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

Six-Month Outcomes from a Prospective, Randomized Study of iStent infinite Versus Hydrus in Open-Angle Glaucoma: The INTEGRITY Study

INTRODUCTION

This was a prospective, randomized, double-masked, multicenter, 24-month study to compare effectiveness and safety outcomes following standalone implantation of two types of current generation trabecular stents in adults with open-angle glaucoma (OAG). An interim analysis was performed at month 6.

METHODS

Eyes with OAG, mean IOP ≤ 24 mmHg on zero to three intraocular pressure (IOP)-lowering medications at screening, and with baseline mean diurnal IOP (MDIOP) 21-36 mmHg after medication washout were randomized to standalone implantation of the current generation of three trabecular micro-bypass stents (iStent infinite) or one trabecular bypass stent (Hydrus). Eyes on medication were to undergo a medication washout prior to the month 6 visit. Analyses included a comparison of the proportion of iStent infinite versus Hydrus eyes achieving MDIOP reduction of 20% or greater from baseline at month 6. Reduction from baseline in MDIOP and number of medications were also assessed. Safety parameters included intraoperative/postoperative complications, corrected visual acuity, slit-lamp biomicroscopy, ophthalmoscopy, gonioscopy, perimetry, and adverse events.

RESULTS

Eyes with primarily mild-to-moderate disease severity were randomized: 91 iStent infinite eyes had screening mean (± standard deviation [SD]) IOP of 17.0 ± 3.2 mmHg on 1.6 ± 0.9 medications and baseline unmedicated MDIOP of 23.7 ± 2.9 mmHg; 89 Hydrus eyes had screening mean (± SD) IOP of 17.1 ± 3.3 mmHg on 1.5 ± 0.9 medications and baseline unmedicated MDIOP of 23.5 ± 2.7 mmHg. At month 6, a similar proportion of iStent infinite eyes (82.7%) versus Hydrus eyes (78.9%) achieved MDIOP reduction ≥ 20% from baseline regardless of IOP medication use or surgical complications. The difference was statistically significantly different (78.2% iStent infinite versus 65.0% Hydrus) for unmedicated MDIOP reduction ≥ 20% from baseline in eyes with no surgical complications (difference 13.2%; 95% confidence interval (CI) 3.0%, 23.3%). Mean MDIOP change from baseline, regardless of IOP medication use or surgical complications, was similar between groups (- 7.4 ± 2.9 mmHg iStent infinite and - 7.2 ± 2.9 mmHg Hydrus), whereas unmedicated MDIOP change from baseline without surgical complications was statistically significantly superior in iStent infinite eyes (- 6.8 ± 4.1 mmHg) versus Hydrus eyes (- 5.7 ± 4.1 mmHg) (difference - 1.1 mmHg; 95% CI - 2.0 mmHg, - 0.2 mmHg). Improper stent placement was reported in one iStent infinite and seven Hydrus eyes (1.1% versus 7.9%). One iStent infinite versus four Hydrus eyes experienced peripheral anterior synechiae > 1 mm (1.1% versus 4.5%). Overall, there were significantly fewer surgical complications in the iStent infinite eyes (3.3%) compared to Hydrus eyes (16.9%; difference of - 13.6%, 95% CI - 23.8%, - 3.4%).

CONCLUSIONS

In this study of standalone implantation of current trabecular stent technologies in subjects with OAG, high proportions in both groups achieved clinically meaningful IOP reduction. When considering surgical complications as failures, a statistically significantly greater proportion of iStent infinite eyes versus Hydrus eyes had no surgical complications and achieved an unmedicated MDIOP reduction of ≥ 20%. The iStent infinite group also had clinically relevant and statistically significantly superior reduction from baseline in unmedicated MDIOP without surgical complications compared to Hydrus.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT05127551.

Minimally invasive glaucoma surgery: comparison of Hydrus microstent with iStent inject in primary open-angle glaucoma

BACKGROUND

To evaluate and compare the efficacy of a single Hydrus and double iStent inject both combined with cataract surgery for the treatment of primary open-angle glaucoma (POAG).

