BACKGROUND: Glaucoma is an optic neuropathy that leads to visual field defects and vision loss. It is the second leading cause of irreversible blindness in the world. Treatment for glaucoma aims to reduce intraocular pressure (IOP) to slow or prevent further vision loss. IOP can be lowered with medications, laser, or incisional surgery. Trabeculectomy is a surgical approach which lowers IOP by shunting aqueous humor to a subconjunctival bleb. Device-modified trabeculectomy techniques are intended to improve the durability and safety of this bleb-forming surgery. Trabeculectomy-modifying devices include the Ex-PRESS, the XEN Gel Stent, the PreserFlo MicroShunt, as well as antifibrotic materials such as Ologen, amniotic membrane, expanded polytetrafluoroethylene (ePTFE) membrane, Gelfilm and others. However, the comparative effectiveness and safety of these devices are uncertain.
OBJECTIVES: To evaluate the benefits and harms of different devices as adjuncts to trabeculectomy on IOP control in eyes with glaucoma compared to standard trabeculectomy.
SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search was August 2021.
SELECTION CRITERIA: We included randomized controlled trials in participants with glaucoma comparing device-modified trabeculectomy techniques with standard trabeculectomy. We included studies that used antimetabolites in either or both treatment groups.
DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. change in IOP and 2. mean postoperative IOP at one year. Our secondary outcomes were 3. mean change in IOP from baseline, 4. mean postoperative IOP at any time point, 5. mean best-corrected visual acuity (BCVA), 6. visual field change, 7. quality of life, 8. proportion of participants who are drop-free at one year, 9. mean number of IOP lowering medications at one year, and 10. proportion of participants with complications.
MAIN RESULTS: Eight studies met our inclusion criteria, of which seven were full-length journal articles and one was a conference abstract. The eight studies included 961 participants with glaucoma, and compared two types of devices implanted during trabeculectomy versus standard trabeculectomy. Seven studies (462 eyes, 434 participants) used the Ex-PRESS, and one study (527 eyes, 527 participants) used the PreserFlo MicroShunt. No studies using the XEN Gel Stent implantation met our criteria. The studies were conducted in North America, Europe, and Africa. Planned follow-up periods ranged from six months to five years. The studies were reported poorly, which limited our ability to judge risk of bias for many domains. None of the studies explicitly masked outcome assessment. We rated seven studies at high risk of detection bias. Low-certainty of evidence from five studies showed that using the Ex-PRESS plus trabeculectomy compared with standard trabeculectomy may be associated with a slightly lower IOP at one year (mean difference (MD) -1.76 mmHg, 95% confidence interval (CI) -2.81 to -0.70; 213 eyes). Moderate-certainty of evidence from one study showed that using the PreserFlo MicroShunt may be associated with a slightly higher IOP than standard trabeculectomy at one year (MD 3.20 mmHg, 95% CI 2.29 to 4.11). Participants who received standard trabeculectomy may have a higher risk of hypotony compared with those who received device-modified trabeculectomy, but the evidence is uncertain (RR 0.73, 95% CI 0.46 to 1.17; I² = 38%; P = 0.14). In the subgroup of participants who received the PreserFlo MicroShunt, there was a lower risk of developing hypotony or shallow anterior chamber compared with those receiving standard trabeculectomy (RR 0.44, 95% CI 0.25 to 0.79; 526 eyes). Device-modified trabeculectomy may lead to less subsequent cataract surgery within one year (RR 0.46, 95% CI 0.27 to 0.80; I² = 0%).
AUTHORS' CONCLUSIONS: Use of an Ex-PRESS plus trabeculectomy may produce greater IOP reduction at one-year follow-up than standard trabeculectomy; however, due to potential biases and imprecision in effect estimates, the certainty of evidence is low. PreserFlo MicroShunt may be inferior to standard trabeculectomy in lowering IOP. However, PreserFlo MicroShunt may prevent postoperative hypotony and bleb leakage. Overall, device-modified trabeculectomy appears associated with a lower risk of cataract surgery within five years compared with standard trabeculectomy. Due to various limitations in the design and conduct of the included studies, the applicability of this evidence synthesis to other populations or settings is uncertain. Further research is needed to determine the effectiveness and safety of other devices in subgroup populations, such as people with different types of glaucoma, of various races and ethnicity, and with different lens types (e.g. phakic, pseudophakic).
AIM: To systematically review the current evidence based on the efficacy and cost of Ex-PRESS implantation and trabeculectomy (Trab) for uncontrolled glaucoma.
METHODS: Clinical trials were identified by electronic databases (PubMed, EMBASE, ISI Web of science and Cochrane library), and data, such as intraocular pressure (IOP), the complete and qualified success rate, the postoperative complications and the cost, were exacted from these relevant studies. Weighted mean difference (WMD), odds ratio (OR) and 95% confidence intervals (CIs) were calculated and were pooled using a random-effects model.
