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

Five-Year Outcomes of Single Trabecular Microbypass Stent (iStent®) Implantation with Phacoemulsification in Korean Patients

INTRODUCTION

This study reports the long-term intraocular pressure (IOP)-lowering efficacy and safety of a single trabecular microbypass stent (iStent®; Glaukos Corp., San Clemente, CA, USA) for medically controlled open-angle glaucoma in Korean patients.

METHODS

This retrospective observational study included 42 eyes of 35 patients with primary open-angle glaucoma (POAG). All subjects underwent single first-generation iStent® implantation with phacoemulsification by a single surgeon with 5 years follow-up. The primary outcomes were changes in IOP and the number of antiglaucoma medications compared to the preoperative values. The secondary outcome was the proportion of eyes with IOP ≤ 18 mmHg without medication, ≤ 15 mmHg without medication, and ≤ 18 mmHg with or without medication. Adverse events and need for secondary glaucoma surgery were also recorded.

RESULTS

The mean IOP decreased from 15.8 ± 2.8 to 13.8 ± 1.7 mmHg and the mean number of medications was reduced from 2.24 ± 1.18 to 0.83 ± 1.12, respectively, at year 5. At 3 and 5 years, 80.6% and 78.6% of eyes, respectively, were receiving fewer medications than preoperative numbers. In contrast, only 50% of eyes on four preoperative medications showed medication reductions at 5 years. At years 3 and 5, 61.3% and 53.5% of eyes achieved IOP ≤ 18 mmHg without medication, whereas 90.3% and 89.3% of eyes achieved ≤ 18 mmHg regardless of medication use, respectively. Four eyes required additional glaucoma surgery (two Ahmed glaucoma valve implantations, one trabeculectomy, and one XEN 45 Gel Stent implantation), and all were receiving four preoperative antiglaucoma medications. Transient IOP elevation (14.3%) was the most common complication, followed by five hyphema, one stent obstruction, one stent malposition, and one severe anterior chamber reaction.

CONCLUSION

This study demonstrated a good safety profile and sustained IOP reduction after the implantation of a single trabecular microbypass stent (iStent®) with phacoemulsification in Korean patients. The majority of subjects with POAG showed a relatively good response; however, eyes receiving a higher number of medications preoperatively (especially four medications) had difficulty achieving a low target IOP.

[Real-world outcomes of glaucoma surgical procedures for open-angle glaucoma]

This article provides an overview of real-world outcomes in glaucoma surgical procedures. While randomized clinical trials provide valuable insights, they do not fully reflect real-world clinical practice. Real-world studies enable the evaluation of outcomes in uncontrolled settings and play a crucial role in counselling and decision-making for glaucoma treatment. By examining real-world data the article aims to identify rare adverse events that may go unnoticed in controlled clinical trials. The focus is on assessing the effectiveness and safety of glaucoma surgical procedures beyond the controlled trial setting.

Which is More Effective and Safer? Comparison of Propensity Score-Matched Microhook Ab Interno Trabeculotomy and iStent Inject

INTRODUCTION

The purpose of this study was to compare the surgical outcomes between ab interno trabeculotomy (LOT) and iStent inject W implantation (iStent) both combined with cataract surgery, matching the background factors including age, intraocular pressure (IOP), medication score, central corneal thickness (CCT), and axial length.

METHODS

A total of 100 eyes from 75/79 patients with primary open-angle glaucoma were included in the LOT/iStent groups. The background factors were matched between the two groups using the propensity score.

RESULTS

There were no significant differences in age, IOP, medication score, CCT, and axial length, preoperatively. The postoperative medication scores were 1.3 ± 1.2 and 1.2 ± 1.2 in the LOT and iStent groups. The postoperative IOPs were 12.8 ± 2.8 and 13.1 ± 2.4 mmHg in the LOT and iStent groups, respectively. The changes in the medication score were  - 0.64 ± 1.4 and  - 0.44 ± 1.6 in the LOT and iStent groups, respectively. The changes in the IOP were  - 2.1 ± 3.3 and  - 1.5 ± 3.0 mmHg in the LOT and iStent groups, respectively. These values were not significantly different between the two groups. The postoperative IOP and changes in the IOP were significantly associated with preoperative IOP and CCT. There was no significant difference in the occurrence of postoperative complications (hyphema, 11.0% and 6.0%, and transient ocular hypertension, 8.0% and 5.0%, in the LOT and iStent groups, respectively).

