Evaluation of a Trabecular Micro-Bypass Stent in Pseudophakic Patients With Open-Angle Glaucoma:

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.

Comparison of Outcomes of Phacoemulsification Combined with Endoscopic Cyclophotocoagulation, iStent, or Both in the Management of Open-Angle Glaucoma

INTRODUCTION

To compare outcomes of phacoemulsification combined with endoscopic cyclophotocoagulation (phaco/ECP), first generation iStent implantation (phaco/iStent), or both (phaco/iStent/ECP) in patients with open-angle glaucoma.

METHODS

A retrospective chart review was performed on patients at the University of Colorado Department of Ophthalmology. Outcomes included intraocular pressure (IOP), medication use, best corrected visual acuity (BCVA), and surgical complications were analyzed. Success was defined as IOP reduction of ≥ 20% and/or reduction by at least one glaucoma medication.

RESULTS

A total of 394 eyes were included in the study. There were 170 eyes (43.1%) in the phaco/ECP group, 175 eyes (44.4%) in the phaco/iStent group, and 49 eyes (12.4%) in the phaco/iStent/ECP group. The mean pre-operative IOP was 15.9 mmHg for phaco/ECP, 15.8 mmHg for phaco/iStent, and 15.2 mmHg for phaco/iStent/ECP. At 24 months, the mean IOP was 13.7 mmHg (p < 0.0001), 14.2 mmHg (p = 0.0001), and 13.0 mmHg (p = 0.0007), respectively. The mean pre-operative number of glaucoma medications was 2.0 for phaco/ECP, 1.4 for phaco/iStent, and 2.2 for phaco/iStent/ECP and at 24 months post-surgery decreased to, 1.8 (p = 0.011), 0.9 (p < 0.0001), and 1.7 (p = 0.01), respectively. The success rate at 24 months was 54.4% for phaco/ECP, 75.3% for phaco/iStent, and 55.6% for phaco/iStent/ECP.

CONCLUSION

Phacoemulsification when combined with ECP, iStent, or both, lowered IOP and glaucoma medication reliance at 24 months. The success rate for phaco/iStent was significantly higher than phaco/ECP. When iStent was added to phaco/ECP, the success rate was higher at earlier postoperative visits compared to the phaco/ECP alone.

FP and EP2 prostanoid receptor agonist drugs and aqueous humor outflow devices for treating ocular hypertension and glaucoma

Prostaglandin (PG) receptors represent important druggable targets due to the many diverse actions of PGs in the body. From an ocular perspective, the discovery, development, and health agency approvals of prostaglandin F (FP) receptor agonists (FPAs) have revolutionized the medical treatment of ocular hypertension (OHT) and glaucoma. FPAs, such as latanoprost, travoprost, bimatoprost, and tafluprost, powerfully lower and control intraocular pressure (IOP), and became first-line therapeutics to treat this leading cause of blindness in the late 1990s to early 2000s. More recently, a latanoprost-nitric oxide (NO) donor conjugate, latanoprostene bunod, and a novel FP/EP3 receptor dual agonist, sepetaprost (ONO-9054 or DE-126), have also demonstrated robust IOP-reducing activity. Moreover, a selective non-PG prostanoid EP2 receptor agonist, omidenepag isopropyl (OMDI), was discovered, characterized, and has been approved in the United States, Japan and several other Asian countries for treating OHT/glaucoma. FPAs primarily enhance uveoscleral (UVSC) outflow of aqueous humor (AQH) to reduce IOP, but cause darkening of the iris and periorbital skin, uneven thickening and elongation of eyelashes, and deepening of the upper eyelid sulcus during chronic treatment. In contrast, OMDI lowers and controls IOP by activation of both the UVSC and trabecular meshwork outflow pathways, and it has a lower propensity to induce the aforementioned FPA-induced ocular side effects. Another means to address OHT is to physically promote the drainage of the AQH from the anterior chamber of the eye of patients with OHT/glaucoma. This has successfully been achieved by the recent approval and introduction of miniature devices into the anterior chamber by minimally invasive glaucoma surgeries. This review covers the three major aspects mentioned above to highlight the etiology of OHT/glaucoma, and the pharmacotherapeutics and devices that can be used to combat this blinding ocular disease.

Combined Microinvasive Glaucoma Surgery - A Review of the Literature and Future Directions

The use of microinvasive invasive glaucoma surgery (MIGS) in the treatment of glaucoma has increased exponentially over the last 10 years. However, practice patterns vary widely given the relative newness of these technologies. Some surgeons perform two or more MIGS simultaneously, such as those that target aqueous production and those that target aqueous outflow. These combined MIGS (cMIGS) may result in lower intraocular pressure (IOP) and reduced medication burden as compared to single MIGS (sMIGS). Current evidence suggests some cMIGS are more effective in reducing medication burden for at least 12 months versus sMIGS. This review focuses on the current evidence related to the efficacy of cMIGS as well as novel combinations of standalone MIGS, limitations of the current literature, and future directions for research.

Systematic Literature Review of Clinical, Economic, and Humanistic Outcomes Following Minimally Invasive Glaucoma Surgery or Selective Laser Trabeculoplasty for the Treatment of Open-Angle Glaucoma with or Without Cataract Extraction

Introduction

Selective laser trabeculoplasty (SLT) and minimally invasive glaucoma surgery (MIGS) are increasingly used options for mild-to-moderate open-angle glaucoma (OAG) care. While most MIGS devices are indicated for use in combination with cataract surgery only, with phacoemulsification playing a role in lowering IOP, newer technologies can also be used as standalone glaucoma surgery.

Methods

This systematic literature review (SLR) aimed to assess the clinical, economic, and humanistic outcomes of MIGS and SLT for the treatment of OAG and was conducted according to PRISMA guidelines. Studies that assessed MIGS or SLT in at least one treatment arm versus any other glaucoma treatment in adults with mild-to-moderate OAG were included. Clinical, humanistic (health-related quality of life [HRQoL] and patient burden), and economic data were extracted, and the methodological quality of included studies was evaluated.

