Prospective unmasked randomized evaluation of the iStent inject (®) versus two ocular hypotensive agents in patients with primary open-angle glaucoma

Five-Year Outcomes of iStent inject Implantation With or Without Phacoemulsification in Eyes with Open-Angle Glaucoma

INTRODUCTION

Minimally invasive glaucoma surgery (MIGS) has become more widespread in open-angle glaucoma (OAG) management. Broad evidence has shown a greater decrease in mean intraocular pressure (IOP) when cataract surgery is combined with MIGS, compared with cataract surgery alone. In this study, we evaluated the effectiveness and safety of second-generation trabecular micro-bypass implantation (iStent inject®) either in combination with cataract surgery (Combined subgroup) or as a standalone procedure (Standalone subgroup) in eyes with OAG. Our hypothesis was that implementing interventional glaucoma management would provide meaningful reductions in IOP and topical medication burden.

METHODS

This long-term retrospective consecutive case series included patients with mild to moderate OAG who received the iStent inject® Trabecular Micro-bypass stent with or without phacoemulsification between 2018 and 2024. Eligible patients were ≥ 18 years of age with mild or moderate OAG, cataract requiring surgery (for the Combined subgroup), and the need for IOP and/or medication reduction. Study outcomes included mean and proportional analyses of IOP and medications over time. Analyses were completed for the overall population and for the Combined/Standalone and Mild/Moderate subgroups.

RESULTS

The study included 271 eyes with mean age 69 years and a mean of 40 months of follow-up (range 10-79 months). In the overall population, mean IOP decreased from 16.4 mmHg at baseline to 13.7 mmHg at last follow-up (p = 0.001), while the mean number of medications decreased from 2.24 at baseline to 0.62 at last follow-up (p = 0.001). IOP reductions were also significant in the Combined/Standalone subgroups and in the Mild/Moderate subgroups (p = 0.001 for all), and all subgroups experienced increased proportions of eyes on no topical medications at last follow-up versus preoperative (p = 0.001 for all).

CONCLUSION

This 5-year real-world study showed significant and sustained reductions in IOP and topical medication burden following iStent inject trabecular micro-bypass with or without cataract surgery in eyes with mild and moderate open-angle glaucoma.

Visual Function After Schlemm's Canal-Based MIGS

Filtration surgery is highly effective in lowering intraocular pressure; however, it is associated with a higher risk of severe complications. Visual dysfunction may persist in relatively uneventful cases because of induced astigmatism or worsening optical aberrations. Therefore, for early- to moderate-stage glaucoma, an increasing number of surgeons are prioritizing surgical safety and preserving postoperative visual function by opting for minimally invasive glaucoma surgery (MIGS). Among the various MIGS techniques, canal-opening surgery-targeting aqueous outflow through the Schlemm's canal (Schlemm's canal-based MIGS, CB-MIGS)-has gained increasing popularity. Unlike filtration surgery, CB-MIGS does not require creating an aqueous outflow pathway between the intraocular and extraocular spaces. Consequently, it is considered a minimally invasive procedure with a reduced risk of severe complications and is increasingly being chosen for suitable cases. Although this surgical technique has limitations in lowering intraocular pressure, it avoids the manipulation of the conjunctiva or sclera and is primarily performed through a small corneal incision. Therefore, a minimal impact on induced astigmatism or postoperative refractive changes is expected. However, few reviews comprehensively summarize postoperative changes in visual function. Therefore, this study reviews the literature on visual function after CB-MIGS, focusing on changes in best-corrected visual acuity (BCVA), refraction, astigmatism, and the effectiveness of visual field preservation to assess the extent of these postoperative changes. Hyphema is the primary cause of early postoperative vision loss and is often transient in cases in which other complications would have led to visual impairment. Severe complications that threaten vision are rare. Additionally, compared with filtration surgery, postoperative visual recovery tends to be faster, and the degree of induced astigmatism is comparable to that of standalone cataract surgery. When combined with cataract surgery, the refractive error is at the same level as that of cataract surgery alone. However, in some cases, mild hyperopic shifts may occur because of axial length shortening, depending on the extent of intraocular pressure reduction. This possibility has been highlighted in several studies. Regarding the effectiveness of slowing the progression of visual field defects, most studies have focused on short- to medium-term postoperative outcomes. Many of these studies have reported the sufficient suppression of progression rates. However, studies with large sample sizes and long-term prospective designs are limited. To establish more robust evidence, future research should focus on conducting larger-scale, long-term investigations.

Safety and Efficacy of Phacoemulsification With Trabecular Microbypass Stent W Implantation in Primary Angle-Closure Glaucoma

Background Investigation of the safety and efficacy of phacoemulsification with trabecular microbypass Stent W implantation in patients with primary angle-closure glaucoma (PACG). Methods Between August and December of 2023, this prospective study evaluated PACG patients who underwent phacoemulsification with iStent inject W implantation. All patients were 18 years and older and were monitored for 6 months after surgery. Changes in intraocular pressure (IOP) and the number of glaucoma medications at 6 months after the surgery were defined as the primary endpoint, while the safety of the iStent inject W implantation in these patients was the secondary endpoint. Results Of the six patients in the study, one was male and five were female, with patient ages ranging from 62 to 83 years. Pre- and postoperative IOP (at 6 months) ranged from 12 to 18 mmHg and 9 to 17 mmHg, respectively, with only one patient exhibiting an increase in the IOP from 12 to 17 mmHg. The number of glaucoma medications decreased in all but one case at six months postoperatively. Neither hyphema nor an IOP spike was observed in the present study. There was no evidence of iStent inject W occlusion or malposition at six months postoperatively in any of the cases. Conclusion In patients with PACG, phacoemulsification with trabecular microbypass Stent W implantation was demonstrated to be a safe and effective procedure.

iStent insertion orientation and impact on trabecular meshwork motion resolved by optical coherence tomography imaging

Significance

The iStent is a popular device designed for glaucoma treatment, functioning by creating an artificial fluid pathway in the trabecular meshwork (TM) to drain aqueous humor. The assessment of iStent implantation surgery is clinically important. However, current tools offer limited information.

