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

Real-world comparison of efficacy and safety of XEN45 implant with phacoemulsification versus iStent inject® W with phacoemulsification

PURPOSE

To compare iStent inject® W+phacoemulsification with XEN45 implant+phacoemulsification over 12 months in mild to moderate glaucoma patients needing cataract surgery at the Hospital General Universitario Dr. Balmis, Alicante, Spain.

METHODS

Retrospective clinical cohort study. Consecutive patients who underwent phacoemulsification either combined with XEN45 implantation or iStent inject® W from 2020 to 2022 were included. The main outcome measure was surgical success at 12 months postoperatively. Intraocular pressure (IOP), number of antiglaucoma medications, intraoperative and postoperative complications, number of revision surgeries, use of the operating room and required visits were also evaluated.

RESULTS

A total of 167 eyes were included in the study, with 101 eyes of 61 patients undergoing iStent+PHACO and 66 eyes of 46 patients undergoing XEN45+PHACO. The proportion of patients achieving a complete success (IOP≥5 and ≤ 18mmHg without medication) at the conclusion of the 12-month follow-up was 47.9% (35/73) in the iStent+PHACO and 48.2% (27/56) in the XEN45+PHACO surgery group, P=1.000. The mean (95% CI) IOP reduction at the conclusion of the study follow-up was -2.4 (-3.5 to -1.3mmHg, P<0.001, iStent+PHACO) and -3.10 (-4.8 to -1.4mmHg, P<0.001, XEN45+PHACO). The mean number of antiglaucoma medications was significantly reduced in both study groups. Rates of intraoperative complications (5 vs. 15.2%), postoperative complications (1 vs. 46.2%), reoperations (0 vs. 24.6%), mean number of operating room visits (1 vs. 1.41), and mean number of required postoperative visits (4.50 vs. 11.13) were all statistically significantly higher in the XEN45+PHACO group (< 0.001).

CONCLUSIONS

Both procedures achieved similar surgical success rates, with comparable reductions in IOP and the number of antiglaucoma medications. After one year, a modest IOP reduction of 10.83% was observed in the iStent group and 13.65% in the Xen group. However, the iStent inject® W demonstrated a better intraoperative and postoperative safety profile.

Longitudinal outcomes of iStent inject with cataract surgery compared with cataract surgery alone: real-world data from the Fight Glaucoma Blindness registry

PURPOSE

To compare combined phacoemulsification and iStent inject with phacoemulsification alone.

SETTING

Fight Glaucoma Blindness (FGB) registry, Sydney, Australia.

DESIGN

Prospective observational registry study.

METHODS

Eyes that had combined phacoemulsification with iStent inject (iStent group), n = 1257 were compared with eyes that had phacoemulsification only (cataract alone, n = 163). The primary outcome was percentage of eyes achieving >20% intraocular pressure (IOP) reduction from baseline 12 months postoperatively. Secondary outcomes included mean IOP and medication reduction, adverse events, and secondary procedures.

RESULTS

At 12 months, the percentage of eyes achieving >20% reduction of IOP was significantly higher in the iStent group compared with the cataract-alone group (40.9% vs 30.1% P < .001). Adverse events occurred at a low rate in both groups, and secondary IOP-lowering procedures were significantly less frequent in the iStent group compared with cataract alone.

CONCLUSIONS

Real-world outcomes from the FGB registry at 12 months show that phacoemulsification combined with iStent inject has a higher efficacy and reduced need for secondary IOP-lowering surgery compared with phacoemulsification alone.

Comparison of Phacoemulsification Alone and With Trabecular Microbypass Stent in Primary Open-Angle Glaucoma and Normal-Tension Glaucoma: An 18-Month Outcome Study

