A Prospective Randomized Trial Comparing Hydrus and iStent Microinvasive Glaucoma Surgery Implants for Standalone Treatment of Open-Angle Glaucoma: The COMPARE Study

Imaging of aqueous outflow in health and glaucoma. Justifying the re-direction of aqueous

A wave of less invasive surgical options that target or bypass the conventional aqueous outflow system has been incorporated into routine clinical practice to mitigate surgical risks associated with traditional glaucoma drainage surgery. A blanket surgical approach for open-angle glaucoma is unlikely to achieve the desired IOP reduction in an efficient or economical way. Developing a precise approach to selecting the most appropriate surgical tool for each patient is dependent upon understanding the complexities of the aqueous outflow system and how devices influence aqueous drainage. However, homoeostatic control of aqueous outflow in health and glaucoma remains poorly understood. Emerging imaging techniques have provided an opportunity to study aqueous outflow responses non-invasively in clinic settings. Haemoglobin Video Imaging (HVI) studies have demonstrated different patterns of aqueous outflow within the episcleral venous system in normal and glaucomatous eyes, as well as perioperatively after trabecular bypass surgery. Explanations for aqueous outflow patterns remain speculative until direct correlation with findings from Schlemm's canal and the trabecular meshwork are possible. The redirection of aqueous via targeted stent placement may only be justifiable once the role of the aqueous outflow system in IOP homoeostasis has been defined.

Interventional glaucoma: Rethinking glaucoma treatment paradigms in the Asian context

The emergence and advancements in glaucoma treatment modalities have expanded the options available to clinicians, particularly for patients with mild to moderate glaucoma. These newer approaches, such as minimally invasive glaucoma surgeries and selective laser trabeculoplasty, aim to effectively reduce intraocular pressure and potentially improve patient outcomes. 'Interventional glaucoma' reflects a paradigm shift in the glaucoma management strategies and involves adopting a more proactive approach and offering these interventions at earlier stages of the disease. By administering them earlier, these interventions can modulate the course of the disease and prevent significant visual loss, thereby reducing or delaying the need for subsequent filtering surgeries. In this review, we discuss the need for interventional glaucoma and the evidence behind these interventional techniques. We highlight key considerations that should be considered when implementing interventional glaucoma approaches in the Asian context.

Comparison of the Intraocular Pressure-Lowering Effect of Minimally Invasive Glaucoma Surgery (MIGS) iStent Inject W and Hydrus-The 12-Month Real-Life Data

Background/Objectives: To compare the efficacy and safety of Hydrus® Microstent and iStent inject® W implants, in combination with phacoemulsification, for lowering intraocular pressure (IOP) in patients with glaucoma in a real-world clinical setting. Methods: This retrospective, single-center study analyzed medical records of glaucoma patients who underwent either Hydrus® Microstent or iStent inject® W implantation combined with cataract surgery at the University Hospital Muenster, Germany. Key outcome measures included absolute and relative IOP reduction, reduction in topical antiglaucoma medication use, overall success rate, and complications. A total of 32 eyes were analyzed, 16 in each treatment group, with a 12-month follow-up. Results: Both groups demonstrated significant postoperative IOP reduction (Hydrus: p < 0.001; iStent inject® W: p = 0.032). The Hydrus group achieved significantly greater relative IOP reduction compared to the iStent inject® W group (p = 0.043). The Hydrus group also showed a significant reduction in daily antiglaucoma medication use (p = 0.002), whereas the iStent inject® W group did not achieve statistical significance in this regard (p = 0.054). The overall success rate was higher in the Hydrus group (38%) than in the iStent inject® W group (13%), though the difference was not statistically significant (p = 0.102). No device-related complications were observed in either group. Conclusions: The Hydrus® Microstent demonstrated superior IOP reduction and a more significant reduction in the need for antiglaucoma medications compared to the iStent inject® W in a real-world setting. These findings support the use of the Hydrus implant as an effective and safe micro-invasive glaucoma surgery (MIGS) option for patients with mild to moderate POAG. Further studies with larger patient populations and long-term follow-up are warranted to confirm the efficacy in patients with PEX and advanced glaucoma.

Minimally invasive glaucoma surgery: comparison of Hydrus microstent with iStent inject in primary open-angle glaucoma

BACKGROUND

To evaluate and compare the efficacy of a single Hydrus and double iStent inject both combined with cataract surgery for the treatment of primary open-angle glaucoma (POAG).

METHODS

The study was designed as a prospective comparative case series. Patients with POAG undergoing trabecular microbypass stent insertion in addition to cataract surgery were recruited and consent was obtained. Baseline demographic information and preoperative, intraoperative and postoperative outcomes including intraocular pressure (IOP), visual acuity and topical glaucoma medication use were recorded and analysed. Treatment outcomes were analysed after propensity score matching to adjust for baseline differences between the two groups. Primary success was defined as an IOP of ≤18 and ≥20% IOP reduction at 12 months; other outcomes included IOP ≤15 mm Hg and ≤21 mm Hg. These were measured against complete success (no medications) and qualified success (one or more medications).

RESULTS

The study comprised 85 eyes in the Hydrus group and 100 eyes in the iStent inject group at commencement, with 12-month follow-up for 85 and 78, respectively. When correcting for baseline differences between the two groups using propensity score matching, Hydrus eyes were not more likely to achieve primary success (average treatment effect -0.79, p=0.15).

CONCLUSION

After adjusting for baseline differences, there was no statistically significant difference between combined Hydrus microstent implantation and cataract surgery when compared with the iStent inject in reducing IOP at 12-month follow-up. This study was limited by statistically significant baseline differences between the two study groups, adjusted for with propensity score matching.

Special Commentary: Reporting Clinical Endpoints in Studies of Minimally Invasive Glaucoma Surgery

Minimally invasive glaucoma surgery (MIGS) refers to a group of procedures generally characterized by an ab interno approach, minimal trauma to ocular tissue, moderate efficacy, an excellent safety profile, and rapid recovery. The number of MIGS procedures continues to increase, and their use has become widespread among glaucoma and cataract specialists. Standardization of the methodology and reporting of clinical endpoints in MIGS investigations enhances interpretation and comparison across different studies. The assessment of surgical interventions not only should consider statistical significance, but also whether the outcome is meaningful to patients. Minimal clinically important difference (MCID) is defined as the smallest change in a treatment outcome that is considered beneficial for an individual patient and prompts a change in their clinical management. Expert consensus is an accepted approach to determine the MCID. The American Academy of Ophthalmology's Glaucoma Preferred Practice Pattern® Committee is an expert panel that develops guidelines identifying characteristics and components of quality eye care. The Committee recommends that the cumulative probability of surgical success at 2 years with Kaplan-Meier survival analysis be used as the primary efficacy endpoint in MIGS studies. The Committee suggests that surgical success for standalone MIGS be defined as intraocular pressure (IOP) of 21 mmHg or less and reduced by 20% or more from baseline without an increase in glaucoma medications, additional laser or incisional glaucoma surgery, loss of light perception vision, or hypotony. The proposed MCID for the cumulative probability of success of standalone MIGS at 2 years is 50%. The panel recommends that surgical success for MIGS combined with cataract extraction with intraocular lens implantation (CE-IOL) be defined as a decrease in glaucoma medical therapy of 1 medication or more from baseline without an increase in IOP or IOP of 21 mmHg or less and reduced by 20% or more from baseline without an increase in glaucoma medications, additional laser or incisional glaucoma surgery, loss of light perception vision, or hypotony. The suggested MCID for the cumulative probability of success for MIGS combined with CE-IOL at 2 years is 65%. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Efficacy and safety of penetrating canaloplasty versus ab externo canaloplasty for primary open-angle glaucoma: A randomized controlled trial

PURPOSE

To report the 2-year efficacy and safety of penetrating canaloplasty versus ab externo canaloplasty for the treatment of primary open-angle glaucoma (POAG).

SETTING

A single surgical site in China.

DESIGN

This was a prospective, randomized controlled trial. POAG patients were randomly assigned to the penetrating canaloplasty or ab externo canaloplasty group.

METHODS

This study enrolled POAG patients who underwent penetrating canaloplasty or ab externo canaloplasty randomly. Surgical success, intraocular pressure (IOP), number of glaucoma medications, and surgical complications were evaluated until 24 months post-operatively. Surgical success was defined as 6 mmHg ≤ IOP ≤21 mmHg with an IOP reduction ≥20%, which included qualified success (with or without medications) and complete success (without medications).

RESULTS

A total of 52 eyes (45 patients) were randomly assigned to one of two groups: the penetrating canaloplasty group (PCP, n = 26) or the ab externo canaloplasty group (CP, n = 26). The probabilities of qualified success and complete success were 92.3% and 76.9%, respectively, in the PCP group and 64.1% and 52.1%, respectively, in the CP group at 24 months (p = 0.013, p = 0.042, log-rank test). The mean IOP decreased from 30.8 ± 10.7 and 28.6 ± 11.8 mmHg to 14.1 ± 3.3 mmHg in the PCP group and 22.1 ± 13.6 mmHg in the CP group at year two (p = 0.007). The PCP group also received fewer medications (0.2 ± 0.5) than did the CP group (0.7 ± 1.2) at year two (p = 0.038). Post-operative complications were similar, and the most common complications were transient IOP elevation and hyphema in the PCP group (42.3%, 46.2%) and the CP group (38.5%, 23.1%) (p > 0.05).

CONCLUSIONS

Compared to ab externo canaloplasty, penetrating canaloplasty had a greater surgical success rate and better IOP reduction with a comparable rate of complications.

