Cataract surgery with trabecular micro-bypass stent implantation in patients with mild-to-moderate open-angle glaucoma and cataract: two-year follow-up

Long-term outcomes of phacoemulsification with iStent inject® implantation in narrow angle glaucoma

PURPOSE

To assess the outcomes of phacoemulsification with iStent inject implantation (phaco-iStent) in patients with narrow angle glaucoma (NAG) at a single tertiary eye centre.

DESIGN

Retrospective clinical cohort study.

METHODS

Patients undergoing phaco-iStent for NAG between March 2018 and October 2020 under the glaucoma team at a tertiary referral hospital were included. Data was analysed from a surgical outcome database. Primary outcomes included postoperative change in the mean intraocular pressure (IOP) and medications. Success was defined at two IOP cut-off points:≤21mmHg and≤15mmHg with (qualified) or without (complete) drops. Failure was repeat glaucoma surgery or loss of light perception (LP).

RESULTS

Fifty-seven eyes with a mean follow-up of 32months (range 12months to 36months) were included. Mean IOP changed from 19.7±4.2mmHg (range 12-28) to 14.0, 14.9 and 14.6 at 12, 24 and 36months. Drops reduced from 2.2±0.7 to 0.92±1.24 at the last follow-up. Complete success for an IOP≤21mmHg was 49%, 39%, 37% and qualified success was 96%, 92% and 95% at 12, 24 and 36months. An IOP≤15mmHg (qualified) was achieved in 74%, 58%, 54% at 6, 12, 24 and 36months. Three patients (5%) required further glaucoma surgery, one patient underwent selective laser trabeculoplasty and one patient requiring peri-ocular steroid treatment due to persistent cystoid macular oedema. There were no other long-term complications.

CONCLUSION

Phacoemulsification with iStent inject is a safe and effective surgical option in the management of narrow angle glaucoma.

Global tendency and research trends of minimally invasive surgery for glaucoma from 1992 to 2023: A visual bibliometric analysis

Background

Minimally invasive glaucoma surgery has become a popular research topic over the past decade. However, no published studies have provided a systematic overview for this field. A bibliometric analysis is urgently required to characterise current international trends and provide an intuitive description of past and emerging trends.

Methods

This study analysed minimally invasive glaucoma surgery-related studies by searching the Web of Science for relevant articles published between 1992 and 2023. All the retrieved titles and abstracts were screened for eligibility, and only articles and reviews written in English were included in the analysis. CiteSpace (version 6.1.6), VOSviewer (version 1.6.19), and the bibliometric package in RStudio were used to construct and visualise the results.

Results

A total of 1533 publications were included in the analysis with 26072 citations. A total of 4482 authors from 1191 organizations in 57 countries and regions published papers in 139 journals. After 2010, the number of publications increased significantly, with the highest annual productivity occurring in 2022 (n = 229, 15 %). Most of these studies were published in ophthalmology journals. The journal "Ophthalmology" ranked first with 30 papers and 5275 citations. Among the 10 most productive countries, the United States had the largest share of publications (n = 423, 36 %) and Switzerland had the highest proportion of multiple-country publications (70 %). Neodymium was the first keyword discovered, appearing in 1992 and continuing for 21 years. Kahook dual-blade, progression, gonioscopy-assisted transluminal trabeculotomy, efficacy, minimally invasive glaucoma surgery, cataract extraction, and primary open-angle glaucoma were the most recent keywords since 2020.

Conclusions

This was the first bibliometric analysis of minimally invasive glaucoma surgery and provides an overview of the developments in this field. Our results identified outstanding studies, countries, institutions, journals, and authors in the field to point the way forward for scientific research and clinical applications of minimally invasive glaucoma surgery.

[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.