METHODS

The study was designed as a prospective comparative case series. Patients with POAG undergoing trabecular microbypass stent insertion in addition to cataract surgery were recruited and consent was obtained. Baseline demographic information and preoperative, intraoperative and postoperative outcomes including intraocular pressure (IOP), visual acuity and topical glaucoma medication use were recorded and analysed. Treatment outcomes were analysed after propensity score matching to adjust for baseline differences between the two groups. Primary success was defined as an IOP of ≤18 and ≥20% IOP reduction at 12 months; other outcomes included IOP ≤15 mm Hg and ≤21 mm Hg. These were measured against complete success (no medications) and qualified success (one or more medications).

RESULTS

The study comprised 85 eyes in the Hydrus group and 100 eyes in the iStent inject group at commencement, with 12-month follow-up for 85 and 78, respectively. When correcting for baseline differences between the two groups using propensity score matching, Hydrus eyes were not more likely to achieve primary success (average treatment effect -0.79, p=0.15).

CONCLUSION

After adjusting for baseline differences, there was no statistically significant difference between combined Hydrus microstent implantation and cataract surgery when compared with the iStent inject in reducing IOP at 12-month follow-up. This study was limited by statistically significant baseline differences between the two study groups, adjusted for with propensity score matching.

Bio-Interventional Cyclodialysis and Allograft Scleral Reinforcement for Uveoscleral Outflow Enhancement in Open-Angle Glaucoma Patients: One-Year Clinical Outcomes

Background

To evaluate the one-year safety and effectiveness of bio-interventional cyclodialysis and scleral reinforcement in open-angle glaucoma (OAG) patients undergoing cataract surgery.

Methods

An ab-interno approach was used to create a sectoral cyclodialysis in OAG patients who were prospectively followed in a consecutive case series. Subsequent visco-cycloplasty with scleral reinforcement using homologous minimally modified allograft scaffold was completed to maintain patency of the cyclodialysis reservoir and increase uveoscleral outflow. Outcomes were mean medicated IOP and mean number of IOP-lowering medications. Safety outcomes were adverse events (AEs) and best-corrected visual acuity (BCVA) changes.

Results

Successful cyclodialysis and allograft bio-scaffold reinforcement was achieved in 117 eyes. There was minimal intraoperatie bleeding and few post-operative adverse events. At baseline, mean BCVA was 0.48 (95% CI: 0.42‒0.54; 20/40 Snellen) and mean ± SD medicated IOP was 20.2 ± 6.0 mmHg on 1.4 ± 1.3 IOP-lowering medications. At 12 months, there was a 27.1% reduction from baseline mean medicated IOP. In eyes with medicated baseline IOP > 21 mmHg (n = 45), there was a 39.7% paired IOP reduction at 12 months with a concurrent reduction in the mean number of IOP lowering medications to 0.8 ± 0.9 which were statistically significant (p < 0.01). For all eyes, 81.9% achieved a medicated IOP ≤ 18 mmHg with no increase in medications at 12 months. To achieve target IOP control, secondary glaucoma surgery was performed in 3.2% of the cases.

Conclusion

IOP lowering through uveoscleral outflow enhancement can be achieved by means of a bio-interventional cyclodialysis procedure with allograft scleral reinforcement.

Outcomes and Baseline Predictors of Failure in Primary Standalone Xen45 Gel Stent versus Trabeculectomy for Glaucoma

PURPOSE

To compare safety, effectiveness, and baseline predictors of failure in standalone primary Xen45 gel stent (Xen) versus trabeculectomy (Trab) in glaucoma.

DESIGN

Retrospective study.

SUBJECTS

Subjects that underwent primary Xen or Trab augmented by mitomycin-C with at least 12 months follow-up.

METHODS

Multinational observational study of eyes in the Fight Glaucoma Blindness international registry MAIN OUTCOME MEASURES: The primary outcome was success at 12 months defined by intraocular pressure (IOP) reduction ≥ 20% from baseline and ≤ threshold IOPs of 15, 18, and 21 mmHg with (qualified) or without (complete) medications and without secondary glaucoma surgery. Multivariable mixed effects Cox regression models were used to identify risk factors for failure in each cohort.