[Insights into the practice of minimally invasive glaucoma surgery]

Minimally invasive glaucoma surgeries (MIGS) offer an alternative approach, aiming to be both safe and effective. Defined by their ab interno technique, which avoids creating a bleb, MIGS procedures seek to reduce intraocular pressure (IOP) by enhancing the outflow pathways of aqueous humor. Techniques include stenting, incisions, and excisions of the trabecular meshwork, canaloplasty of Schlemm's canal, and drainage implants that enhance uveoscleral outflow to the subchoroidal space. Many of these methods show promise in reducing intraocular pressure and decreasing the need for medication. Nevertheless, with the increasing number of these procedures and devices on the market, it is difficult to keep track of the evidence supporting these methods. Although randomized controlled trials exist for many of the new MIGS procedures, the sample sizes are often small, and follow-up periods are limited. Additionally, there are no randomized controlled trials comparing different MIGS techniques or MIGS with traditional glaucoma surgery. These factors continue to make it challenging to select the most appropriate method for each patient. Therefore, it is essential to persist in conducting randomized controlled long-term studies to gain a deeper understanding of the applications of MIGS.

Minimally Invasive Glaucoma Surgery

BACKGROUND

Approximately 1.4 % of the German population aged 35 to 74 suffers from glaucoma, which is one of the more common causes of blindness. The only evidence-based treatment option at present is lowering the intraocular pressure. Modern minimally invasive surgical procedures hold out the prospect of lowering the intraocular pressure without the risk of serious complications.

METHODS

This is a selective review of pertinent publications retrieved by a search in PubMed, including randomized, controlled trials and meta-analyses.

RESULTS

The intraocular pressure can be lowered with eyedrops, laser procedures, and surgery. Trabeculectomy is the reference standard in glaucoma surgery but leads to complications in 3-15% of cases. In minimally invasive glaucoma surgery, very small stents can be implanted to lower the intraocular pressure. These proce - dures have a better safety profile but are only indicated for mild or moderate glaucoma. The Kahook Dual Blade, iStent inject, and Hydrus Microshunt procedures have been studied in randomized, controlled trials. An additional pressure-lowering effect beyond that of cataract surgery was demonstrated only for the latter two procedures (1.9 mmHg and 1.8 mmHg, respectively). Other procedures have only been investigated in cohort studies to date; a pressure-lowering effect was found for some of them. Moreover, iStent and Hydrus Microshunt have been found to slow the progression of visual field defects.

CONCLUSION

There are robust data documenting the effect of iStent and Hydrus Microshunt in lowering the intraocular pressure and lessening the need for eyedrops. High-quality controlled trials are still needed to test the efficacy of other procedures.

Long-term outcomes of phacoemulsification with iStent inject® implantation in narrow angle glaucoma

PURPOSE

To assess the outcomes of phacoemulsification with iStent inject implantation (phaco-iStent) in patients with narrow angle glaucoma (NAG) at a single tertiary eye centre.

DESIGN

Retrospective clinical cohort study.

METHODS

Patients undergoing phaco-iStent for NAG between March 2018 and October 2020 under the glaucoma team at a tertiary referral hospital were included. Data was analysed from a surgical outcome database. Primary outcomes included postoperative change in the mean intraocular pressure (IOP) and medications. Success was defined at two IOP cut-off points:≤21mmHg and≤15mmHg with (qualified) or without (complete) drops. Failure was repeat glaucoma surgery or loss of light perception (LP).

RESULTS

Fifty-seven eyes with a mean follow-up of 32months (range 12months to 36months) were included. Mean IOP changed from 19.7±4.2mmHg (range 12-28) to 14.0, 14.9 and 14.6 at 12, 24 and 36months. Drops reduced from 2.2±0.7 to 0.92±1.24 at the last follow-up. Complete success for an IOP≤21mmHg was 49%, 39%, 37% and qualified success was 96%, 92% and 95% at 12, 24 and 36months. An IOP≤15mmHg (qualified) was achieved in 74%, 58%, 54% at 6, 12, 24 and 36months. Three patients (5%) required further glaucoma surgery, one patient underwent selective laser trabeculoplasty and one patient requiring peri-ocular steroid treatment due to persistent cystoid macular oedema. There were no other long-term complications.

CONCLUSION

Phacoemulsification with iStent inject is a safe and effective surgical option in the management of narrow angle glaucoma.

Surgical Synergy in Primary Open-Angle Glaucoma: Assessing Safety and Efficacy of Hydrus, iStent, and Gonioscopy-Assisted Transluminal Trabeculotomy in Glaucoma Management

Background/Objectives: This paper will compare the outcomes-safety and efficacy-of three minimally invasive glaucoma surgeries (MIGSs),the Hydrus Microstent, iStent, and Gonioscopy-Assisted Transluminal Trabeculotomy (GATT), for intraocular pressure (IOP) reduction in patients with primary open-angle glaucoma (POAG). Methods: A literature search of Ovid Medline and Embase identified studies evaluating the Hydrus, iStent, and GATT. Data on IOP reduction, medication use, and complications were analyzed. Results: Studies show the Hydrus, iStent, and GATT reduce IOP and medication burden in POAG patients, with some complications. For the Hydrus, studies showed 37.09% (27.5 ± 4.4 to 17.3 ± 3.7 mmHg) and 25% (16.8 to 12.6 mmHg) IOP reduction. Meanwhile, medication burden decreased from 2.5 ± 0.7 to 1.0 and from 2.1 to 1.15. For the iStent, studies showed a 36.39% (21.1 to 13.4 mmHg) and 8.19% (17.1 to 15.7 mmHg) IOP drop. Medication burden decreased from 2.87 to 1.24 and from 1.7 to 0.26. For GATT, studies showed a 49.33% (27.70 ± 10.30 to 14.04 ± 3.75) and 39.09% (26.40 ± 6.37 to 16.08 ± 2.38) IOP drop. Medication burden reduced from 3.73 ± 0.98 to 1.82 ± 1.47 and from 3.12 ± 0.80 to 0.45 ± 0.96. Conclusions: The Hydrus, iStent, and GATT are effective alternatives to trabeculectomy for mild to moderate POAG. They reduce and control IOP and dependence on medications with manageable safety profiles. In all three options, there were some clinically significant complications based on the p-value. For the Hydrus, it was PAS. For the iStent, they were PAS, FB sensation, IOP spikes, and microhyphema. For GATT, it was IOP spikes. However, further long-term studies, especially randomized controlled trials, are needed to support these results.

Meta-Analysis of MINIject vs. Two iStents as Standalone Treatment for Glaucoma with 24 Months of Follow-Up

Background: This study compares the long-term intraocular pressure (IOP)-lowering efficacy of standalone MINIject (iSTAR Medical, Belgium) suprachoroidal implantation and two iStent (Glaukos, CA, USA) trabecular bypass implantation using a systematic review and meta-analysis. Methods: Systematic review of standalone implantation of MINIject or iStent inject with at least 24 months of follow up. The mean and standard deviation of IOP and the number of IOP-lowering medications at baseline and at 24 months were extracted. Weighted estimates of the outcome variables were calculated using random-effects meta-analysis models. Heterogeneity in the outcome measures among the studies was quantified using I². Results: Seven studies (three studies for MINIject and four for iStent) comprising 280 eyes were included. At 24 months, there was a greater reduction in IOP from baseline in the MINIject vs. two iStent cohorts (-9.57 vs. -4.92 mmHg, p = 0.03). The change from baseline in mean medication use was -1.00 with MINIject and -0.56 medications with iStent (p = 0.26). The mean percentage IOP reduction at 24 months ranged from 36.3-42.2% with MINIject compared to 5.2-40.7% with iStent, with greater variability in mean change from baseline in IOP observed in the iStent group (I2 = 96.5% vs. 0%). The most frequent adverse events for MINIject were anterior chamber inflammation, best-corrected visual acuity (BCVA) loss, hyphema, and conjunctival hemorrhage, and for iStent, these were device obstruction, BCVA loss, IOP spike, and cataract progression. Conclusions: While both MINIject and iStent inject devices resulted in significant reductions in IOP and IOP medication use, standalone MINIject may provide a greater and more consistent reduction in IOP.

Bio-Interventional Cyclodialysis and Allograft Scleral Reinforcement for Uveoscleral Outflow Enhancement in Open-Angle Glaucoma Patients: One-Year Clinical Outcomes

Background

To evaluate the one-year safety and effectiveness of bio-interventional cyclodialysis and scleral reinforcement in open-angle glaucoma (OAG) patients undergoing cataract surgery.

Methods

An ab-interno approach was used to create a sectoral cyclodialysis in OAG patients who were prospectively followed in a consecutive case series. Subsequent visco-cycloplasty with scleral reinforcement using homologous minimally modified allograft scaffold was completed to maintain patency of the cyclodialysis reservoir and increase uveoscleral outflow. Outcomes were mean medicated IOP and mean number of IOP-lowering medications. Safety outcomes were adverse events (AEs) and best-corrected visual acuity (BCVA) changes.

Results

Successful cyclodialysis and allograft bio-scaffold reinforcement was achieved in 117 eyes. There was minimal intraoperatie bleeding and few post-operative adverse events. At baseline, mean BCVA was 0.48 (95% CI: 0.42‒0.54; 20/40 Snellen) and mean ± SD medicated IOP was 20.2 ± 6.0 mmHg on 1.4 ± 1.3 IOP-lowering medications. At 12 months, there was a 27.1% reduction from baseline mean medicated IOP. In eyes with medicated baseline IOP > 21 mmHg (n = 45), there was a 39.7% paired IOP reduction at 12 months with a concurrent reduction in the mean number of IOP lowering medications to 0.8 ± 0.9 which were statistically significant (p < 0.01). For all eyes, 81.9% achieved a medicated IOP ≤ 18 mmHg with no increase in medications at 12 months. To achieve target IOP control, secondary glaucoma surgery was performed in 3.2% of the cases.

Conclusion

IOP lowering through uveoscleral outflow enhancement can be achieved by means of a bio-interventional cyclodialysis procedure with allograft scleral reinforcement.

Refractive Outcomes Following Combined Cataract and Microinvasive Glaucoma Surgery

PURPOSE

To compare refractive outcomes in eyes undergoing cataract extraction (CE) alone, CE with goniotomy (CE/goniotomy), and CE with Schlemm's canal stent (CE/SCS) insertion.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Eyes from the Bascom Palmer Glaucoma Repository undergoing CE/goniotomy, CE/SCS insertion, or uncomplicated CE alone between July 2014 and February 2022 were identified.