Results

A total of 2720 articles were screened, and 81 publications were included. Fifty-eight reported clinical outcomes. The majority assessed iStent or iStent inject (n=41), followed by OMNI (n=9), gonioscopy-assisted transluminal trabeculotomy (GATT) or the Kahook Dual Blade (KDB) (n=7), Hydrus (n=6), SLT (n=5), Xen Gel Stent (n=2), PreserFlo (n=1), and iTrack (n=1). IOP reduction was observed across prospective studies, varying from -31% to -13.7% at month 6 and from -39% to -11.4% at year 1 versus baseline. Most adverse events were transient and non-serious. Limited humanistic and economic data were identified.

Conclusion

Given their established efficacy and safety, there is a rationale for wider use of MIGS in mild-to-moderate OAG. Of the MIGS devices, iStent and OMNI have the largest clinical evidence base supporting their sustained effectiveness.

The effects of antithrombotic therapy in ab interno trabeculotomy with a spatula-shaped microhook

To evaluate the effects of the discontinuation of antithrombotic drugs on intraocular pressure (IOP) reduction and complications from ab interno trabeculotomy for patients with glaucoma. We performed a retrospective chart review on the data of patients treated with antithrombotic agents who have undergone ab interno trabeculotomy through Tanito microhook combined with cataract surgery at the Asahi General Hospital and the Tokyo University Hospital, with 6 months of follow-up. The patients were classified into two groups depending on whether they discontinued (AT-) or continued (AT+) antithrombotic therapy during the perioperative phase. The demographics, pre- and postoperative IOP, medication score, best-corrected visual acuity (BCVA), and postoperative complications were analyzed preoperatively and postoperatively at 1 week and 1–6 months. The series included 44 eyes from 44 Japanese patients. The AT- and AT+ groups included 21 eyes from 21 patients and 23 eyes from 23 patients, respectively. The decrease in IOP from the baseline at 1 week postoperative was significantly different between the two groups (p = 0.009), but there were no significant differences observed in the other visits. Hyphema and IOP spikes exceeding 30 mmHg occurred in 10% and 10% of AT- participants, and in 43% and 26% of AT+ participants, respectively. Hyphema and spikes with hyphema occurred more frequently in the AT+ than in the AT- group (p = 0.02 and p = 0.05). The number of patients who had spikes was not significantly different (p = 0.27). In trabeculotomy using the Tanito microhook®, discontinuing antithrombotic therapy had better IOP-lowering effects and less postoperative complications.

Comparison of effectiveness and complications in trabeculotomy with phacoemulsification between ab externo and ab interno using a spatula-shaped microhook

To compare the short-term surgical effectiveness and safety profile of trabeculotomy ab externo and ab interno with microhook in terms of the recovery of visual acuity. A retrospective chart review was performed on patients who underwent trabeculotomy combined with phacoemulsification and lens implantation at Asahi General Hospital, with 6 months of follow-up. The patients treated by trabeculotomy were classified into two groups depending on the surgical procedures: ab interno with Tanito microhook (TMH) and ab externo with rigid probe trabeculotome (LOT). The demographics, preoperative and postoperative intraocular pressure (IOP), number of medications (Med), best-corrected visual acuity (BCVA), surgical-induced astigmatism (SIA), and postoperative complications were analyzed at pre-operation, and 1 week and 1–6 months post-operation. Fifty-two eyes of 38 Japanese patients underwent TMH and 42 eyes of 32 patients underwent LOT. The decreases in IOP and Med from the baseline were significant at all time points in both groups (p < 0.001), but there were no significant differences between the two groups. BCVA improved significantly in TMH and LOT after the operation (p < 0.001). BCVA and SIA significantly improved, mostly at 1 week in TMH, compared with LOT (p = 0.02 and 0.003). Hyphema and IOP spike exceeding 30 mmHg (spike) occurred in 11% and 6% of participants in TMH, and 33% and 26% of participants in LOT, respectively. Hyphema and IOP spike occurred more frequently in the LOT than in the TMH group (p = 0.01 and 0.005). Ab interno trabeculotomy showed similar IOP-lowering effects as ab externo, but had less postoperative complications.

Standalone iStent Trabecular Micro-bypass Glaucoma Surgery: A Systematic Review and Meta-Analysis

PRECIS

Standalone trabecular micro-bypass glaucoma surgery with the iStent devices is associated with clinically relevant reductions in intraocular pressure (IOP) sustained over a reasonably long-term while simultaneously reducing medication burden and a relatively favorable safety profile.

PURPOSE

While there is a relatively large body of evidence supporting the implantation of the iStent trabecular micro-bypass devices during phacoemulsification in patients with open-angle glaucoma (OAG), its efficacy as a standalone procedure has been less widely reported. The aims of this study were to systematically identify and quantitatively evaluate the efficacy of iStent devices (iStent and iStent inject) when performed independently of cataract surgery in patients with OAG.

METHODS

A systematic review of the literature was undertaken in August 2019 to identify studies of standalone trabecular micro-bypass glaucoma surgery with iStent devices in patients with OAG. All randomized trials were considered and nonrandomized studies that included at least 6 months of follow-up or more than 10 eyes. Key efficacy analyses included postoperative IOP and medication use, which were used to evaluate weighted mean differences from baseline, and the proportion of eyes free of ocular medication. Postoperative adverse events were descriptively summarized.

RESULTS

A total of 13 studies were identified including 4 randomized controlled trials and 9 nonrandomized or single-arm studies providing data for 778 eyes. In eyes implanted with iStent devices, a weighted mean IOP reduction of 31.1% was observed at 6 to 12 months. In studies reporting longer-term outcomes (36 to 48 mo or 60 mo), the weighted mean IOP reduction was 30.4% and 32.9%, respectively. The pooled weighted mean reduction in IOP from baseline across all studies at 6 to 12 months and 36 to 60 months poststent implantation was 7.01 mm Hg (95% confidence interval: 5.91, 8.11) and 6.59 mm Hg (95% confidence interval: 5.55, 7.63), respectively. Medication burden was reduced by ~1.0 medication at 6 to 18 months and 1.2 medications at 36 to 60 months. Adverse events reported in more than 5% of participants were progression of pre-existing cataract/cataract surgery and loss of best-corrected visual acuity but these rates were no different to those reported in comparator medical therapy study arms.

CONCLUSIONS

The results from these studies support the independent effect of the iStent trabecular bypass devices on IOP and medication burden over a duration of follow-up of up to 5 years.