iStent (Glaukos, San Clemente, CA, USA), a minimally invasive glaucoma device, reduces intraocular pressure (IOP) by enhancing aqueous humor outflow when implanted into Schlemm's canal. Although it has demonstrated effectiveness in lowering IOP and slowing glaucoma progression, its applicability to the Taiwanese population, known for a higher incidence of normal-tension glaucoma (NTG) cases, requires validation. This retrospective case-control study, conducted from January 2018 to December 2020, aimed to assess the effectiveness of combining first-generation iStent with phacoemulsification (phaco-iStent) compared to phacoemulsification alone in Taiwanese patients diagnosed with primary open-angle glaucoma (POAG) and NTG, involving 71 eyes (iStent group: POAG 16 and NTG 8; control group: POAG 28 and NTG 19). The primary outcomes included changes in IOP and the number of antiglaucoma medications, with subgroup analyses for POAG and NTG. Over the 18-month follow-up, the iStent group achieved a significantly greater reduction in antiglaucoma medications compared with the control group (p value = 0.003∼<0.001) without significant IOP rebound. After adjusting for confounding factors, the reduction in the number of antiglaucoma medications with iStent remained significant (β = -0.8, p < 0.001) according to the generalized estimating equation. At 18 months, the iStent group demonstrated higher qualified and complete success rates than the control group (73.3% vs. 16.7%, p value = 0.001% and 53.3% vs. 0%, p value = 0.002, respectively). Notably, the NTG-iStent subgroup achieved the highest complete success rate (85.7% at 18 months). In conclusion, phaco-iStent emerges as an effective standalone treatment for Taiwanese patients with POAG and NTG, providing substantial IOP reduction and higher success rates, especially in NTG cases. These findings propose that phaco-iStent could be a promising intervention for managing POAG and NTG within the Taiwanese population. Trial Registration: ClinicalTrials.gov identifier: NCT06630546.

Three-year analysis of results, safety and progression in patients with open-angle glaucoma or ocular hypertension, undertaking trabecular microsurgery

AIM

To evaluate the efficacy, safety, structural and functional progression following the insertion of iStent inject ® implants in patients with open-angle glaucoma or ocular hypertension at a tertiary-level hospital.

MATERIALS AND METHODS

A retrospective study included 98 eyes (57 males and 41 females) with open-angle glaucoma or ocular hypertension, which underwent iStent inject W® implantation (Glaukos, Corporation, CA) between December 2018 and December 2022. Differences in intraocular pressure (IOP), the number of hypotensive eye drops used, and structural and functional tests were assessed between preoperative values and subsequent reviews during a follow-up period of one (n = 98), two (n = 55), and three years (n = 15) after surgery.

RESULTS

Among the 98 eyes studied, 85% were diagnosed with open-angle glaucoma (50% mild, 32% moderate, and 18% severe) and 15% with ocular hypertension. There was a statistically significant reduction in IOP compared to preoperative values for all visits except the 1-month (p = 0.36) and 3-year (p = 0.39) visits. Visual acuity increased from 0.39 ± 0.25 to 0.72 ± 0.24 (p < 0.01), considering that a significant portion of the interventions included cataract surgery. Before surgery, 66% of the sample used 2 or more hypotensive medications. Post-surgery, the number of hypotensive medications decreased (from 1.88 ± 0.84 to 0.21 ± 0.59 at 3 years) (p < 0.01), with an 88.9% reduction in the number of medications over three years. After surgery, 75% of cases did not require any medication. Regarding structural and functional tests, thickness of retinal nerve fiber layers (RNFL (p = 0.35), excavation / papilla ratio E/P (p = 0.31), visual function index (VFI (p = 0.06), and deviation mean (MD (p = 0.06) showed no statistically significant differences post-intervention. However, standard deviation of the pattern (DSM) did exhibit differences, decreasing from 5.46 ± 4.03 dB to 5.34 ± 3.48 dB (p = 0.02).

CONCLUSION

The results of this study suggest that the iStent inject W® technique constitutes an effective and safe option for tension control and glaucoma treatment.

[Glaucoma surgeries: Long-term results - A review]

The surgical treatment of glaucoma has been and is still based on filtering surgeries, commonly used for about half a century. The safety and efficacy of these techniques have been well described, as it has also been done for cyclophotocoagulation and valves or tubes, indicated in France mostly for refractory glaucoma. Minimally invasive glaucoma surgeries have emerged in recent decades, increasing the number of therapeutic options, and allowing treatment decisions to be as patient-centered as possible. Most of these techniques have now been studied for more than five years. Since glaucoma is a chronic, progressive optic neuropathy, the sustainability of each surgery's results is essential. The amount of available data concerning long-term efficacy and safety of glaucoma surgeries is increasing, so we have decided to describe it through this review of the literature.

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

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

Angle-based minimally invasive glaucoma surgery in normal tension glaucoma: A systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis quantitatively examines the efficacy of angle-based minimally invasive glaucoma surgery (MIGS) in normal tension glaucoma (NTG).

