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

Corneal endothelial safety profile in minimally invasive glaucoma surgery

PURPOSE

To compare 5-year corneal endothelial safety of 3 minimally invasive glaucoma surgery (MIGS) devices (iStent inject , Hydrus Microstent, CyPass Micro-Stent).

SETTING

U.S. multicenter trials.

DESIGN

Post hoc 5-year analysis from prospective randomized single-masked pivotal trials.

METHODS

Mild to moderate open-angle glaucoma subjects received a MIGS implant with phacoemulsification (implant + phaco) or phaco alone (control). In addition, 5-year end points comparing the implant and control groups included proportion of eyes with significant endothelial cell loss (ECL) (>30% or ≥30% vs baseline) and mean endothelial cell density (ECD).

RESULTS

Comparable proportions of eyes in the iStent inject + phaco and control groups had significant 60-month ECL (9.4% vs 6.3%, respectively, diff: 3.2%, 95% CI, -5.0% to 11.3%, P = .77). Hydrus (20.8% vs 10.6%, diff: 10.2%, 95% CI, 3.2% to 17.2%, P = .01) and CyPass (27.2% vs 10.0%, diff: 17.2%, 95% CI, 5.6% to 28.7%, P = .02) had more eyes with ECL vs controls (iStent inject 1.49X, Hydrus 1.96X, CyPass 2.72X vs controls). Mean ECD over 60 months for iStent inject was indistinguishable vs control, whereas greater ECL was observed primarily 3 months postoperative (Hydrus) or accelerated after 2 years (CyPass). No iStent inject or Hydrus subjects developed persistent corneal edema, whereas 7 CyPass-implanted eyes developed ECL-related complications.

CONCLUSIONS

Through 5 years postoperative, there were no differences in proportion of eyes with significant ECL or mean ECD between the iStent inject and control groups. There was greater 5-year ECL and lower ECD in the Hydrus and CyPass groups vs controls. The Hydrus ECL rate mirrored control after 3 months; the CyPass ECL rate accelerated vs control.

7-Year Efficacy and Safety of iStent inject Trabecular Micro-Bypass in Combined and Standalone Usage

INTRODUCTION

This study evaluated 7-year effectiveness and safety of second-generation trabecular micro-bypass implantation (iStent inject) either in combination with cataract surgery or as a standalone procedure (Combined or Standalone subgroups, respectively) in eyes with open-angle glaucoma.

METHODS

This prospective, non-randomized, unmasked, longitudinal study included 125 consecutive iStent inject cases of a single surgeon at a large German academic hospital. Patients had considerable preoperative disease burden, with mean intraocular pressure (IOP) of 23.5 mmHg, 84.8% of eyes on ≥ 2 medications, and 38.4% of eyes with prior glaucoma surgery. IOP, medications, adverse events, and secondary surgeries were assessed through 7 years in the Overall cohort and in Combined (n = 81) and Standalone (n = 44) subgroups.

RESULTS

Over 7-year follow-up, mean IOP decreased by 36.2-40.0% in Overall eyes, 34.1-38.9% in Combined eyes, and 39.5-43.5% in Standalone eyes (p < 0.001 at all timepoints for all groups). Meanwhile, mean medications decreased by 59.3-71.3% in Overall eyes, 57.9-69.0% in Combined eyes, and 62.1-76.2% in Standalone eyes (p < 0.001 at all timepoints in all groups). At last follow-up (mean 77.4 months; 92.8% of patients with last visit at 6 or 7 years), 83.7% of Overall eyes, 82.3% of Combined eyes, and 86.4% of Standalone eyes had achieved ≥ 20% IOP reduction vs preoperative. At last follow-up vs preoperative, 100% of eyes in all groups had the same or lower IOP and 100% had the same or lower medication regimen. Safety outcomes were favorable, with no filtration surgeries and only 4.84% of eyes experiencing clinically significant visual field loss over 7 years of follow-up.

CONCLUSION

iStent inject implantation with or without phacoemulsification produced significant and durable 7-year reductions in IOP (~ 34-44% reduction) and medications (~ 58-76% reduction) while preventing filtering surgery in this cohort of patients with relatively high preoperative disease burden. Combined and Standalone cases had similarly favorable effectiveness and safety.

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.

Clinical outcomes of Ahmed glaucoma valve implantation in primary open-angle glaucoma and pseudoexfoliative glaucoma

PURPOSE

To investigate the clinical outcomes of Ahmed glaucoma valve (AGV) implantation in primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG).

METHODS

The patients who underwent AGV implantation for POAG and PEXG between January 2015 and December 2021 in a single tertiary center eye clinic were reviewed retrospectively. Thirty-one eyes with the diagnosis of POAG constituted Group 1 and 40 eyes with the diagnosis of PEXG constituted Group 2. The primary outcome measures were intraocular pressure (IOP) changes after AGV implantation and surgical success at the last visit. We evaluated complete and qualified surgical success using the following three criteria: (1) IOP ≤ 21mmH g, (2) IOP ≤ 18 mmHg, and (3) IOP ≤ 15 mmHg, as well as the absence of any serious complications, such as light perception loss and phthisis bulbi, and additional de novo glaucoma surgery.

RESULTS

The mean follow-up times were 25.2 (± 21.4) months and 27.6 (± 19.8) months for Groups 1 and 2, respectively (p > 0.05). In Groups 1 and 2, the mean preoperative IOPs were 31.9 ± 9.4 mmHg and 32.3 ± 8.4 mmHg, respectively, which significantly reduced to 14.5 ± 0.7 mmHg and 11.6 ± 0.6 mmHg, respectively at the last postoperative visit (p < 0.001 for both). The mean IOP value at the last visit was statistically significantly lower in Group 2 (p = 0.006). At the last visit, the number of eyes with qualified success according to criteria 1, 2, and 3 was 26 (83.9%), 25 (80.6%), and 18 (58.1%), respectively, in Group 1 and 39 (97.5%), 39 (97.5%), and 32 (80%), respectively, in Group 2. The comparison of the qualified success rates showed statistically significantly higher rates in Group 2 for criterion 2 (p = 0.038).

CONCLUSION

AGV implantation had high success rates in both POAG and PEXG, but at the final visit, lower IOP levels were reached in the latter.

Trabeculectomy in Eyes With High Myopia

PRCIS

Primary trabeculectomy was safe and effective at lowering intraocular pressure (IOP) in patients with primary open angle glaucoma and high myopia.

PURPOSE

To investigate the efficacy and safety of trabeculectomy in patients with glaucoma and high myopia.

PATIENT AND METHODS

Retrospective case-control study. Glaucomatous patients with high myopia undergoing primary trabeculectomy surgery with at least 1 year of follow-up were compared with an age-matched control group without high myopia undergoing the same procedure. Surgical success was defined as: IOP ≤ 15 mm Hg with (qualified) or without (complete) antiglaucoma medications and at least 20% reduction from baseline IOP at the end of 48 months of follow-up.

RESULTS

We included a total of 90 eyes from 90 patients (45 eyes with high myopia and 45 controls). Within the 90 eyes, 70 eyes underwent trabeculectomy and 20 eyes underwent combined phacoemulsification and trabeculectomy. Although patients with high myopia had higher chances for failure (37% vs. 22%) compared with controls, the difference was not statistically significant ( P =0.067). In the multivariable analysis, patients of African descent ( P =0.043) and those with juvenile glaucoma ( P =0.001) had more chances of failure, even after adjusting for myopia. There was no statistically significant difference between complication rates in both groups.

CONCLUSION

Trabeculectomy was effective in reducing IOP in patients with high myopia and glaucoma, without the additional risk of complications compared with a control group.

Four-Year Efficacy and Safety of iTrack Ab-interno Canaloplasty as a Standalone Procedure and Combined with Cataract Surgery in Open-Angle Glaucoma

PURPOSE

To evaluate the long-term effectiveness of ab-interno canaloplasty (ABiC), performed with the iTrack microcatheter (Nova Eye Medical, Fremont, CA, USA), in reducing intraocular pressure (IOP) as well as the number of required glaucoma medications in patients with open-angle glaucoma (OAG).

METHODS

In this retrospective single-center consecutive case series, 27 eyes of 21 patients (mean age 77.3 ± 5.8 years) were treated with ABiC performed as a standalone procedure or combined with cataract surgery. Patients with uncontrolled IOP OAG or controlled IOP (≤ 18 mmHg) OAG with intolerance to medications or lack of compliance were included. Patients were followed for up to 4 years following the procedure. The iTrack microcatheter was used to perform a 360-degree circumferential intubation and viscodilation of Schlemm's canal. Primary efficacy endpoints included IOP and the number of glaucoma medications at 12, 24, 36, and 48 months after surgery.

RESULTS

In all eyes, mean IOP and number of glaucoma medications were significantly reduced from 19.8 ± 5.2 mmHg and 1.9 ± 1.00 at baseline to 14.6 ± 3 mmHg and 0.9 ± 0.8, respectively, at the 48-month follow-up (p < 0.001). IOP was stable from 12 months to 48 months (p > 0.005). After 48 months, 39% of the eyes required zero medications compared to 3.7% at baseline, and 72.2% of eyes required only one medication or less. Of all eyes, 77.8% recorded an IOP ≤ 17 mmHg. No serious complications were recorded.