Aim

We aim to develop innovative assessment strategies for iStent implantation using optical coherence tomography (OCT) to evaluate the position and orientation of the iStent and its biomechanical impact on outflow system dynamics.

Approach

We examined four iStents in the two eyes of a glaucoma patient. Three-dimensional (3D) OCT structural imaging was conducted for each iStent, and a semi-automated algorithm was developed for iStent segmentation and visualization, allowing precise measurement of position and orientation. In addition, phase-sensitive OCT (PhS-OCT) imaging was introduced to measure the biomechanical impact of the iStent on the outflow system quantified by cumulative displacement (CDisp) of pulse-dependent trabecular TM motion.

Results

The 3D structural image processed by our algorithm definitively resolved the position and orientation of the iStent in the anterior segment, revealing substantial variations in relevant parameters. PhS-OCT imaging demonstrated significantly higher CDisp in the regions between two iStents compared to locations distant from the iStents in both OD ( p = 0.0075 ) and OS ( p = 0.0437 ).

Conclusions

Our proposed structural imaging technique improved the characterization of the iStent's placement. The imaging results revealed inherent challenges in achieving precise control of iStent insertion. Furthermore, PhS-OCT imaging unveiled potential biomechanical alterations induced by the iStent. This unique methodology shows potential as a valuable clinical tool for evaluating iStent implantation.

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

Purpose

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

Materials and methods

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

Results

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

Conclusion

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

How to cite this article

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

Intraoperative iStent versus postoperative selective laser trabeculoplasty in early glaucoma patients undergoing cataract surgery: A retrospective comparative study

PURPOSE

To compare the efficacy and safety of iStent inject® versus 360° selective laser trabeculoplasty (SLT) in patients with early glaucoma undergoing cataract surgery.

METHODS

A retrospective non-randomized study was conducted in 73 eyes divided into two groups: cataract surgery+intraoperative iStent (n=40) versus cataract surgery+postoperative SLT at one month (n=33). The primary endpoint was intraocular pressure (IOP) lowering≥20% between baseline and 6 months postoperatively. The secondary endpoints were IOP lowering at 1, 6 and 12 months, and the mean number of IOP-lowering medications at 6 and 12 months.

RESULTS

The mean baseline IOP was 19.1 mmHg with no significant difference between groups. The mean baseline number of IOP-lowering medications was higher in the iStent group (n=1.95) compared to the SLT group (n=1.53; P=0.04). At 6 months, 18 (60%) patients in the SLT group and 20 (51%) patients in the iStent group achieved IOP lowering≥20% with no significant difference between groups (P=0.431). At 6 months, no difference in the mean number of IOP-lowering medications was found between groups (-0.92 and -0.89 in the iStent and SLT groups, respectively). Similar results were found at 12 months.

CONCLUSION

These results suggest similar safety and efficacy of intraoperative iStent and postoperative 360° SLT in lowering IOP and reducing glaucoma eye drops in early glaucoma patients undergoing cataract surgery. Treatment choice should be based on the ophthalmologist's experience and on the cost-benefit ratio.

European Glaucoma Society - A guide on surgical innovation for glaucoma

PROLOGUE: Glaucoma surgery has been, for many decades now, dominated by the universal gold standard which is trabeculectomy augmented with antimetabolites. Tubes also came into the scene to complement what we use to call conventional or traditional glaucoma surgery. More recently we experienced a changing glaucoma surgery environment with the "advent" of what we have become used to calling Minimally Invasive Glaucoma Surgery (MIGS). What is the unmet need, what is the gap that these newcomers aim to fill? Hippocrates taught us "bring benefit, not harm" and new glaucoma techniques and devices aim to provide safer surgery compared to conventional surgery. For the patient, but also for the clinician, safety is important. Is more safety achieved with new glaucoma surgery and, if so, is it associated with better, equivalent, or worse efficacy? Is new glaucoma surgery intended to replace conventional surgery or to complement it as an 'add-on' to what clinicians already have in their hands to manage glaucoma? Which surgery should be chosen for which patient? What are the options? Are they equivalent? These are too many questions for the clinician! What are the answers to the questions? What is the evidence to support answers? Do we need more evidence and how can we produce high-quality evidence? This EGS Guide explores the changing and challenging glaucoma surgery environment aiming to provide answers to these questions. The EGS uses four words to highlight a continuum: Innovation, Education, Communication, and Implementation. Translating innovation to successful implementation is crucially important and requires high-quality evidence to ensure steps forward to a positive impact on health care when it comes to implementation. The vision of EGS is to provide the best possible well-being and minimal glaucomainduced visual disability in individuals with glaucoma within an affordable healthcare system. In this regard, assessing the changes in glaucoma surgery is a pivotal contribution to better care. As mentioned, this Guide aims to provide answers to the crucial questions above. However, every clinician is aware that answers may differ for every person: an individualised approach is needed. Therefore, there will be no uniform answer for all situations and all patients. Clinicians would need, through the clinical method and possibly some algorithm, to reach answers and decisions at the individual level. In this regard, evidence is needed to support clinicians to make decisions. Of key importance in this Guide is to provide an overview of existing evidence on glaucoma surgery and specifically on recent innovations and novel devices, but also to set standards in surgical design and reporting for future studies on glaucoma surgical innovation. Designing studies in surgery is particularly challenging because of many subtle variations inherent to surgery and hence multiple factors involved in the outcome, but even more because one needs to define carefully outcomes relevant to the research question but also to the future translation into clinical practice. In addition this Guide aims to provide clinical recommendations on novel procedures already in use when insufficient evidence exists. EGS has a long tradition to provide guidance to the ophthalmic community in Europe and worldwide through the EGS Guidelines (now in their 5th Edition). The EGS leadership recognized that the changing environment in glaucoma surgery currently represents a major challenge for the clinician, needing specific guidance. Therefore, the decision was made to issue this Guide on Glaucoma Surgery in order to help clinicians to make appropriate decisions for their patients and also to provide the framework and guidance for researchers to improve the quality of evidence in future studies. Ultimately this Guide will support better Glaucoma Care in accordance with EGS's Vision and Mission. Fotis Topouzis EGS President

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

Purpose

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

Design

Narrative literature review.