Special Commentary: Reporting Clinical Endpoints in Studies of Minimally Invasive Glaucoma Surgery

Minimally invasive glaucoma surgery (MIGS) refers to a group of procedures generally characterized by an ab interno approach, minimal trauma to ocular tissue, moderate efficacy, an excellent safety profile, and rapid recovery. The number of MIGS procedures continues to increase, and their use has become widespread among glaucoma and cataract specialists. Standardization of the methodology and reporting of clinical endpoints in MIGS investigations enhances interpretation and comparison across different studies. The assessment of surgical interventions not only should consider statistical significance, but also whether the outcome is meaningful to patients. Minimal clinically important difference (MCID) is defined as the smallest change in a treatment outcome that is considered beneficial for an individual patient and prompts a change in their clinical management. Expert consensus is an accepted approach to determine the MCID. The American Academy of Ophthalmology's Glaucoma Preferred Practice Pattern® Committee is an expert panel that develops guidelines identifying characteristics and components of quality eye care. The Committee recommends that the cumulative probability of surgical success at 2 years with Kaplan-Meier survival analysis be used as the primary efficacy endpoint in MIGS studies. The Committee suggests that surgical success for standalone MIGS be defined as intraocular pressure (IOP) of 21 mmHg or less and reduced by 20% or more from baseline without an increase in glaucoma medications, additional laser or incisional glaucoma surgery, loss of light perception vision, or hypotony. The proposed MCID for the cumulative probability of success of standalone MIGS at 2 years is 50%. The panel recommends that surgical success for MIGS combined with cataract extraction with intraocular lens implantation (CE-IOL) be defined as a decrease in glaucoma medical therapy of 1 medication or more from baseline without an increase in IOP or IOP of 21 mmHg or less and reduced by 20% or more from baseline without an increase in glaucoma medications, additional laser or incisional glaucoma surgery, loss of light perception vision, or hypotony. The suggested MCID for the cumulative probability of success for MIGS combined with CE-IOL at 2 years is 65%. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

MIGS in Severe Glaucoma: 12-Month Retrospective Efficacy and Safety of Microinvasive Glaucoma Surgery with Cataract Extraction

Purpose

Despite holding promise, reports of using MIGS in severe glaucoma are scarce, and none has described combining multiple MIGS in this population. To the best of our knowledge, this is the largest study to report outcomes of phacoemulsification and MIGS (Phaco/MIGS) in patients with severe glaucoma.

Methods

This retrospective review comprised 327 clinical visits of 71 patients with severe glaucoma who underwent Phaco/MIGS with iStent, endocyclodestruction, Kahook Dual Blade, Hydrus Microstent, or a combination of these MIGS (cMIGS) performed between 2016 and 2021. Primary outcomes included intraocular pressure (IOP) and medication burden evaluated by Generalized Estimating Equations, as well as Kaplan-Meier Estimates. Further analyses compared the efficacy of cMIGS and single Phaco/MIGS (sMIGS), procedure duration, visual acuity, and complications.

Results

Mean preoperative IOP was 16.7 mmHg ± 5.8 (SD) on 2.3 ± 1.9 medications overall (N = 71), 16.9 ± 6.3 mmHg on 1.7 ± 1.9 medications in the sMIGS group (N = 37), and 16.4 ± 5.3 mmHg on 2.9 ± 1.6 medications in the cMIGS group (N = 34). Throughout 12 months, Phaco/MIGS led to significant reduction patterns in IOP (p < 0.001) and medications (p = 0.03). At 12 months, 47.5%, 87.5%, and 64.7% of the patients achieved IOP ≤ 12 mmHg, 17 mmHg, or predetermined goal IOP, respectively, without additional medication or procedure. Mean 12-month IOP was 13.5 ± 3.1 mmHg on 1.8 ± 1.7 medications. After adjusting for baseline medication burden, the reduction pattern in IOP (p < 0.05) was different between cMIGS and sMIGS, favoring cMIGS, and the groups had similar reduction patterns in medications (p = 0.75).

Conclusion

The use of Phaco/MIGS in patients with cataract and severe glaucoma may significantly reduce IOP and medication burden throughout 12 months and, thus, may serve as a stepping stone in severe glaucoma patients with visually significant cataract before proceeding with more invasive glaucoma surgery. This effect may be potentiated by the combination effect of cMIGS.