RESULTS

A total of 701 eyes (Xen, 308; Trab, 393) of 596 subjects were included with baseline IOP being significantly higher (22.4 vs. 19.9 mmHg, P < 0.001) and baseline medications significantly lower in the Xen versus the Trab group (2.9 vs. 3.4, P < 0.001). Baseline visual field mean deviation was less severe in the Xen group (-9.47 vs. -13.04 dB, P < 0.001). The proportion of complete surgical success was significantly lower in the Xen versus Trab group across the 3 upper IOP limits at 12 months; 32% versus 52% at 15 mmHg, 37% versus 54% at 18 mmHg, and 39% versus 55% at 21 mmHg (P < 0.001). The incidence of postoperative numerical and symptomatic hypotony was lower in the Xen versus Trab group. In the Xen cohort, a higher failure rate was associated with Asian ethnicity (hazard ratio [HR], 1.97; 95% confidence interval (CI), 1.03-3.79) and use of oral acetazolamide at baseline (HR, 1.74; 95% CI, 1.13-2.70), whereas a lower failure rate was associated with diagnosis of ocular hypertension/open-angle glaucoma suspect (HR, 0.40; 95% CI, 0.20-0.82) and secondary open-angle glaucoma (HR, 0.46; 95% CI, 0.26-0.82). Exposure to prostaglandin analog was associated with greater failure in the Trab group (HR, 2.66; 95% CI, 1.18-6.01).

CONCLUSIONS

There was significantly greater complete success at 12 months across all complete success definitions for Trab compared with Xen, whereas the rate of postoperative hypotony was significantly lower in the Xen group. Asian ethnicity and use of oral acetazolamide at baseline were associated with greater failure in Xen, whereas exposure to prostaglandin analog was associated with greater failure in Trab patients. Such baseline predictors of success and failure may help guide patient selection for subconjunctival minimally invasive glaucoma surgery in patients undergoing surgical intervention.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

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.

Comparison of Superior versus Inferior Canaloplasty and Trabeculotomy Using the OMNI Surgical System

Purpose

To compare outcomes of ab-interno canaloplasty and trabeculotomy of the superior versus inferior angle.

Patients and methods

This was a prospective, non-randomized, interventional comparison study done at the Veteran Affairs Hospital in Long Beach, California. All patients underwent cataract surgery with intraocular lens implantation combined with ab-interno canaloplasty and trabeculotomy with the OMNI Surgical System (SightSciences, Menlo Park, CA, USA), either superiorly or inferiorly. Pre- and post-operative intraocular pressure using Goldmann applanation tonometry and best corrected visual acuity were obtained and compared using paired t-tests. Patients were excluded if they had any prior intraocular surgery or prior laser trabeculoplasty procedures.

Results

38 eyes from 29 patients were analyzed. 19 eyes were included in the superior group and 19 eyes in the inferior group. Mean pre-operative IOP in the superior group was 17.6 ± 5.2 mmHg and in the inferior group was 17.6 ± 4.6 mmHg (p > 0.99). At 12 months, mean postoperative IOP for the superior group decreased 24% to 13.3 ± 2.8 mmHg while the inferior group decreased 26% to 13.1 ± 2.2 mmHg (p = 0.92). Mean preoperative medications in the superior group were 2.2 ± 1.3 and in the inferior group was 2.4 ± 1.3 (p = 0.88). At 12 months, this decreased to 1.3 ± 1.5 post-operatively in the superior group and 2.2 ± 1.6 post-operatively in the inferior group (p = 0.64).

Conclusion

There was no statistical difference in efficacy between superior versus inferior canaloplasty/trabeculotomy with OMNI. Therefore, surgeons can perform the procedure in the direction that is most comfortable for them without affecting outcomes.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Consistency in Standalone Canaloplasty Outcomes Using the iTrack Microcatheter

Purpose

To study the consistency in outcomes of standalone canaloplasty performed via an ab-interno surgical technique in reducing intraocular pressure (IOP) and number of medications in uncontrolled open-angle glaucoma (OAG) eyes over a 12-month period.