Methods

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

Results

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

Conclusion

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

Minimally Invasive Glaucoma Surgery: Safety of Individual Devices

Primary open-angle glaucoma progression in those already on maximal medical therapy has traditionally been treated with trabeculectomy, a surgical procedure that carries a high degree of morbidity. In the last few decades, significant advances have been made in the field of minimally invasive glaucoma surgery (MIGS) devices, which aim to defer or prevent trabeculectomy via less arduous surgical techniques in certain types of glaucoma. Although reviews have been published examining the efficacy of various MIGS techniques, no article synthesises the comparative safety of all available devices. We performed a literature review examining the safety of MIGS devices. Fifteen devices were included, variously attempting to increase aqueous outflow through the trabecular meshwork or the suprachoroidal space, shunting into the subconjunctival space, or reducing aqueous production through ciliary body ablation. Notably, the earliest product attempting to increase outflow to the suprachoroidal space, Alcon's CyPass Micro-Stent, was withdrawn from the market due to concerns regarding increased corneal endothelial cell loss at five years post-implantation. All other devices were described as well-tolerated, with the most common adverse effects including hyphaema, intraocular pressure spikes, and device migration or obstruction. MIGS devices are purported to be uniformly safe, and many studies report no statistically significant increased complications beyond those associated with cataract surgery alone. It is important to note, however, the generally poor quality of current studies, with a dearth of randomised, or even prospective, data, and a large proportion of studies funded by device producers.

Systematic review of the method and quality of reporting of complications from studies evaluating innovative glaucoma surgical procedures

The objective of this systematic review is to identify how reporting of micro-invasive glaucoma surgery (MIGS) procedure complications are reported in randomised controlled trials (RCTs) and the quality of this reporting compared to the CONSORT extension for harms. RCTs evaluating MIGS procedures were identified from a database of systematic reviews and from recent literature. Trials were evaluated in comparison to the CONSORT extension for harms to quantify the quality of harms reporting. Simple descriptive statistics were calculated for the CONSORT checklist. 21 trials were identified as eligible for inclusion, 14 were evaluating iStent, one Trabectome, three Hydrus, one Cypass, one Preseflo MicroShunt and one Excimer laser trabeculotomy. The average number of CONSORT for Harms checklist items fulfilled by the studies was 10 out of 16. No studies used a validated instrument to report severity of harms and only 4 had a list or definition of adverse events. An analysis of harm was conducted by 19 of 21 studies (90%). Appropriate metrics were used for reporting rates of adverse events in 19 of 21 studies but in only 4 studies was there an attempt to give these adverse events a grade of seriousness. In conclusion, most studies evaluating MIGS procedures do make an effort to acknowledge harms data, however this is not done uniformly well or in the same manner. A validated instrument to report severity and a standard list of complications for MIGS surgery would go a long way to helping this.

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.

A Cost-Utility Analysis of Trabecular Bypass Devices Versus Usual Care for Patients With Open-Angle Glaucoma

OBJECTIVE

The aim of this study was to determine whether insertion of a trabecular bypass device (TBD) is a cost-effective intervention for the treatment of open-angle glaucoma (OAG) with mild to moderate vision loss in the Australian setting.

METHODS

We performed a cost-utility analysis of TBD implantation in conjunction with cataract surgery or as a standalone procedure in patients with OAG. The model used a Monte Carlo simulation to follow individual patients through a glaucoma treatment algorithm that included TBD and compared the costs and outcomes with those of patients simulated through an algorithm without TBD (usual care). The model tracked the intraocular pressure (IOP) of individual patients and then, based on this IOP, tracked the progression of the patient's glaucoma. Utility values were assigned dependent on severity of glaucoma. The analysis took the perspective of the Australian health care system. The main outcome was incremental cost per quality-adjusted life-year (QALY) of TBD versus usual care for the treatment of OAG.

RESULTS

In the cataract surgery population, TBD surgery was associated with incremental healthcare costs of A$177 and 0.0726 QALYs per patient, resulting in an incremental cost per QALY gained of A$2430. In the standalone population, the overall incremental cost of TBD surgery versus usual care was A$2234. With QALYs gained of 0.1526 per patient, this equated to an incremental cost per QALY gained ratio of A$14,644.

CONCLUSION

The incremental cost per QALY estimates for TBD were below thresholds generally accepted by Australian healthcare payers, suggesting that TBD is a cost-effective intervention for patients with primary OAG in the Australian setting.

Long-term outcomes of two first-generation trabecular micro-bypass stents (iStent) with phacoemulsification in primary open-angle glaucoma: eight-year results

Background

The short- and medium-term outcomes of iStent have been extensively studied; however, only few studies have investigated its long-term outcomes. Here, we assessed the long-term efficacy and safety of two iStents with concomitant cataract surgery in glaucomatous eyes while also evaluating measures of disease stability using visual field and optical coherence tomography (OCT) of the optic nerve and the macula throughout 8 years of follow-up.