Use of iStent as a Standalone Operation in Patients with Open-Angle Glaucoma

Purpose

The iStent provides a direct pathway for aqueous outflow from the anterior chamber to Schlemm's canal in patients with open-angle glaucoma (OAG). We performed a meta-analysis to evaluate the effectiveness of iStent as a standalone operation in patients with OAG in reducing the intraocular pressure (IOP) and the number of topical glaucoma medications.

Methods

We searched various databases between January 1, 2000, and September 30, 2019, and included only peer-reviewed, prospective, or retrospective clinical studies in our analyses. Details regarding the IOP and the number of medications at baseline and end point were recorded from each study. Standardized mean differences (SMDs) of IOP and medication numbers were calculated. Furthermore, the success rate (the proportion of IOP ≤18 mmHg and IOP reduction ≥20% at end point) and the complication rate were also summarized. Finally, a subgroup analysis was done based on the iStent generation (first and second), follow-up duration (≤6, 6–18, 18–36, and >36 months), and iStent number (one, two, and three). The outcome measures were aggregated SMDs computed from each study.

Results

A total of 17 studies with 978 eyes were included in this analysis. All studies demonstrated a reduction in IOP after iStent implantation. Aggregated SMDs of IOP revealed a significant reduction (SMD = −2.64, 95% confidence interval (CI): −3.21 to −2.07). The success rate was significantly good, and most of the complication rates were low. The number of medications was also significantly reduced (SMD = −1.71, 95% CI: −2.18 to −1.24). The subgroup analysis revealed a reduction in IOP and medication burden in each category of iStent generation, follow-up duration of up to 42 months, and iStent numbers.

Conclusion

Use of iStent as a standalone procedure does reduce the IOP and the number of glaucoma medications. The benefit of iStent lasts for at least 42 months.

iStent inject trabecular microbypass stent implantation with cataract extraction in open-angle glaucoma: early clinical experience

Background

Retrospective, consecutive case series to evaluate the implantation of two second-generation trabecular microbypass stents in combination with cataract surgery in a real-world, clinical setting.

Methods

The series included 56 eyes implanted with the iStent inject device with phacoemulsification. The series consisted of eyes with primary open-angle glaucoma (n = 52) and pseudoexfoliative glaucoma (n = 4). Primary outcome measures included intraocular pressure (IOP) and number of glaucoma medications. Safety outcomes included the need for secondary surgical intervention and the incidence of IOP spikes ≥10 mmHg and ≥ 15 mmHg.

Results

IOP was reduced by 21% to 14.7 ± 2.9 mmHg (p < 0.01) at 6 months postoperative from 18.7 ± 5.8 mmHg at baseline. Preoperatively, the mean number of glaucoma medications was 1.5 ± 0.9 and reduced by 39% to 0.9 ± 1.2 (p < 0.01) at 6 months. At 6 months, 68% of eyes had an IOP ≤15 mmHg, increased from 30% at baseline. 55% of eyes were medication-free at 6 months, up from 18% at baseline. There were no severe postoperative complications. No eyes underwent an additional glaucoma procedure.

Conclusions

Implantation of the iStent inject device with concomitant cataract surgery effectively provides a sustained reduction in IOP with a markedly improved medication burden out to 6 months postoperative. The safety profile is excellent.

Real-world Case Series of iStent or iStent inject Trabecular Micro-Bypass Stents Combined with Cataract Surgery

INTRODUCTION

This real-world retrospective case series assessed 12-month effectiveness and safety following implantation of iStent® or iStent inject® trabecular micro-bypass with cataract surgery.

METHODS

Consecutive patients were implanted with either iStent (comprising 1 stent) or iStent inject (comprising 2 stents), together with cataract surgery. Most patients had primary open-angle glaucoma. Effectiveness outcomes through 12 months included intraocular pressure (IOP) and glaucoma medications. Proportional analyses were completed for eyes achieving IOP ≤ 18 mmHg, IOP ≤ 15 mmHg, or IOP reduction ≥ 20% from preoperative; and eyes on 0 medications or ≥ 2 medications. Safety outcomes included adverse events, secondary surgeries, visual acuity, and visual fields.

RESULTS

This analysis included 137 eyes (67 iStent, 70 iStent inject) with cataract and mild to moderate glaucoma or ocular hypertension. Over 73% of eyes in both groups had early disease, and ~ 22% had prior glaucoma surgery. At 12 months postoperatively, mean IOP decreased from 18.4 ± 4.2 mmHg to 14.2 ± 2.5 mmHg in iStent eyes (p < 0.0001), and from 20.4 ± 5.6 mmHg to 14.4 ± 2.1 mmHg in iStent inject eyes (p < 0.0001). The IOP reduction was significantly greater for iStent inject eyes than iStent eyes (6.0 mmHg versus 4.2 mmHg reduction, p = 0.034). Both groups had high proportions of patients achieving the 12-month IOP endpoints, although consistently greater proportions reached these endpoints after iStent inject than iStent: 95.7% versus 92.5% had IOP ≤ 18 mmHg, respectively; 74.3% versus 71.6% had IOP ≤ 15 mmHg, respectively; and 68.6% versus 62.7% had IOP reduction ≥ 20% from baseline, respectively. Mean medication burden at 12 months decreased from 1.8 ± 0.7 to 0.3 ± 0.5 medications in iStent eyes (84.0% reduction, p < 0.0001), and from 1.3 ± 0.9 to 0.1 ± 0.3 medications in iStent inject eyes (94.7% reduction, p < 0.0001). Significantly more iStent inject eyes were medication-free at 12 months than iStent eyes (92.9% versus 76.1% medication-free, respectively; p = 0.0068). Favorable safety included few adverse events, no secondary glaucoma surgeries, and stable visual acuity and visual fields in both groups.

CONCLUSION

Significant and safe IOP and medication reductions were achieved through 12 months after iStent or iStent inject implantation with cataract surgery. iStent inject eyes had greater absolute IOP reduction and more eyes medication-free versus iStent eyes.

FUNDING

Glaukos Corporation.