METHODS

A literature search was performed on Medline, Embase, PubMed, CINAHL and Cochrane Library from inception until 20 December 2022. Pilot, cohort, observational studies and randomised controlled trials including at least 5 subjects undergoing angle-based MIGS (trabecular-bypass devices, excisional trabeculotomy, goniotomy and ab-interno canaloplasty) for NTG, with or without cataract surgery, were included. Meta-analysis of continuous outcome using the meta routine in R version 2022.12.0+353 was performed to determine mean intraocular pressure (IOP) and anti-glaucoma medication (AGM) reduction post-operatively.

RESULTS

Of the 846 studies initially identified, 15 studies with a pooled total of 367 eyes which underwent combined phacoemulsification and angle-based MIGS were included for final meta-analysis. Outcomes of the iStent were reported in 5 studies, iStent inject in 7 studies, Hydrus Microstent in 1 study, Kahook Dual Blade in 3 studies, and Trabectome in 2 studies. There was significant reduction in both IOP and AGM post-operatively at 6 months (2.44 mmHg, 95%CI: 1.83-3.06; 1.21 AGM, 95%CI: 0.99-1.44), 12 months (2.28 mmHg, 95%CI: 1.71-2.84; 1.18 AGM, 95%CI: 0.90-1.47), 24 months (2.10 mmHg, 95%CI: 1.51-2.68; 1.26 AGM, 95%CI: 0.85-1.68) and 36 months (2.43 mmHg, 95%CI: 1.71-3.15, 0.87 AGM, 95%CI: 0.21-1.53) (all p < 0.05). Subgroup analysis on combined phacoemulsification-iStent inject surgery demonstrated a reduction in both IOP (2.31 mmHg, 95%CI: 1.07-3.56, p < 0.001) and AGM (1.07 AGM, 95%CI: 0.86-1.29, p < 0.001) at 12 months post-operatively.

CONCLUSIONS

Angle-based MIGS combined with phacoemulsification effectively reduces IOP and AGM in NTG eyes for up to 36 months after surgery.

Long-term efficacy and safety of XEN-45 gel stent implantation in patients with normal-tension glaucoma

BACKGROUND

Minimally invasive bleb surgery using the XEN-45 gel stent has not been established for the treatment of normal-tension glaucoma (NTG). The main objective of this study was to evaluate the long-term treatment efficacy and safety of XEN-45 in eyes with uncontrolled NTG.

METHODS

A retrospective analysis of patients with NTG who underwent XEN-45 gel stent implantation at university hospital Tuebingen between 2016 and 2021. The primary outcome measure was surgical success after three years defined as lowering of intraocular pressure (IOP) of ≥ 20%, with target IOP between 6 and 15 mmHg. Success was complete without and qualified irrespective of topical antiglaucoma medication use. The need for further glaucoma surgery, except for needling, was regarded as a failure. The secondary outcome measures included changes in mean IOP, number of antiglaucoma medications, and needling and complication rates.

RESULTS

Twenty-eight eyes from 23 patients were included in the final analysis. Complete and qualified success rates were 56.5% and 75% after three years, respectively. Mean postoperative IOP ± standard deviation decreased significantly after three years from 19.3 ± 2.0 mmHg at baseline to 13.7 ± 4.2 mmHg (n = 22; p < 0.0001). The median number of antiglaucoma medications decreased from 2 (range 0-4) to 0 after three years (range 0-3; p < 0.0001). Sixteen eyes (57%) required a median of 1 (range 1-3) needling procedures. One eye required further glaucoma surgery. No sight-threatening complications were observed.

CONCLUSION

The XEN-45 stent is effective and safe for the long-term treatment of NTG. However, needling was frequently required to improve outcomes.

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

PRCIS

The iStent inject W implanted during phacoemulsification effectively reduces IOP.

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Phacoemulsification with and without iStent: A Systematic Review and Meta-Analysis of Comparative Studies

BACKGROUND

The iStent (Glaukos Corporation; Laguna Hills, CA, USA) is one of the minimally invasive glaucoma devices. It can be inserted at the time of phacoemulsification or as a stand-alone procedure to lower the intraocular pressure (IOP).

OBJECTIVE

Our aim was to conduct a systematic review and meta-analysis comparing the effect of iStent insertion at the time of phacoemulsification with phacoemulsification alone in patients with ocular hypertension or open-angle glaucoma.

METHODS

We searched EMBASE, MEDLINE (OVID and PubMed), CINAHL, and Cochrane Library for articles published between 2008 and June 2022 (PRISMA 2020 for the checklist). Studies comparing the IOP-lowering effect of iStent with phacoemulsification versus phacoemulsification alone were included. The endpoints were IOP reduction (IOPR) and the mean reduction in the number of glaucoma drops. A quality-effects model was used to compare both surgical groups.