CONCLUSION

iTrack ABiC performed as a standalone procedure or in combination with cataract surgery significantly reduced IOP and number of medications in patients with OAG up to 4 years after the procedure.

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.

Position of the ISTENT Inject® Trabecular Micro-Bypass System Visualized with the NIDEK GS-1 Gonioscope-A Postoperative Analysis

Glaucoma is one of the leading causes of irreversible blindness globally and is characterized by the gradual loss of retinal ganglion cells. The primary risk factor for the development and progression of glaucoma is increased intraocular pressure (IOP). Numerous surgical interventions exist to lower IOP should conservative therapy fail. One trend in recent years has been minimally invasive glaucoma surgery (MIGS) as an alternative to traditional methods. The ISTENT inject® is an ab interno trabecular micro-bypass implant designed to be implanted through the trabecular meshwork into the Schlemm's canal to lower IOP. The aim of the study was the postoperative visualization and description of the positioning of the ISTENT inject® using automated circumferential goniophotography. Patients with symptomatic cataracts and mild to moderate primary open-angle glaucoma (POAG), pseudoexfoliation glaucoma (PEX), and pigment-dispersion glaucoma were included who underwent combined cataract surgery with the ISTENT inject® and received postoperative automated gonioscopy with the NIDEK Gonioscope GS-1 to visualize the location of the implant. Twenty-four implants of 14 eyes in 11 patients could be visualized. Out of the implants, 14.3% were in the trabecular meshwork, 46.4% were at the border between the trabecular meshwork and scleral spur, 25% were below the trabecular meshwork, and 14.3% of the implants were not detectable in the gonioscopy. In the overall cohort, a statistically significant IOP reduction was found over the 12-month postoperative observation period. Even in three eyes, in each of which both stents were located below the trabecular meshwork, an IOP reduction over 12 months was observed compared to the baseline IOP. In this study, vertical two-dimensional positioning of the ISTENT inject® was performed for the first time using NIDKE GS-1 automated 360° goniophotography. The method is suitable for postoperative visualization, control, and documentation of positioning after ISTENT inject® implantation. Further studies are needed to analyze the correlation between positioning of the ISTENT inject® in the chamber angle and postoperative IOP reduction.

Safety and efficacy of iStent Inject trabecular micro-bypass stents in combination with phacoemulsification for chronic open angle glaucoma associated with cataract

BACKGROUND

The goal of this study was to assess the efficacy and safety of phacoemulsification combined with iStent Inject® implantation for the treatment of chronic open-angle glaucoma controlled on topical anti-glaucoma medications and associated with cataract.

METHODS

This study was a retrospective analysis of patients who underwent phacoemulsification and implantation of an iStent Inject® for chronic open-angle glaucoma associated with cataract. For all patients, pre- and postoperative characteristics, including number of glaucoma medications and intraocular pressure (IOP), were compared using Paired-sample t-tests and Wilcoxon signed-rank tests, respectively. Postoperative visits were scheduled at 7 days and 1, 3, 6, and 12 months after surgery.

RESULTS

Forty-nine eyes of 39 patients were included in the study. Mean preoperative IOP at baseline was 16.3±4.3mmHg (range, 10-29mmHg) with a mean of 2.2±1.0mmHg antiglaucoma medications. At 1 month, the mean IOP reduction was 16% (P<0.05) along with an 18.7% reduction in the mean number of medications. At 6 months, the mean IOP was 12.8±2.6, with a mean of 1.1±0.9 antiglaucoma medications. The mean IOP reduction at 6 months was 22% (P<0.05) along with a 49% reduction in the mean number of medications. At 12 months, the mean IOP was 13.8±2.5 with a mean of 1.1±1.2 medications. The mean IOP reduction at 12 months was 15% (P<0.05) along with a 47% reduction in the mean number of medications. No severe device-related side effects were observed.

CONCLUSIONS

iStent Inject® implantation combined with phacoemulsification resulted in effective IOP reduction and medication burden in patients with mild to advanced chronic open-angle glaucoma and preoperative IOP well controlled with topical hypotensive medications.

A multicenter prospective comparative study evaluating cataract surgery and endoscopic cyclophotocoagulation either with or without iStent inject implantation in Brazilian patients with glaucoma

Purpose

Compare 12-month (12 M) safety and efficacy of endoscopic cyclophotocoagulation (ECP) + cataract surgery (Group 1) versus ECP + cataract surgery + iStent inject trabecular micro-bypass implantation (Group 2) in Brazilian patients with open-angle glaucoma (OAG).

Methods

This prospective, multicenter, comparative case series included patients with OAG and cataract who were randomized to receive treatment in Group 1 or Group 2. Outcomes included mean and percent reduction versus preoperative in intraocular pressure (IOP) and number of glaucoma medications; visual acuity; occurrence of adverse events; and rate of secondary surgeries.

Results

Preoperatively, Groups 1 and 2 had similar mean IOP (mean ± standard deviation 22.1 ± 3.6 and 22.0 ± 2.5 mmHg, respectively) and mean number of medications (3.3 ± 0.6 and 3.4 ± 0.6 medications, respectively). At all follow-up timepoints through 12 M, both groups achieved significant IOP and medication reductions versus preoperative (IOP p < 0.001 and number of medications p < 0.001 for both groups). At 12 M, IOP reductions were 24.2% (Group 1) and 43.6% (Group 2) (p < 0.001); mean medication reductions were 50.2% and 71.5%, respectively. Mean postoperative IOP and number of medications were higher in Group 1 than Group 2 (IOP p < 0.01 all visits, medication p < 0.01 at 6 M and 12 M). Adverse events were generally mild and infrequent in both groups.

Conclusion

Both treatment groups (ECP + phacoemulsification, with/without iStent inject implantation) achieved significant and safe reductions in IOP and medications versus preoperative in Brazilian OAG patients. Percent reductions were significantly greater, and mean IOP and medications were significantly lower, in the group receiving iStent inject.

Clinical trial registration (CTR)

CAAE project identification #20053019.5.0000.5078. Protocol #3.587.147. Clinical Trial Database of the Federal University of Goiás, Brazil. Registration Date: September 19, 2019.

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

Multicenter Effectiveness and Disease Stability Through 3 Years After iStentTrabecular Micro-Bypass with Phacoemulsification in Glaucoma and Ocular Hypertension

Purpose

To evaluate 3-year safety and efficacy of two second-generation trabecular micro-bypass stents. (iStent inject^®) with phacoemulsification.

Materials and Methods

This multicenter retrospective study of iStent inject implantation with phacoemulsification included data from eight surgeons across Australia. Eyes with cataract and mild to advanced glaucoma [predominantly primary open-angle (POAG), primary angle closure (PAC), or normal-tension (NTG) glaucoma] or ocular hypertension (OHT) were included. Study assessments included intraocular pressure (IOP); number of ocular hypotensive medications; proportions of eyes with 0, 1, 2, or ≥3 IOP-lowering medications; IOP ≤15 mmHg or ≤18 mmHg; visual fields (VF); retinal nerve fiber layer thickness (RNFL); central corneal thickness (CCT); intraoperative complications; adverse events; and secondary surgeries.

Results

A total of 273 eyes underwent surgery and had 36-month follow-up. At 36 months versus preoperative, mean IOP decreased by 15.5% (16.4±4.6 mmHg to 13.9±3.5 mmHg; p<0.001), and 70.3% of eyes achieved IOP of ≤15 mmHg (versus 49.1% preoperatively; p<0.001). The mean medication burden decreased by 68.5% (from 1.51±1.17 to 0.48±0.89 medications; p<0.001); 71.4% of eyes were medication-free (versus 21.6% preoperatively; p<0.001), while 6.2% of eyes were on ≥3 medications (versus 22.3% preoperatively; p<0.001); 96.3% of eyes maintained or reduced medications vs preoperative. Significant IOP and medication reductions occurred across glaucoma subtypes (POAG, PAC, NTG, OHT): 13–22% for IOP (p<0.05 for all) and 42–94% for medication (p<0.05 for all). Favorable safety included few adverse events; stable VF, RNFL, and CCT; and filtering surgery in only 8 eyes (2.9%) over 3 years.

Conclusion

In this multicenter cohort from 8 surgeons across Australia, significant IOP and medication reductions were sustained through 3 years after iStent inject implantation with phacoemulsification. Results were favorable across different glaucoma subtypes (including POAG, PAC, NTG, OHT), severities, and surgeons, thereby underscoring the real-world relevance and efficacy of iStent inject implantation for glaucoma treatment.

Comparative study of 2-year outcomes for Hydrus or iStent inject microinvasive glaucoma surgery implants with cataract surgery

BACKGROUND

To compare real-world 24-month outcomes of phacoemulsification combined with either iStent inject or Hydrus Microstent.