CONCLUSION

LOT and iStent have similar surgical outcomes with sufficient safety. Postoperative IOP was significantly associated with preoperative IOP and CCT in both groups.

Comparison of surgical outcomes between iStent inject W implantation and microhook ab interno trabeculotomy in combination with phacoemulsification in primary open-angle glaucoma patients

Purpose

To examine primary open-angle glaucoma patients after undergoing combined cataract surgery with microhook ab interno trabeculotomy (μLOT-Phaco) or iStent inject W implantation (iStent-Phaco), and then evaluate the surgical outcomes after a minimum of 6 months of follow-up.

Methods

Between October 2020 and July 2022, 39 μLOT-Phaco eyes and 55 iStent-Phaco eyes that underwent surgery were evaluated in this retrospective, multicenter comparative case series. Data that included preoperative and postoperative intraocular pressure (IOP), number of glaucoma medications, and occurrence of complications were collected from medical records and then examined. Surgical failure was defined as patients exhibiting a < 20% reduction in the preoperative IOP or an IOP > 18 mmHg on two consecutive follow-up visits, or when patients were required to undergo reoperation. Success rates were determined based on a Kaplan-Meier survival analysis.

Results

At 3, 6 and 12 months postoperatively, there was a significant postoperative reduction in the IOP (p < 0.001) and in the medications scores (p < 0.001) for both of the groups. In the μLOT-Phaco and iStent-Phaco groups, the probabilities of success at 6 and 12 months were 55.3 and 45.5%, and 48.4 and 45.5% (p = 0.38; log-rank test), respectively. In the iStent-Phaco group, there was a significant decrease in the hyphema.

Conclusion

Comparable surgical outcomes occurred for both the μLOT and iStent inject W procedures.

Clinical Outcomes of Phacoemulsification in Japanese Patients Receiving First and Revised Second-Generation Trabecular Microbypass Stents

PURPOSE

This study evaluated the effectiveness and safety of first and revised second-generation trabecular microbypass stent insertion [iStent (IS) and iStent inject W (IW)] in cataract surgery.

DESIGN

Single-center, retrospective, cohort study.

METHODS

The study included 176 eyes that received trabecular microbypass stents combined with cataract surgery at the Saitama Red Cross Hospital between September 2017 and September 2021. Patients were divided into IS and IW groups depending on the implant type. Demographic characteristics, intraocular pressure (IOP), and the number of antiglaucoma medications (Med) were analyzed preoperatively and 12 months postoperatively. In addition, postoperative complications were compared between the groups.

RESULTS

IS and IW were implanted in 86 eyes and 90 eyes, respectively. IOP and Med at 1, 3, 6, 9, and 12 months decreased significantly from baseline in both groups ( P = 0.04, P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively, for IOP in the IS group; P = 0.02, P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively, for IOP in the IW group; P = 0.03, P = 0.002, P < 0.001, P < 0.001, and P < 0.001, respectively, for Med in the IS group; and P < 0.001 for all time points for Med in the IW group). IOP did not vary significantly between the groups at 1, 3, 6, 9, and 12 months postoperatively. Med was significantly lower in IW than IS at 1, 3, 6, 9, and 12 months postoperatively ( P < 0.001, P < 0.001, P = 0.002, P = 0.002, and P = 0.002, respectively). Hyphema and IOP >30 mm Hg (spike) occurred in 1.2% and 4.4%, and 1.2% and 3.3% of patients in the IS and IW groups, respectively. The probability of successful discontinuation of medications at 12 months postoperatively was 10.5% and 41.1%, respectively ( P < 0.001).

CONCLUSIONS

Postoperative Med was significantly lower in the IW group. Simultaneous insertion of IW in patients with glaucoma requiring cataract surgery may be preferred to IS because it reduces the burden of Med.

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

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

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.

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.

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.

[Micro-invasive glaucoma surgery]

Glaucoma is a severe, rapidly progressing disease that in the absence of proper treatment leads to blindness in 20% of patients. According to the World Glaucoma Association, this disease is the most socially significant in modern ophthalmology and requires searching for new and effective methods of treatment. This article presents the results of research and reviews on this issue, considers both conservative therapy and surgical methods of treatment, analyzes in detail modern methods of micro-invasive eye surgery actively used in clinical practice. The article also describes indications for a various types of interventions, as well as the effect achieved by them and the possible complications, and presents the conclusions about the possibility of using these procedures in wide clinical practice.

