An Update on Implants for Minimally Invasive Glaucoma Surgery (MIGS)

Complications after CyPass® Micro-Stent explantation: a case series

PURPOSE

To describe the in toto explantation of the CyPass® Micro-Stent and its conceivable complications.

METHODS

This is a case series of eighteen eyes from fourteen patients who underwent CyPass® Micro-Stent implantation due to mild to moderate glaucoma and who subsequently suffered from loss of endothelial cell density. Consequently, the CyPass® Micro-Stent was in toto explanted. The surgical procedure and its complications are described and compared with trimming of the CyPass® Micro-Stent.

RESULTS

A postoperative hyphema was developed in 8 of the 18 eyes. In four of them the hyphema was self-limiting, while in two patients an anterior chamber irrigation was necessary. One patient suffered from a severe intracameral bleeding and iridodialysis during explantation, so that the base of the iris had to be scleral fixated. The remaining explantations were without complications.

CONCLUSION

Dealing with implanted CyPass® Micro-Stents poses a challenge for ophthalmic surgeons. An in toto removal can be traumatic, since the CyPass stent often is fibrotic encapsulated and fused with the surrounding tissue. Alternatively, trimming of the CyPass is also a viable option to avoid further endothelial damage. Reported complications of CyPass trimming are consistent with those that can occur after explantation. Further data on the development of the endothelial cells after trimming or explantation are not yet available. Therefore, it remains open whether trimming of the CyPass, in contrast to complete removal, carries the risk of further endothelial cell loss.

The Evolution and Current Landscape of Minimally Invasive Glaucoma Surgeries: A Review

This review examines the evolution, current status, and future potential of minimally invasive glaucoma surgeries (MIGS), a significant advancement in the treatment of glaucoma, a leading cause of irreversible blindness. MIGS offer a less invasive alternative to traditional glaucoma surgeries, primarily aimed at reducing intraocular pressure, minimizing tissue trauma, and providing a safer profile. With the emergence of devices such as the Trabectome, iStent, and others, MIGS have expanded the surgical toolkit, allowing personalized, patient-centered care. Despite their advantages, MIGS face challenges such as efficacy in severe cases, long-term data, and accessibility. Ongoing research and technological innovations continue to refine their capabilities and applications, promising to further transform glaucoma management and patient outcomes. This paper provides an in-depth analysis of MIGS, reflecting on their impact and contemplating future directions in this dynamically evolving field.

Alternatives to Topical Glaucoma Medication for Glaucoma Management

Topical glaucoma medications have favorable safety and efficacy, but their use is limited by factors such as side effects, nonadherence, costs, ocular surface disease, intraocular pressure fluctuations, diminished quality of life, and the inherent difficulty of penetrating the corneal surface. Although traditionally these limitations have been accepted as an inevitable part of glaucoma treatment, a rapidly-evolving arena of minimally invasive surgical and laser interventions has initiated the beginnings of a reevaluation of the glaucoma treatment paradigm. This reevaluation encompasses an overall shift away from the reactive, topical-medication-first default and a shift toward earlier intervention with laser or surgical therapies such as selective laser trabeculoplasty, sustained-release drug delivery, and micro-invasive glaucoma surgery. Aside from favorable safety, these interventions may have clinically important attributes such as consistent IOP control, cost-effectiveness, independence from patient adherence, prevention of disease progression, and improved quality of life.

XEN45 Gel Stent Combined with Healaflow Injectable Viscoelastic Implant

Purpose

To introduce a potential solution for failed glaucoma surgeries by proposing an optional surgical procedure in conjunction with the use of Healaflow (Anteis S.A., Geneva, Switzerland) as a spacer, which may potentially reduce the failure rate. Case Presentation. We present the outcomes of a surgical procedure involving the inferonasal implantation of an ab interno XEN gel stent (Allergan, Dublin, Ireland) in a 74-year-old male patient who was experiencing uncontrolled advanced glaucoma in his left eye. It is important to note that the patient had previously undergone several glaucoma surgeries and procedures in the same eye. During this particular procedure, we utilized Healaflow as a spacer by implanting the stent within a subconjunctival Healaflow "bubble." At 6 months postoperatively, intraocular pressure remained on target. There was no need for additional topical medications, and no change in visual acuity was observed.

Conclusion

For patients with a history of unsuccessful glaucoma surgeries and who are unsuitable candidates for tube shunt procedures or transscleral diode cyclophotocoagulation, an alternative option involves implanting the XEN45 stent in the inferior nasal region in conjunction with the use of subconjunctival Healaflow. This combined approach may provide a potential solution for managing glaucoma in these patients.

Patient-centered empirical research on ethically relevant psychosocial and cultural aspects of cochlear, glaucoma and cardiovascular implants - a scoping review

BACKGROUND

The significance of medical implants goes beyond technical functioning and reaches into everyday life, with consequences for individuals as well as society. Ethical aspects associated with the everyday use of implants are relevant for individuals' lifeworlds and need to be considered in implant care and in the course of technical developments.

METHODS

This scoping review aimed to provide a synthesis of the existing evidence regarding ethically relevant psychosocial and cultural aspects in cochlear, glaucoma and cardiovascular implants in patient-centered empirical research. Systematic literature searches were conducted in EBSCOhost, Philpapers, PsycNET, Pubmed, Web of Science and BELIT databases. Eligible studies were articles in German or English language published since 2000 dealing with ethically relevant aspects of cochlear, glaucoma and passive cardiovascular implants based on empirical findings from the perspective of (prospective) implant-wearers and their significant others. Following a descriptive-analytical approach, a data extraction form was developed and relevant data were extracted accordingly. We combined a basic numerical analysis of study characteristics with a thematically organized narrative synthesis of the data.

RESULTS

Sixty-nine studies were included in the present analysis. Fifty were in the field of cochlear implants, sixteen in the field of passive cardiovascular implants and three in the field of glaucoma implants. Implant-related aspects were mainly found in connection with autonomy, freedom, identity, participation and justice, whereas little to no data was found with regards to ethical principles of privacy, safety or sustainability.

CONCLUSIONS

Empirical research on ethical aspects of implant use in everyday life is highly relevant, but marked by ambiguity and unclarity in the operationalization of ethical terms and contextualization. A transparent orientation framework for the exploration and acknowledgment of ethical aspects in "lived experiences" may contribute to the improvement of individual care, healthcare programs and research quality in this area. Ethics-sensitive care requires creating awareness for cultural and identity-related issues, promoting health literacy to strengthen patient autonomy as well as adjusting healthcare programs accordingly. More consideration needs to be given to sustainability issues in implant development and care according to an approach of ethics-by-design.

Effectiveness and Safety of Xen Gel Stent in Glaucoma Surgery: A Systematic Review of the Literature

Although topical medical therapy and selective-laser-trabeculoplasty represent the treatments of choice to reduce intraocular pressure, many patients do not achieve adequate glaucoma control; therefore, they require further options and eventually surgery. Trabeculectomy is still considered the gold standard, but the surgical management of glaucoma has undergone continuous advances in recent years, XEN-gel-stent has been introduced as a safer and less traumatic means of lowering intraocular pressure (IOP) in patients with open-angle glaucoma (OAG). This study aimed to review the effectiveness and safety of clinical data on XEN-stent in OAG patients with a Synthesis-Without-Meta-analysis (SWiM) methodology. A total of 339 studies were identified following a literature search adhering to PRISMA guidelines and, after evaluation, 96 studies are discussed. XEN63 and XEN45 device data were collected both short and long term. In addition, this document has evaluated different aspects related to the XEN implant, including: its role compared to trabeculectomy; the impact of mitomycin-C dose on clinical outcomes; postoperative management of the device; and the identification of potential factors that might predict its clinical outcomes. Finally, current challenges and future perspectives of XEN stent, such as its use in fragile or high myopia patients, were discussed.

Patient Preferences for Long-Term Implant Care in Cochlear, Glaucoma and Cardiovascular Diseases

In the process of developing and implementing innovative implant technologies the consideration of patient preferences can be beneficial for patients, doctors and developers. Nevertheless, in existing literature, there is still scarce knowledge of patients' perspectives on long-term implant care. In this study, three discrete choice experiments (DCEs) were conducted in the context of cochlear implants (CI, n = 92), glaucoma implants (GI, n = 21) and cardiovascular implants (CVI, n = 23), examining the relative importance of attributes of long-term implant care from the patients' perspective. The participants chose between differently shaped options for implant-related care. The attributes of these care options were generated and selected based on previous literature reviews, group discussions and a diary study with patients. The choice data were analyzed via binary logit regression. In CI-DCE, the technological compatibility of the implant with newer implant models, accessories or devices from other manufacturers was highly valued by participants, whereas in GI-DCE the (in)dependency on glaucoma medication post-implantation had the greatest influence on participants' choice behavior. In CVI-DCE, the attribute with the highest relative importance related to the means of securing long-term treatment success. In all three DCE, shared decision making was relatively important for participants. Our results emphasized the importance of an adequate transfer of technological advancements in implant care for promoting patient benefits, such as the availability of comprehensible, understandable, high-quality information about current developments. Similarly, promoting technological health literacy and further pushing the technological compatibility, durability and safety of implants are directions for future implant development in accordance with patients' preferences. Therefore, the participation of implant wearers in the development process is encouraged.

XEN Gel Stent Versus Nonpenetrating Deep Sclerectomy in Ocular Hypertension and Open Angle Glaucoma Patients

PRCIS

XEN gel stent and nonpenetrating deep sclerectomy, both either alone or in combination with cataract surgery, significantly lowered the intraocular pressure (IOP) and reduced the number of antiglaucoma medications in patients with open angle glaucoma, with no significant differences between them.