METHODS

Analysis of data from the Fight Glaucoma Blindness (FGB) international registry. Anonymized data from 344 eyes with mild-to-moderate open-angle glaucoma, normal-tension glaucoma or ocular hypertension that underwent phacoemulsification combined with either iStent inject (224) or Hydrus Microstent (120) were included. Data were adjusted for baseline characteristics using linear regression and propensity score matching. The primary endpoint was a comparison of mean intraocular pressure (IOP) at 24 months.

RESULTS

At 24 months, there was no significant difference in IOP reduction between the two groups, consistent across all analyses. The matched cohort showed iStent inject achieved 3.1 mmHg reduction and Hydrus a 2.3 mmHg reduction (p = 0.530) and a mean medication reduction of 1.0 for iStent inject versus 0.5 for Hydrus (p = 0.081). 5.4% of eyes in the iStent inject group and 7.5% of eyes in the Hydrus group required subsequent procedures to improve IOP control within 24 months. Complications were rare with no significant differences between the groups.

CONCLUSIONS

Twenty-four-month outcomes showed sustained IOP reduction with a good safety profile for both groups. There was no significant difference in IOP outcomes between the groups. There may be a small additional reduction in glaucoma medication usage following cataract surgery with iStent inject compared to Hydrus.

iStent inject Trabecular Micro-Bypass with or Without Cataract Surgery Yields Sustained 5-Year Glaucoma Control

Introduction

This study evaluated the 5-year effectiveness and safety of iStent inject^® trabecular micro-bypass with or without cataract surgery (Combined or Standalone, respectively) in patients with open-angle glaucoma (OAG).

Methods

This prospective longitudinal case series included consecutive iStent inject cases from a single surgeon at a large German academic hospital. Intraocular pressure (IOP), medications, safety, and indicators of disease stability through 5 years were assessed in the Overall cohort and in subgroup analyses stratified by usage (Combined or Standalone).

Results

Preoperative mean IOP in the Overall cohort (n = 125) was 23.5 ± 6.2 mmHg on 2.68 ± 1.02 mean medications, reducing to 14.1 ± 1.8 mmHg on 0.77 ± 0.82 medications at 5 years (40% and 71% reductions, respectively; both p < 0.001). All but 1 eye (> 99%) were on medication(s) preoperatively, but 46% were medication-free at 5 years (p < 0.001). In Combined eyes (n = 81), mean IOP decreased by 39% (22.6 mmHg to 13.8 mmHg, p < 0.001) and medications by 69% (2.52 to 0.78, p < 0.001). In Standalone eyes, mean IOP reduced by 42% (25.3 mmHg to 14.6 mmHg, p < 0.001) and medications by 75% (2.98 to 0.74, p < 0.001). At final follow-up, 83% of eyes had achieved ≥ 20% IOP reduction, and all but 1 eye (> 99%) had the same or lower IOP versus preoperative; all eyes (100%) maintained or reduced their medication burden versus preoperative. Favorable safety included 0 intraoperative complications and 0 filtration surgeries through 5 years. Long-term indicators of disease stability (visual fields, retinal nerve-fiber layer thickness, and cup:disc ratio) were unchanged over the course of 5-year follow-up.

Conclusions

iStent inject produced significant and durable 5-year reductions in IOP (nearly 10-mmHg reduction) and medications (nearly 2-medication reduction), with stable disease parameters over time. Combined and Standalone subgroups had similar outcomes.

36-month effectiveness of ab-interno canaloplasty standalone versus combined with cataract surgery for the treatment of open-angle glaucoma

PURPOSE

To report the 36-month effectiveness of ab-interno canaloplasty performed with the iTrack microcatheter (Nova Eye Medical, Fremont, USA) as a standalone procedure or combined with cataract surgery.

DESIGN

A single-center, retrospective case series PARTICIPANTS: Eyes diagnosed with primary open-angle glaucoma (POAG).

METHODS

Eyes with POAG were treated with either ab-interno canaloplasty as a standalone procedure (iTrack-alone) or in conjunction with phacoemulsification (iTrack+phaco).

MAIN OUTCOME MEASURES

The main outcome was mean reduction in intraocular pressure (IOP) and number of glaucoma medications at 12, 24, and 36 months postoperatively. Secondary endpoints consisted of visual acuity and the rate of complications.

RESULTS

44 eyes of 44 patients with open-angle glaucoma were included: 23 eyes in the iTrack-alone group and 21 eyes in the iTrack+phaco group. When both groups were analyzed together, both IOP and the number of medications were significantly reduced at 12 months (p<0.0001) and remained stable at 24 and 36 months. IOP decreased from 20.5±5.1 mmHg preoperatively to 13.3±2.1, 13.1±2.4 and 13.3±2.1 mmHg at 12-24-36 months respectively; the number of medications was reduced from 2.8±0.9 preoperatively to 1.1±1.1, 1.0±1.1 and 1.3±1.3 at 12-24 and 36 months postoperatively. Comparable results were observed in the iTrack-alone and iTrack+phaco groups, from a baseline 20.9±6.1 and 20.0±3.9 to 13.2±2.1 and 13.5±2.2 at 36-month respectively. At 36 months, 95.5% of eyes had IOP ≤17 mmHg and 68.2% of eyes were on ≤1 medication. No serious intra-operative or postoperative complications were reported.

CONCLUSION

Ab-interno canaloplasty performed with the iTrack microcatheter was found to be effective in reducing IOP and medication dependence. Comparable results were observed when employed as a standalone procedure or when combined with cataract surgery.

Standalone Implantation of 2-3 Trabecular Micro-Bypass Stents (iStent inject ± iStent) as an Alternative to Trabeculectomy for Moderate-to-Severe Glaucoma

INTRODUCTION

This retrospective consecutive study compared standalone implantation of multiple (2-3) trabecular micro-bypass stents (iStent inject ± iStent) (Multi-Stent group) vs trabeculectomy + mitomycin C (Trab group) in moderate to severe open-angle glaucoma (OAG).

METHODS

Eligible patients underwent Multi-Stent or Trab surgery from 2018 to 2020 and had at least 3-month follow-up; visual field mean deviation (VF MD) - 6 dB or worse; inadequate prior response to maximum medications ± laser procedures; and had trabeculectomy as their next planned intervention. Primary effectiveness, safety-adjusted treatment success, was defined as ≥ 20% intraocular pressure (IOP) reduction on the same or fewer medications, without clinically significant safety events (severe complications, secondary surgeries, reinterventions). Secondary effectiveness included mean IOP and medications; qualified and complete attainment of target IOP (≤ 21/18/15/12 mmHg and > 6 mmHg); health-economic and quality-of-life (QoL) measures; and 2-vs-3-stent subgroup analysis.

RESULTS

The baseline groups (n = 70 Multi-Stent/40 Trab) were similar: mean IOP (21.1 mmHg/22.3 mmHg); medications (2.87/3.10 medications); disease stage (30%/35% severe); VF MD (- 10.1 dB/- 10.4 dB); and mean last follow-up (LFU, 13.1 months/15.7 months) (all differences non-significant). Primary effectiveness: treatment success at LFU was 62.9% vs 30.0% in Multi-Stent vs Trab eyes, respectively (p = 0.001). Secondary effectiveness: At LFU in Multi-Stent vs Trab groups, respectively: mean IOP decreased by 31% to 14.2 mmHg (p < 0.001) vs by 43% to 12.5 mmHg (p < 0.001); mean medications decreased by 51% to 1.31 medications (p < 0.001) vs by 84% to 0.43 medications (p < 0.001). Multi-Stent eyes, compared to Trab eyes, had fewer visits ± reinterventions within 3 months (3.6 vs 6.1, p < 0.001); longer time to first reintervention (12.2 months vs 4.5 months, p = 0.01); fewer total reinterventions (0.26 vs 0.75, p = 0.006); and earlier lifting of postoperative restrictions (12.6 vs 32.1 days, p < 0.001). In 2-vs-3-stent analysis, there was a trend toward more 3-stent eyes achieving target IOP than 2-stent eyes. Visual fields remained stable in both Multi-Stent and Trab eyes.

CONCLUSION

Implanting 2-3 trabecular micro-bypass stents was a viable alternative to trabeculectomy for moderate-to-severe OAG, with clinically appropriate IOP/medication reductions and higher safety-adjusted treatment success vs trabeculectomy.

12-Month Outcomes of Combined Phacoemulsification and iStent Inject in Asian Eyes with Normal Tension Glaucoma: A Single-Centre Experience

PURPOSE

To evaluate efficacy and safety of the iStent inject combined with phacoemulsification in Asian eyes with normal-tension glaucoma (NTG) up to 12 months after surgery.

STUDY DESIGN

Retrospective case series.

METHODS

Retrospective case series of eyes undergoing surgery from April 2017 to August 2019. Outcome measures included intraocular pressure (IOP), number of topical glaucoma medications and adverse outcomes. Data were retrieved from the post-operative day 1 (POD1), week 1 (POW1), month 1 (POM1), month 3 (POM3), month 6 (POM6) and month 12 (POM12) timepoints. Data were analysed at each timepoint for eyes with available clinical data at that visit. Subgroup analysis was performed for a consistent cohort which included only eyes with data at all six follow-up timepoints.