Hydrus microstent implantation for surgical management of glaucoma: a review of design, efficacy and safety

With the advent of microinvasive glaucoma surgery (MIGS), the spectrum of modalities available to manage patients with this chronic and heterogeneous condition has broadened. Despite its novelty however, there has been a rapid evolution in the development of a multitude of devices, each targeting a structure along the aqueous drainage pathway. A growing body of evidence has demonstrated IOP and medication burden reduction, and a more favorable safety profile with MIGS procedures in contrast to traditional incisional surgeries. Among the array of MIGS, the Hydrus® Microstent (Ivantis, Inc., Irvine, CA) is a recent FDA approved device, designed to bypass the trabecular meshwork and provide a scaffold for Schlemm’s canal. The objective of this article is to review the Hydrus from conception to clinical use, and present data on its efficacy and safety to date. The available literature has shown promise, however inherent to all novel devices, only long-term monitoring will ensure sustained IOP control and an acceptable safety profile. Surgical advancements in glaucoma have revolutionized the field, and continued research and development will establish these approaches in clinical treatment algorithms.

One-Year Comparative Evaluation of iStent or iStent inject Implantation Combined with Cataract Surgery in a Single Center

INTRODUCTION

This retrospective consecutive case series assessed 12-month effectiveness and safety of iStent® or iStent inject® trabecular micro-bypass implants with cataract surgery in patients with open-angle glaucoma (OAG) in a real-world clinical setting.

METHODS

Effectiveness outcomes consisted of intraocular pressure (IOP) reduction; glaucoma medication reduction; proportions of eyes achieving IOP < 18, < 15, or < 12 mmHg; and proportional analysis of medication usage. Safety outcomes included adverse events, secondary surgeries, and best-corrected visual acuity (BCVA).

RESULTS

This evaluation included 58 eyes with OAG (35 iStent, 23 iStent inject), with 96.6% of eyes having mild or moderate glaucoma. Diagnoses included primary open-angle glaucoma (the majority; 72.4%), pseudoexfoliative glaucoma, and pigmentary glaucoma. Baseline mean IOP and medications were statistically comparable between groups: 16.1 ± 3.6 mmHg on a mean of 1.8 ± 0.8 medications in the iStent group, and 16.2 ± 3.1 mmHg on a mean of 1.7 ± 0.8 medications in the iStent inject group. Twelve months after stent-cataract surgery, mean IOP was significantly lower in the iStent inject group than in the iStent group (13.1 mmHg vs. 15.4 mmHg, respectively; p < 0.001), and the percent reduction in IOP from baseline was significantly greater in iStent inject eyes than in iStent eyes (19.1% vs. 4.3% reduction, respectively; p < 0.001). At 12 months postoperative, significantly greater proportions of iStent inject eyes than iStent eyes achieved IOP < 18 mmHg (100% vs. 80.0% of eyes, respectively; p = 0.035), IOP < 15 mmHg (73.9% vs. 34.3% of eyes, respectively; p = 0.003), and IOP < 12 mmHg (26.1% vs. 0% of eyes, respectively; p = 0.002). Meanwhile, both groups achieved significant medication reductions at 12 months vs. baseline (94.1% reduction in iStent inject eyes, p < 0.0001; and 72.2% reduction in iStent eyes, p < 0.0001), with the percent reduction being significantly greater in iStent inject eyes than in iStent eyes (p = 0.023). At 12 months, mean number of medications was significantly lower in iStent inject eyes than iStent eyes (0.1 vs. 0.5 medications, respectively; p = 0.021), and significantly more iStent inject eyes (95.7%) than iStent eyes (71.4%) were off medications entirely (p = 0.021). A similarly high safety profile was observed in both groups.

CONCLUSION

iStent or iStent inject implantation with cataract surgery resulted in substantial and safe reductions in IOP and medications through 12 months postoperative. Consistent with prior observations, greater efficacy was observed with iStent inject than with iStent.

FUNDING

The Rapid Service Fees were funded by Glaukos Corporation.

Three-year outcomes of combined trabecular micro-bypass and phacoemulsification in a predominantly Hispanic population with primary open-angle glaucoma

Purpose: To present long-term, real-world outcomes after implanting one trabecular micro-bypass stent with cataract surgery for primary open-angle glaucoma (POAG) in a predominantly Hispanic patient population. Patients and methods: This retrospective, consecutive case series evaluated intraocular pressure (IOP), medications, and safety through 36 months after implanting one iStent^® during phacoemulsification cataract surgery. Eyes were stratified into 2 subgroups classified by preoperative IOP and surgical goal. The Controlled Group had IOP <18 mmHg on ≥1 medications, and goal to reduce medications. The Uncontrolled Group had IOP ≥18 mmHg and/or maximum tolerated medication load, and goal to reduce IOP. Assessments included IOP, medications, visual fields (VF), retinal nerve fiber layer thickness (RNFL), adverse events, and secondary surgeries. Results: Of 168 total operated eyes, 87 eyes (49 Controlled, 38 Uncontrolled) completed 36 months of follow-up and comprise the Consistent Cohort in this report. At baseline, 79.6% (39/49) of Controlled eyes and 71.1% (27/38) of Uncontrolled eyes were from Hispanic patients. In the Controlled Group desiring medication reduction, mean medications were reduced by 77.3% (2.6 medications preoperatively vs 0.6 at 36 months; p<0.001. All Controlled eyes maintained or reduced medications versus preoperative; no eyes were on ≥3 medications (vs 61.2% preoperatively); and 58.3% were medication-free (vs 0% preoperatively). In the Uncontrolled Group desiring IOP reduction, mean IOP decreased by 31.2% (19.4 mmHg preoperatively vs 13.4 mmHg at 36 months; p<0.001), 91.7% of eyes achieved IOP ≤18 mmHg, 69.4% reached IOP ≤15 mmHg, and 77.8% decreased IOP ≥20% vs baseline. Uncontrolled eyes also experienced a 45.3% medication reduction (2.2 medications preoperatively vs 1.2 at 36 months; p<0.001). Favorable safety included no intraoperative complications, and stable VF and RNFL through 36 months. Conclusion: In this predominantly Hispanic patient cohort, significant IOP and medication reductions were sustained safely through 36 months after iStent implantation during cataract surgery.

The long-term outcome of trabeculotomy: comparison with filtering surgery in Japan

Background

To investigate the long-term outcome of trabeculotomy and to compare it with that of trabeculectomy.