Methods

This retrospective multicenter case series included patients who underwent standalone canaloplasty via an ab-interno surgical technique using the iTrack microcatheter (Nova Eye, Inc., Fremont, USA) and had preoperative uncontrolled OAG (IOP≥18mmHg) along with no previous glaucoma surgery. The iTrack microcatheter is used to circumnavigate 360° and viscodilate Schlemm's canal. Consistency of IOP and medications reduction on an eye-by-eye basis were evaluated to understand the outcomes in each single eye.

Results

Sixty-four eyes of 60 patients (age 71.5±13.4 years) were included. Six eyes (9%) that underwent additional glaucoma surgery were considered a failure and were subsequently excluded from analysis. At 12 months, IOP was reduced in 57 of the 58 (89%) remaining eyes; one eye had the same IOP with a reduced number of medications. Of the 57/58 eyes with a reduced IOP: 44 eyes (69%) required fewer medications; 12 eyes (19%) required the same number of medications. Of these 58 eyes, 78% of eyes had a ≥20% reduction in IOP compared to baseline; 69% eyes had a postoperative IOP ≤15 mmHg, and 86% eyes ≤18 mmHg at 12 months. Forty percent of the eyes were medication-free at 12 months compared to none at baseline.

Conclusion

Canaloplasty performed via an ab-interno surgical technique as a standalone procedure consistently reduced IOP and glaucoma medications in almost all eyes.

Accuracy of pattern deviation in estimating the glaucomatous damage in the central 10° visual field in eyes with glaucoma and cataract

BACKGROUND/AIMS

The accuracy of pattern deviation (PD) in estimating the damage to the glaucomatous visual field (VF) in the central 10° in eyes with glaucoma and cataract is unclear.

METHODS

This retrospective study includes 63 eyes of 52 glaucoma patients who successfully underwent cataract surgery or cataract surgery plus iStent implantation. Using the Humphrey Field Analyser 10-2 test, VF was measured within 6 months preoperatively and postoperatively (VFpre and VFpost, respectively). The mean total deviation values in VFpost (mTDpost) indicates glaucomatous damage without cataract and the difference between this value and mean PD values in VFpre (mPDpre) was evaluated (εmPD). The effect of cataract was then evaluated as the difference between mTDpost and mTDpre (ΔmTD), while the effects of mTDpost and ΔmTD on εmPD were also assessed. In addition, based on preoperative visual acuity (VApre) and VFpre, the optimal model for predicting mTDpost was identified. The error of this method (εOptimalModel) was estimated as the difference against mTDpost, which was compared with εmPD.

RESULTS

Compared with mTDpre, there was a significant improvement in mTDpost (p=0.028). A significant difference was observed between mPDpre and mTDpost (p<0.001). Further, εmPD significantly increased with the increase of mTDpost or ΔmTD (p<0.001 and p=0.0444, respectively). The absolute εOptimalModel was significantly smaller than the absolute εmPD (p<0.001).

CONCLUSIONS

This study warns clinicians that PD of the central 10° VF might underestimate the glaucomatous VF damage with the progression of glaucoma and overestimate it as a cataract progresses.

Comparative Effectiveness and Safety of Two Different Trabecular MIGS Devices With and Without Ab Interno Canaloplasty in Patients with Primary Open-Angle Glaucoma

INTRODUCTION

This study compared outcomes of the iStent inject trabecular micro-bypass system versus the Hydrus Microstent in patients with primary open-angle glaucoma (POAG).

METHODS

Forty subjects (80 eyes) with POAG were included in this single-center, retrospective, contralateral-eye analysis. All patients underwent phacoemulsification with either iStent inject or Hydrus implantation in one eye and the other device in the contralateral eye, with ≥ 3-month follow-up. In 58 eyes (27 iStent inject, 31 Hydrus) the surgery also included ab interno canaloplasty (ABiC). Twelve-month outcomes included intraocular pressure (IOP), medications, and adverse events. Subgroup analyses were completed for iStent inject versus Hydrus, and with versus without ABiC.