Methods

This longitudinal, single-center consecutive case series included glaucomatous eyes that underwent implantation of two first-generation trabecular micro-bypass stents (iStent) with concomitant cataract surgery. Eight-year efficacy outcomes included mean intraocular pressure (IOP) and medications, as well as surgical success. Eight-year safety outcomes included best-corrected visual acuity (BCVA), visual field mean deviation (VF-MD), cup-to-disc ratio (CDR), retinal nerve fiber layer (RNFL) thickness, ganglion cell-inner plexiform layer (GC-IPL) thickness, and adverse events.

Results

A total of 62 eyes with primary open-angle glaucoma (POAG) were included. At 8 years postoperative, IOP reduced by 26% from 19.2 ± 3.9 mmHg preoperatively to 14.2 ± 2.4 mmHg (P < 0.001), 91.1% of eyes achieved IOP ≤ 18 mmHg (vs. 51.6% preoperatively), 69.6% of eyes achieved IOP ≤ 15 mmHg (vs. 14.5% preoperatively), and 25% of eyes achieved IOP ≤ 12 mmHg (vs. 1.6% preoperatively). Medication use decreased by 17.9% from 2.8 ± 1.1 preoperatively to 2.3 ± 1.2 (P = 0.018). Surgical success was 90%, as six eyes underwent subsequent glaucoma surgeries. Safety measures of BCVA, CDR, RNFL thickness and GC-IPL thickness remained stable through 8 years postoperative. VF-MD remained stable until postoperative year 5 and subsequently progressed according to the natural history of glaucomatous disease.

Conclusions

Implantation of two iStents with concomitant cataract surgery is an effective and safe treatment option for surgery-naïve POAG eyes, evidenced by significant IOP and medication reductions, reasonable surgical success, and favorable safety outcomes, throughout the 8-year follow-up. Our data additionally supports the efficacy of this combined procedure in stabilizing or slowing disease progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40662-021-00263-1.

Role of minimally invasive glaucoma surgery in the management of chronic open-angle glaucoma

To compare the safety and efficacy of phacoemulsification combined with ab-interno trabeculectomy (Trabectome) and phacoemulsification combined with I-Stent inject in patients with medically uncontrolled primary open-angle glaucoma (POAG). A retrospective comparative case series. 70 eyes of 66 patients completed 2 years follow up after these treatments performed in 2017–2018. 35 eyes of 33 patients underwent combined Phaco-Trabectome (PT); and 35 eyes of 33 patients underwent combined Phaco-I-Stent inject (Pi). Patient demographics and preoperative characteristics are comparable. A 20% drop in IOP was achieved in 27 eyes (77.14%) in PT group and 28 eyes (80%) in Pi group (p = 0.77). Success rate (target IOP achieved and maintained for 2 years) in advance glaucoma was 25% in PT group and 30.7% in Pi group (p = 0.90). In mild to moderate glaucoma, success rate was 85.71% in PT group and 90% in Pi group (p = 0.67). There was no significant difference between two groups with regards to mean reduction in glaucoma medications and complication rates. Trabectome and I-Stent combined with phacoemulsification are equally efficacious and safe for treating patients with medically uncontrolled mild and moderate primary open-angle glaucoma (POAG). However, they are not an effective treatment for patients with advanced glaucoma.

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.

Evaluation of the Effect of the First Generation iStent on Corneal Endothelial Cell Loss-A Match Case-Control Study

Glaucoma is the leading cause of irreversible blindness worldwide. The only proven factor in slowing the progression of glaucomatous neuropathy is lower intraocular pressure (IOP), which can be achieved with pharmacology, laser therapy, or surgery. However, these treatments are associated with various adverse effects, including corneal endothelial cell loss (CECL). In recent years, several novel surgeries for reducing the IOP, collectively referred to as minimally invasive glaucoma surgery (MIGS), have been developed, one of which is the iStent. However, the long-term effects of such surgeries remain unknown. We compared a group of patients with open-angle glaucoma and cataract who underwent phacoemulsification alone with a group of patients with similar demographic and clinical characteristics who underwent simultaneous phacoemulsification and iStent implantation. Overall, 26 eyes of 22 subjects who underwent a combined phacoemulsification-iStent procedure and 26 eyes of 24 subjects who underwent cataract surgery were included. Before surgery, endothelial cells accounted to 2228.65 ± 474.99 in iStent group and 2253.96 ± 404.76 in the control group (p = 0.836). After surgery, their number declined to 1389.77 ± 433.26 and 1475.31 ± 556.45, respectively (p = 0.509). There was no statistically significant difference in CECL between the two groups 18–24 months after surgery, despite increased manipulation in the anterior chamber and the presence of an implant in the trabecular meshwork in those with an iStent implant. Thus, iStent bypass implantation is a safe treatment in terms of CECL for mild-to-moderate open-angle 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.

Cost-utility analysis of trabecular micro-bypass stents (TBS) in patients with mild-to-moderate open-angle Glaucoma in Italy

BACKGROUND

Glaucoma is a disease characterized by progressive damage of the optic nerve. Several therapeutic options are available to lower intraocular pressure (IOP). In primary open-angle glaucoma (POAG) patients with inadequate IOP control (or controlled with multiple medical therapies or for whom medical therapy is contraindicated), the implantation of micro-invasive glaucoma surgery devices (MIGS) and concomitant cataract surgery has proved to be more effective in reducing intraocular pressure (IOP), as compared to cataract surgery alone. The objective of this study was to assess the cost-effectiveness of iStent inject® device with concurrent cataract surgery vs. cataract surgery alone, in patients with mild-to-moderate POAG, adopting the Italian National Health Service (NHS) perspective.