Methods

We retrospectively reviewed the medical records of patients who had undergone standalone trabeculotomy. Inclusion criteria included a follow-up period of at least 6 years, availability of reliable static visual field results, etc. Age- and preoperative intraocular pressure -matched trabeculectomy cases served as controls. A Kaplan-Meier analysis was employed as a measure of surgical success. Additional clinical factors were also analyzed.

Results

Twenty-five eyes of 25 trabeculotomy patients and 20 eyes of 20 trabeculectomy patients with a mean postoperative follow-up period of 8.0 years were selected. The Kaplan-Meier analysis estimated that the success probability defined as intraocular pressure < 16 mmHg was 44.0 ± 9.9% and 75.0 ± 9.7% at 6 years for trabeculotomy and trabeculectomy, respectively. The final mean deviation significantly progressed in trabeculotomy cases in Central 30–2 programs of the Humphrey Field Analyzer (P = 0.025). Patient characteristics and postoperative clinical data were analyzed by Mann-Whitney’s U test and Wilcoxon signed-rank test.

Conclusions

While trabeculotomy was inferior to trabeculectomy in terms of intraocular pressure control and visual field stability in our series, surgical indications should always be determined on an individual basis, pending further research.

Five-Year, Prospective, Randomized, Multi-Surgeon Trial of Two Trabecular Bypass Stents versus Prostaglandin for Newly Diagnosed Open-Angle Glaucoma

PURPOSE

To evaluate 5-year safety and efficacy of 2 trabecular micro-bypass stents versus prostaglandin as initial stand-alone treatment for newly diagnosed, treatment-naive primary open-angle glaucoma (POAG).

DESIGN

Prospective, randomized, controlled, multi-surgeon clinical trial.

PARTICIPANTS

Enrolled eyes (n = 101) were phakic and had a confirmed POAG diagnosis, normal angle anatomy, mean diurnal intraocular pressure (IOP) 21 to 40 mmHg, and vertical cup-to-disc (C:D) ratio ≤0.9.

METHODS

Eyes were randomized (1:1) to receive either 2 stents (iStent trabecular micro-bypass; Glaukos Corporation, San Clemente, CA) or once-daily topical travoprost.

MAIN OUTCOME MEASURES

The primary and secondary efficacy end points were the change from screening in mean diurnal IOP at months 12 and 24, respectively, without glaucoma surgery or add-on medication (any medication in stent eyes or a second medication in travoprost eyes). Two additional secondary end points were the proportion of eyes achieving treatment success at months 12 and 24, defined as IOP 6 to 18 mmHg without additional medication or glaucoma surgery. This report shows these efficacy measures through 60 months. Safety measures included best-corrected visual acuity, C:D ratio, visual field, pachymetry, complications, and adverse events.

RESULTS

Of 101 enrolled eyes (54 stent eyes, 47 travoprost eyes), 90 eyes (49 stent eyes, 41 travoprost eyes) completed 5-year follow-up. Five-year mean diurnal IOP was 16.5±1.2 mmHg in stent eyes (35.3% reduced vs. 25.5±2.5 mmHg preoperatively; P < 0.0001) and 16.3±1.9 mmHg in travoprost eyes (35.1% reduced vs. 25.1±4.6 mmHg preoperatively; P < 0.0001). During follow-up, add-on medication was initiated in 12 stent eyes (22.2% of the initial 54-eyes) and 18 travoprost eyes (38.3% of the initial 47-eyes). By 5 years, 17% (6/35) of stent eyes and 44% (14/32) of travoprost eyes needed add-on medication to control IOP (P = 0.017). Treatment success was achieved in 77% (27/35) of stent eyes and 53% (17/32) of travoprost eyes (P = 0.04). Both groups exhibited excellent safety.

CONCLUSIONS

This prospective randomized trial demonstrates 5-year effectiveness and safety of 2 trabecular bypass stents in patients with newly diagnosed, treatment-naive POAG, with comparably favorable outcomes as topical prostaglandin.

Intermediate Results of iStent or iStent inject Implantation Combined with Cataract Surgery in a Real-World Setting: A Longitudinal Retrospective Study

INTRODUCTION

In this real-world, retrospective, comparative study we evaluated 6-month performance and safety in consecutive eyes following implantation of the iStent® or iStent inject® trabecular micro-bypass device with concomitant cataract surgery.

METHODS

Performance outcomes included intraocular pressure (IOP) reduction; glaucoma medication reduction; proportions of eyes achieving an IOP of < 18, < 16, < 14, or < 12 mmHg; and proportions of eyes on 0, 1, 2, or ≥ 3 medications. Safety outcomes included adverse events, secondary surgeries, and best-corrected visual acuity (BCVA).

RESULTS

A total of 73 eyes with open-angle glaucoma and cataract were included in the study; of these, 38 eyes were implanted with the iStent device and 35 were implanted with the iStent inject device. The two groups of patients had similar baseline characteristics, with the exception of mean age and medication burden (both higher in patients receiving the iStent inject device); over 90% of eyes in both groups had early glaucoma. At 6 months after surgery, mean IOP had fallen from 16.5 ± 3.9 to 13.9 ± 2.3 mmHg in eyes with the iStent implant (p < 0.001), and from 17.3 ± 3.0 to 12.7 ± 1.8 mmHg in those with the iStent inject implant (p < 0.001). This reduction was significantly greater in the iStent inject eyes than in the iStent eyes (26.6 vs. 15.8%) (p = 0.005). Significantly more eyes receiving the iStent inject device compared to the iStent device achieved an IOP of < 18 mmHg at 6 months post surgery (100 vs. 86.8%) (p = 0.033). Average medication usage was reduced from 1.8 to 0.4 medications in iStent eyes (p < 0.001) and from 2.3 to 0.4 medications in iStent inject eyes (p < 0.001). Over 70% of eyes in both groups became medication-free by 6 months post implantation. Adverse events in iStent eyes were mild and resulted in no sequelae; two iStent eyes underwent non-penetrating deep sclerectomy during follow-up. No complications or secondary surgeries were noted in iStent inject eyes. All eyes in both groups maintained or showed improved BCVA versus baseline.