PURPOSE

To compare the surgical outcomes of XEN45 implant and nonpenetrating deep sclerectomy (NPDS), either alone or in combination with cataract surgery, in patients with ocular hypertension and open angle glaucoma (OAG). A retrospective and single-center cohort study was conducted on consecutive patients who underwent a XEN45 implant or an NPDS, either alone or in combination with phacoemulsification. The primary endpoint was the mean change in IOP from the baseline to the last follow-up visit. One hundred twenty-eight eyes, 65 (50.8%) eyes in the NPDS group and 63 (49.2%) eyes in the XEN group, were included in the study. The mean preoperative IOP was significantly lowered from 17.6±5.3 mm Hg and 17.8±6.2 mm Hg to 12.6±2.6 mm Hg and 13.8±2.8 mm Hg at month 12 in the XEN and NPDS groups, respectively; P <0.0001 each. At month 12, 70 (54.7%) eyes were classified as a success, with no significant differences between XEN (57.1%; 36/63 eyes) and NPDS (52.3%; 34/65 eyes) (mean difference: 4.8%; 95% CI: -30.5% to 20.8%; P =0.7115). The number of ocular hypotensive medications was significantly reduced in the XEN (from 2.1±0.7-0.2±0.5, P <0.0001) and in the NPDS (from 2.0±0.8 to 0.3±0.6, P <0.0001) groups, with no significant differences between them ( P =0.2629). The incidence of postoperative adverse events in the overall study population was 12.5%, with no significant differences between groups ( P =0.1275). Seven (11.1%) eyes underwent needling (XEN group) and 10 (15.4%) goniopuncture (NPDS group); P =0.4753.

CONCLUSIONS

XEN45 implant and the NPDS, either alone or in combination with cataract surgery, significantly lowered IOP and reduced the number of ocular hypotensive medications in ocular hypertension and patients with open angle glaucoma.

Use of Digital Methods to Optimize Visualization during Surgical Gonioscopy

Purpose: The aim of this study was to evaluate the efficacy of digital visualization for enhancing the visualization of iridocorneal structures during surgical gonioscopy. Methods: This was a prospective, single-center study on a series of 26 cases of trabecular stent implantation performed by the same surgeon. Images were recorded during surgical gonioscopy, and before stent implantation, with standard colors and with the optimization of various settings, principally color saturation and temperature and the use of the cyan color filter. Subjective analyses were performed by two glaucoma surgeons, and objective contrast measurements were made on iridocorneal structure images. Results: The surgeons evaluating the images considered the optimized digital settings to produce enhanced tissue visibility for both trabecular meshwork pigmentation and Schlemm's canal in more than 65% of cases. The mean difference in the standard deviation of the pixel intensity values was 37.87 (±4.61) for the optimized filter images and 32.37 (±3.51) for the standard-color images (p < 0.001). The use of a cyan filter provided a good level of contrast for the visualization of trabecular meshwork pigmentation. Increasing the color temperature highlighted the red appearance of Schlemm's canal. Conclusions: We report here the utility of optimized digital settings including the cyan filter and a warmer color for enhancing the visualization of iridocorneal structures during surgical gonioscopy. These settings could be used in surgical practice to enhance the visualization of the trabecular meshwork and Schlemm's canal during minimally invasive glaucoma surgery.

Tetrapodal ZnO-Based Composite Stents for Minimally Invasive Glaucoma Surgery

The glaucoma burden increases continuously and is estimated to affect more than 100 million people by 2040. As there is currently no cure to restore the optic nerve damage caused by glaucoma, the only controllable parameter is the intraocular pressure (IOP). In recent years, minimally invasive glaucoma surgery (MIGS) has emerged as an alternative to traditional treatments. It uses micro-sized drainage stents that are inserted through a small incision, minimizing the trauma to the tissue and reducing surgical and postoperative recovery time. However, a major challenge for MIGS devices is foreign body reaction and fibrosis, which can lead to a complete failure of the device. In this work, the antifibrotic potential of tetrapodal ZnO (t-ZnO) microparticles used as an additive is elucidated by using rat embryonic fibroblasts as a model. A simple, direct solvent-free process for the fabrication of stents with an outer diameter of 200-400 μm is presented, in which a high amount of t-ZnO particles (45-75 wt %) is mixed into polydimethylsiloxane (PDMS) and a highly viscous polymer/particle mixture is extruded. The fabricated stents possess increased elastic modulus compared to pure PDMS while remaining flexible to adapt to the curvature of an eye. In vitro experiments showed that the fibroblast cell viability was inhibited to 43 ± 3% when stents with 75 wt % t-ZnO were used. The results indicate that cell inhibiting properties can be attributed to an increased amount of protruding t-ZnO particles on the stent surface, leading to an increase in local contacts with cells and a disruption of the cell membrane. As a secondary mechanism, the released Zn ions could also contribute to the cell-inhibiting properties in the close vicinity of the stent surface. Overall, the fabrication method and the antifibrotic and mechanical properties of developed stents make them promising for application in MIGS.

The case for standalone micro-invasive glaucoma surgery: rethinking the role of surgery in the glaucoma treatment paradigm

PURPOSE OF REVIEW

To highlight progress in glaucoma therapy challenging the traditional medication-first approach and present evidence supporting early standalone surgery in the era of micro-invasive glaucoma surgery (MIGS).

RECENT FINDINGS

Medical therapy is limited by well documented poor adherence that compromises the quality of intraocular pressure reduction. Results from modern clinical trials demonstrate advantages of selective laser trabeculoplasty and MIGS procedures in terms of both IOP control and progression risk.

SUMMARY

The MIGS options for pseudophakic or precataractous patients are limited by regulatory rules that require the performance of some procedures only at the time of cataract surgery. These include the iStent/iStent Inject and the Hydrus implants. Nonbleb-forming procedures currently available for standalone use in eyes with mild-moderate primary open-angle glaucoma include gonioscopy-assisted transluminal trabeculotomy (which lowers IOP by 28-61% and medication use by 38-73% in various studies), trabecular ablation with the Trabectome (23-39% and 21-43%, respectively), excisional goniotomy with the Kahook Dual Blade (15-36% and 15-40%, respectively), ab interno canaloplasty (35% and 57%, respectively), and combined canaloplasty and trabeculotomy using the OMNI system (39-40% and 64-73%, respectively). For patients who would benefit from early standalone surgery, these procedures offer meaningful reductions in both IOP and medication burden.

Phacoemulsification versus Phacoemulsification/Trabeculectomy for the Treatment of Primary Open-Angle Glaucoma Coexistent with Cataract: A Comparative Study

Background: The purpose of this study was to evaluate the clinical outcomes in patients with primary open-angle glaucoma (POAG) and coexistent cataract treated with phacoemulsification cataract surgery, either alone or in combination with trabeculectomy. Methods: Participants in this retrospective study were 52 patients diagnosed with previously controlled POAG and coexistent cataract, who underwent either uneventful phacoemulsification cataract surgery (Group I, n = 27) or combined uneventful phacoemulsification cataract surgery and trabeculectomy (Group II, n = 25), with at least a 24-month postoperative follow-up. We recorded the changes in intraocular pressure (IOP) and in the need of anti-glaucoma medications before and after surgical procedures. Results: There was a statistically significant decrease in IOP at postoperative day 7 in both groups (p < 0.001), which remained until the end of the 24-month follow-up. At month 24, the two groups did not differ significantly in terms of IOP (14.3 ± 1.4 vs. 13.1 ± 1.2 for Group I and Group II, respectively; p = 0.447). In addition, there was a statistically significant decrease in the number of anti-glaucoma medications needed at postoperative day 7 in both groups (p < 0.001 for both groups compared to baseline). At month 24, patients in both groups needed about one additional anti-glaucoma medication to control their IOP. Of note, during the first month after surgery, 20% of patients in Group II needed 0.1 mL 5-FU injections to the bleb, although antimetabolites were not used in the primary surgery. Conclusions: Both surgical interventions, namely phacoemulsification cataract surgery alone and phacoemulsification/trabeculectomy, were found to be effective in the management of POAG with coexistent cataract, presenting a significant decrease in IOP and in the need of anti-glaucoma medications postoperatively at a long-term follow-up period of 24 months.

PreserFlo™ MicroShunt Versus Ab Externo Canaloplasty in Patients With Moderate to Advanced Open-Angle Glaucoma: 12-Month Follow-Up of a Single-Center Retrospective Study

Purpose To evaluate and compare the efficacy and safety of the PreserFlo MicoShunt and the canaloplasty in patients with moderate to advanced glaucoma. Methods In this retrospective study, 300 patients with moderate to advanced glaucoma underwent either the implantation of the PreserFlo™ MicroShunt (group A) or a canaloplasty (group B). All patients underwent regular follow-up examinations in our department every two days, every two weeks, and every three, six, and 12 months postoperatively. Examinations included measurement of the best corrected visual acuity (BCVA), slit-lamp biomicroscopy of the anterior and posterior segments, intraocular pressure (IOP) measurement using Goldmann applanation tonometry, visual field perimetry, and measurement of the endothelial cell density (ECD). Efficacy was shown by the absolute and qualified success rates calculated with the Kaplan-Meyer analysis. Results  In group A, IOP was significantly reduced at 12 months (13.37 ± 3.94 mmHg, p≤ 0.01) postoperatively in comparison to baseline (23.47 ± 8.39 mmHg). In group B, there was also a reduction in IOP at 12 months (14.32 ± 3.59 mmHg, p≤ 0.01) in comparison to the baseline (18.86 ± 5.82 mmHg). Comparing both groups, the IOP of patients who received the PreserFlo™ MicroShunt was significantly lower than the IOP of patients receiving canaloplasty after 12 months (p=0.049). Patients in both groups were treated with significantly fewer topical agents after 12 months (group A: baseline = 2.53±1.56; 12 months: 0.43 ± 0.83, p≤0.01; group B: baseline 2.62 ± 0.87; 12 months: 1.52 ± 0.99, p≤0.01). Patients receiving the PreserFlo™ MicroShunt applied significantly fewer topical agents than patients who underwent canaloplasty (p≤ 0.01). One year after surgery, the cumulative probability of absolute success was 81.33% in group A and 14.67% in group B. After one year, the cumulative probability of qualified success was 93.33% in group A and 82.00% in group B. Conclusion The PreserFlo™ as well as the canaloplasty offer many advantages and only a few disadvantages for patients with glaucoma. However, the respective patient's history and individual risk profile play an important role in the decision of the glaucoma specialist regarding the most appropriate surgical treatment for each patient. Patients with a high risk of conjunctival scarring and postoperative complications may benefit more from a canaloplasty, whereas patients who need a lower average IOP and show intolerance to any topical agents may require the PreserFlo™ implantation.