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.

iStent Trabecular Micro-bypass Stent Implantation Combined with Phacoemulsification for Open-Angle Glaucoma: A 2-Year Post-marketing Surveillance Study in Japan

Introduction

We report 2-year outcomes after implantation of iStent trabecular micro-bypass stent with phacoemulsification, in Japanese patients with mild–moderate open-angle glaucoma (OAG).

Methods

This was a 24-month, prospective, longitudinal, observational, post-marketing study conducted between July 2017 and September 2020. Patients consisted of adults with OAG on antiglaucoma medications who had cataract surgery combined with one iStent implantation. Outcome measures included intraocular pressure (IOP), antiglaucoma medications, treatment success rates (defined as eyes having lower IOP with same or reduced number of medications from baseline, or same IOP with reduced number of medications from baseline, and not requiring secondary glaucoma surgeries postoperatively), and safety. Outcomes were analyzed in the overall cohort and in glaucoma subtypes: primary OAG, normal-tension glaucoma, and exfoliative glaucoma.

Results

Overall, 232 eyes were enrolled. At 24 months, mean ± standard deviation IOP decreased from 17.6 ± 4.0 mmHg preoperatively to 14.3 ± 3.0 mmHg (p < 0.05), and mean number of medications reduced from 2.2 ± 1.2 preoperatively to 0.7 ± 1.2 (p < 0.05). Similar trends were observed across glaucoma subtypes. In the overall cohort, 96.7%, 95.3%, and 93.7% of patients achieved treatment success at 6, 12, and 24 months, respectively. There were 67.6% medication-free eyes at 24 months compared to 3.2% medication-free eyes preoperatively (p < 0.0001). Safety profile was favorable over the 2-year period.

Conclusions

Following iStent implantation with phacoemulsification, clinically relevant and statistically significant reductions in IOP and number of medications were observed in Japanese eyes with OAG over 2 years, with favorable safety profile. These reductions were observed across all glaucoma subtypes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02207-0.

Clinical Outcomes After Second-Generation Trabecular Microbypass Stents (iStent inject®) with Phacoemulsification in Korean Patients

INTRODUCTION

To evaluate the intraocular pressure (IOP)-lowering effect of second-generation trabecular microbypass stents (iStent® inject) with cataract extraction (combination group) and compare refractive changes in the combination group and the control (phacoemulsification only) group.

METHODS

This retrospective case-control study included 36 eyes with cataract and medically controlled open-angle glaucoma with IOP < 21 mmHg and 100 nonglaucomatous eyes with cataract. Data were collected preoperatively and for 6 months postoperatively. Data included IOP, number of glaucoma medications, corrected distance visual acuity, and mean absolute error (MAE) from target refraction, and astigmatic vector analysis. Surgical success for the combination group was defined according to three criteria: (A) IOP < 15 mmHg without medication, (B) IOP < 18 mmHg without medication, and (C) IOP < 18 mmHg with or without medication.

RESULTS

In the combination group, mean IOP was reduced from 15.1 ± 2.9 mmHg to 12.5 ± 2.0 mmHg, and the mean number of medications decreased from 1.9 ± 1.0 to 0.4 ± 0.8 at postoperative 6 months (both P < 0.001). Surgical success rates were 77.8%, 83.3%, and 97.2% at 6 months by criteria A, B, and C, respectively. Mean IOP was reduced from 14.3 ± 2.7 mmHg to 13.1 ± 2.1 mmHg at 1 month in the control group (P < 0.001). The MAE was 0.33 ± 0.26 D, and 83.3% of eyes had spherical equivalent difference within 0.50 D in the combination group (0.38 ± 0.33 D and 76.0% in the control group; P = 0.309 and P = 0.363, respectively). Preoperative and postoperative centroid values were 0.51 D @ 1° and 0.66 D @ 178°, respectively (0.23 D @ 176° and 0.66 D @ 1° in the control group). There were no statistical differences between the two groups with respect to preoperative and postoperative mean absolute values (P = 0.154 and P = 0.322, respectively).

CONCLUSIONS

On the basis of our results using Korean real-world interim experience, iStent® inject with cataract extraction has favorable IOP-lowering effects and minimally impacts refractive outcomes.

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.