RESULTS: Eleven relevant publications and two abstracts met the inclusion criteria. The efficacy of Ex-PRESS was similar to that of Trab in the percentage of IOP reduction (IOPR %) at 1, 2y (WMD -2.01; 95% CI: -7.92-3.90; P=0.50 and WMD 2.89; 95% CI: -8.05-13.83; P=0.60, respectively). Ex-PRESS possessed a significant higher complete and qualified success rate (OR: 1.59; 95% CI: 1.07-2.35; P=0.02 and OR: 1.74; 95% CI: 1.06-2.86; P=0.03, respectively). Moreover, Ex-PRESS exerted a significantly lower frequency of hypotony and hyphema than Trab (OR: 0.39; 95% CI: 0.21-0.72; P=0.003 and OR: 0.27; 95% CI: 0.10-0.69; P=0.003, respectively). However, there was no consistent result on the cost between the two groups according to the previous three studies.
CONCLUSION: Both Trab and Ex-PRESS have equivalent efficacy in lowering IOP, yet Ex-PRESS had a lower risk of hypotony and hyphema than Trab. Nevertheless, whether the cost of Ex-PRESS was less than that of Trab should be further investigated to ensure evidence-based conclusion in the long run.
Glaucoma filtration surgery is performed to reduce intraocular pressure (IOP) in patients for whom maximal tolerable pharmacologic IOP-lowering therapy and/or laser surgery fail to lower IOP sufficiently and/or fail to prevent optic nerve damage or visual field deterioration. For decades, the most widely utilized procedure for glaucoma filtration surgery has been trabeculectomy. Although this approach reliably provides long-term IOP reduction in many patients, the postoperative complication rate is high. This has driven the development of alternative approaches to reduce IOP surgically. The EX-PRESS glaucoma filtration device was developed to mimic IOP control by trabeculectomy and to have a better safety profile. This non-valved, medical-grade stainless steel device diverts aqueous humor from the anterior chamber to an intrascleral space. Despite the widespread use of the EX-PRESS device, only a few studies compare its efficacy and safety with that of trabeculectomy. We analyze available data regarding the safety and efficacy of the EX-PRESS device, particularly in comparison with trabeculectomy.
OBJECTIVE: To evaluate the efficacy and safety of Ex-PRESS implantation (Ex-PRESS) compared to trabeculectomy in the treatment of patients with open-angle glaucoma (OAG).
METHODS: A comprehensive literature search using the Cochrane Methodology Register to identify randomized controlled clinical trials (RCCTs) comparing Ex-PRESS to trabeculectomy in patients with OAG. Efficacy estimates were measured by weighted mean difference (WMD) for the percentage intraocular pressure reduction (IOPR%) from baseline to end-point, and odds ratios (OR) for the complete success rate and postoperative interventions. Safety estimates were measured by OR for postoperative complications. Statistical analysis was performed using the RevMan 5.1 software.
RESULTS: A total of four RCCTs were selected for this meta-analysis, including 215 eyes of 200 patients (110 eyes in the Ex-PRESS group, 105 eyes in the trabeculectomy group). There was no significant difference between Ex-PRESS and trabeculectomy in the IOPR% (WMD = 3.15; 95% confidence interval (CI), -6.17-12.47; P = 0.51). The pooled OR comparing Ex-PRESS to trabeculectomy for the complete success rate at one year after surgery were in favor of Ex-PRESS (OR = 2.93; 95% CI, 1.39-6.16; P = 0.005). The Ex-PRESS procedure was found to be associated with lower number of postoperative interventions (OR = 0.23; 95% CI, 0.07-0.81; P = 0.02) and with a significantly lower frequency of hyphema than trabeculectomy (OR = 0.21; 95% CI, 0.05-0.85; P = 0.03), whereas other complications did not differ statistically.
CONCLUSION: In OAG, Ex-PRESS and trabeculectomy provided similar IOP control, but Ex-PRESS was more likely to achieve complete success, with fewer postoperative interventions. Complication rates were similar for the two types of surgery, except for a lower frequency of hyphema in the Ex-PRESS group.
PURPOSE: To evaluate the efficacy and safety of EX-PRESS implantation compared with trabeculectomy for uncontrolled open-angle glaucoma.
METHODS: Pertinent randomized controlled trials were identified through systematic searches of the PubMed, EMBASE, and Cochrane Library. The efficacy measures utilized were the weighted mean differences (WMDs) for the intraocular pressure reduction (IOPR), the reduction in glaucoma medications, the change of visual acuity, and the relative risks (RRs) for operative success rates. The safety measures utilized were RRs for postoperative complications. The pooled effects were calculated using the random-effects model.