Foreign body reaction after CyPass® Micro-Stent implantation: a case series

PURPOSE

To retrospectively assess the histopathological particularities of explanted CyPass® Micro-Stent of patients with significant loss of endothelial cell density.

METHODS

This is a case series of fourteen eyes from eleven patients who underwent CyPass® Micro-Stent implantation due to mild to moderate glaucoma and who subsequently suffered from loss of endothelial cell density. Therefore, the explantation of the device was necessary. In addition to the retrospective evaluation of the intraocular pressure and the endothelial cell density at the time of implantation and explantation, every surgically removed implant was histologically examined and evaluated.

RESULTS

Fourteen eyes of eleven patients were in total analysed. The patients-seven males and four females-had a mean age of 62.9 years. The average time between CyPass implantation and explantation was 3.7 years. Eight patients suffered from primary-open-angle glaucoma (POAG), while two patients had a pseudoexfoliation glaucoma (PXG) and one patient had low-pressure glaucoma. Ten of the patients were already pseudophakic before the CyPass implantation and four patients underwent previously glaucoma interventions. There was a significant reduction in the intraocular pressure from 18.57 ± 5.27 mmHg at the time of implantation to 14.78 ± 3.32 mmHg at the time of explantation (p = 0.037). The average endothelial cell density decreased from 1843.67 ± 421.81 to 932.92 ± 412.86/mm² at the time of explantation (p < 0.01). The histological findings showed a fibrous obliteration of the CyPass accompanied by a chronic granulomatous inflammation with giant cell macrophages. Histologically, these findings were consistent with a foreign body granuloma.

CONCLUSIONS

Implants made of polyimides such as the CyPass® Micro-Stent are considered to be biocompatible, but there is no guarantee not to be obliterated or encapsulated. This is the first case series that has detected a foreign body granuloma in multiple eyes after CyPass implantation. However, there is no connection with the type of glaucoma, the extent of previous operations or with the presence of a prolonged postoperative inflammatory reaction.

Review of glaucoma medication adherence monitoring in the digital health era

Current glaucoma treatments aim to lower intraocular pressure, often with topical ocular hypotensive medications. Unfortunately, the effectiveness of these medications depends on sustained patient adherence to regimens which may involve instilling multiple medications several times daily. Patient adherence to glaucoma medications is often low. Recent innovations in digital sensor technologies have been leveraged to confirm eyedrop medication usage in real-time and relay this information back to providers. Some sensors have also been designed to deliver medication reminders and notifications as well as assist with correct eyedrop administration technique. Here, we review recent innovations targeted at improving glaucoma medication adherence and discuss their limitations.

[Glaucoma care in Germany-results of a survey among German ophthalmologists-part 2: treatment]

BACKGROUND

The options for glaucoma treatment are quite diverse. The question therefore arises what is considered beneficial and feasible in daily practice. Our anonymized survey among members of the German Ophthalmological Society (DOG) and the Professional Association of Ophthalmologists in Germany (BVA) intends to explore treatment patterns and strategies in routine glaucoma care in Germany.

OBJECTIVE

The current article reflects current opinions of German ophthalmologists regarding glaucoma care, therapeutic strategies, and the role of glaucoma surgery.

MATERIALS AND METHODS

The survey was conducted using an online questionnaire with 26 questions (107 items) regarding care practice for glaucoma diagnosis and treatment. Complete responses were available from 1361 participants.

RESULTS

A total of 84.8% of responders define a target pressure regularly. A systemic therapeutic approach is followed by 44.9%. Two thirds consider side effects of eye drops to impair quality of life. Most common are conjunctival hyperemia and burning. Non-adherence to treatment is estimated to occur in 32% of patients. Approximately 5-10% of glaucoma patients are treated surgically. Among interventional treatment options, 90% consider trabeculectomy beneficial, followed by minimally invasive glaucoma surgery (MIGS) and selective laser trabeculoplasty (SLT), which are, however, the most commonly performed procedures.

CONCLUSION

The choice of treatment should intend a long-lasting reduction of intraocular pressure and yet to be reasonable and manageable. There is a demand for more overview and structured care.

Canaloplasty and trabeculotomy with the OMNI® surgical system in OAG with prior trabecular microbypass stenting

Purpose

Evaluate effectiveness and safety outcomes for patients treated with canaloplasty and trabeculotomy previously treated with a trabecular microbypass stent (TBS).

Methods

Retrospective, multicenter, IRB approved study. Patients treated with TBS (iStent/iStent inject, Glaukos) and subsequently with OMNI surgical system (OSS) (Sight Sciences). From 5 practices in 5 US states. Open-angle glaucoma (OAG), minimum 3 months follow-up after OSS surgery, Pre-OSS IOP ≥ 17 mmHg on ≥ 1 medication. No glaucoma procedures between TBS and OSS. Endpoints: proportion with ≥ 20% reduction in IOP, IOP between 6 and 18 mmHg, mean IOP, change in IOP, mean number of medications. Adverse events and secondary surgical interventions (SSI). Mann–Whitney rank sum test compared pre-OSS IOP and medications with follow-up.

Results

Twenty seven patients. Average age (SD) 72.2 (10.8), 22/27 primary OAG (82%), mean MD − 6.2 (7.0) dB. Mean IOP before OSS 22.3 (4.3) mmHg on 2.2 (1.3) medications. At last follow-up (mean 11 months) IOP was 17.2 mmHg on 1.8 medications, − 5.1 mmHg (− 23%, p < .001), − 0.4 meds (− 18%, p = .193); ≥ 20% IOP reduction (41%), IOP ≤ 18 (56%). Adverse events were non-serious. Hyphema > 1 mm (3, 11%), BCVA decrease (4, 15%), IOP spike (2, 7%). SSI (4, 15%) had higher pre-OSS IOP (23.4 mmHg) and worse MD (− 9.6 dB).

Conclusion

Patients uncontrolled by medication and a prior TBS would once have been candidates for trabeculectomy and tube shunts. OSS offered a minimally invasive option that provided IOP control and avoidance of traditional surgery for the majority over follow-up averaging 11 months and up to 42 months.

Clinical and Visual Field Outcomes Following Minimally Invasive Glaucoma Surgery Combined with Cataract Surgery

Purpose

To determine the change in Humphrey visual field and clinical parameters after minimally invasive glaucoma surgery combined with cataract surgery.

Patients and Methods

Patients undergoing minimally invasive glaucoma surgery combined with cataract surgery in a multicenter retrospective case series between 2013 and 2021 with reliable preoperative and 12 to 18 month postoperative visual field measurements were included. Devices included iStent, XEN, and Hydrus. Clinical parameters were compared with a generalized linear model with generalized estimating equations between preoperative and postoperative visits including best corrected visual acuity, intraocular pressure, number of glaucoma medications and visual fields. Visual field metrics included mean deviation (MD), pattern standard deviation (PSD), visual field index (VFI), and Collaborative Initial Glaucoma Treatment Study (CIGTS) score of total deviation probability and pattern deviation probability.

Results

Forty-four eyes from 39 patients were included. During the follow up period, visual acuity improved from 0.23±0.17 to 0.10±0.14 logMAR (mean ± standard deviation, p<0.001), number of glaucoma medications was reduced from 2.68±1.06 to 1.46±1.32 (p<0.001), and intraocular pressure decreased from 17.08±4.23 mmHg to 14.92±3.13 mmHg (p=0.003). Differences across devices were negligible. The only significant difference was a greater reduction in number of glaucoma medications in the XEN group (p<0.001). There were no significant changes in the global parameters of VFI, MD, PSD, or CIGTS.

Conclusion

Overall, minimally invasive glaucoma surgery combined with cataract surgery appears to be effective at stabilizing visual field function, reducing intraocular pressure, reducing number of glaucoma medications, and improving visual acuity over a 12 to 18 month follow-up period across MIGS devices.

Italian Candidates for the XEN Implant: An Overview from the Glaucoma Treatment Registry (XEN-GTR)

Background The Italian XEN Glaucoma Treatment Registry (XEN-GTR) was created to acquire a comprehensive prospective dataset that includes the patient characteristics, intraoperative variables, and postoperative management of glaucoma patients undergoing the XEN gel stent implantation. Methods This was a prospective observational, longitudinal clinical study involving 10 centres throughout Italy. The baseline examination included a comprehensive evaluation of demographic parameters (age, sex, ethnicity, and systemic condition), specific ophthalmological parameters, and quality of life questionnaire score collection. Results The baseline data of 273 patients were analysed. The median (IQR) age was 72 (65.0 to 78.0) years. Of the 273 patients, 123 (45%) were female and 150 (55%) were male. A total of 86% of the patients had open-angle glaucoma with a mean intraocular pressure of 24 ± 6 (range 12.0–60.0) mmHg. The mean number of medications was 2.7 ± 0.9 at baseline for the patients with a prevalence of prostaglandin analogues combined with a beta-blocker and anhydrase carbonic inhibitor (31.8%). The mean scores of the NEI-VFQ 25 and GSS questionnaires were 78 ± 18 (range 26.5–100) and 85 ± 14 (range 79–93), respectively. Combined XEN/cataract surgeries were scheduled in 73.7% of the patients. The preferred place for the XEN implant was the supero-nasal quadrant (91.6%). Conclusions Observing the baseline characteristics of the typical Italian candidates for the XEN gel implant shows that they are patients affected by POAG and cataracts, with moderate to severe glaucoma damage, all of which has an impact on their quality of life.