Trabecular Microbypass Stent and Phacoemulsification in African American Patients With Open-angle Glaucoma: Outcomes and Effect of Prior Laser Trabeculoplasty

PRECIS

In African American patients with glaucoma, iStent/phacoemulsification lowered intraocular pressure and reduced glaucoma medication usage for up to 1 year, even in patients with prior selective laser trabeculoplasty (SLT).

PURPOSE

Currently, no studies have examined the outcomes of a trabecular microbypass stent and phacoemulsification in African American patients. Here, the authors investigate whether iStent/phacoemulsification decreases intraocular pressure (IOP) and/or medication usage in African American patients with glaucoma. They are also interested in whether prior SLT would affect outcomes of iStent/phacoemulsification.

PATIENTS AND METHODS

A multicenter, retrospective case series of eyes that underwent iStent/phacoemulsification between 2013 and 2017 with up to 1-year follow-up. Eyes with a confirmed diagnosis of glaucoma in African American patients were included. Eyes with neovascular glaucoma or closed angle glaucoma and eyes that underwent previous incisional glaucoma surgery were excluded.

RESULTS

Eighty-nine eyes were included in the study and data for 66 eyes were available at postoperative year 1 (POY1). IOP decreased from 18.3±5.7 mm Hg to 15.9±4.6 (P<0.001) and glaucoma medication usage decreased from 1.9±1.1 to 1.1±1.1 (P<0.001) at POY1. Eyes that underwent prior SLT experienced less of a decrease in IOP when compared with eyes without prior SLT, but IOP at POY1 was not significantly different between these groups. Both groups had a similar reduction in medication usage. The most common complications were IOP spikes on postoperative day 1 and microhyphemas.

CONCLUSIONS

In this cohort, there was a significant decrease in IOP and medication usage 1 year after iStent/phacoemulsification. iStent/phacoemulsification is an effective and safe treatment option in African American patients with glaucoma.

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.

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.

Microinvasive Glaucoma Surgery: An Evidence-Based Review

PURPOSE

Interest in micro-invasive glaucoma surgery (MIGS) has exploded over the last 8 years with an increase in MIGS procedures of at least 400% in the United States, according to Medicare data. MIGS is an umbrella term that can cover many different types of surgeries. This review focuses on peer-reviewed evidence for Trabectome^®, iStent inject^®, Kahook Dual Blade^®, XEN^® Gel Stent, and Hydrus^®.

METHODS

We present key recent studies evaluating the efficacy and safety of MIGS in various types of glaucoma patients with different stages of disease.

CONCLUSION

We conclude that MIGS is generally safe and efficacious, although only some MIGS have been studied through randomized clinical trials. When comparing and contrasting the different MIGS procedures, large prospective studies are not yet the norm. High-quality large prospective studies involving MIGS will be an important next step as ophthalmologists decide how to incorporate MIGS into their surgical armamentarium.

iStent for Adults With Glaucoma: A Health Technology Assessment

BACKGROUND

Glaucoma is a condition that causes progressive damage to the optic nerve, which can lead to visual impairment and potentially to irreversible blindness. The iStent and iStent inject are devices implanted in the eye during a type of minimally invasive glaucoma surgery (MIGS) to reduce intraocular pressure by increasing trabecular outflow by bypassing the trabecular meshwork. We summarized two health technology assessments and additional recent publications that evaluated iStent for people with glaucoma, including effectiveness, safety, cost-effectiveness, the budget impact of publicly funding iStent, and patient preferences and values.

METHODS

We summarized two health technology assessments recently completed in Canada. In addition, we summarized new evidence we identified through expert consultation and scoping of the literature. We reported the quality of the body of clinical evidence as reported by the included health technology assessments, according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria.