RESULTS

At 12 months versus baseline, mean IOP reduced from 16.8 ± 3.7 to 13.6 ± 2.9 (p = 0.003) in iStent inject eyes, and from 18.1 ± 4.5 to 14.9 ± 3.2 mmHg (p = 0.003) in Hydrus eyes (between-group IOP reduction p = 0.582). Mean number of glaucoma medications reduced from 1.23 ± 0.97 to 0.30 ± 0.76 (p < 0.001) in iStent inject eyes and from 1.20 ± 1.02 to 0.39 ± 0.72 (p = 0.001) in Hydrus eyes (between-group medication reduction p = 0.943). At 12 months, 82.6% of iStent inject eyes and 73.9% of Hydrus eyes were medication-free versus 20.0% preoperatively in both groups (p < 0.0001 both groups). There were no statistically significant IOP or medication differences between iStent inject and Hydrus pre- or postoperatively, both in the overall cohort and in the with/without ABiC subgroups. Outcomes also were similar between eyes with/without ABiC in the overall cohort and in the iStent inject/Hydrus subgroups. There were no adverse events in the iStent inject group; two eyes in the Hydrus group had device-related complications requiring five additional surgeries (one Hydrus repositioning, one Hydrus exchange, one Hydrus removal, two goniotomies).

CONCLUSION

In this contralateral-eye comparison of iStent inject versus Hydrus, the groups had similar IOP and medication outcomes, regardless of stratification by ABiC completion. Eyes receiving Hydrus had more complications and subsequent surgeries.

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.

Short-Term Outcomes of Hydrus Microstent With and Without Additional Canaloplasty During Cataract Surgery

PRCIS

Compared with phacoemulsification and microstent alone, we observed that phacoemulsification with combined microstent and canaloplasty resulted in a significantly greater reduction in glaucoma medications while maintaining similar rates of intraocular pressure reduction and low complications.

PURPOSE

The purpose of this study was to compare the outcomes of phacoemulsification combined with Hydrus Microstent (Alcon Inc.) implantation alone or in combination with canaloplasty (OMNI Surgical System, Sight Sciences Inc.).

MATERIALS AND METHODS

Retrospective study of mild-to-moderate primary open angle glaucoma patients who underwent phacoemulsification with microstent alone (42 eyes of 42 patients) or in combination with canaloplasty (canaloplasty-microstent, 32 eyes of 32 patients). The mean number of ocular hypotensive medications and intraocular pressure were assessed preoperatively and postoperatively at 1 week and at 1, 3, and 6 months. Complications and secondary surgical interventions were recorded. Outcomes measures included the percentage of unmedicated eyes and surgical success at 6 months. Surgical success was defined as reaching the target intraocular pressure without medications or secondary surgical interventions.

RESULTS

Mean intraocular pressure at 6 months was 14.1±3.5 mm Hg (13% reduction) after microstent alone and 13.6±3.1 mm Hg (17% reduction) after canaloplasty-microstent. Mean medications at 6 months were 0.57±0.9 (67% reduction) after microstent alone and 0.16±0.4 (88% reduction) after canaloplasty-microstent ( P< 0.05). At 6 months, 64.3% of microstent alone and 87.3% of canaloplasty-microstent were off all medications ( P =0.02). Success probabilities at 6 months were 44.5% for microstent alone and 70.0% for canaloplasty-microstent ( P =0.04). No secondary surgical interventions occurred in either group.

CONCLUSIONS

Microstent combined with canaloplasty resulted in a significantly higher rate of medication-free status compared with microstent alone through 6 months.