METHODS

Refraction data were analyzed at postoperative month (POM) 1 and 6 with Kruskal-Wallis and Dunn's tests. Anisometropia was defined as a spherical equivalent (SE) difference of ≥2D.

MAIN OUTCOME MEASURES

The primary outcome was mean refraction at POM1 and POM6 across the 3 surgical groups. Secondary outcomes were comparisons of refraction and visual acuity (VA) among different goniotomy and Schlemm's canal stent (SCS) devices, as well as incidence of anisometropia.

RESULTS

A total of 8360 eyes (150 CE/goniotomy, 395 CE/SCS, and 7815 CE alone) from 6059 patients were analyzed. At POM1, mean SE in the CE/goniotomy, CE/SCS, and CE alone groups was -0.36 ± 0.91D, -0.31 ± 0.85D, and -0.39 ± 0.88D respectively (P = 0.019). Mean logarithm of the minimum angle of resolution VA was 0.10 ± 0.20, 0.08 ± 0.19, and 0.14 ± 0.26 respectively (P = 0.002, CE/SCS vs. CE alone). No statistically significant differences were noted at POM6. Anisometropia occurred at POM1 in 2 patients (13.3%) in the CE/goniotomy-CE group, 1 patient (3.2%) in the CE/SCS-CE group, and 184 patients (4.9%) in the CE-CE group (P = 0.217). At POM6, mean SEs were -0.38 ± 0.97D (CE/goniotomy), -0.35 ± 0.81D (CE/SCS), and -0.40 ± 0.91D (CE alone; P = 0.473). No significant differences in overall refractive outcomes were observed with different SCS or goniotomy devices. Among primary open-angle glaucoma/normal-tension glaucoma eyes, mean SE at POM1 was -0.36 ± 0.73D (CE/goniotomy), -0.24 ± 0.84D (CE/SCS), and -0.45 ± 0.81D (CE alone; P < 0.001).

CONCLUSIONS

Concurrent SCS insertion or goniotomy with CE was associated with some statistically significant differences in postoperative refraction and VA, although these small magnitude differences were unlikely to be clinically meaningful.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references in the Footnotes and Disclosures at the end of this article.

Effectiveness and biocompatibility of a novel Schlemm's canal microstent for glaucoma management

To evaluate the effectiveness and biocompatibility of Wistend, a novel Schlemm's canal (SC) microstent made of Nitinol designed to improve aqueous humor outflow. New Zealand white (NZW) rabbits were divided into blank, sham-operated and Wistend groups. ICare® Tonovet Plus®, swept-source optical coherence tomography (SS-OCT), slit lamp biomicroscopy, retinal camera and scanning electron microscopy (SEM) were used for preoperative and postoperative observations. Hematoxylin and Eosin (H&E) tissue staining was adopted for biocompatibility. A significant difference in intraocular pressure (IOP) between the Wistend group and the control groups was observed during the six-month follow-up. SS-OCT identified arc line internal reflections within the SC in the anterior chamber angle. Conjunctival congestion and edema gradually diminished in the early stages. No corneal vascularization, no anterior chamber inflammatory response and no significant tissue reactions were noted in any groups. SEM showed the Wistend's windows and orifices remained clear, encircled by minimal incidental ocular tissue and free from blockage. Histopathological examination revealed no discernible differences between the Wistend-implanted and sham-operated eyes. These in vivo studies demonstrate the effectiveness and biocompatibility of the microstent. Our findings suggest a promising potential for Wistend in significantly reducing IOP and effectively facilitating the outflow of aqueous humor.

A Randomized Controlled Trial Comparing STREAMLINE Canaloplasty to Trabecular Micro-Bypass Stent Implantation in Primary Open-Angle Glaucoma

Purpose

To report interim results of the VENICE study, a multi-center, randomized, controlled trial (RCT) comparing STREAMLINE Surgical System (STREAMLINE) canaloplasty with iStent inject W (iStent W) implantation in patients with mild-to-moderate primary open-angle glaucoma (POAG) undergoing phacoemulsification.

Patients and Methods

Safety and efficacy analyses involving the first 72 randomized eyes are included in this report. Following pre- (Screening) and post-medication washout (Eligibility) visits, one eye per subject was randomized 1:1 to STREAMLINE or iStent W after undergoing uncomplicated phacoemulsification. Subjects were evaluated postoperatively at Day 1, Week 1, Month 1, 3, and 6. Intraocular pressure (IOP) measurements, number of IOP-lowering medications, and adverse events (AEs) were assessed at each follow-up visit.

Results

Seventy-two eyes were randomized; 35 underwent STREAMLINE canaloplasty and 37 were implanted with the iStent W. Seventy eyes completed their 6-month follow-up. Both the mean morning post-washout Baseline IOP between STREAMLINE 24.86±3.05 mmHg and iStent W 25.16±3.41 mmHg and the mean IOP at 6 months between STREAMLINE eyes 16.52±3.63 mmHg and iStent W eyes 16.08±3.19 mmHg were not statistically significantly different (p=0.691 and 0.596, respectively). At 6 months, more eyes were on zero glaucoma medications in the STREAMLINE group (81.8%) compared to the iStent W group (78.4%). In medication-free eyes, the mean IOP was reduced from 24.80±2.79 mmHg to 16.00±3.40 mmHg and 24.60±3.18 mmHg to 15.80±2.21 mmHg in the STREAMLINE and iStent W groups, respectively (p=0.752). Both groups showed reduction in IOP-lowering medications at every visit, compared to pre-washout (Screening), with STREAMLINE resulting in numerically fewer medications 0.20±0.48 compared to iStent W 0.40±0.79 at 6 months (P=0.384). AEs were mild and self-limited.

Conclusion

To our knowledge, the VENICE trial is the first RCT involving canaloplasty. These interim findings demonstrated comparable IOP and medication reduction between STREAMLINE canaloplasty and iStent W implantation, when combined with phacoemulsification.

Risk factors for hyphema following goniotomy or trabecular bypass stent placement combined with phacoemulsification

PURPOSE

To report the rates and risk factors for layered hyphemas after goniotomy (PG) and trabecular bypass stent (PTBS) surgery combined with phacoemulsification.

METHODS

Patient data was obtained using a retrospective chart review from adult patients (18 years of age or older) undergoing either PG or PTBS at the West Virginia University Eye Institute between 2013 and 2023. Generalized estimating equations were used to identify significant predictors of layered hyphema on post-operative day one. Predictors evaluated included age, race, glaucoma severity, glaucoma type, surgical time, complex cataract extraction, pre-operative intraocular pressure, post-operative day one intraocular pressure, peri-operative anti-thrombotic therapy (ATT) use, body mass index, and surgery type (i.e., PG or PTBS).

RESULTS

Of the 405 eyes from 279 patients included in the study, the overall layered hyphema rate was 10.1% in the whole sample. In multivariate generalized estimating equation model controlling for glaucoma stage and preoperative IOP, only surgery type (PG vs PTBS) predicted post-operative day one hyphema (β = 2.47, SE = 1.01, p = 0.02). The hyphema rates in the PG group and PTBS groups were 40/316 (12.7%) and 1/89 (1.1%), respectively. Eyes of patients on ATT had a hyphema rate of 16/189 (8.5%) compared to 25/216 (11.6%) in eyes of patients not on ATT.

CONCLUSIONS

Performing PG over PTBS was a significant predictor of a post-operative day one layered hyphema. No other systemic or ocular features, including the use of ATT, showed a statistically significant relationship with post-operative hyphemas.

KEY MESSAGES

What is Known. • The prevalence of minimally invasive glaucoma surgery has significantly increased in recent years. • Hyphema is a common postoperative complication of minimally invasive glaucoma surgery, however risk factors for hyphema in this setting have not been thoroughly evaluated.

WHAT IS NEW

• The use of perioperative antithrombotic therapy did not significantly increase the risk for postoperative hyphema following angle based minimally invasive glaucoma surgery. • Hyphema risk was significantly higher in patients undergoing goniotomy combined with phacoemulsification compared to trabecular bypass stent surgery with phacoemulsification.

Visualization of the Postoperative Position of the Hydrus® Microstent Using Automatic 360° Gonioscopy

Introduction: Glaucoma, one leading cause of irreversible vision loss worldwide, is primarily caused by elevated intraocular pressure (IOP). Recently, minimally invasive glaucoma surgeries (MIGSs) have become popular due to their shorter surgical times, tissue-sparing nature, and faster recovery. One such MIGS, the Hydrus® nickel-titanium alloy Microstent, helps lower IOP by improving aqueous humor outflow. The NIDEK GS-1 automated 360° gonioscope provides advanced imaging of the chamber angle for evaluation and documentation. The aim of this study was to test automated 360° gonioscopy for the detection of postoperative positional variations after Hydrus® Microstent implantation. This study is the largest to date to evaluate post-op positioning of the Hydrus® Microstent using the NIDEK GS-1. Materials and Methods: This study analyzed postoperative outcomes and stent location in eyes diagnosed with mild to moderate glaucoma that underwent Hydrus® Microstent implantation with or without phacoemulsification. Patients with prior IOP-lowering surgery or vitrectomy were excluded. Analyses of the postoperative Hydrus® Microstent position were based on the evaluation of automated 360° gonioscopy images. Results: Twenty-three eyes were included in the study, and all showed a reduction in IOP and a decrease in antiglaucomatous drop use postoperatively. Postoperative gonoscopic images showed variations in implant position. In all cases, the proximal inlet was clearly visible in the anterior chamber. The degree of protrusion into the anterior chamber was variable. The distal tip of the stent was visible behind the trabecular meshwork in Schlemm's canal in five cases, in the anterior chamber in one case, and not visible in seven cases. In no case did postoperative alterations in the position of the implant lead to explantation. Conclusions: This study demonstrated that the Hydrus® Microstent can effectively lower IOP even in the presence of postoperative positional variations. Automated 360° gonioscopy was found to be a useful tool to verify and document the postoperative position of the implant. Positional changes did not require device explantation in any of the cases evaluated.