Efficacy of the XEN45 Implant in Advanced to End-stage Glaucoma Patients

Purpose

To report the efficacy of the XEN45 implant in advanced to end-stage glaucoma patients, after a 6 months follow-up.

Methods

Retrospective, noncomparative electronic health record audit of patients who had undergone an XEN45 procedure. The main outcome measures were intraocular pressure (IOP) reduction and the number of antihypertensive medications. Secondary outcome measures were the rates of early postoperative complications. Complete and qualified success; failure and hypotony were defined according to the World Glaucoma Association guidelines (Shaarawy TM et al.). Needling rates and short-term complications were assessed and a subgroup analysis was performed.

Results

A total of 39 eyes with advanced to end stage-glaucoma were included. Twenty eyes (51%) had undergone combined cataract surgery and 19 (49%), the XEN45 procedure alone. Mean IOP decreased from 19.67 ± 7.87 mm Hg to 13.18 ± 6.09 mm Hg; the number of medications decreased from a median use of 4 (IQR 2–5) to 0 (IQR 0–1). Complete success was achieved in 24 (61.5%) of the eyes, qualified success in 10 (25.6%), and failure in five (12.82%). Needling was required in 15 (38.46%) of the eyes at 6 months. Choroidal detachment occurred in eight (20.51%) eyes, numerical hypotony (IOP ≤ 5 mm Hg) at day 1 was noted in seven (17.95%) eyes with a full resolution by 2 weeks.

Conclusion

In this short-term follow-up, we have seen that XEN45 is a viable, effective, and safe procedure utilized in advanced to end-stage glaucoma patients. Treating cases of significant hypotony using AC reformation with sulfur hexafluoride (SF6) is a safe and effective procedure.

How to cite this article

Hindi I, Berkowitz E, Waizer I, et al. Efficacy of the XEN45 Implant in Advanced to End-stage Glaucoma Patients. J Curr Glaucoma Pract 2022;16(2):84-90.

3-year Outcomes of XEN Implant Compared to Trabeculectomy, With or Without Phacoemulsification for Open-angle Glaucoma

PRCIS

Trabeculectomy surgery reduces the intraocular pressure (IOP) more than the XEN45 implant over 3 years. There is no difference in the number of antiglaucoma medications between the two procedures. The decision to perform either trabeculectomy or XEN45 implantation must be evaluated on a case-by-case basis, taking into account the high rate of needling of the XEN45.

PURPOSE

The aim of this study was to compare the differences between the efficacy and safety of the XEN45 implant and trabeculectomy (TRAB), either alone or in combination with phacoemulsification (PHACO), in patients with open-angle glaucoma (OAG) at 36 months.

METHODS

A retrospective, single-center and comparative study conducted on OAG patients that underwent XEN45 implantation or trabeculectomy from 2016 to 2018. Patients were divided into four groups: group 1 (XEN45 alone); group 2 (XEN45+PHACO); group 3 (TRAB alone); group 4 (TRAB+PHACO). For statistical purposes, groups 1 and 2 were combined (XEN45 implant), while groups 3 and 4 were also combined (TRAB surgery). Intraocular pressure (IOP), number of antiglaucoma medications (NOAM) and adverse events were evaluated. The main outcome measure was the reduction in IOP at 36 months postoperatively.

RESULTS

One hundred and thirty-four patients (134 eyes; 63 XEN45 and 71 TRAB) were included. The mean (95% CI) IOP reduction at the end of the study follow-up was-6.3 (-11.0 to -1.6 mmHg, P=0.025, XEN45 alone),-8.9 (-11.0 to-6.8 mmHg, P<0.001, TRAB alone),-2.5 (-4.5 to -0.4 mmHg, P=0.019, XEN45+PHACO), and-5.6 (-7.7 to-3.4 mmHg, P<0.001, TRAB±PHACO). The proportion of patients achieving an IOP≥6 and≤16 mmHg without treatment at the end of the 36-month follow-up were 50.8% (32/63) in the XEN45 implant and 49.3% (35/71) in the TRAB surgery group, P=0.863. The mean number of antiglaucoma medications was significantly reduced in all the study groups. The needling rate was 19% in XEN45 versus 5.6% in the TRAB group (P=0.030), and 2.81% and 36.6% of eyes in the TRAB group presented anterior chamber (AC) flattening and hyphema, respectively.

CONCLUSIONS

Trabeculectomy surgery lowered IOP significantly more than XEN45 implant with or without phacoemulsification over 3 years and had a significantly lower need for additional needling surgery. Both procedures reduce the number of antiglaucoma medications to a similar rate. These findings are relevant to the informed consent process and patient decisions for one procedure over the other.

Trabeculopuncture as a predictive test of distal outflow resistance in canal-based surgery

We investigated whether trabeculopuncture (TP) could detect distal outflow resistance to predict the outcome of canal-based glaucoma surgery such as ab interno trabeculectomy (AIT). These procedures have a high utilization in open angle glaucoma, but fail in eyes with an unidentified distal outflow resistance. We assigned 81 porcine eyes to two groups: trial (n = 42) and control (n = 39). At 24 h, four YAG-laser trabeculopunctures were placed nasally, followed by a 180° AIT at the same site at 48 h. The proportion of TP responders between both AIT groups was compared. Histology and outflow canalograms were determined. Both post-TP and post-AIT IOPs were lower than baseline IOP (p = 0.015 and p < 0.01, respectively). The success rates of TP and AIT were 69% and 85.7%, respectively. Sensitivity and specificity values of TP as predictive test for AIT success were 77.7% and 83.3%, respectively. The positive and negative predictive values were 96.6% and 38.5%, respectively. We conclude that a 10% reduction in IOP after TP can be used as a predictor for the success (> 20% IOP decrease) of 180° AIT in porcine eyes.

Degeneration of retina-brain components and connections in glaucoma: Disease causation and treatment options for eyesight preservation

Eyesight is the most important of our sensory systems for optimal daily activities and overall survival. Patients who experience visual impairment due to elevated intraocular pressure (IOP) are often those afflicted with primary open-angle glaucoma (POAG) which slowly robs them of their vision unless treatment is administered soon after diagnosis. The hallmark features of POAG and other forms of glaucoma are damaged optic nerve, retinal ganglion cell (RGC) loss and atrophied RGC axons connecting to various brain regions associated with receipt of visual input from the eyes and eventual decoding and perception of images in the visual cortex. Even though increased IOP is the major risk factor for POAG, the disease is caused by many injurious chemicals and events that progress slowly within all components of the eye-brain visual axis. Lowering of IOP mitigates the damage to some extent with existing drugs, surgical and device implantation therapeutic interventions. However, since multifactorial degenerative processes occur during aging and with glaucomatous optic neuropathy, different forms of neuroprotective, nutraceutical and electroceutical regenerative and revitalizing agents and processes are being considered to combat these eye-brain disorders. These aspects form the basis of this short review article.

Modified Trabeculectomy versus Glaucoma Drainage Implant Surgery: A Retrospective Comparative Study for Refractory Glaucoma Treatment

Purpose

To observe and compare the efficacy of modified trabeculectomy (TE), Ahmed drainage valve implantation (AGV), and EX-PRESS glaucoma shunt for refractory glaucoma (RG).

Methods

The study population of this retrospective study comprised 73 patients (76 eyes) who were suffering from RG and treated with modified TE, AGV, and EX-PRESS glaucoma shunt in our hospital from October 2012 to October 2020. The number of cases who underwent modified TE, AVG, and EX-PRESS glaucoma shunt was 36 (38 eyes). 19 (20 eyes), and 18 patients (18 eyes), respectively. The intraocular pressure (IOP), best-corrected visual acuity (BCVA), postoperative antiglaucoma medications, filter bubble morphology, anterior chamber depth (ACD), successful rate, and postoperative complications were recorded and statistically analyzed preoperative and 1 d, 1 w, 1 mon, 3 mon, 6 mon, and the end follow-up after operation.

Results

The BCVA differed insignificantly among the three cohorts before and 6 months after surgery. Compared to preoperative BCVA, the postoperative BCVA of the three groups had no statistical significance. An obvious reduction in IOP was observed in all the three group after operation (P < 0.05). An obvious decrease in antiglaucoma medications was observed after surgery in all the three groups (P < 0.05). The AGV group showed deeper ACD postoperatively, while no marked difference was found in postoperative ACD in the other two groups. The total success rates in modified TE and AGV groups were slightly higher than those in the EX-PRESS group. The three groups differed insignificantly in filter bubble morphology after operation.

Conclusion

Modified TE, AGV, and EX-PRESS glaucoma shunt showed equivalent efficacy for RG, which could validly reduce IOP and postoperative antiglaucoma medications. However, the success rates of modified TE and AGV were slightly higher than those of EX-PRESS glaucoma shunt in the last follow-up, and their complications were slightly less than those of the EX-PRESS glaucoma shunt.