METHODS

Simulation of outcomes and costs was undertaken using a Markov model with 4 health states and one-month cycles, that is used to simulate the prognosis of these patients. Efficacy data were obtained from the randomized clinical trial (RCT). A lifetime horizon was adopted in the analysis. A discount rate of 3.5% was applied to both costs and effects. The Italian National Healthcare Service (NHS) perspective was considered, therefore only healthcare direct costs (acquisition of main interventions and subsequent procedures; medications; monitoring and follow-up; adverse events). Model robustness was tested through sensitivity analyses.

RESULTS

Results of the base-case analysis showed that the total lifetime costs were higher in the iStent inject® + concurrent cataract surgery, compared with the cataract surgery alone group (€8368.51 vs. €7134.71 respectively). iStent inject® + concurrent cataract surgery was cost-effective vs. cataract surgery alone, with an incremental cost-effectiveness ratio of €13,037.01 per quality-adjusted life year (QALY) gained. Both one-way deterministic and probabilistic sensitivity analyses confirmed robustness of base-case results. The cost-effectiveness accessibility curve (CEAC) showed that iStent inject® + cataract surgery would have a 98% probability of being cost-effective, compared to cataract surgery alone, when the willingness to pay (WTP) is equal to €50,000 per QALY gained.

CONCLUSIONS

The results of the cost-utility analysis confirm that iStent inject® + cataract surgery is a cost-effective option for the treatment of patients affected by mild-to-moderate POAG, compared with cataract surgery alone, when evaluated from the Italian NHS perspective.

Efficacy of Selective Laser Trabeculoplasty after iStent Implantation in Primary Open-Angle Glaucoma

iStent implantation is thought to augment the trabecular outflow channel in the anterior segment of the eye. We hypothesized that iStent with subsequent selective laser trabeculoplasty (SLT) would better control the intraocular pressure (IOP) compared to standalone SLT in patients with primary open-angle glaucoma (POAG). We, therefore, determined if the presence of an iStent combined with SLT was statistically associated with IOP lowering compared to standalone SLT. Through retrospective electronic medical record review, records of 824 eyes from 440 patients who received primary SLT without a history of iStent were considered. Additionally, 42 eyes from 28 patients who received SLT after combined phacoemulsification and iStent implantation that failed to control intraocular pressure (IOP) and/or the progression of the disease were retrospectively reviewed. IOP and number of medications, which were tracked in each patient for up to 12 months post laser, were also examined. Successful outcome was defined as a statistically significant reduction in IOP or number of medications at 6 months. As defined in univariate analysis (p ≤ 0.01), multivariate analysis included iStent, age, sex, race, and initial IOP as variables. IOP reduction was statistically associated with patients pre-SLT IOP (p < 0.001) but not with patients with iStent (p = 0.222). Medication reduction was statistically associated with the pre-SLT number of medications (p < 0.001) and iStent (p < 0.001). In eyes that received SLT, iStent was not statistically associated with a greater reduction in IOP compared to controls, but was associated with a higher reduction in the overall number of medications used 6 months after receiving SLT. The work presented should guide clinicians to consider SLT as an effective therapy after iStent implantation, in terms of glaucoma medication reduction in iStent patients, but clinicians should know that the presence of an iStent does not necessarily make subsequent SLT more effective at lowering IOP.

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.

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.

Drug Delivery via the Suprachoroidal Space for the Treatment of Retinal Diseases

The suprachoroidal space (SCS), a potential space between the sclera and choroid, is becoming an applicable method to deliver therapeutics to the back of the eye. In recent years, a vast amount of research in the field has been carried out, with new discoveries in different areas of interest, such as imaging, drug delivery methods, pharmacokinetics, pharmacotherapies in preclinical and clinical trials and advanced therapies. The SCS can be visualized via advanced techniques of optical coherence tomography (OCT) in eyes with different pathologies, and even in healthy eyes. Drugs can be delivered easily and safely via hollow microneedles fitted to the length of the approximate thickness of the sclera. SCS injections were found to reach greater baseline concentrations in the target layers compared to intravitreal (IVT) injection, while agent clearance was faster with highly aqueous soluble molecules. Clinical trials with SCS injection of triamcinolone acetonide (TA) were executed with promising findings for patients with noninfectious uveitis (NIU), NIU implicated with macular edema and diabetic macular edema (DME). Gene therapy is evolving rapidly with viral and non-viral vectors that were found to be safe and efficient in preclinical trials. Here, we review these novel different aspects and new developments in clinical treatment of the posterior segment of the eye.

Selective Laser Trabeculoplasty Versus MIGS: Forgotten Art or First-Step Procedure in Selected Patients with Open-Angle Glaucoma

Introduction

To evaluate the long-term effect on intraocular pressure (IOP) and glaucoma medication of selective laser trabeculoplasty (SLT) compared to minimally invasive glaucoma surgery (MIGS) in primary open-angle glaucoma (POAG) and its potential in clinical practice.

Methods

A total of 342 consecutive patients (stand-alone procedures) were included. One hundred and five patients underwent SLT treatment (360° SLT, 95–105 spots, Trabeculas SLT ARCLaser, Nürnberg, DE), 107 patients had an ab interno-derived trabeculotomy (Trabectome^®, NeoMedix, Tustin, USA), and 130 patients received iStent inject^® implantation (2 implants-Glaukos, CA, USA). IOP and glaucoma therapy were evaluated preoperatively, 1 day, 6 weeks, 3 months, 6 months, and 1, 2, and 3 years postoperatively. Statistical analysis was performed using a regression model and propensity matching score (reduced cohort number) using SPSS v20.0. Kaplan–Meier analysis was included using the following six criteria: criterion A (IOP ≤ 21 mmHg with or without medication, qualified success), criterion B (IOP ≤ 18 mmHg with or without medication, qualified success), criterion C (IOP ≤ 21 mmHg without medication, complete success), criterion D (IOP ≤ 18 mmHg without medication, complete success), criterion E (IOP ≤ 21 mmHg and IOP reduction > 20% after therapy), and criterion F (IOP ≤ 18 mmHg and IOP reduction > 20% after therapy).