MIGS in Severe Glaucoma: 12-Month Retrospective Efficacy and Safety of Microinvasive Glaucoma Surgery with Cataract Extraction

Purpose

Despite holding promise, reports of using MIGS in severe glaucoma are scarce, and none has described combining multiple MIGS in this population. To the best of our knowledge, this is the largest study to report outcomes of phacoemulsification and MIGS (Phaco/MIGS) in patients with severe glaucoma.

Methods

This retrospective review comprised 327 clinical visits of 71 patients with severe glaucoma who underwent Phaco/MIGS with iStent, endocyclodestruction, Kahook Dual Blade, Hydrus Microstent, or a combination of these MIGS (cMIGS) performed between 2016 and 2021. Primary outcomes included intraocular pressure (IOP) and medication burden evaluated by Generalized Estimating Equations, as well as Kaplan-Meier Estimates. Further analyses compared the efficacy of cMIGS and single Phaco/MIGS (sMIGS), procedure duration, visual acuity, and complications.

Results

Mean preoperative IOP was 16.7 mmHg ± 5.8 (SD) on 2.3 ± 1.9 medications overall (N = 71), 16.9 ± 6.3 mmHg on 1.7 ± 1.9 medications in the sMIGS group (N = 37), and 16.4 ± 5.3 mmHg on 2.9 ± 1.6 medications in the cMIGS group (N = 34). Throughout 12 months, Phaco/MIGS led to significant reduction patterns in IOP (p < 0.001) and medications (p = 0.03). At 12 months, 47.5%, 87.5%, and 64.7% of the patients achieved IOP ≤ 12 mmHg, 17 mmHg, or predetermined goal IOP, respectively, without additional medication or procedure. Mean 12-month IOP was 13.5 ± 3.1 mmHg on 1.8 ± 1.7 medications. After adjusting for baseline medication burden, the reduction pattern in IOP (p < 0.05) was different between cMIGS and sMIGS, favoring cMIGS, and the groups had similar reduction patterns in medications (p = 0.75).

Conclusion

The use of Phaco/MIGS in patients with cataract and severe glaucoma may significantly reduce IOP and medication burden throughout 12 months and, thus, may serve as a stepping stone in severe glaucoma patients with visually significant cataract before proceeding with more invasive glaucoma surgery. This effect may be potentiated by the combination effect of cMIGS.

12-month Safety and Efficacy Outcomes of a Standalone Trabecular Bypass Device

Purpose

To analyze the outcomes of the iStent inject in a real-world clinical setting as a standalone procedure to lower intraocular pressure (IOP) in open-angle glaucoma.

Materials and methods

Patients with open-angle glaucoma having undergone iStent inject insertion without concurrent cataract extraction were included in this multicenter observational real-world study in Australia. Patient data was entered into the Fight Glaucoma Blindness! Registry. Assessments through 12 months included glaucoma subtype, IOP, medications, best-corrected visual acuity (BCVA), secondary surgical procedures, and adverse events. Kaplan-Meier survival curves for outcomes were reported according to the World Glaucoma Association (WGA).

Results

Sixty-one eyes from 44 patients with a mean age of 76 ± 11.4 underwent standalone iStent inject implantation. The mean ± SD preoperative IOP was 17.5 ± 7.5 mm Hg, and the mean preoperative number of topical medications was 2.5 ± 1.5. At 12 months postoperatively, there was no statistically significant IOP reduction, while the number of glaucoma medications used was reduced to 1.4 ± 1.5 (p < 0.001). Fourteen point one percent of eyes required a secondary pressure-lowering procedure within the 12-month follow-up window.

Conclusion

This assessment of standalone iStent inject implantation did not show any significant reduction in IOP, but there was a significant decrease in medication use in the real-world clinical setting. The procedure is safe with minimal adverse outcomes; however, a subset of patients required secondary procedures within 12 months of follow-up.

How to cite this article

Huynh B, Clement C, Nguyen V, et al. 12-month Safety and Efficacy Outcomes of a Standalone Trabecular Bypass Device. J Curr Glaucoma Pract 2024;18(3):103-109.

Ab interno canaloplasty versus gonioscopy-assisted transluminal trabeculotomy in open-angle glaucoma: a randomised controlled trial

OBJECTIVE

To compare the efficacy and safety of ab interno canaloplasty (ABiC) with gonioscopy-assisted transluminal trabeculotomy (GATT) in patients with open-angle glaucoma (OAG).

METHOD

This randomised clinical trial recruited eyes with OAG and no previous incisional ocular surgery, among which 38 were randomised to ABiC and 39 to GATT. Follow-ups were performed at 1, 3, 6 and 12 months postoperatively. The primary outcome measures were intraocular pressure (IOP) and use of glaucoma medication at 12 months postoperatively. The secondary outcome measure was complete surgical success (not requiring glaucoma surgery, IOP ≤21 mm Hg and non-use of glaucoma medications).

RESULTS

Both groups had similar demographic and ocular characteristics. A total of 71 of the 77 subjects (92.2%) completed 12-month follow-up. At 12 months, mean IOP was 19.0±5.2 mm Hg in the ABiC group and 16.0±3.1 mm Hg in the GATT group (p=0.003). Overall, 57.2% of ABiC patients and 77.8% of GATT patients were medication free (p=0.06). The number of glaucoma medications was 0.9±1.3 in the ABiC group and 0.6±1.2 in the GATT group (p=0.27). The 12-month cumulative rate of complete surgical success was 56% in the ABiC group and 75% in the GATT group (p=0.09). Three eyes in the ABiC group and one eye in the GATT group required additional glaucoma surgery. Hyphema (87% vs 47%) and supraciliary effusion (92% vs 71%) were noted more often in the GATT group than in the ABiC group.

CONCLUSIONS

The preliminary result showed that GATT had an advantage over ABiC in IOP reduction for OAG patients, accompanied by favourable safety at 12-month postoperatively.

TRIAL REGISTRATION NUMBER

ChiCTR1800016933.

Two-Year Performance and Safety Results of the MINIject Supraciliary Implant in Patients With Primary Open-Angle Glaucoma: Meta-Analysis of the STAR-I, II, III Trials

PURPOSE

To evaluate the performance and safety of minimally invasive glaucoma surgery with a supraciliary drainage device (MINIject; iSTAR Medical, Wavre, Belgium) in primary open-angle glaucoma (POAG) as a stand-alone procedure.

DESIGN

Meta-analysis.

METHODS

At 11 sites in Colombia, France, Germany, India, Panama, and Spain, 82 patients were treated in 3 prospective, multicenter, interventional, nonrandomized trials (STAR-I, II, III). Data were pooled in a meta-analysis of up to 2 years of follow-up postimplantation. The main outcome measures were mean relative and absolute reduction in diurnal intraocular pressure (IOP) compared to baseline. Secondary outcomes included patients with IOP ≤18 mmHg, patients with IOP reduction ≥20%, number of IOP-lowering medications, adverse events, and endothelial cell density loss.

RESULTS

At the 2-year follow-up (n = 66), mean IOP was reduced from 23.8 ± 3.3 mmHg at baseline to 14.4 ± 4.5 mmHg (-39.3%; P < 0.0001). An IOP reduction of ≥20% was achieved in 89.4% of patients, with 84.8% having an IOP ≤18 mmHg. IOP-lowering medications were reduced from a mean of 2.4 ± 1.1 to 1.4 ± 1.4 (P < 0.0001), with 37.9% of patients being medication-free at 2 years. Mean endothelial cell density loss at 2 years was 6.2 ± 9.1% compared to baseline and no patient had a loss >30%.

CONCLUSIONS

This meta-analysis demonstrates the favorable safety and efficacy profile of a supraciliary device implanted in a stand-alone, ab-interno procedure in patients with mild-to-moderate POAG. The data demonstrate that MINIject is a safe and effective, bleb-free treatment option for patients requiring low target IOP up to 2 years.

Glaucoma surgical procedures under development

PURPOSE OF REVIEW

Rapid innovation in glaucoma surgery is expanding surgical options in the angle, subconjunctival space, and supraciliary space.

RECENT FINDINGS

Advancements in glaucoma surgery make it possible for surgeons to provide treatments with less risk. In particular, new devices and lasers are available for minimally invasive glaucoma surgeries. There are also new implants and techniques for bleb-forming glaucoma surgery.

SUMMARY

As glaucoma surgeons have access to an increasing number of procedures, devices, and treatments, it is important for evidence to drive decision-making.

How much does cataract surgery contribute to intraocular pressure lowering?

PURPOSE OF REVIEW

To review the literature evaluating the effect of cataract surgery on intraocular pressure (IOP) in patients with glaucoma.

RECENT FINDINGS

Recent high-quality secondary analyses of large and primary trials continue to show IOP lowering following cataract surgery. Likewise, cataract surgery remains a key treatment for angle closure glaucoma. Some micro-invasive glaucoma surgeries (MIGS) have strong evidence to be performed at the time of cataract surgery. Data clarifying when these surgeries should be combined with cataract surgery is emerging. The mechanism underlying IOP lowering after cataract surgery remains unclear.

SUMMARY

Patients who are glaucoma suspects with visually significant cataracts would benefit from cataract surgery alone. Those with mild-moderate damage on 1-2 classes of medications would most likely benefit from additional MIGS. Patients with advanced disease would benefit from cataract surgery and a choice of additional surgery, which depends on disease status and patient factors. Clear lens extraction is becoming a more accepted practice as a primary procedure for patients with angle closure and high IOP or glaucoma. The role of additional MIGS in angle closure needs further study.

Trabecular Procedures Combined with Cataract Surgery for Open-Angle Glaucoma: A Report by the American Academy of Ophthalmology

PURPOSE

To determine the intraocular pressure (IOP) reduction of various trabecular procedures (a form of minimally invasive glaucoma surgery [MIGS]) combined with cataract surgery compared with cataract surgery alone, to compare the safety of the various trabecular procedures, and to highlight patient characteristics that may favor one trabecular procedure over another.