RESULTS: Four randomized controlled trials of 292 eyes were included in this meta-analysis. The WMDs of the IOPR comparing the EX-PRESS with trabeculectomy were -0.25 (95% Cl: -3.61 to 3.11) at 6 month, 0.053 (-4.31 to 4.42) at 12 months, 0.81 (-4.06 to 5.67) at 24 months, and 0.20 (-2.11 to 2.51) at final follow-up. There was no statistically significance for IOPR at any point after surgery. There were also no significant differences in the reduction in glaucoma medications or visual acuity between the groups. The pooled relative risks comparing EX-PRESS with Trabeculectomy were 1.36 (1.11 to 1.66) for the complete operative success rate and 1.05 (0.94 to 1.17) for the qualified operative success rate. EX-PRESS and Trabeculectomy were associated with similar incidences in most complications with the exception of hyphema, with pooled RR being 0.18 (0.046 to 0.66).
CONCLUSIONS: EX-PRESS implantation and trabeculectomy have similar efficacy in IOP-lowering, medication reduction, vision recovery, and qualified operative success rates. EX-PRESS associated with higher rates of complete operative success and fewer hyphema than with Trabeculectomy. However, these should be interpreted with caution because of the inherent limitations of the included studies.
OBJECTIVE: To evaluate the efficacy and tolerability of Ex-PRESS implantation (Ex-Press) compared with trabeculectomy (Trab) in the treatment of patients with uncontrolled glaucoma.
METHODS: A comprehensive literature meta-analysis was performed according to the Cochrane Collaboration methodology to identify controlled clinical trials comparing Ex-Press with Trab. Efficacy estimates were measured by weight mean difference (WMD) for the percentage intraocular pressure (IOP) reduction from baseline to end-point, odds ratio (OR) for complete success, and qualified success rates. Tolerability estimates were measured by OR for adverse events. All outcomes were reported with a 95% confidence interval (CI). Data were synthesized by Stata 11.0 SE for Windows.
RESULTS: Eight controlled clinical trials meeting the predefined criteria were included in the meta-analysis. A total of 605 eyes from 559 patients with medically uncontrolled glaucoma were included. The weighted mean difference of the percentage IOP reduction from baseline was 2.33 (95% confidence interval: -2.59-7.24) when comparing Ex-Press with Trab. Ex-Press was associated with numerically greater, but nonsignificant, IOP lowering efficacy than Trab. The pooled odds ratio comparing Ex-Press with Trab were 0.93 (0.39, 2.23) for the complete success rate and 1.00 (0.39, 2.56) for the qualified success rate. Ex-Press was associated with a significantly lower frequency of hypotony and hyphema than Trab, with pooled ORs of 0.29 (0.13, 0.65) and 0.36 (0.13, 0.97), respectively.
CONCLUSION: Ex-Press was associated with equivalent efficacy to Trab in lowering IOP. Comparable proportions of patients reached the IOP target with Ex-Press and Trab. Ex-Press was better tolerated than Trab.
OBJECTIVE: To review the published literature and summarize clinically relevant information about novel, or emerging, surgical techniques for the treatment of open-angle glaucoma and to describe the devices and procedures in proper context of the appropriate patient population, theoretic effects, advantages, and disadvantages.
DESIGN: Devices and procedures that have US Food and Drug Administration clearance or are currently in phase III clinical trials in the United States are included: the Fugo blade (Medisurg Ltd., Norristown, PA), Ex-PRESS mini glaucoma shunt (Alcon, Inc., Hunenberg, Switzerland), SOLX Gold Shunt (SOLX Ltd., Boston, MA), excimer laser trabeculotomy (AIDA, Glautec AG, Nurnberg, Germany), canaloplasty (iScience Interventional Corp., Menlo Park, CA), trabeculotomy by internal approach (Trabectome, NeoMedix, Inc., Tustin, CA), and trabecular micro-bypass stent (iStent, Glaukos Corporation, Laguna Hills, CA).
METHODS: Literature searches of the PubMed and the Cochrane Library databases were conducted up to October 2009 with no date or language restrictions.
MAIN OUTCOME MEASURES: These searches retrieved 192 citations, of which 23 were deemed topically relevant and rated for quality of evidence by the panel methodologist. All studies but one, which was rated as level II evidence, were rated as level III evidence.
RESULTS: All of the devices studied showed a statistically significant reduction in intraocular pressure and, in some cases, glaucoma medication use. The success and failure definitions varied among studies, as did the calculated rates. Various types and rates of complications were reported depending on the surgical technique. On the basis of the review of the literature and mechanism of action, the authors also summarized theoretic advantages and disadvantages of each surgery.