RESULTS

Data from 91 eyes in the collective subject group was analysed. Majority of subjects were male (53, 58.2%) and Chinese (79, 86.8%). Mean age was 73.2 ± 7.2 years. Pre-operatively, mean IOP was 14.3 ± 3.0 mmHg and mean number of medications was 1.5 ± 0.8. Significant IOP reduction was observed at all timepoints except POW1 and POM12. The number of medications was reduced at all timepoints (p < 0.001). By POM12, there was reduction of 1.2 ± 1.0 medications (p < 0.001). Both the collective and consistent cohorts demonstrated a trend towards decreasing surgical efficacy with time, in IOP reduction and decrease in medications. None of the eyes experienced sight-threatening complications.

CONCLUSIONS

Asian eyes with NTG undergoing combined phacoemulsification and iStent inject surgery demonstrated significant and sustained reduction in number of glaucoma medications up to 12 months post-operatively.

Three-Year Outcomes of Second-generation Trabecular Micro-bypass Stents (iStent inject) With Phacoemulsification in Various Glaucoma Subtypes and Severities

PRECIS

This longitudinal case series provides valuable long-term data on the safety and efficacy of iStent inject with concomitant cataract surgery. Patients experienced significant and durable reductions in both intraocular pressure (IOP) and medication burden through 3 years postoperative.

PURPOSE

The purpose of this study was to examine the 3-year effectiveness and safety of iStent inject second-generation trabecular micro-bypass stent implantation with concomitant phacoemulsification cataract surgery in eyes with various glaucoma subtypes and severities.

METHODS

This was a single-center consecutive case series. Three-year outcomes included mean IOP and medications, the proportions of eyes with IOP ≤18, ≤15, and ≤12 mm Hg, and success (absence of secondary glaucoma interventions). Safety included best-corrected visual acuity (BCVA), cup-to-disc ratio, visual field (VF) mean deviation, retinal nerve fiber layer (RNFL), and ganglion cell-inner plexiform layer (GCIPL) thickness, and adverse events.

RESULTS

A total of 124 eyes with different glaucoma subtypes and severities were included. At 3 years postoperative, mean IOP reduced from 16.90±3.85 mm Hg preoperatively to 13.17±2.83 mm Hg (22% reduction, P<0.001) and mean medication burden decreased from 2.38±1.29 medications preoperatively to 1.16±1.22 medications (51% reduction, P<0.001). At 3 years, 96% of eyes achieved IOP ≤18 mm Hg (vs. 69% preoperatively), 80% of eyes achieved IOP ≤15 mm Hg (vs. 40% preoperatively), and 42% of eyes achieved IOP ≤12 mm Hg (vs. 7% preoperatively) with 76% of eyes eliminating ≥1 medication and 37% of eyes eliminating ≥2 medications versus preoperative medication burden. The 3-year cumulative survival rate was 74%. Postphacoemulsification BCVA improvement was preserved, and cup-to-disc ratio, VF mean deviation, and RNFL and GCIPL thickness remained stable. A favorable safety profile included no intraoperative complications and few, transient, postoperative adverse events.

CONCLUSION

Significant and sustained IOP and medication reductions were achieved through 3 years after iStent inject implantation with cataract surgery in a real-world clinical population with mild-to-severe glaucoma, along with favorable safety including stable BCVA, VF, and RNFL and GCIPL thickness.

iStent versus iStent inject implantation combined with phacoemulsification in open angle glaucoma

Purpose

To compare the outcomes of iStent vs. iStent inject implantation combined with phacoemulsification.

Methods

This single center retrospective comparative case series included subjects with open angle glaucoma who underwent iStent or iStent inject implantation combined with phacoemulsification with ≥1 year follow-up. The main outcome measures were in-group and between-group changes in intraocular pressure (IOP) and medication number, proportion of eyes that achieved IOP ≤15 mmHg, and surgical success defined as 20% IOP reduction from baseline at 6/12 months. Univariate/multivariate regression analyses were done to identify predictors of surgical failure.

Results

One hundred ninety-seven eyes of 148 patients were included (122 iStent, 75 iStent inject). Both groups achieved significant IOP and medication reduction at months 6/12 (P < 0.05). At month 6, IOP was significantly lower in iStent inject vs. iStent eyes (P = 0.003), but the difference was insignificant by month 12 (P = 0.172). Medication number was comparable in both groups at months 6/12 (P > 0.05). More iStent inject eyes achieved IOP ≤15 mmHg at month 6 (P = 0.003) and 12 (P = 0.047). Surgical success was comparable in both groups at months 6/12 (P > 0.05). Kaplan-Meier survival analysis showed similar cumulative rate of surgical failure at year-1 in both groups (P = 0.644). The multivariate model identified older age (P = 0.017) and lower baseline IOP (P = 0.002) as the strongest predictors of surgical failure.

Conclusion

Compared to iStent, iStent inject achieved lower IOP at month 6 and higher proportion of eyes achieved IOP ≤15 mmHg at month 6/12. However, surgical success was similar in both groups. Predictors of surgical failure were older age and lower baseline IOP rather than the stent type.

Surgical Outcomes of Combined 2nd-Generation Trabecular Microbypass (iStent Inject) and Cataract Surgery for the Treatment of Primary Open-Angle Glaucoma in the Saudi Population

INTRODUCTION

To investigate the 24-month efficacy and safety of iStent inject trabecular microbypass system implantation combined with phacoemulsification in subjects with primary open-angle glaucoma (POAG) and concomitant cataract.

METHODS

This prospective, uncontrolled, interventional case series included 36 eyes (29 subjects) with POAG of mild to moderate severity and coexisting cataract that underwent combined phacoemulsification and implantation of a second-generation trabecular microbypass stent (iStent inject®). Main outcome measures involved mean intraocular pressure (IOP), number of antiglaucoma medications, and proportional analysis of eyes with IOP ≤ 18 mmHg or ≤ 15 mmHg, or with 0 or ≥ 2 glaucoma medications. Secondary outcome measures involved the cup-to-disc ratio, corrected distance visual acuity (CDVA), and adverse issues.

RESULTS

In 36 eyes, the mean IOP at baseline was 18.28 ± 2.87 mmHg, which decreased to 14.24 ± 1.36 (22.1%) and 14.46 ± 1.56 mmHg (20.9%) at 18 and 24 months, respectively (p < 0.001). At the last follow-up, 100% of eyes had an IOP ≤ 18 mmHg (vs. 50% preoperatively), and 75.7% of eyes had an IOP ≤ 15 mmHg (vs. 16.7% preoperatively); 58.3% of eyes achieved ≥ 20% IOP reduction from preoperative status. At baseline, eyes were treated with a mean of 2.35 ± 1.18 medications, which was reduced to 0.80 ± 1.04 (66% reduction) and 0.69 ± 0.95 medications (70.6% reduction) at 18 and 24 months, respectively (p < 0.001). At the last follow-up, 54.1% of eyes were medication-free (vs. 0% preoperatively) and 24.3% of eyes were treated with ≥ 2 medications (vs. 64.9% preoperatively). This combined procedure demonstrated an excellent safety profile with no reported intraoperative complications or adverse events; CDVA was maintained throughout the entire follow-up period.

CONCLUSIONS

This real-world series demonstrated that iStent inject device implantation at the time of phacoemulsification is a safe and effective method to decrease IOP and the necessity for antiglaucoma medications in patients with mild-to-moderate POAG and cataract; no associated vision-threatening complications were noted.

Treatment Success Across Different Levels of Preoperative Disease Burden: Stratified Two-Year Outcomes from the Pivotal Trial of iStent inject ® Trabecular Micro-Bypass in Primary Open-Angle Glaucoma and Cataract

PURPOSE

To examine effectiveness outcomes stratified by preoperative disease burden in the pivotal trial of iStent inject ® with cataract surgery (INJ) vs cataract surgery alone (CS).

MATERIALS AND METHODS

Prospective, 3:1 randomized, single-masked, concurrently-controlled, multicenter trial enrolling 505 subjects with cataract and mild-to-moderate primary open-angle glaucoma who underwent iStent inject implantation with phacoemulsification or phacoemulsification alone, and were followed for 2 years including annual medication washouts. Post hoc stratification was completed for baseline mean diurnal intraocular pressure (BL DIOP; Low-DIOP <25mmHg, Mid-DIOP ≥25 to <30 mmHg, High-DIOP ≥30mmHg) and preoperative medication burden (Low-Med 1 medication, Mid-Med 2 medications, High-Med ≥3 medications).