Results

In the matched cohort, the SLT cohort showed an IOP reduction of 31.2% from 19.9 ± 2.3 to 13.7 ± 2.7 mmHg (p < 0.001) 3 years postoperatively; in Trabectome^® IOP decreased by 31.4% from 20.5 ± 1.3 to 13.8 ± 2.0 mmHg (p < 0.001) and in iStent inject^® by 29.9% from 19.5 ± 2.0 to 13.8 ± 2.7 mmHg (p < 0.001). Trabectome^® and iStent inject^® could not demonstrate a significant reduction in glaucoma therapy (Trabectome^®p = 0.138, iStent inject^®p = 0.612); a significant drop was noted in SLT (2.2 ± 1.2 to 1.7 ± 1.2, p = 0.046). SLT and MIGS achieved good to moderate survival rates using criterion A (93.3% SLT, 79.7% Trabectome^®, 77.6% iStent inject^®) and criterion B (74.5% SLT, 48.0% Trabectome^®, 56.2% iStent inject^®). As expected, low survival rates were obtained with non-filtering procedures: criterion C 11.1% in SLT, 6.5% in Trabectome^®, 7.0% in iStent inject^® and criterion D 3.0% in SLT, 4.3% in Trabectome^®, 3.7% in iStent inject^® in 3-year follow-up.

Conclusion

The SLT is a low-complication and effective method for reducing pressure in mild to moderate POAG. SLT is suitable as an initial procedure when setting up a step scheme; MIGS is the treatment of choice as a follow-up for mild to moderate forms of glaucoma and accepted topical therapy. Ethic approval had been given by the Ethikkommission Charité – Universitätsmedizin Berlin, EA4/047/20—retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-021-00347-0.

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.

Ethics of Glaucoma Widgets

How to cite this article: Dada T, Ramesh P, Sethi A, et al. Ethics of Glaucoma Widgets. J Curr Glaucoma Pract 2020;14(3):77–80.

Kahook Dual Blade Goniotomy vs iStent inject: Long-Term Results in Patients with Open-Angle Glaucoma

Purpose

Efficacy and safety evaluation of Kahook Dual Blade (KDB) goniotomy vs iStent inject implantation.

Materials and Methods

Retrospective study in patients that underwent goniotomy with KDB or iStent inject implantation, stand-alone or combined with cataract surgery. Main outcome parameters were intraocular pressure (IOP), number of glaucoma medications, proportion of eyes achieving >20% IOP reduction and number of eyes with postoperative IOP <19 mmHg at last follow-up.

Results

A total of 29 patients (30 eyes) were included in the iStent inject group and 30 patients (32 eyes) in the KDB group. Mean follow-ups were 20.9±6.5 (KDB-alone) to 29.5±7.6 (phaco-iStent inject) months. Pre- and post-operative IOPs were 22.2±5.8 mmHg and 15.9±4.3 mmHg (P=0.004) in the KDB-alone, 24.2±6.8 mmHg and 16.2±6.7 mmHg (P=0.001) in the phaco-KDB, 20.6±5.4 mmHg and 20.9±6.8 mmHg (P=0.598) in the iStent inject-alone as well as 20.9±5.5 mmHg and 15.6±3.4 mmHg (P=0.003) in the phaco-iStent inject subgroups. No major complications occurred.

Conclusion

All KDB and iStent subgroups except the stand-alone iStent inject subgroup showed a clinically significant IOP-lowering effect as a stand-alone procedure or combined with cataract surgery. Goniotomy with KDB in this setting seems to offer an advantageous IOP reduction compared to iStent inject.

Treatment of Open-Angle Glaucoma with iStent Implantation Combined with Phacoemulsification in Polish Caucasian Population

Purpose

The aim of this investigation was to evaluate the impact of iStent (the first-generation trabecular bypass) implantation with phacoemulsification on the intraocular pressure (IOP) and glaucoma medication in subjects with mild to moderate open-angle glaucoma (OAG) and cataract in a Polish Caucasian population.

Patients and Methods

This prospective case series covered 78 eyes of (57 Polish Caucasian patients) that had undergone iStent implantation in conjunction with cataract surgery. Patients were surveyed preoperatively and at postoperative day 1, week 1, and months 1, 3, 6, 12, and 24. Pre- and postoperative outcome measurements included visual acuity, IOP, and medication burden. Intraoperative and postoperative complications were noted for the safety profile. For effective treatment, an IOP reduction ≥20% was assumed, regardless of the use of IOP-lowering drops. Complete surgical success was defined as an IOP ≤ 15 mmHg, medications free, and a qualified surgical success as IOP ≤ 15 mmHg with or without medications.

Results

Post-operatively at two years, mean IOP reduced from 18.5 mmHg to 16.1 mmHg. The mean medication burden dropped from 1.8 to 0.4 at the end of follow-up. Preoperatively, 2 (2.6%) eyes were medication free, but by postoperative month 24, 53 (68%) eyes were medication-free (p < 0.05). Effective treatment was achieved in 50 cases (64%) at the end of follow-up period. Kaplan–Meier cumulative incidence of qualified success was 51.9% after 24 months, CI₉₅ [41.9%; 64.4%], while cumulative incidence of complete success after 2 years of observation was 35.1%, CI₉₅ [25.9%; 47.5%].

Conclusion

The iStent device combined with a cataract surgery served to decrease, significantly and positively, both IOP and medication use in the 24-months follow-up in patients with coexistent OAG and cataract in Polish patients.

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.

Influence of Selective Laser Trabeculoplasty (SLT) on the iStent inject® outcomes

Background

To evaluate the influence of Selective Laser Trabeculoplasty (SLT) on iStent inject® outcomes in open-angle glaucoma (OAG).