METHODS

A search of English-language peer-reviewed literature in the PubMed database was initially conducted in February 2021 and updated in April 2023. This yielded 279 articles. Twenty studies met initial inclusion and exclusion criteria and were assessed for quality by the panel methodologist. Of these, 10 were rated level I, 3 were rated level II, and 7 were rated level III. Only the 10 level I randomized controlled trials (RCTs) were included in this assessment, and all were subject to potential industry-sponsorship bias.

RESULTS

The current analysis focuses on the amount of IOP reduction (in studies that involved medication washout) and on IOP reduction with concurrent medication reduction (in studies that did not involve medication washout). Based on studies that performed a medication washout, adding a trabecular procedure to cataract surgery provided an additional 1.6 to 2.3 mmHg IOP reduction in subjects with hypertensive, mild to moderate open-angle glaucoma (OAG) at 2 years over cataract surgery alone, which itself provided approximately 5.4 to 7.6 mmHg IOP reduction. In other words, adding a trabecular procedure provided an additional 3.8% to 8.9% IOP reduction over cataract surgery alone, which itself provided 21% to 28% IOP reduction. There was no clear benefit of one trabecular procedure over another. Patient-specific considerations that can guide procedure selection include uveitis predisposition, bleeding risk, metal allergy, and narrowing of Schlemm's canal. There are no level I data on the efficacy of trabecular procedures in subjects with pretreatment IOP of 21 mmHg or less.

CONCLUSIONS

Trabecular procedures combined with cataract surgery provide an additional mild IOP reduction over cataract surgery alone in hypertensive OAG subjects. Additional research should standardize outcome definitions, avoid industry sponsorship bias, and study the efficacy of these procedures in normotensive OAG.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Biotissue stent for supraciliary outflow in open-angle glaucoma patients: surgical procedure and first clinical results of an aqueous drainage biostent

BACKGROUND/AIMS

To report a first-in-human trial in open-angle glaucoma (OAG) subjects treated with a new microinterventional biostent-reinforced cyclodialysis technique to enhance supraciliary aqueous drainage.

METHODS

Subjects (N=10; 74.1±7.9 years old) with OAG and cataracts underwent combined phacoemulsification cataract surgery with implantation of a permanent endoscleral supraciliary biostent to reinforce a controlled cyclodialysis cleft. The biostent comprised decellularised scleral allograft tissue microtrephined into a polymer tubular implant intraoperative/postoperative safety, intraocular pressure (IOP) and glaucoma medications were tracked through 12 months postimplantation.

RESULTS

Baseline medicated IOP averaged 24.2±6.9 mm Hg with subjects using 1.3±0.8 IOP-lowering medications. Successful biostent implantation was achieved in all individuals without significant complications. Immediate IOP lowering was sustained through 1 year. Twelve-month mean IOP was reduced 40% from baseline to 14.6±3.2 mm Hg (p=0.004; paired two-tailed t-test), and 80% of patients achieved >20% IOP reduction. Biostenting reduced glaucoma medication use 62%, from a baseline mean of 1.3 required medications to 0.5 medications (p=0.037) at postoperative 12 months. The biotissue implant was well tolerated and demonstrated good endothelial safety with only 11% endothelial cell loss at 12 months after combined phaco-biostenting surgery, similar to that expected after phacoemulsification alone. Mean BCVA increased from baseline 20/130 Snellen to 20/36 at postoperative 12 months (p=0.001).

CONCLUSION

Supraciliary biostenting in OAG patients is well tolerated, has a good safety profile and produces long-term IOP-lowering while reducing glaucoma medication requirements.

Consistency in Standalone Canaloplasty Outcomes Using the iTrack Microcatheter

Purpose

To study the consistency in outcomes of standalone canaloplasty performed via an ab-interno surgical technique in reducing intraocular pressure (IOP) and number of medications in uncontrolled open-angle glaucoma (OAG) eyes over a 12-month period.

Methods

This retrospective multicenter case series included patients who underwent standalone canaloplasty via an ab-interno surgical technique using the iTrack microcatheter (Nova Eye, Inc., Fremont, USA) and had preoperative uncontrolled OAG (IOP≥18mmHg) along with no previous glaucoma surgery. The iTrack microcatheter is used to circumnavigate 360° and viscodilate Schlemm's canal. Consistency of IOP and medications reduction on an eye-by-eye basis were evaluated to understand the outcomes in each single eye.

Results

Sixty-four eyes of 60 patients (age 71.5±13.4 years) were included. Six eyes (9%) that underwent additional glaucoma surgery were considered a failure and were subsequently excluded from analysis. At 12 months, IOP was reduced in 57 of the 58 (89%) remaining eyes; one eye had the same IOP with a reduced number of medications. Of the 57/58 eyes with a reduced IOP: 44 eyes (69%) required fewer medications; 12 eyes (19%) required the same number of medications. Of these 58 eyes, 78% of eyes had a ≥20% reduction in IOP compared to baseline; 69% eyes had a postoperative IOP ≤15 mmHg, and 86% eyes ≤18 mmHg at 12 months. Forty percent of the eyes were medication-free at 12 months compared to none at baseline.

Conclusion

Canaloplasty performed via an ab-interno surgical technique as a standalone procedure consistently reduced IOP and glaucoma medications in almost all eyes.

Glaucoma Surgery and Ocular Blood Flow in Colour Doppler Imaging: Is There a Link?

Glaucoma is a common cause of blindness worldwide. This disease is characterised by increased intraocular pressure (IOP) and the concomitant disruption of ocular haemodynamic. Several studies have demonstrated that trabeculectomy is associated with changes in extraocular blood flow. In this study, we reviewed the available evidence on the use of colour Doppler imaging to evaluate and manage patients with open-angle glaucoma. We present the detailed anatomy of ocular blood flow to provide a background for the research findings. We also discuss the physiological foundations of ocular blood flow and detailed flow characteristics of specific extraocular vessels. Finally, we reviewed published studies that analysed the effects of glaucoma surgery on the blood flow parameters of the eye.

A Rare Case of Postoperative Uveitis and Obstructive Peripheral Anterior Synechiae Following Combined OMNI Canaloplasty and Hydrus Microstent Implantation

Purpose

This study seeks to highlight and explore the occurrence of uveitis with obstructive peripheral anterior synechiae (PAS) after a combined OMNI canaloplasty and Hydrus microstent implantation with phacoemulsification, particularly in a patient with a background of psoriatic arthritis.

Observations

A 56-year-old male with a medical history of psoriatic arthritis (in remission for 10 years) and primary open-angle glaucoma (POAG) underwent a combined OMNI canaloplasty and Hydrus microstent with phacoemulsification. The surgical procedure was uncomplicated. However, within 2 weeks postsurgery, the patient presented with severe symptoms, including uveitis, elevated intraocular pressure (IOP), and a significant reduction in best-corrected visual acuity (BCVA). This postoperative response was unexpected, especially given the lack of any past history of uveitis in the patient. The complication, potentially influenced by the patient's history of psoriatic arthritis, led to the need for additional interventions, including the implantation of an Ahmed glaucoma valve.

Conclusion

This case underscores the potential for postoperative complications, specifically uveitis with obstructive PAS, following combined OMNI canaloplasty and Hydrus microstent with phacoemulsification, especially in patients with a history of autoimmune diseases. Careful preoperative history, postoperative monitoring, and a nuanced approach to surgical planning are crucial. The association between systemic inflammatory conditions and ocular complications warrants deeper exploration to ensure optimal patient care.

How to cite this article

Dossantos J, An J. A Rare Case of Postoperative Uveitis and Obstructive Peripheral Anterior Synechiae Following Combined OMNI Canaloplasty and Hydrus Microstent Implantation. J Curr Glaucoma Pract 2024;18(1):37-41.

Analyzing the Shortcomings of Trabecular Micro-bypass Stents for Surgical Management of Glaucoma

How to cite this article: Dada T, Beri N. Analyzing the Shortcomings of Trabecular Micro-bypass Stents for Surgical Management of Glaucoma. J Curr Glaucoma Pract 2024;18(1):1-3.

Comparative Effectiveness and Safety of Two Different Trabecular MIGS Devices With and Without Ab Interno Canaloplasty in Patients with Primary Open-Angle Glaucoma

INTRODUCTION

This study compared outcomes of the iStent inject trabecular micro-bypass system versus the Hydrus Microstent in patients with primary open-angle glaucoma (POAG).

METHODS

Forty subjects (80 eyes) with POAG were included in this single-center, retrospective, contralateral-eye analysis. All patients underwent phacoemulsification with either iStent inject or Hydrus implantation in one eye and the other device in the contralateral eye, with ≥ 3-month follow-up. In 58 eyes (27 iStent inject, 31 Hydrus) the surgery also included ab interno canaloplasty (ABiC). Twelve-month outcomes included intraocular pressure (IOP), medications, and adverse events. Subgroup analyses were completed for iStent inject versus Hydrus, and with versus without ABiC.

RESULTS

At 12 months versus baseline, mean IOP reduced from 16.8 ± 3.7 to 13.6 ± 2.9 (p = 0.003) in iStent inject eyes, and from 18.1 ± 4.5 to 14.9 ± 3.2 mmHg (p = 0.003) in Hydrus eyes (between-group IOP reduction p = 0.582). Mean number of glaucoma medications reduced from 1.23 ± 0.97 to 0.30 ± 0.76 (p < 0.001) in iStent inject eyes and from 1.20 ± 1.02 to 0.39 ± 0.72 (p = 0.001) in Hydrus eyes (between-group medication reduction p = 0.943). At 12 months, 82.6% of iStent inject eyes and 73.9% of Hydrus eyes were medication-free versus 20.0% preoperatively in both groups (p < 0.0001 both groups). There were no statistically significant IOP or medication differences between iStent inject and Hydrus pre- or postoperatively, both in the overall cohort and in the with/without ABiC subgroups. Outcomes also were similar between eyes with/without ABiC in the overall cohort and in the iStent inject/Hydrus subgroups. There were no adverse events in the iStent inject group; two eyes in the Hydrus group had device-related complications requiring five additional surgeries (one Hydrus repositioning, one Hydrus exchange, one Hydrus removal, two goniotomies).