CONCLUSION

Significant and safe IOP and medication reductions were observed after iStent or iStent inject implantation with concomitant cataract surgery. Trends toward greater effectiveness and fewer adverse events were observed with the iStent inject device compared with the iStent device.

FUNDING

Article processing charges were provided by Glaukos Corporation.

Supraciliary microstent implantation for open-angle glaucoma: multicentre 3-year outcomes

Objective

To describe the safety and effectiveness of CyPass supraciliary microstent implantation alone in eyes with open-angle glaucoma (OAG) followed up for up to 3 years.

Methods and analysis

This registry study included subjects with primary or secondary OAG who underwent CyPass Micro-Stent implantation alone at 12 sites in four European countries to reduce intraocular pressure (IOP) and/or use of IOP-lowering medications. The primary safety outcome was the incidence of adverse events. Secondary efficacy outcomes included mean changes from baseline in IOP and IOP-lowering medications. Eyes were subgrouped into those with low (< 21 mm Hg) and high (> 21 mm Hg) baseline IOP.

Results

This study included 225 eyes of 178 patients, with mean baseline IOP of 22.6 ± 6.7 mm Hg and a mean 2.2 ± 1.2 medications per eye. Common ocular adverse events included device obstruction (10.2%), IOP elevation > 10 mm Hg during follow-up (8.9%), retinal complications (4.4%) and loss of > 2 lines of best-corrected visual acuity (2.7%). Seventy-one eyes (31.6%) required secondary glaucoma surgery, with trabeculectomy (33 eyes) and second microstent implantation (13 eyes) being most common. At months 6–36, mean IOP reductions ranged from 4.4 to 5.1 mm Hg (15.8%–19.5%) and mean medication reductions from 0.2 to 1.2 (9.1%–54.5%). Mean IOP reduction was greater in eyes with higher than lower baseline IOP. Both subgroups showed reductions of 0.5–1.0 medication at 12–18 months.

Conclusion

CyPass microstent implantation demonstrated a safety profile consistent with other minimally invasive glaucoma surgeries and effectively lowered IOP for up to 3 years in eyes with OAG.

Prospective, Non-randomized, 36-Month Study of Second-Generation Trabecular Micro-Bypass Stents with Phacoemulsification in Eyes with Various Types of Glaucoma

Introduction

The aim of this study was to assess 36-month outcomes after cataract surgery and implantation of two second-generation trabecular micro-bypass stents (iStent inject, Glaukos Corporation, San Clemente, CA, USA) into eyes with predominantly primary open-angle glaucoma (POAG) or pseudoexfoliative glaucoma (PEX).

Methods

This prospective, non-randomized, consecutive cohort study included eyes with POAG (n = 60), PEX (n = 15), appositional narrow-angle (n = 4), pigmentary (n = 1), or neovascular (secondary) (n = 1) glaucoma and cataract requiring surgery. All eyes (n = 81) underwent ab interno iStent inject implantation following cataract surgery. Effectiveness endpoints through 36 months included intraocular pressure (IOP), number of medications, and proportion of eyes with ≥ 20% IOP reduction, IOP ≤ 18 mmHg, and IOP ≤ 15 mmHg. Safety measures included corrected distance visual acuity (CDVA), adverse events, and secondary surgeries. Outcomes were evaluated for the overall cohort, and for the POAG and PEX subgroups.

Results

Preoperatively, 32.1% of eyes had undergone prior glaucoma surgery, 56% were on 3–4 medications, and 1 eye (1%) was medication-free. At 36 months postoperatively, mean IOP reduced by 37% (14.3 ± 1.7 mmHg versus 22.6 ± 6.2 mmHg preoperatively), and mean medication burden decreased by 68% (0.8 ± 0.9 versus 2.5 ± 1.1 medications preoperatively). IOP reduced by ≥ 20% in 78% of eyes; 100% of eyes reached IOP ≤ 18 mmHg and 71% reached ≤ 15 mmHg. Medication burden reduced considerably: 22 eyes (54%) were medication-free compared to 1 eye (1%) preoperatively; 1 eye (2%) required ≥ 3 medications compared to 45 eyes (56%) preoperatively; and 92.7% of eyes required reduced medications postoperatively. From 3 through 36 months, mean IOP remained ≤ 15.0 mmHg, and mean number of medications remained ≤ 0.9. Outcomes in the POAG and PEX subgroups included 33% and 32% lower IOP, and 68% and 64% fewer medications, respectively. iStent inject showed a favorable safety profile, including no intraoperative complications, minimal adverse events, and a stable CDVA.

Conclusion

This real-world cohort of eyes with various types of glaucoma and considerable disease burden exhibited durable and safe IOP and medication reductions through 36 months following iStent inject implantation with cataract surgery. Outcomes were similarly beneficial in eyes with POAG and PEX.

Funding

Article processing charges were funded by Glaukos Corporation (San Clemente, CA, USA).

Six-Month Outcomes of Goniotomy Performed with the Kahook Dual Blade as a Stand-Alone Glaucoma Procedure

INTRODUCTION

To characterize the reduction in intraocular pressure (IOP) and IOP-lowering medication use following goniotomy via trabecular meshwork excision performed using the Kahook Dual Blade as a stand-alone procedure in adult eyes with glaucoma uncontrolled on a regimen of 1-3 topical IOP-lowering medications.

METHODS

In this retrospective analysis, data from consecutive patients undergoing goniotomy with the Kahook Dual Blade by 11 surgeons were analyzed. Preoperative, intraoperative, and postoperative follow-up data through 6 months of follow-up were collected. The primary efficacy endpoint was IOP reduction from preoperative baseline; reduction in IOP-lowering medication use was a secondary endpoint.

RESULTS

Data were collected from 53 eyes of 42 subjects. Mean (± SE) preoperative IOP was 23.5 ± 1.1 mmHg, and from day 1 through 6 months of postoperative follow-up mean IOP reductions of 7.0-10.3 mmHg (29.8-43.8%; p < 0.001 at each time point) were observed. Mean preoperative medication use was 2.5 ± 0.2 medications per eye and was reduced by month 6 to 1.5 ± 0.2 (a 40.0% reduction; p < 0.05). Eyes with higher baseline IOP experienced mean IOP reductions of 13.7 mmHg (- 46.4%) at month 6, while eyes with lower baseline IOP experienced mean IOP reductions of 3.8 mmHg (- 21.0%) at month 6. Mean medications were reduced by 1.3 medications in high-IOP eyes and by 0.9 in low-IOP eyes at month 6. No significant sight-threatening adverse events were observed.