RESULTS

Ten studies were included, reporting on 1,453 eyes. Eight hundred fifty three eyes had the combined iStent and phacoemulsification, and 600 eyes underwent phacoemulsification alone. IOPR was higher in the combined surgery at of 4.7 ± 2 mm Hg compared to 2.8 ± 1.9 mm Hg in phacoemulsification alone. A greater decrease in postoperative eye drops was noted in the combined group having a decrease of 1.2 ± 0.3 eye drops versus of 0.6 ± 0.6 drops in isolated phacoemulsification. The quality effect model showed an IOPR weighted mean difference (WMD) of 1.22 mm Hg (confidence interval [CI]: [-0.43, 2.87]; Q = 315.64; p < 0.01; I2 = 97%) and decreased eye drops WMD 0.42 drops (CI: [0.22, 0.62]; Q = 42.6; p < 0.01; I2 = 84%) between both surgical groups. Subgroup analysis shows that the new generation iStent may be more effective in reducing IOP.

CONCLUSION

iStent has a synergetic effect with phacoemulsification. The reduction of IOP and glaucoma eye drops was higher when iStent is combined with phacoemulsification compared with isolated phacoemulsification.

Effectiveness and Safety of iStent Infinite Trabecular Micro-Bypass for Uncontrolled Glaucoma

PRCIS

The iStent Infinite Trabecular Micro-Bypass System implanted in patients with open angle glaucoma (OAG) (uncontrolled by prior surgical or medical therapy) was effective in reducing mean diurnal intraocular pressure with a favorable safety profile.

PURPOSE

The purpose of this study is to evaluate safety and effectiveness of the iStent infinite Trabecular Micro-Bypass System in patients with OAG uncontrolled by prior surgical or medical therapy.

DESIGN

Prospective, multicenter, single-arm, open-label clinical trial.

METHODS

Implantation of iStent infinite (3 iStent inject W stents) was performed as a stand-alone surgical procedure in eyes with OAG uncontrolled by prior incisional or cilioablative surgeries or maximum tolerated medical therapy (MTMT). Prospectively declared effectiveness endpoints were proportion of eyes achieving ≥20% mean diurnal intraocular pressure (MDIOP) reduction from baseline at month 12 on the same or fewer intraocular pressure (IOP)-lowering medication classes (responder endpoint) and mean change in MDIOP from baseline at month 12. Safety parameters included visual acuity, slit-lamp and fundus examinations, gonioscopy, perimetry, surgical complications, and adverse events.

RESULTS

Seventy-two eyes of 72 patients (mean age 71.9 y) with preoperative mean medicated MDIOP of 23.4±2.8 mm Hg on a mean of 3.1±0.9 IOP-lowering medication classes were enrolled: 61 eyes with failed prior surgery/ies (Failed-Surgery subgroup) and 11 eyes uncontrolled on MTMT (MTMT subgroup). A total of 76.1% of all enrolled patients met the responder endpoint (73.4% Failed-Surgery, 90.9% MTMT), with mean reduction (SE) in MDIOP at month 12 of 5.9(0.6) mm Hg [5.5(0.7) mm Hg Failed-Surgery subgroup, 8.1(0.9) mm Hg MTMT subgroup]. For patients on the same or fewer medication(s) as baseline, 53.0% achieved ≥30% MDIOP reduction without surgical interventions/other events. Safety was favorable, with no explants, infection, or device-related interventions or hypotony.

CONCLUSIONS

iStent infinite stand-alone surgery achieved clinically significant IOP reduction and favorable safety in patients with OAG uncontrolled by prior therapy.

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.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Clinical trial registration (CTR)

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

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.

Prospective 12-month outcomes of combined iStent inject implantation and phacoemulsification in Asian eyes with normal tension glaucoma

BACKGROUND

Glaucoma is the leading cause of irreversible blindness. Normal tension glaucoma (NTG) is a subset of open-angle glaucoma, demonstrating glaucomatous optic nerve damage in the absence of raised intraocular pressure (IOP). NTG is more prevalent in Asian populations. While generally slow-progressing, NTG may be associated with significant central visual field loss. In recent years, minimally invasive glaucoma surgery has been added to the armamentarium of glaucoma surgery. This prospective study aims to evaluate 12-month surgical outcomes of combined iStent inject (Glaukos Corporation, Laguna Hills, CA) implantation and phacoemulsification in Asian eyes with NTG.