RESULTS

Comparing iStent with pharmacotherapy, there may be no difference in comparative clinical effectiveness (GRADE: Very low to Low). There was uncertainty around the comparative clinical effectiveness of iStent compared with filtration surgery and of iStent plus cataract surgery compared with a different MIGS procedure plus cataract surgery (GRADE: Very low). iStent with cataract surgery may improve comparative clinical effectiveness (reduced intraocular pressure and number of medications) compared with cataract surgery alone (GRADE: Low).iStent may be cost-effective compared with pharmacotherapy (incremental cost-effectiveness ratios [ICER]: $14,120-$25,596/quality-adjusted life-year [QALY]; 60%-76% and 65%-100% of iterations cost-effective at willingness-to-pay values of $50,000/QALY and $100,000/QALY, respectively). iStent with cataract surgery may not be cost-effective compared with cataract surgery alone (ICERs: $108,934-$112,380/QALY; 17%-46% and 46%-68% of iterations cost-effective at willingness-to-pay values of $50,000/QALY and $100,000/QALY, respectively). iStent may not be cost-effective compared with filtration surgery (iStent was less effective and more expensive than filtration surgery). These estimates are influenced by the long-term effectiveness of iStent.The iStent device costs approximately $1,250 (for two iStent or iStent inject devices). Based on a recent analysis by Quebec's Institut national d'excellence en santé et en services sociaux (INESSS) and our previous analysis on MIGS, publicly funding iStent may reduce some spending on glaucoma medication but, overall, iStent is likely to lead to additional costs for the public health care system. In Ontario, publicly funding MIGS over 5 years is estimated to cost a total of $40 million if uptake is slow (25,000 people) and $199 million, if uptake is fast (100,000 people). In Quebec, publicly funding iStent over 3 years is estimated to cost a total of $29 million (15,000 people).People with glaucoma with whom we spoke reported that pharmacotherapy can be challenging and that they relied on trust in their physician to determine if surgery was necessary to avoid potential consequences of glaucoma, such as blindness. Those who received MIGS procedures found it beneficial, with minimal side effects and recovery time. However, they were often unaware what type of MIGS procedure they received, so they could not specifically comment on iStent.

CONCLUSIONS

We are uncertain about the comparative clinical effectiveness of iStent compared with filtration surgery, as well as iStent combined with cataract surgery versus other MIGS procedures combined with cataract surgery. There may be no difference in the comparative clinical effectiveness of iStent compared with pharmacotherapy. iStent combined with cataract surgery may improve clinical effectiveness (mainly intraocular pressure and number of medications) when compared with cataract surgery alone.In some instances, iStent may be cost-effective (i.e., when compared with pharmacotherapy) but in other instances it may not be cost-effective (i.e., when iStent combined with cataract surgery is compared with cataract surgery alone or when iStent is compared with filtration surgery). Publicly funding iStent may reduce some spending on pharmacotherapy but, overall, is likely to lead to additional costs for the public health system. People with glaucoma reported that pharmacotherapy adherence could be challenging, and that avoiding blindness was their main priority for treatment. Experiences with MIGS procedures were positive, although patients were unable to comment on iStent specifically.

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.

Factors Associated With Unqualified Success After Trabecular Bypass Surgery: A Case-control Study

PRECIS

An older age, a low number of baseline glaucoma medications, an early glaucoma stage, lower intraocular pressure (IOP) values during the first postoperative month, and combined surgery are possible predictors of unqualified success after a trabecular by-pass microinvasive glaucoma surgery (MIGS) procedure.

PURPOSE

The purpose of this study was to identify the potential predictors of unqualified success (IOP<18 mm Hg with no glaucoma medication) after trabecular by-pass MIGS.

MATERIALS AND METHODS

We designed a case-control study using logistic regression modeling that included all trabecular by-pass surgeries with at least 3 months of follow-up, performed at a single center from June 2017 to December 2019. Eyes that achieved an endpoint of unqualified success (dependent variable) were considered cases. All other eyes were used as the controls. Cases and controls were paired by sex and postoperative time. We tested the following independent variables: age, race, laterality (right eye or left eye), glaucoma stage, type of surgery (combined or stand-alone), type of trabecular bypass, intraoperative complications, baseline number of medications, baseline IOP, and postoperative IOP on days 1, 15, and 30. Additional analysis using IOP <15 mm Hg as a threshold and including eyes with at least 12 months of follow-up were performed.

RESULTS

One hundred ninety-four eyes were included in the analysis. We observed complete success in 56.7% of eyes. The mean follow-up time for the entire population was 12.3±6.8 months. All variables were considered in the first step of the modeling process; however, only age, day-15 IOP, day-30 IOP, baseline number of medications, glaucoma stage, and type of surgery remained until the completion of our model, with adequate significance (P<0.05). The additional analysis confirmed our results.

CONCLUSION

We identified that an older age, a low number of baseline glaucoma medications, an early glaucoma stage, lower IOP values during the first postoperative month, and combined surgery were associated with a higher chance of unqualified success at 12 months after a trabecular by-pass MIGS procedure.