Anterior segment imaging in minimally invasive glaucoma surgery - A systematic review

Minimally invasive glaucoma surgery (MIGS) has grown in popularity over the past decade. This systematic review explores the peri-operative and intraoperative application of anterior segment imaging to maximize the efficacy and safety of MIGS. A review of the PubMed, EMBASE and CINAHL databases was conducted, with inclusion criteria restricted to MIGS that had received United States Food and Drug Administration (FDA) premarket approval, FDA 510(K) premarket notification, or were listed as a class 1 device exempt from FDA approval or notification. 21 manuscripts from 21 unique studies were identified pertaining to MIGS devices including the XEN Gel Stent, Trabectome, iStent Inject, 1st-generation iStent and the Kahook Dual Blade (KDB). Anterior segment imaging modalities included anterior segment optical coherence tomography (AS-OCT), ultrasound biomicroscopy (UBM), aqueous angiography, OCT volumetric scans and in vivo confocal microscopy. Identification and evaluation of aqueous outflow pathways before and after MIGS have potential for improving patient preoperative patient selection and postoperative outcomes. Intraoperative imaging potentially provides the resolution needed for good visualization of angle anatomy and accurate evaluation of surgical endpoints in angle-based MIGS. Anterior segment imaging has been used to identify procedural complications, provide objective information on implant location in relation to surrounding anatomy, assess the post-implantation structural impact of MIGS devices and manage bleb failure and scarring. Technical difficulties in incorporating imaging modalities into the surgical microscope, variable quality of images and optical interference from ocular structures or surgical instruments are remaining barriers, which discourage the widespread clinical use of this technology.

Interim Analysis of STREAMLINE® Surgical System Clinical Outcomes in Eyes with Glaucoma

Purpose

To characterize the clinical outcomes of a novel ab interno minimally invasive procedure with the STREAMLINE^® Surgical System for creation of incisional goniotomies and canal of Schlemm viscodilation in eyes with mild to severe primary open-angle glaucoma (POAG).

Methods

In a prospective, single-arm, first-in-human case series, 20 eyes of 20 subjects with mild to severe POAG underwent creation of incisional goniotomies and canal of Schlemm viscodilation following phacoemulsification cataract extraction after washout of all intraocular pressure (IOP)-lowering medications. The angle surgery portion was performed with a single-use handpiece tipped with a microcannula that creates precise goniotomies through the trabecular meshwork into the canal of Schlemm and delivers a small volume of ophthalmic viscosurgical device directly into the canal via precise catheterization. Outcomes in this interim analysis included mean reduction in IOP and medications through 6 months of follow-up, as well as the proportion of eyes achieving IOP reduction ≥20% from baseline.

Results

At month 6, mean IOP reduction of ≥20% from baseline was achieved in 89.5% of eyes (17/19). Mean (standard deviation) medicated IOP at screening was 16.3 (3.6) mmHg and unmedicated baseline IOP (after washout) was 23.5 (2.5) mmHg. Mean IOP was significantly reduced from baseline through 6 months of follow-up to 14.7 (2.4) mmHg (p<0.001), representing an IOP reduction of 8.8 mmHg (36.9%). Overall, 57.9% (11/19) of eyes decreased dependence on IOP-lowering medications by at least one medication, and 42.1% (8/19) were medication free. Mean medication use was reduced from 2.0 (0.8) at screening to 1.1 (1.1) at 6 months (p<0.001). Three eyes had transient IOP spikes treated with topical medications.

Conclusion

The creation of incisional goniotomies and canal of Schlemm viscodilation safely and effectively reduced IOP and the need for IOP-lowering medications by both clinically and statistically significant magnitudes in eyes with mild to severe POAG undergoing concomitant phacoemulsification cataract extraction through the first 6 months of follow-up.

A New and Easier Approach to Preserflo MicroShunt Implantation

PRESERFLO™ MicroShunt is a new minimally invasive glaucoma surgical (MIGS) device, implanted with an ab externo approach, which drains the aqueous humor to the subconjunctival space. It has been designed as a safer and less invasive approach for treating medically uncontrolled primary open-angle glaucoma (POAG) patients. The classic way of MicroShunt implantation involves different key steps, which includes creating a small scleral pocket with a 1mm blade; passing a 25-gauge (25G) needle through the scleral pocket into the anterior chamber (AC); and subsequently flushing the stent with a 23-gauge (23G) thin-wall cannula. However, sliding the needle into the scleral pocket can create false passages, thus making the device’s threading more difficult. The purpose of the current paper is to propose a simplified implantation approach. Our method proposes to make the scleral tunnel by using directly the 25G needle and, at the limbus, this 25G needle is used to slightly depress the sclera and enter into the AC. The MicroShunt is subsequently assembled on a 23G cannula mounted on a 1mL syringe. The syringe can then be used to flush the device. Outflow can thus be confirmed immediately by seeing drops of aqueous humor leaking from the external opening of the stent. This new approach may have different potential advantages, such as better control of the site of entry, avoids wrong passages, reduces or eliminates the risk of aqueous humor sideway flow, facilitates a parallel path to the iris plane, and it is faster.

Does mitomycin-C concentration have any influence on XEN45 gel stent outcomes in a real-world setting?

BACKGROUND

To compare the effectiveness and safety of XEN45 implanted with mitomycin-C (MMC) 0.01% versus (vs) XEN45 implanted with MMC 0.02%.

METHODS

Retrospective and single-center study conducted on consecutive patients with open-angle glaucoma or ocular hypertension who underwent XEN45-implant, either alone or in combination with cataract surgery. The primary end-point was the mean change in intraocular pressure (IOP) from baseline to the last follow-up visit.

RESULTS

Fifty-five patients (63 eyes) were included. Thirty-seven (58.7%) eyes underwent surgery with MMC 0.01% and 26 (41.3%) ones with MMC 0.02%. In the overall study sample, the mean (standard error) IOP was significantly lowered from 17.6 (0.7) mm Hg at baseline to 12.6 (0.3) mm Hg at month 12. The IOP was significantly lowered from 17.3 (15.4 to 19.2) mm Hg and 17.9 (16.1 to 17.8) mm Hg at baseline to 12.3 (11.3 to 13.3) mm Hg and 13.1 (12.3 to 13.9) mm Hg at month 12 in the MMC 0.01% and MMC 0.02% groups, respectively; p < 0.0001 each. The mean number of ocular-hypotensive medications significantly decreased from 2.1 (1.9 to 2.3) at baseline to 0.2 (0.04 to 0.3) at month 12, p < 0.0001, with no significant differences between MMC 0.01% and MMC 0.02% groups, p = 0.5181. At month 12, 50 (80.6%) eyes had functioning blebs. Regarding safety, 18 (28.6%) eyes have experience adverse events.

CONCLUSION

XEN45, either alone or in combination with cataract surgery, showed a good effectiveness and safety profile. MMC dose had no influence on the IOP lowering, which may support the use of the lowest dose.

National Health Care data system analysis of glaucoma surgery activity in France in 2016

PURPOSE

To describe the glaucoma surgery offer in France in 2016.

METHODS

We used the French National Health Care System database to identify all medical procedures carried out in 2016. The study investigated the entire population aged 30 years and older that had undergone glaucoma surgery, alone or combined with another surgery. We calculated the incidence of surgeries per 100 000 inhabitants 30 years of age and older performed by ophthalmologists carrying out at least 50 procedures annually, the number of surgeons doing these surgeries, the mean age of these practitioners, and the number of surgeons older than 55 years.

RESULTS

In 2016, 16 854 glaucoma surgeries were performed in patients aged 30 years and older, for an incidence of 40.8 per 100 000 inhabitants aged 30 years and older. The most frequent procedure performed was trabeculectomy followed by non-penetrating deep sclerectomy (16.7 and 11.7, respectively, per 100 000 inhabitants 30 years of age and older). Private practice glaucoma surgery accounted for 47% of the activity of surgeons performing at least 50 surgeries per year and 60% of the total surgical activity. Of the private practice ophthalmologists performing at least 50 glaucoma surgery procedures per year, 58.5% were over 55 years of age, and 23.5% of public hospital ophthalmologists were over 55 years of age.

CONCLUSIONS

This study demonstrates that surgeons performing glaucoma surgeries are often older. It is necessary to take note of the country's educational capacity to ensure that the number of ophthalmological surgeons remains adapted to demand.

Three-dimensional heads-up surgery in ab-interno trabeculotomy: Image processing-assisted trabeculotomy

Purpose

We compared the visibility and surgeon posture between image-processing-assisted trabeculotomy (IP-LOT) using the NGENUITY^® 3D visual system and conventional microsurgery (microscope-assisted trabeculotomy; MS-LOT).

Methods

IP-LOT was performed for five pig eyes. The visibility of the trabecular mesh work was evaluated on images of the trabecular mesh work and the posterior surface of the cornea (Cor) obtained under three different conditions. Images were then analyzed using ImageJ^® to measure differences in luminance between the trabecular mesh work and Cor. IP-LOT was also performed for eleven human eyes, and the data were analyzed using the same approach as that used for the pig eyes. The length from the surgeon’s abdomen to the operative eye (working distance) during MS-LOT and IP-LOT was measured for 12 different surgeons and compared to evaluate surgeon posture.

Results

Image processing significantly increased the difference in luminance between the trabecular mesh work and Cor in both pig and human eyes (p < 0.05). Moreover, the working distance in IP-LOT was significantly shorter than that in MS-LOT (p < 0.05).

Conclusion

Our findings suggest that the NGENUITY^® 3D visual system provides better trabecular mesh work visibility than a normal microscope in conventional surgical methods, and it allows surgeons to operate without moving far from the operative eye.