CONCLUSION

In this contralateral-eye comparison of iStent inject versus Hydrus, the groups had similar IOP and medication outcomes, regardless of stratification by ABiC completion. Eyes receiving Hydrus had more complications and subsequent surgeries.

Short-Term Efficacy and Safety of Phacoemulsification Associated With iStent Inject W in Patients With Controlled Open Angle Glaucoma

PRCIS

The iStent inject W implanted during phacoemulsification effectively reduces IOP.

PURPOSE

The purpose of this study was to evaluate the efficacy and safety of iStent inject W combined with phacoemulsification in patients with controlled open angle glaucoma undergoing cataract surgery.

PATIENTS AND METHODS

We conducted a retrospective, bicentric study of patients with controlled chronic open angle glaucoma who underwent phacoemulsification combined with the injection of 2 iStent inject Ws. Patient characteristics, including intraocular pressure (IOP) and the number of glaucoma medications, were evaluated preoperatively and 1 week, 1 month, and 6 months postoperatively. The primary end point was IOP reduction, and the secondary end point was the reduction in the number of glaucoma medications.

RESULTS

In this study, 85 eyes were included. The majority of patients had primary open angle glaucoma (85% of eyes). Preoperative mean IOP was 16.1±2.0 mm Hg with a mean of 2.3±0.5 glaucoma medications. At 1 week postoperatively, the mean IOP was 16.7±3.1 mm Hg with a mean of 2.0±0.7 hypotensive medications. At 1 and 6 months, the mean IOP was 14.2±2.1 and 13.0±1.5 mm Hg, with a mean of 2.0±0.6 and 1.8±0.5 glaucoma medications, respectively. The percentage IOP reduction at 1 and 6 months was 11.6% ( P =0.001) and 19.3% ( P <0.0001), respectively. Regarding glaucoma medications, at 1 and 6 months, the reduction in the number of medications was 12.9% ( P =0.025) and 22.4% ( P =0.003), respectively. The most frequent significant postoperative adverse events were corneal edema in 7%, IOP spikes in 6%, and hyphema in 6% of eyes, which resolved spontaneously.

CONCLUSIONS

The iStent inject W implanted during phacoemulsification effectively reduces IOP and the number of glaucoma medications needed at 6 months of follow-up, with a favorable safety profile in patients with controlled open angle glaucoma.

Microfluidics in the eye: a review of glaucoma implants from an engineering perspective

Glaucoma is a progressive optic neuropathy in the eye, which is a leading cause of irreversible blindness worldwide and currently affects over 70 million individuals. Clinically, intraocular pressure (IOP) reduction is the only proven treatment to halt the progression of glaucoma. Microfluidic devices such as glaucoma drainage devices (GDDs) and minimally invasive glaucoma surgery (MIGS) devices are routinely used by ophthalmologists to manage elevated IOP, by creating an artificial pathway for the over-accumulated aqueous humor (AH) in a glaucomatous eye, when the natural pathways are severely blocked. Herein, a detailed modelling and analysis of both the natural microfluidic pathways of the AH in the eye and artificial microfluidic pathways formed additionally by the various glaucoma implants are conducted to provide an insight into the causes of the IOP abnormality and the improvement schemes of current implant designs. The mechanisms of representative glaucoma implants have been critically reviewed from the perspective of microfluidics, and we have categorized the current implants into four groups according to the targeted drainage sites of the AH, namely Schlemm's canal, suprachoroidal space, subconjunctival space, and ocular surface. In addition, we propose to divide the development and evolution of glaucoma implant designs into three technological waves, which include microtube (1st), microvalve (2nd) and microsystem (3rd). With the emerging trends of minimal invasiveness and artificial intelligence in the development of medical implants, we envision that a comprehensive glaucoma treatment microsystem is on the horizon, which is featured with active and wireless control of IOP, real-time continuous monitoring of IOP and aqueous rate, etc. The current review could potentially cast light on the unmatched needs, challenges, and future directions of the microfluidic structural and functional designs of glaucoma implants, which would enable an enhanced safety profile, reduced complications, increased efficacy of lowering IOP and reduced IOP fluctuations, closed-loop and on-demand control of IOP, etc.

Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

The development of minimally invasive glaucoma surgeries (MIGSs) was intended to provide safe and modestly efficacious modalities for early intervention of mild-to-moderate glaucoma, with minimal trauma and rapid recovery. They were mainly ab interno procedures that reduce intraocular pressure by facilitating the aqueous outflow by bypassing the trabecular meshwork resistance, reinforcing the uveoscleral flow via the supraciliary space, and reducing aqueous production by the ciliary body. While the cumulating evidence helps shape the role of the available MIGS, the exponential new development and advancement in this field has expanded the territory of MIGS. Apart from developing subconjunctival MIGS filtration devices (Xen gel stent and PRESERFLO MicroShunt), there is a tendency to revisit the "traditional" MIGS for alternative use and to modify the procedures with consideration of the fundamental aqueous outflow physiology. Combined MIGS has also been suggested, based on the theory that their different mechanisms may provide additive or synergistic effects. The advancement of laser procedures is also promising and could supplement unmet needs along the glaucoma treatment algorithm. This review examines the broad array of MIGS, updates the recent findings, discusses their potential alternative applications, and explores future challenges.

Development and material characteristics of glaucoma surgical implants

Background

Glaucoma is the leading cause of irreversible blindness worldwide. The reduction of intraocular pressure has proved to be the only factor which can be modified in the treatment, and surgical management is one of the important methods for the treatment of glaucoma patients.

Main text

In order to increase aqueous humor outflow and further reduce intraocular pressure, various drainage implants have been designed and applied in clinical practice. From initial Molteno, Baerveldt and Ahmed glaucoma implants to the Ahmed ClearPath device, Paul glaucoma implant, EX-PRESS and the eyeWatch implant, to iStent, Hydrus, XEN, PreserFlo, Cypass, SOLX Gold Shunt, etc., glaucoma surgical implants are currently undergoing a massive transformation on their structures and performances. Multitudinous materials have been used to produce these implants, from original silicone and porous polyethylene, to gelatin, stainless steel, SIBS, titanium, nitinol and even 24-carat gold. Moreover, the material geometry, size, rigidity, biocompatibility and mechanism (valved versus nonvalved) among these implants are markedly different. In this review, we discussed the development and material characteristics of both conventional glaucoma drainage devices and more recent implants, such as the eyeWatch and the new minimally invasive glaucoma surgery (MIGS) devices.

Conclusions

Although different in design and materials, these delicate glaucoma surgical implants have widely expanded the glaucoma surgical methods, and improved the success rate and safety of glaucoma surgery significantly. However, all of these glaucoma surgical implants have various limitations and should be used for different glaucoma patients at different conditions.

Effects of Schlemm's Canal Suture Implantation Surgery and Pilocarpine Eye Drops on Trabecular Meshwork Pulsatile Motion

The trabecular meshwork is an important structure in the outflow pathway of aqueous humor, and its movement ability directly affects the resistance of aqueous humor outflow, thereby affecting the steady state of intraocular pressure (IOP). (1) Objective: The purpose of this study was to preliminarily estimate the effects of pilocarpine eye drops and trabeculotomy tunneling trabeculoplasty (3T) on trabecular meshwork (TM) pulsatile motion via phase-sensitive optical coherence tomography (Phs-OCT). (2) Method: In a prospective single-arm study, we mainly recruited patients with primary open-angle glaucoma who did not have a history of glaucoma surgery, and mainly excluded angle closure glaucoma and other diseases that may cause visual field damage. The maximum velocity (MV) and cumulative displacement (CDisp) of the TM were quantified via Phs-OCT. All subjects underwent Phs-OCT examinations before and after the use of pilocarpine eye drops. Then, all subjects received 3T surgery and examinations of IOP at baseline, 1 day, 1 week, 1 month, 3 months, and 6 months post-surgery. Phaco-OCT examinations were performed at 3 and 6 months post-surgery, and the measurements were compared and analyzed. (3) Results: The MV of TM before and after the use of pilocarpine eye drops was 21.32 ± 2.63 μm/s and 17.00 ± 2.43 μm/s. The CDisp of TM before and after the use of pilocarpine eye drops was 0.204 ± 0.034 μm and 0.184 ± 0.035 μm. After the use of pilocarpine eye drops, both the MV and CDisp significantly decreased compared to those before use (p < 0.001 and 0.013, respectively). The IOP decreased from baseline at 22.16 ± 5.23 mmHg to 15.85 ± 3.71 mmHg after 3 months post-surgery and from 16.33 ± 2.51 mmHg at 6 months post-surgery, showing statistically significant differences (p < 0.001). The use of glaucoma medication decreased from baseline at 3.63 ± 0.65 to 1.17 ± 1.75 at 3 months and 1.00 ± 1.51 at 6 months post-surgery; the differences were statistically significant (p < 0.001). Additionally, there was no statistically significant difference in the MV between 3 and 6 months after surgery compared to baseline (p = 0.404 and 0.139, respectively). Further, there was no statistically significant difference in the CDisp between 3 and 6 months after surgery compared to baseline (p = 0.560 and 0.576, respectively) (4) Conclusions: After the preliminary study, we found that pilocarpine eye drops can attenuate TM pulsatile motion, and that 3T surgery may reduce IOP without affecting the pulsatile motion status of the TM.

Preventing Blindness with Early Cataract Surgery and Micro-Invasive Glaucoma Surgery in Patients Over 50: Guidance for Patients, Physicians and World Governments in Dealing with Glaucoma

Purpose

To offer clinical guidance and address safety and efficacy concerns regarding the growing use of micro-invasive glaucoma surgery (MIGS) as an initial treatment for glaucoma in adult patients.

Design

Narrative literature review.

Methods

A review was conducted to assess outcomes and complications of MIGS in the treatment of glaucoma, both alone and in combination with lens replacement. These outcomes were compared with those of standard glaucoma surgery and/or glaucoma management with medication.