Safety of 3 Tesla Magnetic Resonance Imaging on iStent Implants: An Ex-Vivo Study

PRCIS

Our study shows that iStent implant does not cause significant image artifacts, heating, or displacement during magnetic resonance imaging (MRI) scan. This device can be safely used in patients undergoing MRI scans using 3 Tesla (3T) machines.

PURPOSE

The iStent is a medical grade titanium implant commonly implanted in the anterior chamber angle of glaucomatous eyes in order to reduce intraocular pressure and medication burden. As many people now have these devices implanted in their eyes, the issue of their compatibility with MRI in terms of safety and interference with interpretation of these studies commonly arises. The purpose of this study is to evaluate the safety of 3T MRI scans in eyes that have undergone iStent implantation and to assess the interference of the implant to the scan interpretation.

MATERIALS AND METHODS

An ex vivo model of sheep eye with an iStent and proximately placed heat detector probe was used to study changes in the temperature during MRI 3T scan. The study included 2 fresh eyes with preserved extraocular muscles and orbital fat tissue placed in the orbital cavity of a human skull. Each eye with orbital content was scanned with a 3T MRI machine.

RESULTS

No displacement of the implant was observed during MRI scanning. The heat detector showed mild temperature elevation during the first minutes of the scan from 14.6 to 16.5°C. The iStent was best visualized in T2 turbo spin echo sequences and showed no significant artifacts.

CONCLUSION

iStent implants did not move during the MRI scan, showed minimal interaction with the magnetic field in terms of heating and image distortion. These interactions were not strong enough to present a substantial risk to patients with this implant undergoing an MRI scan.

iStent Inject (Second-generation Trabecular Microbypass) Versus Nonpenetrating Deep Sclerectomy in Association With Phacoemulsification for the Surgical Treatment of Open-angle Glaucoma and Cataracts: 1-Year Results

PRECIS

Both nonpenetrating deep sclerectomy (NPDS) and iStent inject are safe and effective when combined with phacoemulsification. The NPDS group presented lower final intraocular pressure (IOP); however, more postoperative intervention and longer recovery time was required.

AIM

The aim of this study was to assess the 1-year efficacy and safety of second-generation trabecular microbypass stent implantation (iStent inject) versus NPDS in association with phacoemulsification (Phaco) for the concomitant surgical treatment of open-angle glaucoma and cataracts.

MATERIALS AND METHODS

This was a single-center longitudinal retrospective comparative study of eyes treated with Phaco-NPDS, with adjunctive use of collagen matrix implant and mitomycin C (group 1), or Phaco-iStent inject (group 2). The main outcome measures were success rates [absolute success: proportion of eyes with IOP<18 mm Hg without any glaucoma medication; relative success: proportion of eyes achieving different target IOPs (<18; <15; and <12 mm Hg) with or without medication]; mean reduction (%) in IOP and medication use; number of postoperative reinterventions (goniopuncture, needling, and reoperation); and number of complications.

RESULTS

The mean age (y) was 69.3 in group 1 and 72.7 in group 2. Groups 1 (n=51) and 2 (n=32) achieved absolute success rates of 74.5% and 81.3%, respectively (P=0.333). Concerning relative success rates, no significant difference was found for IOP<18 mm Hg or an IOP<15 mm Hg between the 2 groups. However, significantly more eyes achieved an IOP <12 mm Hg in the Phaco-NPDS group. The mean percentage of IOP reduction from baseline to the end of follow-up was also statistically higher in group 1 (39.9% vs. 24.5%). Both groups achieved similar results in the mean reduction of medications per eye. No significant complications were found in either group, but patients in group 1 required more postoperative intervention than group 2.

CONCLUSIONS

Both techniques are safe and effective for the concomitant surgical treatment of open-angle glaucoma and cataracts and presented comparable relative success rates at different target IOP levels (<18 and <15 mm Hg). A larger proportion of patients in group 1 achieved a target IOP <12 mm Hg; however, more postoperative intervention was required.

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.

Comparison of a second-generation trabecular bypass (iStent inject) to ab interno trabeculectomy (Trabectome) by exact matching

Purpose

To achieve a highly balanced comparison of trabecular bypass stenting (IS2, iStent inject) with ab interno trabeculectomy (T, Trabectome) by exact matching.

Methods

Fifty-three IS2 eyes were matched to 3446 T eyes. Patients were matched using exact matching by baseline intraocular pressure (IOP), the number of glaucoma medications, and glaucoma type, and using nearest neighbor matching by age. Individuals without a close match were excluded. All surgeries were combined with phacoemulsification.