CONCLUSIONS

Goniotomy via trabecular meshwork excision performed using the Kahook Dual Blade effectively and safely lowered IOP when performed as a stand-alone procedure in eyes with glaucoma. The significant drop in IOP met or exceeded the recommended targets for these glaucoma patients.

FUNDING

New World Medical, Inc.

A cost minimisation analysis comparing iStent accompanying cataract surgery and selective laser trabeculoplasty versus topical glaucoma medications in a public healthcare setting in New Zealand

PURPOSE

To produce an economic comparison of the iStent ab interno trabecular microbypass implant accompanying cataract surgery and selective laser trabeculoplasty (SLT) as first-line treatment versus topical medications for open-angle glaucoma in New Zealand in 2016.

METHODS

The current annual costs of 19 available fully subsidised topical glaucoma medications by Pharmaceutical Management Agency (Pharmac) in 2016 were identified. Adjustments for pharmacist prescribing charges and previously described wastage levels were applied. The costs to perform iStent implantation and the cost to perform SLT were obtained from the local distributors, with the latter taking into account staff and consumable cost. Procedure costs divided by eye drops' cost produced a break-even level in equivalent years of eye drops use.

RESULTS

The range of annual eye drop cost was NZD$42.25 to NZD$485.11, with an average of NZD$144.81. Comparison of annual eye drop cost with iStent cost revealed 3 of 19 (15.8%) drops breaking even within 5 years, 9 of 19 (47.3%) within 10 years, and 12 of 19 (63.2%) within 15 years. The cost of bilateral SLT performed by a consultant was NZD$102.30 (breaking even in 0.71 years). The equivalent cost for a registrar was NZD$97.59 (breaking even in 0.67 years).

CONCLUSION

Economically, the iStent would appear to be a reasonably cost-effective treatment for glaucoma patients undergoing cataract surgery in a public healthcare setting in New Zealand, particularly for those using more expensive topical glaucoma medications, whilst SLT appears to be a worthwhile consideration as a first-line treatment for glaucoma in New Zealand.

Prospective Evaluation of Two iStent® Trabecular Stents, One iStent Supra® Suprachoroidal Stent, and Postoperative Prostaglandin in Refractory Glaucoma: 4-year Outcomes

Introduction

This study evaluates long-term outcomes of two trabecular micro-bypass stents, one suprachoroidal stent, and postoperative prostaglandin in eyes with refractory open angle glaucoma (OAG).

Methods

Prospective ongoing 5-year study of 80 eligible subjects (70 with 4-year follow-up) with OAG and IOP ≥ 18 mmHg after prior trabeculectomy and while taking 1–3 glaucoma medications. Subjects received two iStent^® trabecular micro-bypass stents, one iStent Supra^® suprachoroidal stent, and postoperative travoprost. Postoperative IOP was measured with medication and annually following medication washouts. Performance was measured by the proportion of eyes with ≥ 20% IOP reduction on one medication (the protocol-specified prostaglandin) versus preoperative medicated IOP (primary outcome); and the proportion of eyes with postoperative IOP ≤ 15 and ≤ 18 mmHg on one medication (secondary outcome). Additional clinical and safety data included medications, visual field, pachymetry, gonioscopy, adverse events, visual acuity, and slit-lamp and fundus examinations.

Results

Preoperatively, mean medicated IOP was 22.0 ± 3.1 mmHg on 1.2 ± 0.4 medications, and mean unmedicated IOP was 26.4 ± 2.4 mmHg. Postoperatively, among eyes without later cataract surgery, mean medicated IOP at all visits through 48 months was ≤ 13.7 mmHg (≥ 37% reduction), and annual unmedicated IOP was ≤ 18.4 mmHg (reductions of ≥ 30% vs. preoperative unmedicated IOP and ≥ 16% vs. preoperative medicated IOP). At all postoperative visits among eyes without additional surgery or medication, ≥ 91% of eyes had ≥ 20% IOP reduction on one medication versus preoperative medicated IOP. At month 48, 97 and 98% of eyes achieved IOP ≤ 15 and ≤ 18 mmHg, respectively, on one medication. Six eyes required additional medication, no eyes required additional glaucoma surgery, and safety measurements were favorable throughout follow-up.

Conclusion

IOP control was achieved safely with two trabecular micro-bypass stents, one suprachoroidal stent, and postoperative prostaglandin. This microinvasive, ab interno approach introduces a possible new treatment option for refractory disease.

Trial Registration

NCT01456390.

Funding

Glaukos Corporation.

Electronic supplementary material

The online version of this article (10.1007/s12325-018-0666-4) contains supplementary material, which is available to authorized users.

Long-term titrated IOP control with one, two, or three trabecular micro-bypass stents in open-angle glaucoma subjects on topical hypotensive medication: 42-month outcomes

Purpose

Evaluate long-term outcomes after one, two, or three trabecular micro-bypass stents implanted in a standalone procedure in eyes with open-angle glaucoma taking ocular hypotensive medication.

Patients and methods

Prospective randomized ongoing study of 119 subjects (109 with 42-month follow-up) with open-angle glaucoma, preoperative intraocular pressure (IOP) 18-30 mmHg on one to three glaucoma medications, and unmedicated (post-washout) IOP 22-38 mmHg. Subjects were randomized to receive one (n=38), two (n=41), or three (n=40) iStent trabecular micro-bypass stents in a standalone procedure. Postoperatively, IOP was measured with medication and annually following washout. Data included IOP, medications, gonioscopy, pachymetry, visual field, visual acuity, adverse events, and slit-lamp and fundus examinations.