RESULTS

The 24-month primary and secondary effectiveness endpoints were met, with significant treatment-over-control differences in percent of eyes achieving ≥20% unmedicated DIOP reduction and in unmedicated DIOP reduction, respectively. In subgroup analyses, the proportions of INJ eyes achieving the primary endpoint remained steady across all BL DIOP (75.4%, 77.1%, 74.4% in Low/Mid/High-DIOP strata, respectively) and preoperative medication levels (76.8%, 70.8%, 79.7% in Low/Mid/High-Med strata, respectively); meanwhile, the proportions of CS eyes diminished with higher BL DIOP (64.5%, 63.6%, 33.3%, respectively) and more medications (69.0%, 63.3%, 29.4%, respectively). Regarding secondary effectiveness, postoperative DIOP reduction increased with higher BL DIOP in INJ eyes (6.2mmHg, 7.8mmHg, 9.8mmHg, respectively) but plateaued in CS eyes (5.2mmHg, 5.8mmHg, 5.4mmHg, respectively). INJ eyes also had consistent DIOP reduction regardless of preoperative medication burden (6.8mmHg, 6.7mmHg, 7.8mmHg, respectively), while DIOP reduction diminished with more medications in CS eyes (6.1mmHg, 5.0mmHg, 3.3mmHg, respectively). Safety was favorable, comparable to phacoemulsification alone.

CONCLUSION

Significant IOP reductions occurred across all levels of BL DIOP and preoperative medication burden in iStent inject eyes. DIOP reductions increased with higher BL DIOP and remained stable across all levels of preoperative medication burden, suggesting the device's potential utility in more medically challenging cases.

iStent inject: comprehensive review

Microinvasive glaucoma surgeries (MIGSs) are new surgical procedures for treatment of glaucoma. They aim to safely and effectively reduce intraocular pressure (IOP) with minimal trauma to the eye and less complications. The first-generation iStent is the first approved ab interno MIGS implant for management of open-angle glaucoma. It works by allowing aqueous humor to drain directly from the anterior chamber into Schlemm canal bypassing the trabecular meshwork, the major site of outflow resistance. The second-generation iStent inject is the smallest available trabecular device that occupies less than 0.5 mm. It is designed to facilitate the surgical technique and allow simultaneous implantation of 2 stents, aiming for more IOP reduction. This review examines publications about the iStent inject, focusing on the device's efficacy, safety, and comparison with the first generation iStent. Both devices were found to be a safe and effective tool in management of open-angle glaucoma.

Minimally Invasive Glaucoma Surgery: A Critical Appraisal of the Literature

Micro- or minimally invasive glaucoma surgeries (MIGS) have been the latest addition to the glaucoma surgical treatment paradigm. This term refers not to a single surgery, but rather to a group of distinct procedures and devices that aim to decrease intraocular pressure. Broadly, MIGS can be categorized into surgeries that increase the trabecular outflow [Trabectome, iStent (first and second generations), Hydrus microstent, Kahook Dual Blade and gonioscopy-assisted transluminal trabeculotomy], surgeries that increase suprachoroidal outflow (Cypass microstent and iStent Supra), and conjunctival bleb-forming procedures (Xen gel stent and InnFocus microshunt). Compared to traditional glaucoma surgeries, such as trabeculectomy and glaucoma drainage device implantation (Ahmed, Baerveldt, and Molteno valves), MIGS are touted to have less severe complications and shorter surgical time. MIGS represent an evolving field, and the efficacy and complications of each procedure should be considered independently, giving more importance to high-quality and longer-term studies.

Comparison of 1-year surgical outcomes of combined cataract surgery and gonioscopy-assisted transluminal trabeculotomy (GATT) versus cataract surgery and iStent Inject

PURPOSE

Evaluate the efficacy, safety, and complication rates of phacoemulsification cataract surgery when combined with either gonioscopy-assisted transluminal trabeculotomy (GATT) or iStent Inject.

METHODS

This is a retrospective case-control study to compare the surgical outcomes of combined phacoemulsification cataract surgery with either GATT (phaco-GATT) or iStent Inject (phaco-iStent). Both groups had at least 1-year follow-up. The primary outcome measures were IOP and number of glaucoma medications (NGMs) at 1 year. Secondary outcomes measures were best corrected visual acuity (BCVA) and intra- or postoperative complications within the first year of follow-up. Success was defined as intraocular pressure (IOP) < 21 mmHg and ≥ 20% reduction in IOP at 1 year regardless of the NGM.

RESULTS

Each group included 37 patients. The median baseline IOP (24 vs 17) and NGM (3 vs 2) were higher in the phaco-GATT group (p < 0.001). Phaco-GATT achieved a 38% (p < 0.0001) reduction in IOP compared to 13.2% (p < 0.001) in the phaco-iStent group at 1-year follow-up. The reduction in IOP and NGM was significantly higher in the phaco-GATT group (p < 0.01). After adjusting for baseline IOP, the reduction in IOP at 12 months was still significantly higher in the phaco-GATT group (p = 0.042). At 1 year, 86.4% of patients in the phaco-GATT group met the success criteria compared to 35.1% in the phaco-iStent group. Safety outcomes were slightly favourable in the phaco-iStent group.

CONCLUSION

Phaco-GATT and phaco-iStent showed a significant reduction in IOP and NGM, with phaco-GATT having a significantly higher reduction. Phaco-iStent appears to have a higher safety profile and is probably preferable in monocular patients and those with a high risk of bleeding.

Two-Year Comparative Outcomes of First- and Second-Generation Trabecular Micro-Bypass Stents with Cataract Surgery

INTRODUCTION

This retrospective comparative study assessed real-world effectiveness and safety of first-generation (iStent®) and second-generation (iStent inject®) trabecular micro-bypass stents with cataract surgery in patients with open-angle glaucoma (OAG).

MATERIAL AND METHODS

Through a 24-month postoperative follow-up, the effectiveness was quantified by intraocular pressure (IOP) reduction; mean glaucoma medication reduction; proportional analysis of eyes meeting IOP cutoffs (<18, <15, <12 mmHg) either with or without medications; and proportional analysis of medication burden. Safety measures included visual acuity, adverse events, and secondary surgery.

RESULTS

A total of 82 consecutive eyes (39 iStent, 43 iStent inject) with a 24-month follow-up were analyzed. Most eyes (74.4%) had primary open-angle glaucoma, with the remainder having pseudoexfoliative or pigmentary glaucoma; all eyes had mild-to-moderate disease. At 24 months postoperative, the mean IOP was lower, and the percent reduction from baseline was greater, in iStent inject eyes (26.0% reduction, 17.7mmHg to 13.1mmHg) than in iStent eyes (9.8% reduction, 16.4mmHg to 14.8mmHg) (between-groups comparison, p=0.019). Within each group, the postoperative IOP reduction was greater in eyes with higher baseline IOP (p<0.001). Medication burden decreased significantly in both groups, from 1.74 to 0.51 mean medications for iStent (70.7% reduction, p<0.0001), and 2.19 to 0.65 for iStent inject (70.3% reduction, p<0.0001). Both groups exhibited excellent safety.

CONCLUSION

iStent or iStent inject with phacoemulsification produced significant IOP and medication reductions, with effects enduring for two years. IOP reductions were greater for iStent inject than for iStent. Within each group, higher preoperative IOP was associated with greater postoperative IOP reduction.

Safety and efficacy of microinvasive glaucoma surgery with cataract extraction in patients with normal-tension glaucoma

This study assesses the safety and efficacy of microinvasive glaucoma surgery (MIGS) with cataract extraction in patients with normal-tension glaucoma (NTG). In our sample of 45 NTG patients, mean intraocular pressure (IOP) decreased from 13.7 to 12.3 mmHg at 2.5 years, and mean medication burden decreased from 2.0 to 1.1 at 1.5 years. For success defined as IOP reduction ≥ 30% from baseline IOP with medication burden reduction from preoperative levels, success probability was 5.4% at 1.5 years. For success defined as medication burden reduction with an IOP reaching goal IOP as determined by the glaucoma specialist, success probabilities were 67.2% at 1.5 years and 29.4% at 2.5 years. At the last follow-up visit, eyes with two MIGS procedures with different mechanisms of action achieved successful medication reduction 68.8% of the time versus 35.7% achieved by a single MIGS procedure (p = 0.052). At their last visit, visual acuity was unchanged or improved in all eyes (100%). MIGS with cataract surgery results in modest reductions in IOP and medication burden in NTG patients, which may lead to lower costs and better therapeutic compliance. A combination of two MIGS procedures with different mechanisms of action may potentially be more effective in reducing medication burden than a single MIGS procedure in NTG patients. Further research is necessary to ascertain whether MIGS for NTG patients may help decrease medication burden while helping achieve goal IOP.

Matched Cohort Study of Cataract Surgery With and Without Trabecular Microbypass Stent Implantation in Primary Angle-Closure Glaucoma

PURPOSE

To compare 1-year outcomes of phacoemulsification alone (phaco-only) vs phacoemulsification with implantation of 2 trabecular microbypass stents (iStent or iStent inject; phaco-stent) in eyes with primary angle-closure glaucoma (PACG).

DESIGN

Retrospective matched clinical cohort study.

METHODS

PACG eyes that underwent phaco-only vs phaco-stent at a single ophthalmology center. Groups were matched for baseline intraocular pressure (IOP) and medication use with a tolerance of ±2 mm Hg and ±1 medication, respectively. Primary outcomes included postoperative change in the mean IOP and medications. One-year outcomes were assessed using generalized estimating equations corrected for baseline intergroup differences.