Results

A total of 78 eyes (39 in each group) could be matched as exact pairs with a baseline IOP of 18.3 ± 5.1 mmHg and glaucoma medications of 2.7 ± 1.2 in each. IOP in IS2 was reduced to 14.6 ± 4.2 mmHg at 3 months and in T to a minimum of 13.1 ± 3.2 mmHg at 1 month. In IS2, IOP began to rise again at 6 months, eventually exceeding baseline. At 24 months, IOP in IS2 was 18.8 ± 9.0 mmHg and in T 14.2 ± 3.5 mmHg. IS2 had a higher average IOP than T at all postoperative visits (p < 0.05 at 1, 12, 18 months). Glaucoma medications decreased to 2.0 ± 1.5 in IS2 and to 1.5 ± 1.4 in T.

Conclusion

T resulted in a larger and sustained IOP reduction compared with IS2 where a rebound occurred after 6 months to slightly above preoperative values.

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.

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.

Outcomes of phacoemulsification combined with two iStent inject trabecular microbypass stents with or without endocyclophotocoagulation

AIM

Comparing outcomes after combined phacoemulsification, two iStents insertion and endocyclophotocoagulation (ECP) versus phacoemulsification-iStents alone.

METHODS

This is a longitudinal retrospective 12 months study in eyes with ocular hypertension or early-to-moderate open angle glaucoma. Level of disease, intraocular pressure (IOP) and tolerance of glaucoma medication were considered before planning surgery. Best-corrected visual acuity (BCVA-logMAR), IOP (mm Hg), number of medications were assessed at baseline, week 1, week 5, month 3, 6, 12 postop.

MAIN OUTCOME

percentage (%) in IOP reduction at 12 months vs medicated baseline.

SECONDARY OUTCOMES

absolute values of IOP/medication reduction, BCVA and postop complications.

RESULTS

The ICE2 (two iStents-cataract extraction-ECP) group included 63 eyes and Phaco-iStent group included 46 eyes. Baseline IOP was higher in the ICE2 than phaco-iStent group (19.97±4.31 mm Hg vs 17.63±3.86 mm Hg, p=0.004) and mean deviation was lower (-7.20±2.58 dB vs -4.94±4.51 dB, p=0.037). Number of medications were comparable at baseline: 2.22±1.06 (ICE2) vs 2.07±1.02 (phaco-iStent), p=0.442. At month 12 postop, IOP in the ICE2 group decreased 35% from baseline vs 21% in the phaco-iStent group (p=0.03); absolute IOP reduction was significantly lower than baseline in each group (p<0.001), yet final IOP was lower in the ICE2 group than phaco-iStent group (13.05±2.18 mm Hg vs 14.09±1.86 mm Hg, p=0.01). Similar results were found for glaucoma medication (1.24±1.05 in ICE2 group vs 1.39±1.03 in phaco-iStent group, p=0.01). Final BCVA was 0.11±0.18 (phaco-iStent group) vs 0.08±0.08 (ICE2 group), p=0.309. Safety outcomes were comparable between groups.

CONCLUSION

ICE2 procedure offers better results in IOP/medication reduction at 12 months than phacoemulsification-iStents alone.

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.

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.

Open-Angle Glaucoma: Burden of Illness, Current Therapies, and the Management of Nocturnal IOP Variation

Glaucoma is a chronic, debilitating disease and a leading cause of global blindness. Despite treatment efforts, 10% of patients demonstrate loss of vision. In the US, > 80% of glaucoma cases are classified as open-angle glaucoma (OAG), with primary open-angle (POAG) being the most common. Although there has been tremendous innovation in the surgical treatment of glaucoma as of late, two clinical variants of OAG, normal-tension glaucoma (NTG) and severe POAG, are especially challenging for providers because patients with access to care and excellent treatment options may progress despite achieving a “target” intraocular pressure value. Additionally, recent research has highlighted the importance of nocturnal IOP control in avoiding glaucomatous disease progression. There remains an unmet need for new treatment options that can effectively treat NTG and severe POAG patients, irrespective of baseline IOP, while overcoming adherence limitations of current pharmacotherapies, demonstrating a robust safety profile, and more effectively controlling nocturnal IOP.

Funding The Rapid Service Fees were funded by the corresponding author, Tanner J. Ferguson, MD.

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).