Results

MIGS are effective at lowering intraocular pressure (IOP) over long periods of follow-up. These techniques share a similarly high safety profile between one another. MIGS were found to have lower complication rates and to be more effective in reducing the total amount of medication needed to maintain control of intraocular pressure than standard surgery approaches.

Conclusion

MIGS techniques are growing in popularity and have been demonstrated to be a safe and effective alternative to standard glaucoma surgery. Guidance in the implementation of these procedures has been outlined.

Clinical and Optical Coherence Tomography Evidence of Aqueous Humor Flow from the Suprachoroidal Space to Conjunctival Lymphatics

A surgical technique was developed to enhance aqueous humor (AH) flow through the non-trabecular outflow pathway by rerouting it from the anterior chamber (AC) to the suprachoroidal space (SCS) without detaching the ciliary body from the scleral spur. Medium- and long-term surgical outcomes were retrospectively analyzed in a case series of 58 glaucoma patients. At 6, 12, and 24 months, the mean IOP decreased from 27.8 ± 8.3 to 14.9 ± 5.0 mmHg, median 15.0 (25th percentile (p25)13.0; 75th percentile (p75) 18.0) and 15.2 ± 3.3 mmHg, and hypotensive medication use reduced from a median (p25; p75) of 3 (2; 3) to 0 (0; 2), 0 (0; 2), and 0 (0; 1.5), respectively. Intra- and postoperative complications were few and manageable. Following surgery, no bleb formation occurred in any of the cases (as confirmed by optical coherence tomography). Conjunctival lymphatic vessels (CLVs) developed in 50% of eyes (29/58). Clinically, they developed directly from sclera and had no connection to the surgical site. Analysis further showed that the development of CLVs and their longer visibility period had poor prognostic value for IOP control. If the fluid flow from the SCS to CLVs was resistance-free, no CLV development was evident. However, if any resistance existed in the flow, the fluid accumulated in lymphatics, resulting in their engorgement. The proposed technique was safe and effective in decreasing IOP in glaucoma patients by enhancing AH flow from the SCS to CLVs via connecting intrascleral microchannels.

Short-Term Outcomes of Hydrus Microstent With and Without Additional Canaloplasty During Cataract Surgery

PRCIS

Compared with phacoemulsification and microstent alone, we observed that phacoemulsification with combined microstent and canaloplasty resulted in a significantly greater reduction in glaucoma medications while maintaining similar rates of intraocular pressure reduction and low complications.

PURPOSE

The purpose of this study was to compare the outcomes of phacoemulsification combined with Hydrus Microstent (Alcon Inc.) implantation alone or in combination with canaloplasty (OMNI Surgical System, Sight Sciences Inc.).

MATERIALS AND METHODS

Retrospective study of mild-to-moderate primary open angle glaucoma patients who underwent phacoemulsification with microstent alone (42 eyes of 42 patients) or in combination with canaloplasty (canaloplasty-microstent, 32 eyes of 32 patients). The mean number of ocular hypotensive medications and intraocular pressure were assessed preoperatively and postoperatively at 1 week and at 1, 3, and 6 months. Complications and secondary surgical interventions were recorded. Outcomes measures included the percentage of unmedicated eyes and surgical success at 6 months. Surgical success was defined as reaching the target intraocular pressure without medications or secondary surgical interventions.

RESULTS

Mean intraocular pressure at 6 months was 14.1±3.5 mm Hg (13% reduction) after microstent alone and 13.6±3.1 mm Hg (17% reduction) after canaloplasty-microstent. Mean medications at 6 months were 0.57±0.9 (67% reduction) after microstent alone and 0.16±0.4 (88% reduction) after canaloplasty-microstent ( P< 0.05). At 6 months, 64.3% of microstent alone and 87.3% of canaloplasty-microstent were off all medications ( P =0.02). Success probabilities at 6 months were 44.5% for microstent alone and 70.0% for canaloplasty-microstent ( P =0.04). No secondary surgical interventions occurred in either group.

CONCLUSIONS

Microstent combined with canaloplasty resulted in a significantly higher rate of medication-free status compared with microstent alone through 6 months.

Combined Phacoemulsification and STREAMLINE Surgical System Canal of Schlemm Transluminal Dilation in Eyes of Hispanic Patients with Mild to Moderate Glaucoma

Purpose

To characterize clinical outcomes of transluminal dilation of the canal of Schlemm using the STREAMLINE Surgical System combined with phacoemulsification in eyes of Hispanic patients diagnosed with mild to moderate primary open-angle glaucoma.

Methods

This was a prospective analysis of all cases performed and followed up to 12 months. All eyes underwent medication washout preoperatively. Reduction in intraocular pressure (IOP) from unmedicated baseline, as well as medications from pre-washout baseline, were analyzed at postoperative Day 1, Week 1, and Months 1, 3, 6, 9, and 12.

Results

All 37 patients were Hispanic, 83.8% were female, and mean (standard deviation) age was 66.0 (10.5) years. Mean medicated preoperative IOP was 16.9 (3.2) mmHg using a mean of 2.1 (0.9) medications, unmedicated baseline IOP (after washout) was 23.2 (2.3) mmHg, and mean IOP at every postoperative study visit was significantly lower (p<0.0002). Mean IOP from month 1 through the first postoperative year ranged from 14.7-16.2 mmHg, representing a reduction of 7.0-8.5 mmHg (30.7-36.5%). At month 12, 80% of all eyes (28/35) and 77.8% of medication-free eyes (14/18) had IOP reduction ≥20% from unmedicated baseline, and 51.4% of eyes (18/35) were medication-free. Mean medication use was significantly reduced (by 59.9-74.6%, p<0.0001) at every postoperative study visit. The only adverse event occurring in >1 eye was high IOP (n=4) which was responsive to topical medical therapy; no adverse events were attributed to the transluminal dilation procedure.

Conclusion

Transluminal dilation of the canal of Schlemm using the STREAMLINE Surgical System combined with phacoemulsification safely and effectively reduced both IOP and dependence on IOP-lowering medications in a Hispanic population diagnosed with POAG and should be considered at the time of phacoemulsification in Hispanic patients who have a need for IOP reduction, medication reduction, or both.

Hydrus microstent for the treatment of primary open-angle glaucoma: overview of its safety and efficacy

INTRODUCTION

Minimally invasive glaucoma surgeries (MIGS) are now a consolidated reality in many surgical units. The Hydrus Microstent is one of several MIGS devices bypassing trabecular outflow and had excellent results over the years. This article aims to review the key features of the Hydrus Microstent in terms of design, efficacy, and safety.

AREAS COVERED

The present review analyses the main characteristics of the device by evaluating the technical and physical details of its functioning. The evidence that supports a clinical decision summarizes the most influential clinical trials and the most accurate systematic reviews.

EXPERT OPINION

The Hydrus device has been extensively studied regarding biocompatibility and outflow potential. The subsequent clinical studies have been well-built and proved that the device effectively reduces intraocular pressure (IOP) and the eyedrop load. The device covers almost a quarter of Schlemm's canal circumference, offering at least two advantages: cannulating the Schlemm's canal provides evidence that the device has been implanted correctly; covering a larger area potentially allows to target multiple collector channels or at least areas of active outflow. This scaffold may prove more effective in naïve patients or subjects who used antiglaucoma eyedrops for a limited period, as the prolonged use of hypotonic medications has been associated with the surgical failure of ab interno microhook trabeculotomy.

Spotlight on Schlemm's Canal MicroStent Injection in Patients with Glaucoma

Minimally invasive glaucoma surgery (MIGS) has revolutionized glaucoma care with its favorable safety profile and ability to delay or minimize the need for traditional, bleb-based procedures. Microstent device implantation is a type of angle-based MIGS, which reduces intraocular pressure (IOP) through bypass of the juxtacanalicular trabecular meshwork (TM) and facilitation of aqueous outflow into the Schlemm's canal. Although there are limited microstent devices on the market, multiple studies have evaluated the safety and efficacy of iStent^® (Glaukos Corp.), iStent Inject^® (Glaukos Corp.), and Hydrus^® Microstent (Alcon) in the treatment of mild-to-moderate open-angle glaucoma, with and without concurrent phacoemulsification. This review attempts to provide a comprehensive evaluation of injectable angle-based microstent MIGS devices in the treatment of glaucoma.

Five-Year Clinical Outcomes of Inferior Quadrant Trabectome Surgery for Open Angle Glaucoma

PRCIS

This retrospective study of 264 eyes having inferior quadrant trabectome surgery confirms its safety and relative effectiveness. Most patients however still require IOP-lowering agents, and a considerable proportion may need additional glaucoma surgery.

PURPOSE

To report outcomes from a large single-center cohort of inferiorly-applied trabectome surgery.

PATIENTS AND METHODS

Retrospective review of patients undergoing trabectome surgery for chronic open angle glaucoma (COAG) at the University Eye Clinic Bonn, Germany, from 2012 to 2020.

RESULTS

Two hundred sixty-four eyes of 206 patients with COAG were included. The mean review period was 45.43 (range 12-101) months. One hundred five eyes (39.8%) underwent standalone surgery, of which 74 were pseudophakic and 31 phakic. The mean preoperative IOP was 17.58 mm Hg (range 12-50 mm Hg). One hundred five eyes (39.8%) developed a 'failure event' according to pre-defined criteria at a mean interval of 14.8 months postoperative. In absolute terms, 211 patients (79.9%) had a long-term IOP >14 mm Hg at 7.6 months, 174 patients (65.9%) >16 mm Hg at 10.6 months, 127 patients (48.1%) >18 mm Hg at 10.9 months, and 77 patients (29.2%) >21 mm Hg at 11.1 months. Over a five-year period, overall mean IOP remained stable at 13 mm Hg. The majority of patients were still on glaucoma drops (the mean number reduced from 2.9 to 2.7 agents). Subgroup analyses showed that a higher preoperative IOP was a positive predictor for failure, whereas combined surgery (with phaco) had better IOP outcomes (16.5 mm Hg vs. 19.3 mm Hg, respectively). Forty-one patients (15.5%) developed minor complications: 22 had high postoperative IOP within 3 months, 11 developed a self-resorbing hyphema, and 6 had fibrinous uveitis.