CONCLUSIONS: The novel glaucoma surgeries studied all show some promise as alternative treatments to lower intraocular pressure in the treatment of open-angle glaucoma. It is not possible to conclude whether these novel procedures are superior, equal to, or inferior to surgery such as trabeculectomy or to one another. The studies provide the basis for future comparative or randomized trials of existing glaucoma surgical techniques and other novel procedures.
Glaucoma is an optic neuropathy that leads to visual field defects and vision loss. It is the second leading cause of irreversible blindness in the world. Treatment for glaucoma aims to reduce intraocular pressure (IOP) to slow or prevent further vision loss. IOP can be lowered with medications, laser, or incisional surgery. Trabeculectomy is a surgical approach which lowers IOP by shunting aqueous humor to a subconjunctival bleb. Device-modified trabeculectomy techniques are intended to improve the durability and safety of this bleb-forming surgery. Trabeculectomy-modifying devices include the Ex-PRESS, the XEN Gel Stent, the PreserFlo MicroShunt, as well as antifibrotic materials such as Ologen, amniotic membrane, expanded polytetrafluoroethylene (ePTFE) membrane, Gelfilm and others. However, the comparative effectiveness and safety of these devices are uncertain.
OBJECTIVES:
To evaluate the benefits and harms of different devices as adjuncts to trabeculectomy on IOP control in eyes with glaucoma compared to standard trabeculectomy.
SEARCH METHODS:
We used standard, extensive Cochrane search methods. The latest search was August 2021.
SELECTION CRITERIA:
We included randomized controlled trials in participants with glaucoma comparing device-modified trabeculectomy techniques with standard trabeculectomy. We included studies that used antimetabolites in either or both treatment groups.
DATA COLLECTION AND ANALYSIS:
We used standard Cochrane methods. Our primary outcomes were 1. change in IOP and 2. mean postoperative IOP at one year. Our secondary outcomes were 3. mean change in IOP from baseline, 4. mean postoperative IOP at any time point, 5. mean best-corrected visual acuity (BCVA), 6. visual field change, 7. quality of life, 8. proportion of participants who are drop-free at one year, 9. mean number of IOP lowering medications at one year, and 10. proportion of participants with complications.
MAIN RESULTS:
Eight studies met our inclusion criteria, of which seven were full-length journal articles and one was a conference abstract. The eight studies included 961 participants with glaucoma, and compared two types of devices implanted during trabeculectomy versus standard trabeculectomy. Seven studies (462 eyes, 434 participants) used the Ex-PRESS, and one study (527 eyes, 527 participants) used the PreserFlo MicroShunt. No studies using the XEN Gel Stent implantation met our criteria. The studies were conducted in North America, Europe, and Africa. Planned follow-up periods ranged from six months to five years. The studies were reported poorly, which limited our ability to judge risk of bias for many domains. None of the studies explicitly masked outcome assessment. We rated seven studies at high risk of detection bias. Low-certainty of evidence from five studies showed that using the Ex-PRESS plus trabeculectomy compared with standard trabeculectomy may be associated with a slightly lower IOP at one year (mean difference (MD) -1.76 mmHg, 95% confidence interval (CI) -2.81 to -0.70; 213 eyes). Moderate-certainty of evidence from one study showed that using the PreserFlo MicroShunt may be associated with a slightly higher IOP than standard trabeculectomy at one year (MD 3.20 mmHg, 95% CI 2.29 to 4.11). Participants who received standard trabeculectomy may have a higher risk of hypotony compared with those who received device-modified trabeculectomy, but the evidence is uncertain (RR 0.73, 95% CI 0.46 to 1.17; I² = 38%; P = 0.14). In the subgroup of participants who received the PreserFlo MicroShunt, there was a lower risk of developing hypotony or shallow anterior chamber compared with those receiving standard trabeculectomy (RR 0.44, 95% CI 0.25 to 0.79; 526 eyes). Device-modified trabeculectomy may lead to less subsequent cataract surgery within one year (RR 0.46, 95% CI 0.27 to 0.80; I² = 0%).
AUTHORS' CONCLUSIONS:
Use of an Ex-PRESS plus trabeculectomy may produce greater IOP reduction at one-year follow-up than standard trabeculectomy; however, due to potential biases and imprecision in effect estimates, the certainty of evidence is low. PreserFlo MicroShunt may be inferior to standard trabeculectomy in lowering IOP. However, PreserFlo MicroShunt may prevent postoperative hypotony and bleb leakage. Overall, device-modified trabeculectomy appears associated with a lower risk of cataract surgery within five years compared with standard trabeculectomy. Due to various limitations in the design and conduct of the included studies, the applicability of this evidence synthesis to other populations or settings is uncertain. Further research is needed to determine the effectiveness and safety of other devices in subgroup populations, such as people with different types of glaucoma, of various races and ethnicity, and with different lens types (e.g. phakic, pseudophakic).