RESULTS

One hundred fifty-eight eyes (79 per group) were included. At 1 year, IOP decreased by 13% (from 16.8 ± 3.1 mm Hg preoperatively) in the phaco-only group (P < .001) and by 27% (from 17.6 ± 3.2 mm Hg) in the phaco-stent group (P < .001). Medication use decreased by 11% (from 1.8 ± 1.3 medications preoperatively) in the phaco-only group (P < .001) and by 46% (from 2.2 ± 1.2 medications) in the phaco-stent group (P < .001). The phaco-stent group experienced significantly larger reductions in IOP and medications compared with the phaco-only group (P < .001). The incidence of IOP spikes was significantly greater in the phaco-only group (18%) compared with the phaco-stent group (4%; P = .005). Safety was favorable with few transient postoperative adverse events.

CONCLUSION

The results of this study highlight that phacoemulsification with implantation of 2 trabecular microbypass stents is more effective and possibly more protective than phaco-only in PACG eyes, as evidenced by significantly larger IOP and medication reductions and smaller incidences of IOP spikes among the phaco-stent eyes.

Surgical Management of Pseudoexfoliative Glaucoma: A Review of Current Clinical Considerations and Surgical Outcomes

INTRODUCTION

Pseudoexfoliative glaucoma (PEXG) is the most common cause of secondary open-angle glaucoma worldwide. It is more aggressive and often more resistant to conventional treatments than primary open-angle glaucoma, yet there is currently no clear consensus on best management practices. This review explores current literature on PEXG to assess the safety and efficacy of currently available surgical techniques, and discusses clinical considerations on the diagnosis and management of the disease.

METHODS

A PubMed and Google Scholar search identified 2271 articles. These were reviewed to exclude irrelevant or duplicate data. A total of 47 studies reporting specifically on PEXG were retained and analyzed.

REVIEW

One of the most significant ophthalmic consequences of pseudoexfoliative (PEX) syndrome is the compromising of the blood-aqueous barrier resulting in the leakage of inflammatory cytokines and extracellular matrix material into the anterior chamber. Considering the high risk of developing PEXG and the aggressive nature of this type of glaucoma, accurate and timely diagnosis of PEX is critical. Therefore, systematic attentive examination for PEX deposits is crucial. Patients diagnosed with PEX need frequent glaucoma assessments. Patient information is key to improving compliance. Gonioscopy and diurnal tension curves or 24-hour intraocular pressure (IOP) monitoring are integral part of the diagnostic work-up and risk-assessment of PEXG. Because of the lability of IOP in PEX, clinical decisions on the basis of single IOP measurements should be avoided. Cataract extraction was shown to provide persistent IOP-lowering effect in the order of 10% in PEXG. A number of other surgical options may offer wider IOP reduction, and both XEN 45 gel stents and angle-based glaucoma procedures were suggested to achieve better outcomes in PEXG than in primary open-angle glaucoma. Yet, more significant IOP reductions may be achieved with filtering surgery or glaucoma drainage device. Same day postoperative IOP monitoring is recommended to treat the frequent IOP spikes following surgery, and more aggressive anti-inflammatory therapy may reduce the rates of postoperative adverse events in PEXG.

CONCLUSION

Specific studies of the surgical management of PEXG remain scarce in the medical literature, and more long-term and comparative studies are warranted to define more robust recommendations.

Mid-Term Evaluation of iStent Inject® Trabecular Micro-Bypass Stent Implantation with or without Phacoemulsification: A Retrospective Study

Introduction

This study evaluated the 6-month performance and safety of micro-invasive glaucoma surgery (MIGS) with iStent inject either with or without cataract surgery.

Material and Methods

Longitudinal retrospective study of 86 surgeries in 49 patients with inadequately controlled open-angle glaucoma (OAG) or ocular hypertension who underwent iStent inject trabecular micro-bypass implantation either alone (isolated group) or combined with cataract surgery (combined group). The two primary outcomes included an intraocular pressure (IOP) drop of ≥20% versus preoperative values (adequate drop) and IOP maintenance between 6 and 18 mmHg (adequate Range). For both outcomes, we determined “complete” and “qualified” success if patients did not require or did require glaucoma medications, respectively, at the end of follow-up. Safety outcomes included best-corrected visual acuity, adverse events, and secondary surgeries.

Results

In the adequate drop analysis, 30.2% achieved “complete success,” and 37.2% achieved “qualified success.” For adequate range, 40.7% achieved “complete success” and 39.5% achieved “qualified success.” There was no difference in medication decrease (p=0.77) nor IOP reduction (p=0.46) between the isolated and combined groups. Safety was generally favorable and similar between groups, with mild transient adverse events that resulted in no sequelae.

Discussion/Conclusion

iStent inject implantation either with or without cataract surgery was able to safely decrease IOP and medication requirements through 6 months after surgery.

The Effects of Trabecular Bypass Surgery on Conventional Aqueous Outflow, Visualized by Hemoglobin Video Imaging

PRECIS

Hemoglobin Video Imaging (HVI) provides a noninvasive method to quantify aqueous outflow (AO) perioperatively. Trabecular bypass surgery (TBS) is able to improve, and in some cases re-establish, conventional AO.

PURPOSE

The purpose of this study was to use HVI to illustrate and quantify effects of TBS on AO through the episcleral venous system.

DESIGN

This is a prospective observational cohort study.

PARTICIPANTS

Patients were recruited from Sydney Eye Hospital, Australia. The study included 29 eyes from 25 patients, 15 with glaucoma and 14 normal controls. TBS (iStent Inject) was performed on 14 glaucomatous eyes (9 combined phacoemulsification/TBS and 5 standalone TBS). Cataract surgery alone was performed on the remaining eye from the glaucoma group and 2 eyes from the control group.

METHODS

We used HVI, a novel clinic-based tool, to visualize and quantify AO perioperatively during routine follow-up to 6 months. Angiographic blood flow patterns were observed within prominent aqueous veins on the nasal and temporal ocular surface. Aqueous column cross-section area (AqCA) was compared before and after surgery.

MAIN OUTCOME MEASURES

AqCA, number of aqueous veins, intraocular pressure (IOP) before and after surgery, and number of IOP-lowering medications.

RESULTS

Patients with glaucoma had reduced AqCA compared with normal controls (P=0.00001). TBS increased AqCA in 13 eyes at 1 month (n=14; P<0.002), suggesting improved AO. This effect was maintained at 6 months in 7 eyes (n=9, P≤0.05). All patients with unrecordable AO before surgery (n=3; 2 standalone TBS, 1 combined cataract/TBS) established measurable flow after TBS. IOP and/or medication burden became reduced in every patient undergoing TBS. Cataract surgery alone (n=3) increased AqCA in nasal and temporal vessels at 4 weeks after surgery.

CONCLUSIONS

HVI provides a safe method for detecting and monitoring AO perioperatively in an outpatient setting. Improvement of AO into the episcleral venous system is expected after TBS and can be visualized with HVI. TBS is able to improve, and in some cases re-establish, conventional AO. Cataract surgery may augment this. Some aqueous veins were first seen after TBS and these patients had unstable postoperative IOP control, which possibly suggests reorganization of aqueous homeostatic mechanisms. HVI may confirm adequacy of surgery during short-term follow-up, but further work is required to assess the potential of HVI to predict surgical outcomes and assist with personalized treatment decisions.

Two-Year Multicenter Outcomes of iStent inject Trabecular Micro-Bypass Stents Combined with Phacoemulsification in Various Types of Glaucoma and Ocular Hypertension

Purpose

This multicenter study evaluated 2-year effectiveness and safety following implantation of two second-generation trabecular micro-bypass stents (iStent inject^®) with phacoemulsification.

Materials and Methods

This was a retrospective study of iStent inject implantation with phacoemulsification by nine surgeons across Australia. Eyes had mild to advanced glaucoma (predominantly primary open-angle/POAG, appositional angle-closure/ACG, or normal-tension/NTG) or ocular hypertension (OHT), and cataract. Evaluations included intraocular pressure (IOP); medications; proportions of eyes with 0 or ≥2 medications, reduced/stable medications versus preoperative, and IOP ≤15 mmHg; visual acuity; cup-to-disc ratio (CDR); visual fields (VF); adverse events; and secondary surgery.

Results

A total of 340 eyes underwent surgery and had 24-month follow-up data. At 24 months, mean IOP decreased by 16% from 16.4±4.7 mmHg preoperatively to 13.7±3.1 mmHg (p<0.001), and 77% of eyes achieved IOP of ≤15 mmHg versus 49% preoperatively (p<0.001). Mean number of medications decreased by 67% to 0.49±0.95 versus 1.49±1.20 preoperatively (p<0.001), with 74% of eyes medication-free versus 25% preoperatively (p<0.001), and 14% of eyes on ≥2 medications versus 46% preoperatively (p<0.001). Medication burden was reduced or stable in 98% of eyes versus preoperative. Stratified analyses showed significant IOP and medication reductions across glaucoma subtypes (POAG, ACG, NTG, OHT): 13–22% for IOP (p<0.01 for all) and 62–100% for medication (p<0.001 for all). Favorable safety included few adverse events; stable CDR, VF, and visual acuity; and filtering surgery in only 8 eyes (2.4%) over 2 years.

