Combined phacoemulsification and microinvasive glaucoma surgery in comparison to phacoemulsification alone for open angle glaucoma

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.

Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

The development of minimally invasive glaucoma surgeries (MIGSs) was intended to provide safe and modestly efficacious modalities for early intervention of mild-to-moderate glaucoma, with minimal trauma and rapid recovery. They were mainly ab interno procedures that reduce intraocular pressure by facilitating the aqueous outflow by bypassing the trabecular meshwork resistance, reinforcing the uveoscleral flow via the supraciliary space, and reducing aqueous production by the ciliary body. While the cumulating evidence helps shape the role of the available MIGS, the exponential new development and advancement in this field has expanded the territory of MIGS. Apart from developing subconjunctival MIGS filtration devices (Xen gel stent and PRESERFLO MicroShunt), there is a tendency to revisit the "traditional" MIGS for alternative use and to modify the procedures with consideration of the fundamental aqueous outflow physiology. Combined MIGS has also been suggested, based on the theory that their different mechanisms may provide additive or synergistic effects. The advancement of laser procedures is also promising and could supplement unmet needs along the glaucoma treatment algorithm. This review examines the broad array of MIGS, updates the recent findings, discusses their potential alternative applications, and explores future challenges.

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.

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.

Three-Year Outcomes of a Schlemm Canal Microstent (Hydrus Microstent) with Concomitant Phacoemulsification in Open-Angle Glaucoma

PURPOSE

HORIZON trials have reported the medium- and long-term outcomes of the Hydrus microstent. However, outside of randomized clinical trials, outcomes beyond 24 months have not been previously reported. Here, we examine the 3-year outcomes of the Hydrus microstent with cataract surgery outside of a randomized clinical trial setting.

DESIGN

Single-surgeon consecutive case series.

PARTICIPANTS

Glaucomatous eyes that underwent implantation of a Hydrus microstent with concomitant cataract surgery at a single ophthalmology center in Montreal, Canada.

METHODS

Success was defined according to the absence of specific failure criteria: (A) glaucoma reoperation; (B) selective laser trabeculoplasty; (C) intraocular pressure (IOP) < 5 mmHg, > 18 mmHg, or increase in the number of antiglaucoma medications (AGMs) used (after the first postoperative month), or loss of light perception due to glaucoma; (D) aggregation of criteria A-C. Predictors of treatment failure and postoperative changes in IOP and AGM use were assessed. Safety included best-corrected visual acuity (BCVA), cup-to-disc ratio (CDR), retinal nerve fiber layer (RNFL) thickness, ganglion cell inner plexiform layer (GC-IPL) thickness, visual field mean deviation (VF-MD) and pattern standard deviation (VF-PSD), and adverse events.

MAIN OUTCOME MEASURES

Surgical success, predictors of treatment failure, postoperative changes in IOP and AGM use, and structural and functional markers of disease stability.

RESULTS

One hundred six eyes were included. The 3-year surgical success according to Criteria A to D was 86%, 83%, 91%, and 67%, respectively. Intraocular pressure decreased by 26.5% from 18.9 ± 4.8 to 13.9 ± 2.3 mmHg (P < 0.001) and AGM use reduced by 33% from 3.0 ± 1.2 to 2.0 ± 1.2 medications (P < 0.001). The postoperative improvement in BCVA was preserved (P < 0.001). The structural and functional markers of disease stability, including CDR, RNFL, and GC-IPL thickness, as well as VF-MD and VF-PSD, remained stable (P > 0.05). Postoperative adverse events were few and transient.

CONCLUSIONS

The 36-month results from this study show that the Hydrus microstent with phacoemulsification is safe and effective in reducing the IOP and AGM among patients with mild to severe open-angle glaucoma and can slow down the disease progression by preserving both structural and functional parameters.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

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.

Systematic Literature Review of Clinical, Economic, and Humanistic Outcomes Following Minimally Invasive Glaucoma Surgery or Selective Laser Trabeculoplasty for the Treatment of Open-Angle Glaucoma with or Without Cataract Extraction

Introduction

Selective laser trabeculoplasty (SLT) and minimally invasive glaucoma surgery (MIGS) are increasingly used options for mild-to-moderate open-angle glaucoma (OAG) care. While most MIGS devices are indicated for use in combination with cataract surgery only, with phacoemulsification playing a role in lowering IOP, newer technologies can also be used as standalone glaucoma surgery.

Methods

This systematic literature review (SLR) aimed to assess the clinical, economic, and humanistic outcomes of MIGS and SLT for the treatment of OAG and was conducted according to PRISMA guidelines. Studies that assessed MIGS or SLT in at least one treatment arm versus any other glaucoma treatment in adults with mild-to-moderate OAG were included. Clinical, humanistic (health-related quality of life [HRQoL] and patient burden), and economic data were extracted, and the methodological quality of included studies was evaluated.