Methods

In this retrospective comparative cohort outcome study, 66 patients who were treated with two iStent inject® devices were included. Patients were divided into two subgroups consisting of patients without SLT treatment prior to surgery and patients who had been treated previously with 360° SLT but without sufficient response. Outcome measures included intraocular pressure (IOP) and number of antiglaucoma medications after 6 weeks with three, six, 12, and 24 month follow-ups.

Results

Mean preoperative IOP decreased from 20.4 ± 5.3 mmHg to 14.8 ± 3.0 mmHg for patients without SLT treatment prior to surgery (p = 0.001) and from 19.2 ± 4.5 mmHg to 14.0 ± 1.6 mmHg for patients with insufficient response to 360° SLT treatment (p = 0.027) at 12 months after iStent inject® implantation. No significant difference was found between the two groups (p >  0.05). The number of antiglaucoma medications did not change in both groups (p >  0.05) and showed no significant difference between the two groups (p >  0.05).

Conclusion

Prior SLT treatment seems to have no negative influence on the IOP lowering-effect of iStent inject® implantation in patients with OAG. It is therefore an appropriate incremental procedure with no exclusion criterion for an iStent inject® implantation.

Effectiveness and limitations of minimally invasive glaucoma surgery targeting Schlemm's canal

Glaucoma surgery is performed to lower intraocular pressure (IOP); ideally, the IOP reduction is safely maintained for an extended period of time. Although trabeculectomy was considered the gold standard for glaucoma surgery for many years because of its effective IOP reduction, yet now it is considered unsafe because of serious complications. In recent years, minimally invasive glaucoma surgery (MIGS), which emphasizes safety and can be performed rapidly, has become widespread. Because MIGS does not involve conjunctival incisions, patients can undergo future trabeculectomy. If IOP reduction can be maintained safely, the number of anti-glaucoma drops can be reduced and visual function maintained, good outcomes for patients with glaucoma. Currently, many types of MIGS approved in Japan are reported to yield relatively good results, with targets of approximately 15-19 mmHg. However, the IOP-lowering effects of MIGS are limited. In procedures targeting Schlemm's canal, it is difficult to lower IOP beyond episcleral venous pressure. In some instances, a beneficial effect cannot be achieved if function is reduced beyond the collector channel. There are many unclear aspects regarding long-term outcomes following MIGS. Notably, investigation is ongoing to determine which patients are likely to benefit most from surgery. Based on previous reports, this review describes the characteristics and results of MIGS, approved in Japan, as well as underlying factors that affect the preoperative predictions and outcomes of the surgical procedure.

Manchester iStent study: long-term 7-year outcomes

OBJECTIVES

To determine the efficacy and safety of combined phacoemulsification and single first-generation iStent implantation over 84 months.

SUBJECTS/METHODS

Single-surgeon, single-centre, uncontrolled prospective interventional study in real-world settings. Forty-one patients with open-angle glaucoma on at least one antihypertensive drop underwent phaco-iStent surgery. This cohort was monitored over the subsequent 84 months. The primary outcome measure was intraocular pressure (IOP). Secondary outcome measures were number of glaucoma drops, visual acuity, cup-disc-ratio (CDR), mean deviation (MD) and visual field index (VFI). Thirty-one (76%) patients survived to 48 months and 19 (46%) patients to 84 months.

RESULTS

At 84 months, we demonstrate an absolute mean reduction of 4.87 mmHg (95% CI 1.62-7.64) for IOP and 0.59 (95% CI 0.03-1.16) for number of glaucoma drops. At the final clinic visit, LogMAR VA improved by 0.21 (95% CI 0.08-0.34), with no significant change in CDR, MD and VFI. Attrition was mainly due to death (27%) and further glaucoma surgery (12%). A single patient suffered from postoperative hyphaema, with no sequalae. Patients at high risk for progression to filtration surgery were defined as those on oral acetazolamide for IOP control, or those fulfilling all the following criteria: IOP ≥ 20 mmHg, CDR ≥ 0.7, MD ≤ -4.0 dB, number of drops ≥ 2. This group is to be considered for surgery as the next step in management according to NICE glaucoma guidelines. These patients (n = 14) demonstrated a more marked final IOP reduction of 6.85 mmHg (95% CI 3.97-9.75) vs 1.62 mmHg (95% CI 0.04-3.22) in their low-risk counterparts (n = 27). Reduction in glaucoma drops was 0.86 (95% CI 0.07-1.64) for the high-risk and 0.56 (95% CI 0.06-1.05) for the low-risk cohort. Further glaucoma surgery was required for 4 (29%) high-risk and 1 (0.5%) low-risk patients over the study period.

CONCLUSIONS

Our results strongly suggest that the expected outcome of phaco-iStent surgery is a maintained reduction in intraocular pressure and number of glaucoma medications over 7 years. This is combined with a negligible rate of complications, a sustained improvement in central visual acuity, and a reliable maintenance of peripheral visual function.

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.

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.

The Effectiveness of First-Generation iStent Microbypass Implantation Depends on Initial Intraocular Pressure: 24-Month Follow-Up-Prospective Clinical Trial

Background

Evaluation of efficacy of the iStent trabecular bypass implant in reducing intraocular pressure (IOP) depending on the value pretreatment IOP and number of medications used before surgery in patients with primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PXG) and coexisting cataract.

Methods

A prospective, uncontrolled, interventional case series. 72 patients, on a mean age of 72.42 ± 9.17, were divided into two groups depending on baseline IOP: group I < 26 mmHg and group II ≥ 26 mmHg. All subjects underwent ab interno implantation of a single iStent together with cataract surgery. Best-corrected visual acuity (BCVA), IOP, number of antiglaucoma medications, visual field, and number and type of complications were examined before and after surgery. Postoperative patients were followed up at 1, 7, and 30 days and 3, 6, 12, and 24 months. All the patients were washed out preoperatively as well as postoperatively.