Results

Preoperative mean medicated IOP was 19.8±1.3 mmHg on 1.71 medications in one-stent eyes, 20.1±1.6 mmHg on 1.76 medications in two-stent eyes, and 20.4±1.8 mmHg on 1.53 medications in three-stent eyes. Post-washout IOP prior to stent implantation was 25.0±1.2, 25.0±1.7, and 25.1±1.9 mmHg in the three groups, respectively. Postoperatively, Month 42 medicated IOP was 15.0±2.8, 15.7±1.0 and 14.8±1.3 mmHg in the three groups, and post-washout IOP (Months 36-37) was 17.4±0.9, 15.8±1.1 and 14.2±1.5 mmHg, respectively. IOP reduction ≥20% without medication was achieved in 89%, 90%, and 92% of one-, two-, and three-stent eyes, respectively, at Month 12; and in 61%, 91%, and 91% of eyes, respectively, at Month 42. The need for additional medication remained consistent at Months 12 and 42 in multi-stent eyes (four two-stent eyes and three three-stent eyes at both time points), whereas it increased in single-stent eyes (four eyes at Month 12 versus 18 eyes at Month 42). Safety parameters were favorable in all groups.

Conclusion

The standalone implantation of either single or multiple iStent^® device(s) produced safe, clinically meaningful IOP and medication reductions through 42 months postoperatively, with incrementally greater and more sustained reductions in multi-stent eyes.

Ab Interno Gel Implant for the Treatment of Glaucoma Patients With or Without Prior Glaucoma Surgery: 1-Year Results

PURPOSE

The purpose of this study is to evaluate IOP lowering effects and complication management of an ab interno gel implant for the treatment of patients refractory to antiglaucoma medication or glaucoma surgery.

METHODS

Retrospective analysis of the medical records of 242 consecutive eyes of 146 patients with uncontrolled intraocular pressure (IOP) despite maximum tolerated medical therapy or prior surgical intervention that underwent XEN45 implantation (as sole procedure or in combination with cataract surgery) between March 2014 and June 2015. Data included IOP, number of glaucoma medications, the need for additional surgery, needling, and complications.

RESULTS

During the study period, mean IOP had decreased by 54.1% from 32.19 (±9.1) mm Hg to 14.24 (±4.0) mm Hg (P=0.00; Wilcoxon test). The number of antiglaucoma medications had decreased from a mean of 3.13±1.0 to 0.3±0.7 (P=0.00; Wilcoxon test). Needling was required between week 1 and months 3 in 27.7% of all eyes to enhance the outflow. Hypotony (IOP<6 mm Hg) was observed in 9 eyes (4.0%) at 1 month but normalized in all eyes at 12 months postoperatively. Two eyes experienced hypotony requiring the refill of the anterior chamber.

CONCLUSIONS

Our data indicate that the XEN45 gel implant has a favorable safety profile and is an effective treatment option for controlling IOP in glaucoma patients with unregulated IOP despite IOP lowering medical therapy or prior surgical intervention. It offers an effective approach, both as sole procedure and in combination with cataract surgery.

Safety and Efficacy of Microinvasive Glaucoma Surgery

Microinvasive glaucoma surgery (MIGS) is emerging as a new therapeutic option for glaucoma patients who wish to reduce their medication burden and avoid the postoperative complications of conventional glaucoma filtration surgery. These devices differ in terms of their efficacy and safety profile. Schlemm's canal devices have the most favorable safety profile at the compromise of modest efficacy, while subconjunctival and suprachoroidal devices are potentially more effective at lowering the intraocular pressure at the expense of a higher rate of complications. This review consolidates the latest evidence on the efficacy and safety of the MIGS devices in clinical use and provides an overview on upcoming devices which would likely also become viable treatment options in the near future. These clinical data would assist a glaucoma surgeon in selecting the most appropriate MIGS device for each patient based on the glaucoma severity and patient expectations.

Microbypass stent implantation with cataract extraction and endocyclophotocoagulation versus microbypass stent with cataract extraction for glaucoma

PURPOSE

To compare the outcomes of combined microbypass stent implantation, cataract extraction, and endocyclophotocoagulation (ECP) with those of implantation of the same microbypass stent with concomitant cataract surgery in patients with open-angle glaucoma (OAG).

SETTING

Private Practice, Sioux Falls, South Dakota, USA.

DESIGN

Retrospective consecutive case series.

METHODS

Patients from January 2015 to August 2016 were included. The study group comprised eyes that had implantation of a microbypass stent in combination with cataract extraction and ECP. To compare outcomes, a control group of eyes with similar baseline characteristics that had implantation of a stent in combination with cataract surgery was established. Data were collected preoperatively and postoperatively at 1 day, 1 week, and 1, 3, 6, and 12 months. Data included intraocular pressure (IOP) and number of glaucoma medications.

RESULTS

The mean preoperative IOP was 21.49 mm Hg ± 9.56 (SD) in the study group (51 eyes) and 20.66 ± 3.23 mm Hg in the control group (50 eyes). Twelve months postoperatively, the mean IOP reduction was 7.14 mm Hg in the study group and 4.48 mm Hg in the control group and the medication reduction was 38% (0.68) and 63% (1.06), respectively.

CONCLUSIONS

Patients who had implantation of the microbypass stent in combination with cataract surgery and ECP had significantly better IOP reduction than those who did not have ECP. The combination procedure was also effective in patients with severe OAG.

Minimally invasive glaucoma surgery as primary stand-alone surgery for glaucoma

Recently, many new devices and procedures have been developed to lower intraocular pressure in a less invasive and purportedly safer manner than traditional glaucoma surgery. These new devices might encourage an earlier transition to surgery and reduce the long-term commitment to topical glaucoma medications with their associated compliance and intolerance issues. Although often seen as an adjunct to cataract surgery, a growing body of evidence suggests that primary minimally invasive glaucoma surgery may be a viable initial treatment option. New studies have shown that primary ab interno trabeculectomy (Trabectome, NeoMedix Inc., Tustin, CA, USA), trabecular micro-bypass stent insertion (iStent and iStent Inject, Glaukos Corporation, Laguna Hills, CA, USA), canalicular scaffolding (Hydrus, Invantis Inc., Irvine CA, USA), the ab interno gel Implant (XEN, Allergan, Dublin, Ireland) or supraciliary stenting (CyPass Micro-Stent, Alcon, Fort Worth, TX, USA) may lower the lowering intraocular pressure and/or topical medication burden in phakic or pseudophakic patients with glaucoma. This effect seems to last at least 12 months but reliable cost-effectiveness and quality of life indicators have not yet been established by investigator-initiated randomized trials of sufficient size and duration.