Conclusion

This 340-eye multicenter dataset provides robust evidence of the safety and efficacy of iStent inject implantation with phacoemulsification, with significant and sustained IOP and medication reductions through 2 years. Results were similarly favorable across glaucoma subtypes (including POAG, ACG, NTG, OHT) and were attained across various glaucoma severities, clinical sites, and surgeons, highlighting the real-world versatility and utility of this treatment modality.

iStent Trabecular Micro-Bypass Stent Implantation with Cataract Surgery in a Japanese Glaucoma Population

Introduction

This study assesses two-year efficacy and safety following implantation of a single trabecular micro-bypass stent (iStent^®) with concomitant phacoemulsification cataract surgery in Japanese patients with open-angle glaucoma (OAG).

Materials and Methods

This retrospective, consecutive case series included eyes that underwent iStent implantation with phacoemulsification and were followed for 24 months postoperative. Efficacy and safety measures included intraocular pressure (IOP), number of glaucoma medications, adverse events, secondary surgeries, visual fields, and endothelial cell counts.

Results

Of 73 operated eyes, 53 eyes had 24 months of follow-up and are analyzed. Diagnoses included primary open-angle glaucoma (POAG, n=25), normal-tension glaucoma (NTG, n=16), and pseudoexfoliative glaucoma (PXG, n=12). At 24 months, mean IOP reduced by 18% to 13.6±3.0 mmHg versus 16.5±3.4 mmHg preoperatively (p<0.0001), and mean medication number reduced by 81% to 0.37±0.74 versus 1.96±0.98 preoperatively (p<0.0001). The percentage of medication-free eyes was 77% versus 0% preoperatively, and 81% of eyes had IOP ≤15 mmHg versus 42% preoperatively. Results were similarly favorable across glaucoma subtypes (POAG, NTG, PXG). Notably, mean IOP in NTG eyes decreased to 12.8±1.4 mmHg from 14.4±3.0 mmHg preoperatively (p=0.03), and medications decreased by 87% to 0.31±0.70 versus 2.38±0.72 preoperatively (p<0.0001). At 24 months, 81% of NTG eyes were medication-free (versus 0% preoperatively); 2 NTG eyes (13%) were on ≥2 medications (versus 100% preoperatively). Throughout the follow-up, visual fields and endothelial cell counts remained stable; 1 eye (1.9%) underwent filtration surgery.

Discussion

Favorable safety and significant IOP and mediation reductions were achieved through two years following iStent implantation with phacoemulsification in a Japanese population. These gains were achieved across all glaucoma subtypes (including POAG, NTG, PXG).

Conclusion

This real-world study supports the viability of iStent implantation to treat Japanese patients with glaucoma and shows that the benefits extend to those with NTG or PXG in addition to POAG.

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

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

Prospective Interventional Cohort Study of Ocular Surface Disease Changes in Eyes After Trabecular Micro-Bypass Stent(s) Implantation (iStent or iStent inject) with Phacoemulsification

Introduction

This study sought to assess ocular surface disease changes following cataract surgery combined with trabecular micro-bypass stent(s) implantation (iStent or iStent inject).

Methods

This prospective interventional single-arm clinical trial enrolled 47 eyes with mild-to-moderate open-angle glaucoma (OAG) on 1–4 glaucoma medications who underwent phacoemulsification and trabecular micro-bypass stent(s) implantation. Key glaucoma and ocular surface data through 3 months postoperatively included the Ocular Surface Disease Index score (OSDI), corneal/conjunctival staining (Oxford Schema), fluorescein tear break-up time (FTBUT), conjunctival hyperemia (Efron Scale), glaucoma medications, and intraocular pressure (IOP).

Results

Mean OSDI scores improved from 40.1 ± 21.6 (severe) preoperatively to 17.5 ± 15.3 (mild) at 3 months (p < 0.0001). While 73% of eyes had moderate or severe OSDI scores preoperatively, 29% had such scores at 3 months, and the OSDI score was normal in 57% of eyes versus 9% preoperatively. Mean FTBUT increased from 4.3 ± 2.4 s preoperatively to 6.4 ± 2.5 s at 3 months (p < 0.0001); mean Oxford corneal/conjunctival staining reduced from 1.4 ± 1.0 preoperatively to 0.4 ± 0.6 at 3 months (p < 0.0001); mean Efron conjunctival hyperemia score reduced from 1.4 ± 0.7 preoperatively to 1.2 ± 0.6 at 3 months (p = 0.118). The number of glaucoma medications decreased from 1.5 ± 0.9 to 0.6 ± 0.8 mean medications (60% reduction, p < 0.0001), with all eyes maintaining or reducing medications versus preoperatively and 55% of eyes becoming medication-free (versus 0% preoperatively). Mean IOP reduced from 17.4 ± 4.2 mmHg to 14.5 ± 3.2 mmHg (p < 0.0001). The safety profile was excellent.

Conclusion

Implantation of trabecular micro-bypass stent(s) (iStent or iStent inject) with cataract surgery produced significant improvements in ocular surface health, alongside significant reductions in IOP and medications.

Trial registration

ClinicalTrials.gov identifier, NCT04452279.

Second-Generation Trabecular Micro-Bypass (iStent inject) with Cataract Surgery in Eyes with Normal-Tension Glaucoma: One-Year Outcomes of a Multi-Centre Study

Purpose

The efficacy and safety of the trabecular micro-bypass stents (iStent and iStent inject) have been well documented in various open-angle glaucoma subtypes. However, their outcomes remain understudied in normal-tension glaucoma (NTG). The present study aimed to assess the 1-year outcomes related to the implantation of two second-generation trabecular micro-bypass stents (iStent inject) concomitant with cataract surgery (CE-TMS), exclusively in eyes with NTG.

Methods

This multi-center, consecutive case series included eyes with cataract and normal-tension glaucoma that underwent CE-TMS to reduce intraocular pressure or glaucoma medication use. The 12-month efficacy measures included change in average intraocular pressure (IOP) and medication burden. Safety included change in best-corrected visual acuity, cup-to-disc ratio, visual field mean-deviation and retinal nerve fiber layer thickness. Intra- or postoperative adverse events were noted.

Results

A total of 62 eyes with mild-to-severe NTG and average preoperative IOP of 15.82 ± 2.94 mmHg on 1.50 ± 1.28 glaucoma medications were included. Postoperatively, IOP declined by 22% from 15.82 ± 2.94 mmHg to 12.32 ± 2.58 (p < 0.001), all eyes had IOP ≤ 18 mmHg (versus 74% preoperatively), and half had IOP ≤ 12 mmHg (versus 15% preoperatively). Medication burden decreased by 70% from 1.50 ± 1.28 to 0.45 ± 0.86 (p < 0.001), and 73% of the eyes were medication-free (versus 23% preoperatively). Safety was favorable, with no evidence of sight-threatening adverse events.

Conclusion

Implantation of iStent inject (two second-generation trabecular micro-bypass stents) combined with cataract surgery is efficacious in reducing IOP and medication burden with a favorable safety profile in eyes with mild-to-severe NTG.

Minimally Invasive Glaucoma Surgery: Where Is the Evidence?

PURPOSE

The last decade has witnessed an unprecedented growth in glaucoma treatment options through the introduction of minimally invasive glaucoma surgeries (MIGS). The aim of the present review is to provide an understanding of the currently available MIGS and to examine what data are currently available to guide treatment choice.

DESIGN

Meta-analysis and systematic review of randomized and non-randomized control trials.

METHODS

Out of 2567 articles identified, a total of 77 articles were retained for analysis, including 28 comparative studies and 12 randomized control trials. Overall, 7570 eyes were included. When data permitted, the weighted mean difference in intraocular pressure reduction was calculated for comparison purposes.

RESULTS

Weighted mean intraocular pressure reductions from all analyzed studies were: 15.3% (iStent), 29.1% (iStent inject), 36.2% (ab interno canaloplasty), 34.4% (Hydrus), 36.5% (gonioscopically-assisted transluminal trabeculotomy), 24.0% (trabectome), 25.1% (Kahook dual blade), 30.2% (Cypass), 38.8% (XEN), and 50.0% (Preserflo).

CONCLUSIONS

One of the advantages of the heterogenous range of available MIGS options is the chance to tailor therapy in an individualized manner. However, high-quality data are required to make this choice more than an educated guess. Overall, this review confirms the efficiency of assessed MIGS compared with standalone phacoemulsification, but it highlights that only few studies compare different MIGS techniques and even fewer assess MIGS against criterion standard treatments. Current evidence, while non-negligible, is mostly limited to heterogenous nonrandomized studies and uncontrolled retrospective comparisons, with few quality randomized control trials. We suggest that future research should be comparative and include relevant comparators, standardized to report key outcome features, long-term to assess sustainability and late complications, and ideally randomized.