Animal models and drug candidates for use in glaucoma filtration surgery: A systematic review

Glaucoma, a degenerative disease of the optic nerve, is the leading cause of irreversible blindness worldwide. Currently, there is no curative treatment. The only proven treatment is lowering intraocular pressure (IOP), the most important risk factor. Glaucoma filtration surgery (GFS) can effectively lower IOP. However, approximately 10% of all surgeries fail yearly due to excessive wound healing, leading to fibrosis. GFS animal models are commonly used for the development of novel treatment modalities. The aim of the present review was to provide an overview of available animal models and anti-fibrotic drug candidates. MEDLINE and Embase were systematically searched. Manuscripts until September 1st^, 2021 were included. Studies that used animal models of GFS were included in this review. Additionally, the snowball method was used to identify other publications which had not been identified through the systematic search. Two hundred articles were included in this manuscript. Small rodents (e.g. mice and rats) are often used to study the fibrotic response after GFS and to test drug candidates. Due to their larger eyes, rabbits are better suited to develop medical devices. Novel drugs aim to inhibit specific pathways, e.g. through the use of modulators, monoclonal antibodies, aqueous suppressants or gene therapy. Although most newly studied drugs offer a higher safety profile compared to antimetabolites, their efficacy is in most cases lower when compared to MMC. Current literature on animal models and potential drug candidates for GFS were summarized in this review. Future research should focus on refining current animal models (for example through the induction of glaucoma prior to undertaking GFS) and standardizing animal research to ensure a higher reproducibility and reliability across different research groups. Lastly, novel therapies need to be further optimized, e.g. by conducting more research on the dosage, administration route, application frequency, the option of creating combination therapies, or the development of drug delivery systems for sustained release of anti-fibrotic medication.

Therapeutic Drugs and Devices for Tackling Ocular Hypertension and Glaucoma, and Need for Neuroprotection and Cytoprotective Therapies

Damage to the optic nerve and the death of associated retinal ganglion cells (RGCs) by elevated intraocular pressure (IOP), also known as glaucoma, is responsible for visual impairment and blindness in millions of people worldwide. The ocular hypertension (OHT) and the deleterious mechanical forces it exerts at the back of the eye, at the level of the optic nerve head/optic disc and lamina cribosa, is the only modifiable risk factor associated with glaucoma that can be treated. The elevated IOP occurs due to the inability of accumulated aqueous humor (AQH) to egress from the anterior chamber of the eye due to occlusion of the major outflow pathway, the trabecular meshwork (TM) and Schlemm’s canal (SC). Several different classes of pharmaceutical agents, surgical techniques and implantable devices have been developed to lower and control IOP. First-line drugs to promote AQH outflow via the uveoscleral outflow pathway include FP-receptor prostaglandin (PG) agonists (e.g., latanoprost, travoprost and tafluprost) and a novel non-PG EP2-receptor agonist (omidenepag isopropyl, Eybelis^®). TM/SC outflow enhancing drugs are also effective ocular hypotensive agents (e.g., rho kinase inhibitors like ripasudil and netarsudil; and latanoprostene bunod, a conjugate of a nitric oxide donor and latanoprost). One of the most effective anterior chamber AQH microshunt devices is the Preserflo^® microshunt which can lower IOP down to 10–13 mmHg. Other IOP-lowering drugs and devices on the horizon will be also discussed. Additionally, since elevated IOP is only one of many risk factors for development of glaucomatous optic neuropathy, a treatise of the role of inflammatory neurodegeneration of the optic nerve and retinal ganglion cells and appropriate neuroprotective strategies to mitigate this disease will also be reviewed and discussed.

Efficacy and safety of Ab interno XEN gel implant after a failed filtering surgery

Purpose: To evaluate the efficacy and safety of Ab interno XEN gel stent in patients with open angle glaucoma who underwent a previous failed filtering surgery. Methods: A retrospective, observational, multi-centered and descriptive cohort study was conducted from January 2019 to February 2020 on patients with primary open angle glaucoma (POAG) who underwent XEN gel stent implant after a failed filtering surgical procedure. Main parameters evaluated were: changes in IOP measured with Goldmann applanation tonometer, number of anti-glaucomatous eye drops, postoperative complications, and necessity of further surgical procedures. The quantification of quality of life was obtained from the VFQ-25 questionnaire. A descriptive analysis based on pre- post- and intra-operative data was carried out. Results: In all patients included in the study (6 patients for a total of 7 eyes), IOP dropped during the follow up time. We found a mean percentage reduction of -41.5% at 9 months compared to the preoperative data (baseline). IOP lowered from 21.71 ± 4.64 mmHg to 9 ± 3,21 mmHg 1 day after the operation, 11 ± 3.21 at 1 week, 11.42 ± 1.81 mmHg at 1 month, 12.42 ± 3.10 mmHg at 3 months, 13.57 ± 3.45 at 6 months, 12.71 ± 1.79 at 9 months. In 71.4%, the procedure turned out to be complication free and only one case required needling of the bleb in order to achieve optimal intraocular pressure control. A total of 71.4% patients reached a medication free regimen with a percentage of reduction in the mean number of drugs needed of -88.9%. Conclusion: In our experience, XEN gel stent implant performed in Caucasian patients with POAG and a history of failed filtrating surgery, showed to be an effective and safe procedure.

XEN Gel Staining with Trypan Blue: A Simple and Effective Technique to Improve Device Visualization during Implantation

The Xen Gel Stent (Allergan, Irvine, CA, USA) is a hydrophilic collagen-based gelatin tube of 6 mm in length which creates a channel of communication between the anterior chamber and the subconjunctival space allowing aqueous humor outflow. XEN is an ab interno, minimally invasive, glaucoma surgery device which has a better safety profile and offers a less invasive way of lowering intraocular pressure. Unfortunately, one of its weaknesses is that visualization of the implant during surgery is difficult, and this difficulty may be exacerbated, for instance, by a subconjunctival hemorrhage. The purpose of this paper is to describe a simple and effective technique for improving device visualization (XEN 45 μm) during the implantation. How to cite this article: Ramovecchi V, Franco F, Barbera GR. XEN Gel Staining with Trypan Blue: A Simple and Effective Technique to Improve Device Visualization during Implantation. J Curr Glaucoma Pract 2021;15(3):161-163.

Endothelial Cell Density After XEN Implant Surgery: Short-term Data From the Italian XEN Glaucoma Treatment Registry (XEN-GTR)

PRECIS

XEN implant was associated with low endothelial cell density (ECD) reduction. In fact, when combined with phacoemulsification, the reduction in ECD was similar to that expected after phacoemulsification alone.

PURPOSE

The purpose of this study was to assess the impact of XEN implant, either alone or in combination with phacoemulsification, on ECD.

METHODS

Multicenter, prospective, observational study conducted on consecutive open-angle glaucoma patients, who were enrolled in the Italian XEN Glaucoma Treatment Registry and have complete endothelial cell count data at baseline and at 6 months after implantation. The primary endpoint was the mean percentage change in ECD between baseline and month 6.

RESULTS

The study included 108 open-angle glaucoma eyes (68 in the XEN-solo and 40 eyes in the XEN+phaco groups) and 60 control eyes (phaco-solo group). As compared with baseline, mean (95% confidence interval, CI) ECD reduction was -5.6% (-7.0% to -4.9%), -11.3% (-13.8% to -10.9%), and -13.0% (14.8% to -11.8%) in the XEN-solo, XEN+phaco, and phaco-solo groups, respectively (P=0.0004, <0.0001, and <0.0001, respectively). As compared with the XEN-solo group, the ECD reduction was significantly greater in the XEN+phaco group (mean difference=5.7%; 95% CI: 4.1%-7.3%, P<0.0001) and in the phaco-solo group (mean difference=7.4%; 95% CI: 5.7%-9.1%, P<0.0001). ECD reduction was similar in XEN+phaco and phaco-solo groups (P=0.9). In absolute terms, ECD reduction was significantly greater in the XEN+phaco (mean difference=169±306, P=0.021) and in the phaco-solo (mean difference=192±302, P=0.0022) groups than in the XEN-solo group.

CONCLUSIONS

The mean ECD reduction 6 months after XEN implantation was low. The ECD reduction in the XEN+phaco group was larger than in the XEN-solo group but was similar to that observed in the phaco-solo group.

12-month clinical outcomes of combined phacoemulsification and ab interno trabeculectomy for open-angle glaucoma in the United Kingdom

BACKGROUND/OBJECTIVES

To describe intraocular pressure (IOP) and ocular hypotensive medication outcomes of combined phacoemulsification and ab interno trabeculectomy with the Kahook Dual Blade (KDB; New World Medical, Inc, Rancho Cucamonga, CA) in adults with cataract and open-angle glaucoma (OAG).

SUBJECTS/METHODS

Retrospective chart review of existing medical records. Data collected included intraocular pressure (IOP) and IOP-lowering medication use preoperatively and through up to 24 months postoperatively. Paired t-tests were utilized to compare preoperative to postoperative mean IOP and mean medications used.

RESULTS

Data from 32 eyes of 26 subjects were analyzed. Subjects were predominantly Caucasian (25/26) had mean (standard error) age of 79.3 (1.2) years, and eyes had moderate-advanced OAG (mean visual field mean deviation -8.3 [1.3] dB). Mean IOP was 19.8 (0.8) mmHg at baseline and 15.5 (0.6) mmHg (p<0.0001) after mean follow-up of 11.5 (1.0) months; IOP reductions of ≥20% were achieved in 20/32 eyes (62.5%). Mean medication use declined from 2.4 (0.2) medications per eye at baseline to 0.5 (0.2) at last follow-up (p<0.0001); 23/32 eyes (71.9%) were medication-free at last follow-up. No vision-threatening complications were observed.

CONCLUSIONS

Combined phacoemulsification and ab interno trabeculectomy with the KDB safely provided mean IOP reductions of 21.7% and mean IOP medication reductions of 83% after mean follow-up of 12 months in eyes with moderate to advanced OAG. This procedure provides medication-independence in most eyes with statistically and clinically significant IOP reductions.