Prospective, Randomized Controlled Trial of Cataract Surgery vs Combined Cataract Surgery With Insertion of iStent Inject

PURPOSE

To evaluate the efficacy and safety of combined cataract surgery with insertion of an ab interno trabecular microbypass device (iStent Inject, Glaukos Corporation) compared to cataract surgery alone in patients with mild-to-moderate glaucoma.

DESIGN

Prospective, randomized, assessor-masked controlled trial at a single centre.

PARTICIPANTS

Eyes with visually-significant cataract and mild-to-moderate glaucoma with preoperative intraocular pressure (IOP) of 12 to 30 mmHg on 0 to 3 ocular hypotensive medications.

METHODS

Participants eyes were randomized (2017-2020) 1:1 to combined cataract surgery with iStent Inject (treatment group, n = 56) or cataract surgery alone (control group, n = 48), and followed up for 2 years.

MAIN OUTCOME MEASURES

The co-primary effectiveness endpoints were the number of ocular hypotensive medications and IOP at 24-months post-surgery. The secondary effectiveness endpoints were ocular comfort as measured by the Ocular Surface Disease Index (OSDI) and vision-related quality of life as measured by the Glaucoma Activity Limitation Questionnaire (GAL-9) at 24-months. Safety measures included postoperative visual acuity, any unplanned return to the operating theatre, adverse events, and complications.

RESULTS

Participants (67.3% male) were aged 53 to 85 years, and treatment groups were similar in terms of mean medicated IOP (treatment group 17.7 mmHg ± 4.0; control group 17.1 mmHg ± 3.1), and number of ocular hypotensive medications (treatment group 1.69 ± 1.05; control group 1.80 ± 1.22) at baseline. At 24 months, the number of ocular hypotensive medications were 0.7 ± 0.9 in the treatment groups compared to 1.5 ± 1.9 in the control group, with an adjusted difference of 0.6 fewer medications per eye in the treatment group (95% CI 0.2-1.1, P = 0.008). In the treatment group, 57% of eyes were on no glaucoma medications compared to 36% in the control group. There was no significant difference in IOP between the 2 groups beyond the 4-weeks. There were no differences in patient-reported outcomes between the 2 groups. The visual outcomes and safety profiles were similar between the 2 groups.

CONCLUSIONS

Combined cataract surgery with iStent Inject achieved a clinically- and statistically-significantly greater reduction in ocular hypotensive medication usage at 24-months compared to cataract surgery alone, with no significant difference in IOP.

FINANCIAL DISCLOSURE(S)

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

Mid-term real world outcomes of the Hydrus® Microstent in open angle glaucoma

PURPOSE

To evaluate the mid-term clinical results and the safety aspects of the Hydrus® Microstent (Ivantis, Inc, Irvine, CA) in a real-life setting.

DESIGN

Retrospective case series.

METHODS

Hydrus® Microstent was implanted in phakic eyes (88 eyes, 87.1%) and in pseudophakic eyes (13 eyes, 12.9%), respectively. Mean follow-up time was 16 ± 9 months with 27 eyes having a follow-up time of more than 24 months.

MAIN OUTCOME MEASURES

The primary endpoint was reduction in IOP compared to baseline. Target IOP levels were set at ≤20 mmHg, ≤18 mmHg and ≤15 mmHg. Kaplan-Meier survival was defined as a reduction in IOP of ≥20% compared to baseline. Secondary endpoints were reduction in number of glaucoma medications and safety assessments addressing visual acuity, adverse events, re-surgery rate and identification of factors that made the implantation more difficult.

RESULT

101 eyes underwent Hydrus® implantation. The mean preoperative IOP was 21.60 mmHg (SD 6.6) on 2.18 (SD 1.3) medications. After a mean follow up time of 16 months, the mean IOP was reduced to 14.61 ± 3.7 mmHg on 1.12 (SD 1.1) medication classes (p < 0.001). Mean decrease in IOP was 26.7%. Analysis of the target IOP levels showed that in 29%, 34% and 35% of cases an IOP of ≤15 mmHg, ≤18 mmHg and ≤20 mmHg respectively could be achieved. BCVA improved from 0.56 ± 0.3 at baseline to 0.85 ± 0.3 more than 24 months after surgery (p < 0.001). The rate of re-operation was low at <3%. Adverse events occurred in 4 eyes (<4%).