Minimally Invasive Glaucoma Surgery: A Review of the Literature

Minimally invasive glaucoma surgery (MIGS) has emerged as a novel approach in the glaucoma treatment spectrum, offering a range of diverse procedures and devices aimed at reducing intraocular pressure (IOP). MIGS can be broadly classified into several categories: those that enhance trabecular outflow (Trabectome, iStent, Hydrus Microstent, Kahook Dual Blade, high frequency deep sclerotomy, and gonioscopy-assisted transluminal trabeculotomy), those that augment suprachoroidal outflow (CyPass Microstent and iStent Supra), those that target Schlemm's canal (TRAB360 and the OMNI Surgical System, Streamline, and Ab Interno Canaloplasty), and conjunctival bleb-forming procedures (EX-PRESS Glaucoma Filtration Device, Xen Gel Stent and PreserFlo MicroShunt). MIGS is considered to have a shorter surgical time and fewer severe complications when compared to traditional glaucoma surgeries such as trabeculectomy and glaucoma drainage device implantation (Ahmed, Baerveldt, and Molteno valves). This literature review comprehensively examines the distinct MIGS devices and procedures, their underlying mechanisms, and clinical outcomes, emphasizing the importance of evaluating the efficacy and complications of each approach individually. As the field of MIGS continues to evolve, it is crucial to prioritize high-quality, long-term studies to better understand the safety and effectiveness of these innovative interventions in glaucoma management.

Hydrus microstent for the treatment of primary open-angle glaucoma: overview of its safety and efficacy

INTRODUCTION

Minimally invasive glaucoma surgeries (MIGS) are now a consolidated reality in many surgical units. The Hydrus Microstent is one of several MIGS devices bypassing trabecular outflow and had excellent results over the years. This article aims to review the key features of the Hydrus Microstent in terms of design, efficacy, and safety.

AREAS COVERED

The present review analyses the main characteristics of the device by evaluating the technical and physical details of its functioning. The evidence that supports a clinical decision summarizes the most influential clinical trials and the most accurate systematic reviews.

EXPERT OPINION

The Hydrus device has been extensively studied regarding biocompatibility and outflow potential. The subsequent clinical studies have been well-built and proved that the device effectively reduces intraocular pressure (IOP) and the eyedrop load. The device covers almost a quarter of Schlemm's canal circumference, offering at least two advantages: cannulating the Schlemm's canal provides evidence that the device has been implanted correctly; covering a larger area potentially allows to target multiple collector channels or at least areas of active outflow. This scaffold may prove more effective in naïve patients or subjects who used antiglaucoma eyedrops for a limited period, as the prolonged use of hypotonic medications has been associated with the surgical failure of ab interno microhook trabeculotomy.

Spotlight on Schlemm's Canal MicroStent Injection in Patients with Glaucoma

Minimally invasive glaucoma surgery (MIGS) has revolutionized glaucoma care with its favorable safety profile and ability to delay or minimize the need for traditional, bleb-based procedures. Microstent device implantation is a type of angle-based MIGS, which reduces intraocular pressure (IOP) through bypass of the juxtacanalicular trabecular meshwork (TM) and facilitation of aqueous outflow into the Schlemm's canal. Although there are limited microstent devices on the market, multiple studies have evaluated the safety and efficacy of iStent^® (Glaukos Corp.), iStent Inject^® (Glaukos Corp.), and Hydrus^® Microstent (Alcon) in the treatment of mild-to-moderate open-angle glaucoma, with and without concurrent phacoemulsification. This review attempts to provide a comprehensive evaluation of injectable angle-based microstent MIGS devices in the treatment of glaucoma.

Emerging glaucoma treatments: are we seeing an improvement in adherence?

Introduction

Non-adherence to glaucoma medication and poor follow-up is a global health concern.

Areas covered

Glaucoma remains one of the largest causes of irreversible blindness worldwide. Traditional treatment guidelines suggest topical eye drop medication as first line therapy followed by addition of supplementary medications before proceeding to more invasive glaucoma surgeries. Unfortunately, poor glaucoma self-management remains high, leading to disease progression and blindness. Recent advancements in the field of pharmacotherapies, surgeries, and behavioral approaches have taken aim at increasing support for glaucoma self-management. We review the current and emerging approaches towards glaucoma management, with the exception of bleb-based surgical approaches, to investigate if they have had an impact on adherence. Literature searches were conducted via MEDLINE (PubMed), Embase (Elsevier), Cochrane Library (Wiley), and Preprints from January 1st, 2018, to January 26th, 2023.