Surgical and Perioperative Considerations for the Treatment of Cataract in Eyes with Glaucoma: A Literature Review

Cataract surgery in the presence of glaucoma poses certain challenges that need to be addressed to offer the maximum benefit without complications. In this paper, we are reviewing the preoperative assessment, surgical options, the planning, and postoperative care. Cataract surgery can help reduce the intraocular pressure alone or combined with MIGS. When performed in patients with glaucoma, it can transiently increase the intraocular pressure and later on decrease the IOP to levels lower than the postoperative. The preoperative IOP and biometric characteristics are the main predictors of the postoperative course of IOP. The combination of cataract surgery with trabeculectomy remains controversial, in terms of best timing of each operation.

Early Experience with the New XEN63 Implant in Primary Open-Angle Glaucoma Patients: Clinical Outcomes

The new XEN63 implant is a minimally invasive glaucoma surgery device with limited experience in real life. This retrospective study included open-angle glaucoma patients who underwent XEN63 implant, either alone or in combination with cataract surgery. Primary endpoints were the intraocular pressure (IOP) at month 3 and the incidence of serious adverse events. Twenty-three eyes of 23 patients were included. Mean age was 67.8 ± 15.3 years and 15 (65.2%) were women. Mean IOP was significantly lowered from 27.0 ± 7.8 mmHg at baseline to 12.2 ± 3.4 mmHg at month 3 (p < 0.0001). Mean IOP lowering was 40.8 ± 23.5%, with 14 (60.9%) and 16 (69.6%) eyes achieving an IOP lowering ≥30% and ≥20% without hypotensive medication, respectively. The number of hypotensive medications (NHM) was significantly reduced from 2.27 ± 0.94 drugs at baseline to 0.09 ± 0.42 drugs at month 3, p < 0.0001. Four (17.4%) eyes had hypotony (IOP ≤ 6 mmHg) at postoperative day one, which was successfully resolved without sequelae. Four (17.4%) eyes had choroidal detachment (3 at day 7 and 1 at day 15), which was successfully resolved with medical treatment, at the month 1 visit. Three (13.0%) eyes required needling (mean time for needling 35.6 ± 9.7 days). XEN63 significantly lowered IOP and reduced the NHM, with a good short-term safety profile.

Safety and efficacy of incisional goniotomy as an adjunct with phacoemulsification in primary angle-closure glaucoma

PURPOSE

To evaluate the intraocular pressure (IOP)-lowering efficacy and safety of incisional goniotomy as an adjunct to phacoemulsification in primary angle-closure glaucoma (PACG) patients.

METHODS

Consecutive patients with PACG (high or borderline IOP) deemed fit for phacoemulsification were enrolled. After phacoemulsification, incisional goniotomy was performed with or without goniosynechialysis. Patient demographic profile, clinical data, and adverse events, if any, were analyzed during at least a 6-month follow-up period. Success was defined as IOP of 18 mm Hg or lesser with or without medications.

SETTING

Tertiary care Ophthalmic hospital.

DESIGN

Prospective interventional case series.

RESULTS

Of 46 eyes (38 patients) included, 69.6% eyes were classified as having advanced glaucoma. The mean treated IOP decreased by 7.3 ± 1.0 (SE) mm Hg (95% CI, 5.2-9.3) from 21.4 ± 6.6 to 14.2 ± 3.7 mm Hg at a mean duration of 11.7 ± 5.5 months (6-22 months) postoperatively (P < .001, paired t test). There was 66.6% reduction in median number of hypotensive medications (P < .001, Wilcoxon signed-rank test). Observed complications included hyphema (13 eyes [28%]), IOP spike (3 eyes [6.5%]), and cyclodialysis (1 eye [2.17%]). High treated IOP and number of medications were significantly associated with failure in univariate analysis (P < .05, Fisher exact test). The cumulative survival probability for qualified success at 22 months was 87.8% ± 0.07 (95% CI, 0.65-0.96).

CONCLUSIONS

Incisional goniotomy as an adjunct with phacoemulsification resulted in a significant and sustained reduction in IOP along with decrease in number of glaucoma medications in chronic PACG eyes, irrespective of the disease stage.

History, presence, and future of mitomycin C in glaucoma filtration surgery

PURPOSE OF REVIEW

Mitomycin C (MMC) is an alkylating agent with extraordinary ability to crosslink DNA, preventing DNA synthesis. By this virtue, MMC is an important antitumor drug. In addition, MMC has become the gold standard medication for glaucoma filtration surgery (GFS). This eye surgery creates a passage for drainage of aqueous humor (AqH) out of the eye into the sub-Tenon's space with the aim of lowering the intraocular pressure. A major cause of failure of this operation is fibrosis and scarring in the sub-Tenon's space, which will restrict AqH outflow. Intraoperative application of MMC during GFS has increased GFS success rate, presumably mainly by reducing fibrosis after GFS. However, still 10% of glaucoma surgeries fail within the first year.

RECENT FINDINGS

In this review, we evaluate risks and benefits of MMC as an adjuvant for GFS. In addition, we discuss possible improvements of its use by adjusting dose and method of administration.

SUMMARY

One way of improving GFS outcome is to prolong MMC delivery by using a drug delivery system.

[Micropulsed diode laser transscleral cyclophotocoagulation: An effective technique whose role remains to be defined]

Micropulse Transscleral Cyclophotocoagulation (MP-TSCP) is a recently developed cyclodestructive procedure less aggressive than conventional TSCP. In this study, we aimed to evaluate the safety and efficacy of MP-TSCP in a real-life setting.

MATERIAL AND METHODS

We retrospectively included all MP-TSCP cases performed in the Bicêtre Hospital Ophthalmology department between January 2017 and September 2019. Intraocular pressure (IOP) and hypotensive medications were recorded preoperatively, at month 1, 3, 6 and at the conclusion of follow-up, as well as postoperative adverse events. Success was defined as an IOP between 6 and 21mmHg with a decrease of at least one medication or an IOP reduction>20%.

RESULTS

Thirty eyes (28 patients) were included. Preoperative IOP was 27.2±10.6mmHg, with 3.5±0.6 hypotensive medications, the mean deviation on the Humphrey 24-2 visual field was -21.9±6.9dB, and 43% of eyes had a past history of filtering surgery. The mean follow-up was 13.5±8.1 months. Eleven patients (37%) had to be retreated with MP-TSCP during follow-up. At 3 and 6 months and at the conclusion of follow-up, the IOP was 18.3±7.3mmHg (-33%; P<0.0001), 22.5±11.8mmHg, (-17%; P=0.052), 22.7±12.0mmHg (-16,5%; P<0.050), respectively. The success rates were 57%, 50% et 53% at 3 months, 6 months and at the conclusion of follow-up, respectively. Severe adverse events included 3 cases of corneal ulcers and 2 cases of severe but transient ocular hypotony without visual impairment.

CONCLUSION

MP-TSCP is an effective procedure for severe and/or refractory glaucoma, but retreatments are required in more than one-third of cases. Further studies are warranted to define factors predictive of success and indications for retreatment.

Safety and efficacy of bilateral simultaneous XEN implant surgery: a pilot study

OBJECTIVE

To evaluate the efficacy and safety of the bilateral simultaneous XEN (BISIXEN) surgery in open-angle glaucoma patients.

METHODS

Retrospective analysis of a prospective data base conducted on uncontrolled glaucoma patients who underwent BISIXEN surgery. Primary endpoint measure was the incidence of sight-threatening complications. Secondary endpoints included intraocular pressure (IOP) reduction and in number of required antiglaucoma medications.

RESULTS

Ten patients (20 eyes) were included in the analysis. Median (95% confidence interval) follow-up was 12.0 (7.0-12.0) months, with 14 eyes having a follow-up of 12 months. No sight-threatening complications, such as endophthalmitis, retinal detachment, corneal decompensation, or intraocular hemorrhages were observed in any eye of study sample. Mean IOP decreased significantly from 25.2 (21.5-28.9) mm Hg at baseline to 15.1 (13.4-16.8) mm Hg at the last follow-up visit (p = 0.0001). Mean number of antiglaucoma medications was significantly reduced from 2.9 (2.5 to 3.3) drugs at baseline to 0.40 (0.00-0.70) at the end of the study (p < 0.0001). At the last study visit, 14 (70.0%) eyes had an IOP ≥ 6 and ≤ 18 mm Hg without treatment. Two eyes needed surgical revision and three ones needed a new glaucoma surgery: two underwent Ahmed valves (one eye with aniridia and the other previously operated on) and one underwent non-penetrating deep sclerectomy.

CONCLUSIONS

Bilateral simultaneous XEN implantation may be a feasible strategy in those patients with high anesthetic risk.

Glaucoma: Management and Future Perspectives for Nanotechnology-Based Treatment Modalities

Glaucoma, being asymptomatic for relatively late stage, is recognized as a worldwide cause of irreversible vision loss. The eye is an impervious organ that exhibits natural anatomical and physiological barriers which renders the design of an efficient ocular delivery system a formidable task and challenge scientists to find alternative formulation approaches. In the field of glaucoma treatment, smart delivery systems for targeting have aroused interest in the topical ocular delivery field owing to its potentiality to oppress many treatment challenges associated with many of glaucoma types. The current momentum of nano-pharmaceuticals, in the development of advanced drug delivery systems, hold promises for much improved therapies for glaucoma to reduce its impact on vision loss. In this review, a brief about glaucoma; its etiology, predisposing factors and different treatment modalities has been reviewed. The diverse ocular drug delivery systems currently available or under investigations have been presented. Additionally, future foreseeing of new drug delivery systems that may represent potential means for more efficient glaucoma management are overviewed. Finally, a gab-analysis for the required investigation to pave the road for commercialization of ocular novel-delivery systems based on the nano-technology are discussed.