METHODS

This is a prospective, single-centre case series of 30 eyes followed up until 12 months after surgery. Outcome measures included IOP, number of glaucoma medications, best-corrected visual acuity (BCVA) and intra and postoperative complications.

RESULTS

Mean age of subjects was 73.1 ± 6.3 years. Majority were ethnic Chinese (n = 27, 90%). Baseline medicated mean IOP was 13.8 ± 2.4 mmHg and mean number of glaucoma medications was 1.3 ± 0.7. Mean Humphrey visual field mean deviation was - 13.7 ± 7.6. The mean IOP reduction at all timepoints from postoperative month (POM) 3 onwards was statistically significant (all P < 0.05), with mean reduction of 1.2 mmHg (95% CI: 0.1-2.2, P = 0.037) by POM12. There was statistically significant reduction in mean number of medications from postoperative day (POD) 1 onwards (all P < 0.05), with mean decrease of 1.0 medication (95% CI: 0.9-1.1, P < 0.001) by POM12. By POM12, 25 (83.3%) eyes were medication-free. Three (10%) eyes had stent occlusion by iris requiring laser iridoplasty. One eye had gross hyphema which resolved on conservative management before POM1. Mean BCVA improved from the baseline 0.3 ± 0.3 logMAR to 0.1 ± 0.1 logMAR postoperatively (P < 0.001). There were no major adverse or sight-threatening events. No eyes required further glaucoma surgery during the 12-month follow-up period.

CONCLUSION

Asian eyes with NTG which underwent combined iStent inject implantation and phacoemulsification demonstrated a significant and sustained reduction in IOP and glaucoma medications, up to 12 months postoperatively.

Refractive outcomes of toric intraocular lens in combined trabecular micro bypass stent implantation and cataract surgery in glaucomatous eyes

PURPOSE

To evaluate the impact of trabecular micro bypass stents (iStent Inject) on refractive outcomes with toric intraocular lens (IOL) in glaucomatous eyes.

METHODS

We identified glaucomatous eyes receiving a toric IOL between October 2017 and December 2020. Eyes with iStent implantation were included in the study group and eyes undergoing isolated phacoemulsification served as controls. Corrected and uncorrected visual acuity, manifest refraction, intraocular pressure (IOP), and number of hypotensive drugs three months after surgery were evaluated.

RESULTS

26 eyes comprised the study group and 41 eyes the control group. Mean postoperative refractive cylinder was 0.26D in the control and 0.11D in the iStent group, with 63% and 85% of eyes with a cylinder of 0 and 85% and 92% of eyes with a cylinder ≤ 0.5D respectively. The mean absolute difference between target and outcome spherical equivalent was 0.26D in the control and 0.22D in the iStent group, with all eyes within 0.75D of target. LogMar uncorrected postoperative vision in eyes targeted for emmetropia was 0.04 in the control and 0.03 in the iStent group. There was a statistically significant reduction in IOP and number of hypotensive drugs in both groups, with a mean decrease in IOP of 8.6% in the control and 15.7% in the iStent group. The number of hypotensive drugs dropped from 1.63 ± 0.80 to 1.34 ± 0.91 in the control group and from 2.12 ± 0.65 to 0.44 ± 0.71 in the iStent group.

CONCLUSION

Toric IOLs provide predictable refractive outcomes in glaucomatous eyes undergoing combined phacoemulsification with iStent implantation, reducing postoperative spectacle dependence.

Normal-tension glaucoma: Current concepts and approaches-A review

Normal tension glaucoma (NTG) has remained a challenging disease. We review, from an epidemiological perspective, why we should redefine normality, act earlier at lower pre-treatment intraocular pressure (IOP) level, and the role of ocular perfusion pressures, noting that perfusion is affected by defective vascular bed autoregulation and endothelial dysfunction. The correlation of silent cerebral infarcts (SCI) and NTG may indicate that NTG belongs to a wider spectrum of small vessel diseases (SVD), with its main pathology being also on vascular endothelium. Epidemiological studies also suggested that vascular geometry, such as fractal dimension, may affect perfusion efficiency, occurrence of SCI, SVD and glaucoma. Artificial intelligence with deep learning, may help predicting NTG progression from vascular geometry. Finally, we review latest evidence on the role of minimally-invasive glaucoma surgery, lasers, and newer drugs. We conclude that IOP is not the only modifiable risk factors as, many vascular risk factors are readily modifiable.

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

Introduction

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

Methods

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

Results

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

Conclusions

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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.