the outcome of trabeculectomy. Clinical \u0026amp; experimental ophthalmology. 2014;42(4):334\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLim SH, Cha SC. Long-term Outcomes of Mitomycin-C Trabeculectomy in Exfoliative Glaucoma Versus Primary Open-Angle Glaucoma. Journal of glaucoma. 2017;26(4):303\u0026ndash;10.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEhrnrooth P, Lehto I, Puska P, Laatikainen L. Long-term outcome of trabeculectomy in terms of intraocular pressure. Acta ophthalmologica Scandinavica. 2002;80(3):267\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNakakura S, Asaoka R. Comparison of surgical outcomes between initial trabeculectomy and Ex-PRESS in terms of achieving an intraocular pressure below 15 and 18 mmHg: a retrospective comparative study. Eye and vision. 2022;9(1):9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSugimoto Y, Mochizuki H, Ohkubo S, Higashide T, Sugiyama K, Kiuchi Y. Intraocular Pressure Outcomes and Risk Factors for Failure in the Collaborative Bleb-Related Infection Incidence and Treatment Study. Ophthalmology. 2015;122(11):2223\u0026ndash;33.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaw SK, Hosseini H, Saidi E, Nassiri N, Neelakanta G, Giaconi JA, et al. Long-term outcomes of primary trabeculectomy in diabetic patients with primary open angle glaucoma. The British journal of ophthalmology. 2013;97(5):561\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTojo N, Hayashi A, Otsuka M. Factors influencing the filtration-bleb volume after Ex-PRESS((R)) surgery. Clinical ophthalmology. 2018;12:1675\u0026ndash;83.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDjordjevic-Jocic J, Zlatanovic G, Veselinovic D, Jovanovic P, Djordjevic V, Zvezdanovic L, et al. Transforming growth factor beta1, matrix-metalloproteinase-2 and its tissue inhibitor in patients with pseudoexfoliation glaucoma/syndrome. Vojnosanitetski pregled. 2012;69(3):231\u0026ndash;6.\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":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"international-ophthalmology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"inte","sideBox":"Learn more about [International Ophthalmology](https://www.springer.com/journal/10792)","snPcode":"10792","submissionUrl":"https://submission.nature.com/new-submission/10792/3","title":"International Ophthalmology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Ex-PRESS, glaucoma, risk factor, surgical outcomes, 10 years","lastPublishedDoi":"10.21203/rs.3.rs-9372905/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9372905/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e \u003cp\u003eTo evaluate the long-term outcomes of Ex-PRESS glaucoma filtration surgery and identify risk factors for surgical failure.\u003c/p\u003e\u003ch2\u003ePatients and Methods:\u003c/h2\u003e \u003cp\u003e This retrospective single-center study included 139 patients (171 eyes) who underwent Ex-PRESS surgery and were followed for at least 1 year. Surgical success was evaluated using two criteria. Criterion A was defined as a post-operative intraocular pressure (IOP) reduction of \u0026ge;\u0026thinsp;20% from the preoperative IOP and an IOP of 5\u0026ndash;18 mmHg. Criterion B was defined as a post-operative IOP reduction of \u0026ge;\u0026thinsp;20% from the preoperative IOP and an IOP of 5\u0026ndash;15 mmHg. The use of additional glaucoma medications was not considered in the definition of surgical success. The following six potential risk factors were evaluated using a Cox proportional hazards model: (1) age, (2) central corneal thickness, (3) preoperative IOP, (4) glaucoma type (primary open-angle glaucoma or pseudo-exfoliation glaucoma), (5) surgical methods (Ex-PRESS surgery alone or combined with cataract surgery), and (6) history of trabeculotomy.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eEx-PRESS surgery significantly reduced IOP. The mean preoperative IOP was 24.4\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9 mmHg. The mean postoperative IOP was 11.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3 mmHg at 5 years and 10.4\u0026thinsp;\u0026plusmn;\u0026thinsp;4.4 mmHg at 10 years. The 5-year and 10-year surgical success rates were 75.7% and 45.4%, respectively, for criterion A, and 67.8% and 44.1%, respectively, for criterion B. Pseudoexfoliation glaucoma (p\u0026thinsp;=\u0026thinsp;0.045) and higher preoperative IOP (p\u0026thinsp;=\u0026thinsp;0.046) were significant risk factors for surgical failure.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eEx-PRESS surgery requires long-term follow-up, as IOP increased in some patients even after 5 years.\u003c/p\u003e","manuscriptTitle":"Long-term surgical outcomes of Ex-PRESS glaucoma filtration surgery: a 10-year follow-up study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-24 00:41:17","doi":"10.21203/rs.3.rs-9372905/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-05-15T06:20:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"300232152865456641393814668822866037599","date":"2026-04-18T04:43:02+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-15T09:31:08+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-11T16:31:36+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-11T16:31:30+00:00","index":"","fulltext":""},{"type":"submitted","content":"International Ophthalmology","date":"2026-04-09T23:40:06+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"international-ophthalmology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"inte","sideBox":"Learn more about [International Ophthalmology](https://www.springer.com/journal/10792)","snPcode":"10792","submissionUrl":"https://submission.nature.com/new-submission/10792/3","title":"International Ophthalmology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"df560ba9-6260-4400-b8aa-41c981703c5e","owner":[],"postedDate":"April 24th, 2026","published":true,"recentEditorialEvents":[{"type":"editorInvitedReview","content":"","date":"2026-05-15T06:20:07+00:00","index":26,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-24T00:41:17+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-24 00:41:17","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9372905","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9372905","identity":"rs-9372905","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}