Conjunctival bleb tearing by XEN gel stent after conjunctival compression sutures

PURPOSE

As minimally invasive glaucoma surgery devices emerge, newer complications are reported. XEN gel stent is safer than classic glaucoma surgery but may also lead to severe adverse effects as hypotony. Compression conjunctival sutures are a useful treatment for overfiltration hypotony after XEN gel stent implantation, but might force bleb tearing by the implant as it gets tightly close to the sutured conjunctiva. This complication has not been previously reported.

METHODS

We report a patient with overfiltration hypotony after XEN gel implantation. Conjunctival compression sutures and implant relocation ab interno were performed obtaining a good outcome. As conjunctiva got tightly close to the stent, the device eroded the bleb so leakage and implant extrusion were found.

RESULTS

Bleb reconstruction by conjunctival autograft was performed in order to avoid hypotony due to continuous conjunctival leakage.

CONCLUSION

Conjunctival compression sutures may be used for overfiltration control after XEN gel implantation but we must be aware of potential conjunctival damage due to implant erosion even if it is correctly positioned. Close follow-up and early suture release may be convenient in these patients.

Xen Gel Stent as a minimally invasive option for intraocular pressure control after DSAEK: A case study

PURPOSE

This case study describes the implantation of a Xen45 Gel Stent in a patient that had previously undergone Descemet stripping automated endothelial keratoplasty (DSAEK). Glaucoma might worsen after corneal transplant, and while medical treatment is the first-line therapy to achieve intraocular pressure (IOP) control, a surgical approach is required when medication does not reach the target IOP.

METHODS

In 2017, the patient underwent treatment in both eyes with ocular hypotensive eye drops for pseudoexfoliative (PXF) glaucoma. In May 2017, DSAEK was performed on the right eye because of the presence of a pseudophakic bullous keratopathy. An increase in IOP, resistant to medical treatment, was observed after the corneal transplant. In November 2017, a Xen45 Gel Stent was implanted.

RESULTS

The patient had a positive outcome with a Xen45 Gel Stent implant in surgical glaucoma treatment after DSAEK. The case demonstrated excellent postoperative IOP control, stable vision and a healthy ocular graft at short-term and long-term follow-ups.

CONCLUSION

Studies with larger numbers of patients in this particular form of therapy are required. Nevertheless, Xen45 Gel Stent implantation appears to be a promising option in preventing or limiting glaucoma in patients who have previously undergone DSAEK. It is a brief, minimally invasive procedure with reduced postoperative inflammation, faster visual recovery and a lower risk of graft damage or hypotony, even in the case of PXF glaucoma.

Minimally Invasive Surgery in Mild-to-Moderate Glaucoma Patients in Italy: Is It Time to Change?

Medical therapy is the first treatment choice for most patients with glaucoma; however, in a relevant proportion of patients, intraocular pressure (IOP) reduction is achieved with multi-therapy and/or high therapeutic doses. Conventional surgery is the standard alternative to medical therapy when this is not effective or not tolerated. Recently, selective laser trabeculoplasty (SLT) has been advocated as first-line therapy, and "minimally invasive glaucoma surgery" (MIGS) has been developed as safer and less traumatic surgical intervention for patients with glaucoma. Schlemm's canal surgery has emerged as one of the approaches with the most favorable risk-benefit profile for glaucoma patients in need of cataract surgery. However, despite the promising results, use of MIGS in Italy has been extremely low. We aimed to investigate the reasons of the lower-than-expected use of Schlemm's canal-based MIGS devices in Italy, share our perspective on their potential place in therapy, and give practical suggestions to improve the management of glaucoma patients.

XEN 63 gel stent device in glaucoma surgery: A 5-years follow-up prospective study

PURPOSE

To evaluate the efficacy and safety of the XEN63 Gel Stent in patients with open-angle glaucoma (OAG).

METHODS

Prospective, nonrandomized, open-label, not-controlled, and single center study conducted on OAG patients who underwent glaucoma surgery with the XEN63 gel stent. The main outcome measure was intraocular pressure (IOP). Secondary end-points were number of topical ocular hypotensive drugs, percentage of patients achieving an IOP reduction ⩾20%, and treatment-related adverse events.

RESULTS

Eleven eyes from 11 patients were treated with XEN 63. Mean (95% confidence interval, CI) age was 78.8 (73.7-85.9). Two eyes (18.2%) underwent XEN alone, while nine eyes (81.8%) underwent combined XEN + cataract extraction (phacoemulsification). The median (95% CI) IOP reduction was 17.7% (-13.3% to 34.9%). At the end of the study 9 (81.8%) eyes had an IOP ⩽ 18 mm Hg, six of them without treatment. Six (54.6%) eyes obtained an IOP reduction ⩾20%. Compared to baseline, there was a significant reduction in the number of ocular hypotensive drugs (p = 0.0039). There were no treatment-related serious adverse events. Early postoperative complications included diplopia (1), blood in endothelium (2), ocular hypertension (1), corneal edema (1), folds in Descemet's membrane (1), and contact between the implant and the iris (1). All the adverse events were successfully solved without sequalae. One eye required bleb needling.

CONCLUSION

The XEN63 implant significantly reduced both IOP and the amount of ocular hypotensive medications while maintaining a good safety profile.

Efficacy and safety of XEN 45 gel stent alone or in combination with phacoemulsification in advanced open angle glaucoma patients: 1-year retrospective study

AIM

To assess the effectiveness of the XEN 45 gel stent, either alone or combined with cataract surgery, in advanced stage open angle glaucoma (OAG) patients.

METHODS

Retrospective and single-center study conducted on consecutive OAG patients who underwent a XEN 45 gel stent implantation surgery, between July 2017 and September 2018. The primary efficacy end-point was the mean intraocular pressure (IOP) reduction at the end of the follow-up period. Success was defined as an IOP reduction of at least 20% and an IOP value ≤18 mm Hg without (complete) or with (qualified) hypotensive medication.

RESULTS

Seventy-four patients (80 eyes) were included in the study. In the overall study sample, XEN implant significantly reduced IOP from 21.0 (19.8 to 22.1) mm Hg at baseline to 9.3 (8.2 to 10.4), 10.7 (9.6 to 11.9), 13.4 (12.2 to 14.7), 14.5 (13.6 to 15.4), 14.7 (13.8 to 15.6), and 14.7 (13.9 to 15.4) mm Hg at 1d, 1wk, 1, 3, 6, and 12mo of follow-up, respectively (P<0.0001 each). In the overall study population, at the end of the study the mean IOP reduction was 27.4% (23.3% to 31.5%). Adjusted IOP reduction was similar in XEN and XEN+phacoemulsification groups [30.0 (23.4 to 36.4) mm Hg vs 24.8 (18.4 to 31.2) mm Hg, respectively, P=0.2939]. At the last follow-up visit, 52 (65.0%) eyes were considered success, 29 (36.3%) eyes as complete success and 23 (28.7%) as qualified success. Mean number of hypotensive medications was significantly reduced from 2.8 (2.7 to 3.0) at baseline to 1.1 (0.8 to 1.3), P<0.0001. Kaplan-Meier survival analysis did not find any difference in the success rate between XEN and XEN+PHACO, mean hazard ratio 0.56, 95%CI 0.26 to 1.23; P=0.1469. Needling was performed in 7 (8.8%) eyes at months 1 (n=3); 3 (n=2); 4 (n=1) and 11 (n=1). Eleven (13.8%) eyes presented adverse events.

CONCLUSION

XEN implant, either alone or in combination with phacoemulsification, significantly reduced the IOP and the number of hypotensive medications in patients with OAG in advanced stage.

Chronic Granulomatous Inflammation after CyPass® Implantation

A 65-year-old patient suffering from pseudoexfoliation glaucoma and multiple previous surgeries at the right eye underwent CyPass® explantation 19 months after CyPass® Micro-Stent implantation due to chronic inflammation in the an-terior chamber. Histologically, a foreign body granuloma around and in the CyPass® implant was found. We conclude that patients with previous multiple glaucoma surgeries should not undergo CyPass® Micro-Stent implantation.

Comparing Medium-Term Clinical Outcomes following XEN® 45 and XEN® 63 Device Implantation

Purpose

To evaluate medium-term clinical outcomes with XEN® 45 or XEN® 63 Gel Stent (Allergan, Dublin, Ireland) for treatment of primary open angle glaucoma (POAG). Materials and Methods. Retrospective, descriptive, and observational study involving 40 patients implanted with a XEN® 45 Gel Stent and 34 implanted with a XEN® 63 Gel Stent who had undergone POAG surgery and had been followed up and controlled between 12 and 36 months.

Results

IOP dropped from 18.02 ± 5.23 mmHg preop to 13.81 ± 1.88, 14.80 ± 2.23, and 14.62 ± 1.90 at 1, 2, and 3 years after surgery (p < 0.001) consecutively with XEN® 45 and from 19.00 ± 6.11 mmHg preop to 15.47 ± 2.45, 14.66 ± 2.45, and 15.46 ± 2.48 at 1, 2, and 3 years after surgery (p < 0.001) with XEN® 63. The number of drugs used by patients to treat their glaucoma decreased after undergoing surgery in both groups. Within the XEN® 45 group, mean changes at 1 year, 2 years, and 3 years amounted to 70%, 74.3%, and 37.5%, respectively, whereas within the XEN® 63 group, the mean reduction was 75%, 79.8%, and 71.9%. When comparing the outcomes for two groups, the differences did not prove to be statistically significant. More than 90% of the procedures included in the study (using either gel-stent device) were completed without any noteworthy complications.

Conclusion

POAG surgical procedures with either XEN® 45 or XEN® 63 Gel Stent implantation could be a safe and effective treatment approach.