Results

The mean observation time was 20 months. The mean preoperative IOP was 21.03 ± 1.44 mmHg in group I and reduced to mean 15.60 ± 2.12 mmHg after operation. In group II, mean IOP reduced from 26.00 ± 0.00 to 18.56 ± 1.81 (p=0.003). Mean glaucoma medications decreased from 1.35 ± 0.65 to 0.29 ± 0.52 in group I (p < 0.001) and from 2.89 ± 1.18 to 1.33 ± 1.50 in group II (p < 0.001). At 24 months, medication reduction was significantly greater in group I than group II (p=0.026).

Conclusions

Combined cataract surgery with implantation of iStent seems to be an effective procedure in patients with mild-to-moderate open-angle glaucoma and cataract. In patients with baseline IOP < 26 mmHg, surgery reduced IOP and medication use significantly declined to 2 years, with greater reductions achieved versus patients with baseline IOP ≥ 26 mmHg. This trial is registered with NCT03807869.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Combined iStent® Inject Trabecular Micro-Bypass and Phacoemulsification in Australian Patients with Open-Angle Glaucoma

Purpose

This retrospective audit aimed to evaluate the impact of combined iStent^®Inject (iSI) and phacoemulsification on medication number in Australians with open-angle glaucoma. Secondary outcomes included intraocular pressure (IOP), best-corrected visual acuity, refraction and visual fields.

Patients and Methods

Patients with glaucoma that received combined iSI and phacoemulsification by the same surgeon between 1 February 2016 and 1 February 2018 were audited for postoperative medication number, pressures after 1 day, 1 week, 4 weeks and 6, 12, 18 and 24 months, visual acuity, refraction and visual fields. These parameters were compared to baseline levels and with those from a separate cohort of patients without glaucoma that received standalone phacoemulsification.

Results

Forty-one patients (63 eyes) received the combined procedure. Thirty-four patients (59 eyes) received standalone phacoemulsification. Four weeks after receiving combined iSI and phacoemulsification the mean medication number was significantly reduced by 1.3 (p < 0.001) for those on medication at baseline and by 0.5 (p = 0.002) overall. Mean IOP was significantly reduced from baseline after 6 months (–16%; p = 0.012; n = 35) and 12 months (–29%; p = 0.004; n = 16). Patients receiving standalone phacoemulsification had short-term reductions in IOP at 4 weeks (–8%; p < 0.001; n = 57) and 6 months (–16%; p < 0.001; n = 32). These patients without glaucoma had lower pressures overall compared to those with glaucoma that received the combined procedure (p = 0.019). There were no differences in final visual acuity or refractive outcomes between groups.

Conclusion

This audit suggests that iSI and phacoemulsification are at least as effective in controlling IOP as medical therapy. It may have an important role in reducing the medication burden in Australians with cataract and glaucoma. This study is one of the first to confirm refractive stability in concomitant iSI and phacoemulsification.

Prospective Studies of Minimally Invasive Glaucoma Surgeries: Systematic Review and Quality Assessment

Glaucoma is a common blinding disease; while there is no cure, effective treatments include medications, laser, and incisional surgery. There is significant interest from patients and doctors to develop safer surgical options throughout the spectrum of disease, to minimize treatment burden in mild glaucoma patients and to minimize risk of complications in patients needing more aggressive treatment. Surgical procedures called Minimally or Micro-Invasive Glaucoma Surgery (MIGS) are growing in popularity. Eighty-seven prospective studies on MIGS were identified and assessed for quality. Most (74%) did not have a control group. Twelve of the highest quality were reviewed. MIGS procedures appeared to have fewer complications, and lowered intraocular pressure, and reduced medication use. Studies were limited by small sample size, narrow spectrum of glaucomatous disease, and/or conflicts of interest. There is a need for high quality, independently funded and performed, comparative studies on the MIGS to help make treatment decisions.

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.

The Efficacy and Safety of High-Frequency Deep Sclerotomy in Treatment of Chronic Open-Angle Glaucoma Patients

Purpose

Highlights the high-frequency deep sclerotomy as a competing ab interno surgery in open-angle glaucoma patients and evaluates the efficacy of high-frequency deep sclerotomy in lowering IOP of chronic open-angle glaucoma patients, in addition to the evaluation of the safety of the procedure on the corneal endothelium.

Design

A prospective study. It was performed in the Research Institute of Ophthalmology, Cairo.

Participants

43 eyes were enrolled for the study. All eyes were diagnosed with chronic open-angle glaucoma.

Methods

The procedure was performed using the abee® glaucoma tip of Oertli phacoemulsification machine (OS3, Switzerland) and goniolens performing nasal six pockets penetrating 1 mm deep into the trabecular meshwork and Schlemm's canal. Patients were followed up regarding vision and intraocular pressure (IOP) for 9 months. Endothelial cell count and coefficient of variation were calculated using specular microscopy preoperatively and 9 months postoperatively.

Results

The mean preoperative IOP was 31.4 ± 4.71 mmHg (range: 22 to 42 mmHg). All patients were followed up for nine months. The mean IOP was 19.06 ± 1.907 mmHg (range: 15 to 26 mmHg) by the end of the study. The reduction across the follow-ups was statistically significant (P < 0.0001). The percentage of total success was 90.7% (39 eyes). Four eyes (9.3%) had IOP > 21 (failed) after surgery and continued on antiglaucoma therapy.

Conclusion

High-frequency deep sclerotomy is a safe and promising minimally invasive procedure which successfully achieves a lower IOP for chronic open-angle glaucoma patients, but not adequate for advanced glaucoma patients. This trial is registered with PACTR201910823824561.

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).