Results

A total of 2720 articles were screened, and 81 publications were included. Fifty-eight reported clinical outcomes. The majority assessed iStent or iStent inject (n=41), followed by OMNI (n=9), gonioscopy-assisted transluminal trabeculotomy (GATT) or the Kahook Dual Blade (KDB) (n=7), Hydrus (n=6), SLT (n=5), Xen Gel Stent (n=2), PreserFlo (n=1), and iTrack (n=1). IOP reduction was observed across prospective studies, varying from -31% to -13.7% at month 6 and from -39% to -11.4% at year 1 versus baseline. Most adverse events were transient and non-serious. Limited humanistic and economic data were identified.

Conclusion

Given their established efficacy and safety, there is a rationale for wider use of MIGS in mild-to-moderate OAG. Of the MIGS devices, iStent and OMNI have the largest clinical evidence base supporting their sustained effectiveness.

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.

Incidence and Clinical Characteristics of Postoperative Endophthalmitis After Ab-Interno Canaloplasty

Introduction

Postoperative endophthalmitis (POE) is a rare but devastating complication of ophthalmic surgeries. Microinvasive glaucoma surgery (MIGS) procedures have become increasingly utilized for the surgical reduction of intraocular pressure (IOP). Ab-interno canaloplasty (ABiC) is a popular MIGS procedure, but POE rates and clinical effects following ABiC have not been studied.

Methods

This study conducted a retrospective review of all consecutive cases of either standalone ABiC or combined ABiC with phacoemulsification performed at a tertiary care academic referral center from 2015 to 2021. Exclusion criteria included a history of incisional glaucoma surgery, retinal surgery, or additional concurrent microinvasive glaucoma surgery (MIGS) at the time of ABiC. The rates of POE after ABiC were calculated with 95% confidence intervals (CI) based on the Clopper-Pearson exact method.

Results

Of 3256 cases of ABiC, one case (0.03%, 1/3256, 95% CI: 0.00–0.17%) of post-ABiC endophthalmitis was identified. The rate of POE in standalone ABiC was 0.00% (0/1332 cases, 95% CI: 0.00–0.28%), whereas the rate in combined ABiC with phacoemulsification was 0.05% (1/1924 cases, 95% CI: 0.00–0.29%). Additionally, the rate of POE following stand-alone cataract surgery, 0.10%, 11/11,470 cases, 95% CI: 0.05–0.17%), total cataract surgeries, 0.06% (17/28,013 cases, 95% CI: 0.04–0.10%), total MIGs, excluding ABiC, surgeries, 0.08%, (3/3845 cases, 95% CI: 0.02–0.23%) portray non-inferiority of ABiC in the risk of POE. The case of ABiC-POE presented four days after surgery and required a vitreous tap with intraocular injection of antibiotics and pars plana vitrectomy. No causative organism was identified. A final 1-year follow-up revealed a corrected distance visual acuity of 20/40 and stable glaucoma.

Conclusion

The rate of POE after ABiC (1 per 3256 cases) is statistically non-inferior to the reported incidence of POE after other MIGS and incisional glaucoma surgeries.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes of Resident Performed Hydrus, iStent, and Kahook Glaucoma Procedures in a Predominantly African American Population

PRCIS

This retrospective study characterized the efficacy and safety of 3 different microinvasive glaucoma surgery (MIGS) procedures in a predominantly African American population at the Philadelphia Veterans Affairs Hospital (Hydrus, Kahook, iStent), demonstrating no significant difference in intraocular pressure (IOP) and medication reduction between the 3 at long-term follow-up.

PURPOSE

To compare the efficacy and safety of 3 different MIGS procedures in a predominantly African American population.

METHODS

Retrospective cohort study of patients undergoing cataract extraction combined with 1 of 3 MIGS procedures (Hydrus, iStent, Kahook) at the Philadelphia Veterans Affairs Medical Center between January 1, 2015 and November 1, 2020. Analysis of variance and regression models were used to compare reduction in IOP and medication use among 3 MIGS types.

RESULTS

A total of 123 eyes of 112 patients were included, including 56 (45.5%) eyes for Hydrus, 40 (32.5%) eyes for iStent, and 27 (22.0%) eyes for Kahook. Adjusted mean IOP reduction was greater for Hydrus at postoperative day 1 (-4.49 vs. -1.76 for iStent and -1.69 for Kahook, P=0.05 and greater for Kahook at postoperative week 1 (-2.53 vs. +0.70 for iStent vs. -1.41 for Hydrus, P=0.02), but did not differ significantly between MIGS types at subsequent postoperative visits (all P>0.05). In multivariable analysis, MIGS type was not significantly associated with reduction in IOP or medication use at 9 to 12 months postoperatively. There were no significant differences in complication rates across MIGS types.

CONCLUSION

In this study, the difference in IOP lowering and medication reduction postoperatively between the Hydrus, iStent, and Kahook was not statistically significant after postoperative day 1. More studies are needed to evaluate outcomes of MIGS surgeries in glaucoma populations of different disease severity.