Four-Year Outcomes of Two Second-Generation Trabecular Micro-Bypass Stents in Patients with Open-Angle Glaucoma on One Medication

INTRODUCTION

This study evaluated long-term reductions in intraocular pressure (IOP) and medication following implantation of 2 second-generation trabecular micro-bypass stents (iStent inject®) in eyes with open-angle glaucoma (OAG) not controlled on 1 preoperative medication.

MATERIAL AND METHODS

In this prospective interventional multi-surgeon study, standalone implantation of 2 iStent inject stents was performed in 57 eyes of 57 subjects with OAG, preoperative IOP of 18-30 mmHg on 1 medication, and preoperative post-washout IOP of 22-38 mmHg. The main outcome measures included the proportions of eyes achieving medication-free IOP ≤18 mmHg, IOP ≤15 mmHg, or ≥20% IOP reduction versus preoperative unmedicated IOP. Assessments included IOP, medications, visual acuity, visual field, pachymetry, complications, and interventions. Subjects were followed for 48 months with follow-up continuing in all eyes.

RESULTS

At Month 48 (n=57), 95% of eyes achieved an IOP reduction of ≥20% without medication versus preoperative washout IOP; and although they had eliminated medication, 81% of eyes still had an IOP reduction of ≥20% versus preoperative IOP on 1 medication. Mean 48-month unmedicated IOP decreased by 46% to 13.2±1.6 mmHg vs 24.4±1.3 mmHg preoperatively (p<0.0001), with 95% of medication-free eyes having IOP ≤18mmHg and 82% having IOP ≤15mmHg. Over the course of follow-up, 3 eyes had medication added and 1 eye underwent a secondary glaucoma surgery, and safety parameters were favorable.

DISCUSSION

Standalone iStent inject implantation in OAG patients on 1 preoperative medication resulted in average IOP reduction to ≤15 mmHg with the elimination of medication and favorable safety through 48 months.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT02868190.

Second-generation trabecular micro-bypass stent implantation: Retrospective analysis after 12- and 24-month follow-up

BACKGROUND

The study aimed to investigate the 24-month safety and efficacy of implantation of two second-generation iStent inject trabecular micro-bypass stents with concomitant cataract surgery.

METHODS

This consecutive case series included 164 eyes of 109 patients implanted with the iStent inject® device with concomitant cataract surgery. The series was comprised of eyes with primary open-angle glaucoma (n = 84), pseudoexfoliation glaucoma (n = 42), normal-tension glaucoma (n = 18), and ocular hypertension (n = 20). All 164 eyes reached 9-14 months of follow-up ("12-month consistent cohort"), with a subset of 88 eyes reaching 21-26 months of follow-up ("24-month consistent cohort"). Performance outcome measures included intraocular pressure (IOP) and number of glaucoma medications. Safety outcomes included intra- or postoperative complications, the need for secondary procedures and corrected distance visual acuity. Comparisons of change in continuous (e.g., IOP) and categorical (e.g., proportions of eyes on zero medications) measures between baseline and postoperative times were made with the paired t-test and McNemar's chi-squared test, respectively.

RESULTS

At 12 months postoperatively, IOP was reduced by 25.5% (from 20.0 ± 5.5 mmHg to 14.9 ± 2.0 mmHg; p < 0.001); at 24 months postoperatively, IOP was reduced by 26.6% (from 20.3 ± 6.1 mmHg to 14.9 ± 1.9 mmHg; p < 0.001). At 12 months postoperatively, mean number of glaucoma medications was reduced by 85.0% (from 2.0 ± 1.0 to 0.3 ± 0.8 medications; p < 0.001); at 24 months postoperatively, mean number of medications was reduced by 81.0% (from 2.1 ± 1.1 to 0.4 ± 0.8 medications; p < 0.001). After 12 months, 96.3% of eyes had an IOP ≤ 18 mmHg and 58.5% of eyes had an IOP ≤ 15 mmHg, with 81.1% of eyes free of any medication, compared to 1.8% of eyes medication-free in the 12-month cohort at baseline. After 24 months, 98.9% of eyes had an IOP ≤ 18 mmHg and 53.4% of eyes had an IOP ≤ 15 mmHg, with 72.7% free of medication compared to 1.1% of eyes medication-free in the 24-month cohort at baseline. Overall, a high safety profile was observed with no significant postoperative complications.

CONCLUSIONS

The insertion of iStent inject (comprised of two second-generation trabecular micro-bypass stents) with cataract surgery effectively provides a sustained reduction in IOP with a markedly improved medication burden up to 24 months postoperatively.

One-Year Outcomes of Second-Generation Trabecular Micro-Bypass Stents (iStent Inject) Implantation with Cataract Surgery in Different Glaucoma Subtypes and Severities

PURPOSE

To assess the 1-year efficacy and safety of the implantation of two second-generation trabecular micro-bypass stents (iStent Inject®) with concomitant cataract surgery in various subtypes and severities of glaucoma.

METHODS

This single-surgeon, consecutive case series from a Canadian academic ophthalmology center included subjects with cataract, glaucoma, and the need to reduce intraocular pressure (IOP) and/or medications. The 12-month outcomes included mean IOP and medication burden as well as the proportions of eyes with IOP ≤ 18, ≤ 15, and ≤ 12 mmHg compared to baseline. Other measures included corrected distance visual acuity (CDVA), cup-to-disc ratio (CDR), visual field mean deviation (VF MD), retinal nerve fiber layer (RNFL) thickness, ganglion cell inner plexiform layer (GCIPL) thickness, and adverse events.

RESULTS

In 118 eyes, mean IOP reduced from 17.00 ± 3.82 mmHg preoperatively to 13.97 ± 2.65 mmHg at the 12-month follow-up mark (17.8% reduction, p < 0.001), and mean medication burden decreased from 2.31 ± 1.33 preoperatively to 1.03 ± 1.10 medications (56% reduction, p < 0.001). After 12 months, 93% of eyes achieved IOP ≤ 18 mmHg (versus 69% preoperatively), 70% of eyes achieved IOP ≤ 15 mmHg (versus 42% preoperatively), and 29% of eyes achieved IOP ≤ 12 mmHg (versus 7% preoperatively). For all eyes, topical medications were either maintained or decreased from baseline, with ≥ 1 medication eliminated from the preoperative regimen for 83% of eyes and ≥ 2 medications eliminated for 36% of eyes. Visual acuity improved significantly, consistent with expectations for cataract surgery, while CDR, VF MD, and RNFL and GCIPL thicknesses remained stable. Safety was favorable, with no intraoperative complications and few transient adverse events postoperatively.

CONCLUSION

iStent Inject implantation with cataract surgery safely reduced IOP and medication burden in a real-world clinical population with mild to severe glaucoma, and stabilized visual field, as well as RNFL and GCIPL thicknesses on OCT.

FUNDING

The Rapid Service Fees were funded by Glaukos Corporation.

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.

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.

Second-Generation Trabecular Micro-Bypass Stents as Standalone Treatment for Glaucoma: A 36-Month Prospective Study

Introduction

To evaluate long-term outcomes following stand-alone implantation of two second-generation trabecular micro-bypass stents (iStent inject^®, Glaukos Corp., San Clemente, CA, USA) in eyes with predominantly primary open-angle glaucoma (POAG) and considerable preoperative disease burden.

Methods

Eyes with POAG, pseudoexfoliative glaucoma (PXG), appositional narrow-angle glaucoma (NAG, with open-angle configuration in the area of implantation), or secondary glaucoma were included in this prospective, non-randomized, consecutive case series. All eyes underwent ab interno iStent inject implantation as a sole procedure. Assessments through 36 months included IOP, medications, corrected distance visual acuity (CDVA), secondary glaucoma surgeries, and complications and adverse events.

Results

Two iStent inject stents were implanted in 44 consecutive eyes (POAG = 38, PXG = 4, appositional NAG = 1, secondary neovascular glaucoma = 1) of 31 patients, and 33 eyes had 36-month follow-up data. Preoperative mean IOP was 25.3 ± 6.0 mmHg on a mean of 2.98 ± 0.88 medications, with 75% of eyes on 3–5 medications, no eyes medication-free, and 50% of eyes with history of prior glaucoma surgery. At 36 months postoperatively, mean IOP reduced by 42% to 14.6 ± 2.0 mmHg (p < 0.0001) and 87.9% of eyes achieved an IOP reduction of ≥ 20% versus preoperatively. In addition, 97% of eyes reached IOP ≤ 18 mmHg (vs. 9.1% preoperatively; p < 0.0001) and 70.0% of eyes reached IOP ≤ 15 mmHg (vs. 2.3% preoperatively; p < 0.0001). Mean medication burden decreased by 82% to 0.55 ± 0.79 (p < 0.0001), and 61% of eyes became medication-free. All eyes maintained or decreased their 36-month medication burden versus preoperatively. Safety was favorable, including minimal adverse events and stable CDVA through 36 months postoperatively.

Conclusion

This real-world cohort of glaucomatous eyes with substantial preoperative disease burden experienced significant, sustained, safe IOP and medication reductions through 36 months following stand-alone iStent inject implantation.

Funding

Article processing charges and writing assistance were provided by Glaukos Corp. (San Clemente, CA, USA).

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.