CONCLUSIONS

Trabectome surgery is a safe and relatively effective procedure for lowering IOP, but most patients still need IOP-lowering agents, and a considerable proportion may need additional glaucoma surgery within a relatively short time. Inferior quadrant treatment may result in inferior IOP outcomes when compared with nasal quadrant surgery.

Recently Approved Drugs for Lowering and Controlling Intraocular Pressure to Reduce Vision Loss in Ocular Hypertensive and Glaucoma Patients

Serious vision loss occurs in patients affected by chronically raised intraocular pressure (IOP), a characteristic of many forms of glaucoma where damage to the optic nerve components causes progressive degeneration of retinal and brain neurons involved in visual perception. While many risk factors abound and have been validated for this glaucomatous optic neuropathy (GON), the major one is ocular hypertension (OHT), which results from the accumulation of excess aqueous humor (AQH) fluid in the anterior chamber of the eye. Millions around the world suffer from this asymptomatic and progressive degenerative eye disease. Since clinical evidence has revealed a strong correlation between the reduction in elevated IOP/OHT and GON progression, many drugs, devices, and surgical techniques have been developed to lower and control IOP. The constant quest for new pharmaceuticals and other modalities with superior therapeutic indices has recently yielded health authority-approved novel drugs with unique pharmacological signatures and mechanism(s) of action and AQH drainage microdevices for effectively and durably treating OHT. A unique nitric oxide-donating conjugate of latanoprost, an FP-receptor prostaglandin (PG; latanoprostene bunod), new rho kinase inhibitors (ripasudil; netarsudil), a novel non-PG EP2-receptor-selective agonist (omidenepag isopropyl), and a form of FP-receptor PG in a slow-release intracameral implant (Durysta) represent the additions to the pharmaceutical toolchest to mitigate the ravages of OHT. Despite these advances, early diagnosis of OHT and glaucoma still lags behind and would benefit from further concerted effort and attention.

Emerging glaucoma treatments: are we seeing an improvement in adherence?

Introduction

Non-adherence to glaucoma medication and poor follow-up is a global health concern.

Areas covered

Glaucoma remains one of the largest causes of irreversible blindness worldwide. Traditional treatment guidelines suggest topical eye drop medication as first line therapy followed by addition of supplementary medications before proceeding to more invasive glaucoma surgeries. Unfortunately, poor glaucoma self-management remains high, leading to disease progression and blindness. Recent advancements in the field of pharmacotherapies, surgeries, and behavioral approaches have taken aim at increasing support for glaucoma self-management. We review the current and emerging approaches towards glaucoma management, with the exception of bleb-based surgical approaches, to investigate if they have had an impact on adherence. Literature searches were conducted via MEDLINE (PubMed), Embase (Elsevier), Cochrane Library (Wiley), and Preprints from January 1st, 2018, to January 26th, 2023.

Expert opinion

The ability to offer patients a multitude of choices enables patients to tailor their glaucoma treatment to their values and lifestyle. Offering personalized patient education and coaching to support chronic glaucoma self-management would better enable patient engagement in whichever treatment path is chosen. Currently, literature regarding the impact of these new advancements on treatment engagement is lacking; this field is ripe for additional intervention and assessment.

[Minimally invasive glaucoma surgery-Comparison of angle based procedures]

Surgical procedures are playing an increasing role in the care of patients with glaucoma. Within the last decade, new surgical procedures have been established, which are summarized under the term minimally invasive glaucoma surgery (MIGS). A wide variety of different procedures are aimed at the structures in the angle of the anterior chamber, such as the trabecular meshwork and Schlemm's canal, to improve the physiological outflow or to improve the alternative uveoscleral outflow. The implementation of the treatment goal differs in the individual procedures, as does the maximum pressure reduction that can be achieved. Compared to trabeculectomy with the use of cytostatic agents, the achievable pressure reduction is usually significantly lower. In contrast, the significantly lower intraoperative and postoperative complication rates are emphasized as an advantage of these procedures. With increasing clinical experience and the growth of sufficient data on these new surgical procedures, a well-founded classification in the treatment algorithm of glaucoma surgery becomes easier; nevertheless, due to the small differences with respect to efficacy and safety profile, the final decision for an individual procedure often remains dependent on the surgeon's personal preferences.

Design and Conduct of Randomized Clinical Trials Evaluating Surgical Innovations in Ophthalmology: A Systematic Review

PURPOSE

Surgical innovations are necessary to improve patient care. After an initial exploratory phase, novel surgical technique should be compared with alternative options or standard care in randomized controlled trials (RCTs). However, surgical RCTs have unique methodological challenges. Our study sought to investigate key aspects of the design, conduct, and reporting of RCTs of novel surgeries.

DESIGN

Systematic review.

METHODS

The protocol was prospectively registered in PROSPERO (CRD42021253297). RCTs evaluating novel surgeries for cataract, vitreoretinal, glaucoma, and corneal diseases were included. Medline, EMBASE, Cochrane Library, and Clinicaltrials.gov were searched. The search period was January 1, 2016, to June 16, 2021.

RESULTS

A total of 52 ophthalmic surgery RCTs were identified in the fields of glaucoma (n = 12), vitreoretinal surgery (n = 5), cataract (n = 19), and cornea (n = 16). A description defining the surgeon's experience or level of expertise was reported in 30 RCTs (57%) and was presented in both control and intervention groups in 11 (21%). Specification of the number of cases performed in the particular surgical innovation being assessed prior to the trial was reported in 10 RCTs (19%) and an evaluation of quality of the surgical intervention in 7 (13%). Prospective trial registration was recorded in 12 RCTs (23%) and retrospective registration in 13 (25%); and there was no registration record in the remaining 28 (53%) studies.

CONCLUSIONS

Important aspects of the study design such as the surgical learning curve, surgeon's previous experience, quality assurance, and trial registration details were often missing in novel ophthalmic surgical procedures. The Idea, Development, Exploration, Assessment, Long-term follow-up (IDEAL) framework aims to improve the quality of study design.

Microinvasive glaucoma surgeries: critical summary of clinical trial data with and without phacoemulsification

PURPOSE OF REVIEW

To critically summarize and examine published data from randomized controlled clinical trials (RCTs) investigating the safety and efficacy of microinvasive glaucoma surgeries (MIGS) with and without cataract surgery versus cataract surgery alone.

RECENT FINDINGS

Three RCTs with standardized outcomes and rigorous methodology demonstrate superiority of the iStent (Glaukos), CyPass (Alcon), and Hydrus (Alcon) MIGS devices in combination with cataract surgery versus cataract surgery alone. The trials all involved medication washouts at baseline and also after 24 months of follow-up. In each of the trials, a greater proportion of participants randomized to the combined MIGS procedures achieved at least 20% unmedicated intraocular pressure (IOP) lowering compared with cataract surgery alone. With the exception of the CyPass device, which has been voluntarily withdrawn from the market, adverse events associated with MIGS were acceptable and consistent with routine intraocular surgeries. Follow-up studies demonstrate sustained efficacy, greater probabilities of visual field preservation, increased cost-effectiveness, and enhanced quality of life associated with MIGS procedures.

SUMMARY

Data related to MIGS platforms for treatment of open-angle glaucoma with or without co-existing cataract supports their continued adoption in clinical practice. Future studies comparing various techniques and devices in a standardized fashion are needed.

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.

Three-Year Outcomes of a Schlemm Canal Microstent (Hydrus Microstent) with Concomitant Phacoemulsification in Open-Angle Glaucoma

PURPOSE

HORIZON trials have reported the medium- and long-term outcomes of the Hydrus microstent. However, outside of randomized clinical trials, outcomes beyond 24 months have not been previously reported. Here, we examine the 3-year outcomes of the Hydrus microstent with cataract surgery outside of a randomized clinical trial setting.

DESIGN

Single-surgeon consecutive case series.

PARTICIPANTS

Glaucomatous eyes that underwent implantation of a Hydrus microstent with concomitant cataract surgery at a single ophthalmology center in Montreal, Canada.

METHODS

Success was defined according to the absence of specific failure criteria: (A) glaucoma reoperation; (B) selective laser trabeculoplasty; (C) intraocular pressure (IOP) < 5 mmHg, > 18 mmHg, or increase in the number of antiglaucoma medications (AGMs) used (after the first postoperative month), or loss of light perception due to glaucoma; (D) aggregation of criteria A-C. Predictors of treatment failure and postoperative changes in IOP and AGM use were assessed. Safety included best-corrected visual acuity (BCVA), cup-to-disc ratio (CDR), retinal nerve fiber layer (RNFL) thickness, ganglion cell inner plexiform layer (GC-IPL) thickness, visual field mean deviation (VF-MD) and pattern standard deviation (VF-PSD), and adverse events.

MAIN OUTCOME MEASURES

Surgical success, predictors of treatment failure, postoperative changes in IOP and AGM use, and structural and functional markers of disease stability.

RESULTS

One hundred six eyes were included. The 3-year surgical success according to Criteria A to D was 86%, 83%, 91%, and 67%, respectively. Intraocular pressure decreased by 26.5% from 18.9 ± 4.8 to 13.9 ± 2.3 mmHg (P < 0.001) and AGM use reduced by 33% from 3.0 ± 1.2 to 2.0 ± 1.2 medications (P < 0.001). The postoperative improvement in BCVA was preserved (P < 0.001). The structural and functional markers of disease stability, including CDR, RNFL, and GC-IPL thickness, as well as VF-MD and VF-PSD, remained stable (P > 0.05). Postoperative adverse events were few and transient.

CONCLUSIONS

The 36-month results from this study show that the Hydrus microstent with phacoemulsification is safe and effective in reducing the IOP and AGM among patients with mild to severe open-angle glaucoma and can slow down the disease progression by preserving both structural and functional parameters.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.