Expert opinion

The ability to offer patients a multitude of choices enables patients to tailor their glaucoma treatment to their values and lifestyle. Offering personalized patient education and coaching to support chronic glaucoma self-management would better enable patient engagement in whichever treatment path is chosen. Currently, literature regarding the impact of these new advancements on treatment engagement is lacking; this field is ripe for additional intervention and assessment.

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

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

Comparative outcomes of phacoemulsification combined with micro-invasive glaucoma surgery plus: Schlemm canal microstent versus Ab interno trabecular excision

PURPOSE

To report the relative efficacy of combining phacoemulsification with a Schlemm's canal microstent (Phaco/Hydrus) or dual blade trabecular excision (Phaco/KDB).

DESIGN

Retrospective study.

METHODS

One hundred and thirty-one eyes of 131 patients who underwent Phaco/Hydrus or Phaco/KDB procedures from January 2016 to July 2021 at a tertiary care center were included and assessed for up to 36months postoperatively. Primary outcomes were intraocular pressure (IOP) and number of glaucoma medications, evaluated by generalized estimating equations (GEE). Two Kaplan-Meier estimates (KM) assessed survival without additional intervention or pressure lowering medication while maintaining: (1) IOP≤21mmHg and≥20% IOP reduction or (2) IOP≤preoperatively designated goal.

RESULTS

Mean preoperative IOP was 17.70±4.91 (SD) mmHg on 0.28±0.86 medications in the Phaco/Hydrus cohort (n=69) and 15.92±4.34mmHg on 0.19±0.70 medications in the Phaco/KDB cohort (n=62). At 12months, mean IOP was reduced to 14.98±2.77mmHg on 0.12±0.60 medications after Phaco/Hydrus and 13.52±4.13mmHg on 0.04±0.19 medications after Phaco/KDB. GEE models of IOP (P<0.001) and medication burden (P<0.05) showed significant patterns of reduction across all timepoints in both cohorts. There were no differences in IOP reduction (P=0.94), number of medications (P=0.95) or survival (P=0.72 by KM1, P=0.11 by KM2) between procedures.

CONCLUSIONS

Both Phaco/Hydrus and Phaco/KDB resulted in significantly reduced IOP and medication burden for over 12months. Phaco/Hydrus and Phaco/KDB confer similar outcomes in terms of IOP, medication burden, survival, and procedural time in a population with predominantly mild and moderate open-angle glaucoma.

Comparison of Safety and Efficacy of Hydrus and iStent Combined with Phacoemulsyfication in Open Angle Glaucoma Patients: 24-Month Follow-Up

The paper presents the results of a 24-month-long observation comparing the effectiveness and safety of two micro-invasive glaucoma surgery (MIGS) devices: Hydrus Microstent and iStent Trabecular Bypass in combination with cataract phacoemulsification in the treatment of open-angle glaucoma. We also analyzed the impact of preoperative factors on achieving surgical success in both surgical methods. The prospective, comparative, non-randomized study included 65 glaucoma surgeries. In 35 patients (53.8%), an iStent implant procedure was performed, while 30 patients (46.2%) underwent a Hydrus implant procedure. The demographic data was similar in both treatment groups. At 24 months after surgery, the mean IOP in the iStent group was 15.9 ± 3.0 mmHg and in the Hydrus group 16.2 ± 1.8 mmHg. The difference between the mean iStent vs Hydrus after two years of treatment was -0.3 (p = 0.683). At the 24 month follow-up, the average change in the number of antiglaucoma medications used was 71.7% in the iStent group and 79.6% in the Hydrus group. The difference in mean percentage change between groups was 7.9% in favor of Hydrus. Patients under the age of 70 may benefit from a greater risk reduction in the Hydrus group (HR = 0.81), while those over the age of 70 may benefit from a risk reduction in the iStent group (HR = 1.33). IOP cases with >18 mmHg before the surgery have a better chance of surgical success with the Hydrus method (HR = 0.28), and with IOP < 18 mmHg in the iStent group (HR = 1.93). Cases with more drugs (≥3 drugs) are more favorable in the Hydrus group (HR = 0.23), while those with a maximum of two drugs have a better prognosis in the iStent group (HR = 2.23). The most common postoperative complication was the presence of erythrocytes in the anterior chamber (AC), found in 40.0% of operated eyes in the Hydrus group. The profile of observed complications and significant improvement in visual acuity allows us to consider both implants as a safe way of treating patients with early or moderate glaucoma and co-existing cataracts.