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

PRECIS

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

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Intraocular Pressure After Cataract Surgery Combined With Ab Interno Trabeculectomy Versus Trabecular Micro-bypass Stent: An Intrasubject Same-surgeon Comparison

PRECIS

Combining Trabectome or iStent with phacoemulsification equally reduces intraocular pressure (IOP) and IOP-lowering medication burden during a 24-month follow-up, with a possible advantage to the Trabectome in the early postoperative period.

PURPOSE

Intrasubject same-surgeon comparison between phacoemulsification combined with Trabectome (Phaco/Trabectome) versus one first-generation iStent (Phaco/iStent).

SETTINGS

Private glaucoma and cataract practice.

DESIGN

This is a retrospective interventional case series.

METHODS

Data collected at 3 to 4 and 20 to 24 hours and up to 30 months following Phaco/Trabectome in 1 eye and Phaco/iStent in the contralateral eye in patients with bilateral visually-significant cataract and open-angle glaucoma. Evaluations included IOP, intraocular pressure-lowering medications (IOPmeds), visual acuity, and complications.

RESULTS

Forty-five patients (90 eyes) were identified (age 76.5, 57 to 95 y). At 3 to 4 hours, IOP was above baseline in 12 and 13 eyes following Phaco/Trabectome and Phaco/iStent, respectively, but the degree of IOP elevation was smaller (P=0.048) following Phaco/Trabectome: 4.3 mm Hg, 2.0 to 6.6 mm Hg (95% confidence interval) versus Phaco/iStent: 8.7 mm Hg, 3.8 to 13.6 mm Hg. At 20 to 24 hours, compared with baseline, IOP was significantly lower after Phaco/Trabectome (P=0.004) but not after Phaco/iStent (P=0.14) although the rate of hyphema was higher following Phaco/Trabectome (12/45 vs. 2/45 eyes, P=0.007). IOP reduction from baseline at 3 to 4 hours was significantly larger (P=0.020) in the 21 eyes with hyphema: -3.9, -6.4 to -1.4 versus the 69 eyes without hyphema: -0.3, -2.0 to +1.4. At 1, 6, 12, and 24 months, IOP and number of IOPmeds were similar and significantly lower compared with baseline following either procedure. No complications were encountered in either group.

CONCLUSIONS

Combined phacoemulsification with either Trabectome or first-generation iStent similarly lowers IOP and IOPmeds burden at 1, 6, 12, and 24 months following surgery. The Trabectome may have an advantage in lowering IOP faster and lessening the degree of IOP elevations in the early postoperative period.

<p>Effect of Excisional Goniotomy with the Kahook Dual Blade (KDB) on Surgically Induced Astigmatism</p>

Purpose

To determine the effect of Kahook Dual Blade goniotomy with phacoemulsification (Phaco-KDB) compared to phacoemulsification alone (Phaco) on surgically induced astigmatism (SIA).

Design

Prospective study.

Participants

Forty eyes of 28 patients treated with Phaco-KDB and 20 eyes of 13 patients treated with Phaco between 12/27/16 and 7/23/19 with a minimum 1 month follow-up were prospectively enrolled.

Methods

Corneal astigmatism was assessed pre- and post-operatively using the simulated K (simK) values from the Pentacam Holladay report.

Main Outcome Measures

SIA was compared between Phaco-KDB and Phaco groups using mean magnitude SIA, rate of ≥0.50 D SIA, and SIA centroids.

Results

The difference in mean magnitude SIA was not statistically significant between Phaco-KDB and Phaco (mean = 0.28 D and 0.25 D, respectively, P = 0.621). The difference in the rate of ≥0.50 D SIA was not statistically significant between Phaco-KDB and Phaco (11.6% and 10.0%, respectively, P = 1.00). The SIA centroid for Phaco-KDB was 0.05 D @ 51° ± 0.40 D and 0.07 D @ 3° ± 0.32 D for Phaco.

Conclusion

Neither the mean magnitude SIA nor the rate of astigmatic change ≥0.50 D was significantly different between Phaco-KDB and Phaco groups. SIA centroids between groups showed comparable and negligible effect on corneal astigmatism. KDB combined with phacoemulsification may not significantly affect SIA compared to phacoemulsification alone based on postoperative topography and is likely an astigmatically neutral procedure.

Minimally Invasive Glaucoma Surgery: Where Is the Evidence?

PURPOSE

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

An Update on Microinvasive Glaucoma Surgery Concurrent With Cataract Extraction

Purpose of Review

In this article, we review the current options for microinvasive glaucoma surgery (MIGS) combined with cataract extraction in the USA and the efficacy of the various approaches.

Recent Findings

MIGS is a rapidly growing area of research and clinical interest. Available surgeries aim to reduce intraocular pressure by improving aqueous outflow through the trabecular or subconjunctival pathways or by reducing aqueous production.

Summary

Multiple approaches to MIGS are utilized in clinical practice. On average, these surgeries are safe and modestly effective in reducing intraocular pressure. Future research will demonstrate which surgical approaches are most efficacious, whether and how to combine MIGS, and the role of MIGS in improving patient quality of life.