Devices and Treatments to Address Low Adherence in Glaucoma Patients: A Narrative Review

Poor adherence to topical glaucoma medications has been linked to worse visual field outcomes in glaucoma patients. Therefore, identifying and overcoming the adherence barriers are expected to slow down the progression of disease. The most common barriers to adherence, in addition to the lack of knowledge, include forgetfulness, side effects of medications, difficulties with drop instillation and low self-efficacy. Symptoms and signs of ocular surface disease, which importantly reduce patients' quality of life, are decreased by using preservative-free topical medications. Sustained drug delivery systems using different vehicles seem promising for relieving the burden of drop administration. Currently, only the bimatoprost sustained-release intracameral implant is available for clinical use and single administration. In the era of digitalization, smart drug delivery-connected devices may aid adherence and, by sharing data with care providers, improve monitoring and adjusting treatment. Selective laser trabeculoplasty as first-line treatment delays the need for drops, whereas minimally invasive glaucoma procedures with and without devices combined with cataract surgery increase the likelihood of patients with early-to-moderate glaucoma to remain drop free or reduce the number of drops needed to control intraocular pressure. The aim of this narrative review is to present and discuss devices and treatments that may improve adherence by reducing the need for drops and side effects of medications and aiding in glaucoma monitoring. For the future, there is a need for studies focusing on clinically important outcomes, quality of life and the cost of intervention with longer post-interventional follow up.

Comparison of Hydrus and iStent microinvasive glaucoma surgery implants in combination with phacoemulsification for treatment of open-angle glaucoma: systematic review and network meta-analysis

OBJECTIVES

To compare the efficacy and safety of two Schlemm's canal-based microinvasive glaucoma surgery (MIGS) devices, the Hydrus Microstent and the iStent Trabecular Bypass combined with phacoemulsification for treatment of open-angle glaucoma.

DESIGN

Systematic review and network meta-analysis.

METHODS

Literature searches were conducted on PubMed, Web of Science, Cochrane Library and ClinicalTrials.gov to identify randomised controlled trials (RCTs) assessing the Hydrus or the iStent implantation combined with phacoemulsification for treatment of open-angle glaucoma until September 2020. Risk of bias was assessed using a six-item modified Jadad scale. Effects were estimated using the intraocular pressure (IOP) reduction (IOPR), the percentage of IOPR and the proportion of medication-free patients at follow-up end. Safety was estimated using the proportions of adverse events. The network meta-analysis was conducted within a Bayesian framework using the Markov Chain Monte Carlo method in ADDIS software.

RESULTS

Six prospective RCTs comprising 1397 patients were identified. Regarding the absolute value and the percentage of IOPR, the Hydrus and 2-iStent implantation combined with phacoemulsification were significantly more effective than phacoemulsification alone. Rank probability analysis revealed the Hydrus might be the best choice to lower IOP. There was no significant difference in the proportion of medication-free patients among groups. The Hydrus and 2-iStent implantation had a higher probability to achieve the medication-free status versus the 1-iStent implantation and phacoemulsification alone. Overall safety profiles were good for each device with the focal peripheral anterior synechiae more frequently reported in Hydrus eyes.

CONCLUSIONS

The Hydrus implantation may have a slight advantage over the 1-iStent or 2-iStent implantation in combination with phacoemulsification to treat open-angle glaucoma. Our findings might be of some uncertainty due to the limited included data. Further studies are needed to investigate whether our findings are robust, including high-quality RCTs to directly compare these MIGS devices.