CONCLUSION

This study underlines the effectiveness and the safety of the Hydrus® Microstent in an elective setting, but it also demonstrates certain limits and risk factors of this procedure.

Trabecular Procedures Combined with Cataract Surgery for Open-Angle Glaucoma: A Report by the American Academy of Ophthalmology

PURPOSE

To determine the intraocular pressure (IOP) reduction of various trabecular procedures (a form of minimally invasive glaucoma surgery [MIGS]) combined with cataract surgery compared with cataract surgery alone, to compare the safety of the various trabecular procedures, and to highlight patient characteristics that may favor one trabecular procedure over another.

METHODS

A search of English-language peer-reviewed literature in the PubMed database was initially conducted in February 2021 and updated in April 2023. This yielded 279 articles. Twenty studies met initial inclusion and exclusion criteria and were assessed for quality by the panel methodologist. Of these, 10 were rated level I, 3 were rated level II, and 7 were rated level III. Only the 10 level I randomized controlled trials (RCTs) were included in this assessment, and all were subject to potential industry-sponsorship bias.

RESULTS

The current analysis focuses on the amount of IOP reduction (in studies that involved medication washout) and on IOP reduction with concurrent medication reduction (in studies that did not involve medication washout). Based on studies that performed a medication washout, adding a trabecular procedure to cataract surgery provided an additional 1.6 to 2.3 mmHg IOP reduction in subjects with hypertensive, mild to moderate open-angle glaucoma (OAG) at 2 years over cataract surgery alone, which itself provided approximately 5.4 to 7.6 mmHg IOP reduction. In other words, adding a trabecular procedure provided an additional 3.8% to 8.9% IOP reduction over cataract surgery alone, which itself provided 21% to 28% IOP reduction. There was no clear benefit of one trabecular procedure over another. Patient-specific considerations that can guide procedure selection include uveitis predisposition, bleeding risk, metal allergy, and narrowing of Schlemm's canal. There are no level I data on the efficacy of trabecular procedures in subjects with pretreatment IOP of 21 mmHg or less.

CONCLUSIONS

Trabecular procedures combined with cataract surgery provide an additional mild IOP reduction over cataract surgery alone in hypertensive OAG subjects. Additional research should standardize outcome definitions, avoid industry sponsorship bias, and study the efficacy of these procedures in normotensive OAG.

FINANCIAL DISCLOSURE(S)

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

Comparative evaluation of iStent versus iStent inject W combined with phacoemulsification in open angle glaucoma

PURPOSE

The study aimed to compare the 12-month post-operative outcomes of iStent and iStent inject W (inject W), and the factors associated with their success in open-angle glaucoma.

METHODS

This single-center, retrospective comparative case series evaluated the medical records of patients who underwent iStent (comprising 1 stent) or inject W (comprising 2 stents) implantation with cataract surgery for primary open-angle glaucoma and normal tension glaucoma between January 2019 and March 2022. The 12-month post-operative efficacy outcomes included intraocular pressure (IOP), glaucoma medications, and survival analysis of the probability of success. "Failure" was defined as any of the following conditions compared to baseline: 1) IOP elevation, 2) increased glaucoma medication, or 3) IOP decline not exceeding 20% when glaucoma medication scores were comparable, and 4) need for additional glaucoma surgery. The safety outcomes included intra- and post-operative adverse events and changes in the best-corrected visual acuity and visual field.

RESULTS

The study comprised 55 eyes in the iStent and 105 in the inject W groups. At 12 months, treatment success was achieved in 66.0% of iStent and 78.4% of inject W eyes. The mean IOP was lower, and the percent reduction from baseline was equal in iStent-treated eyes (8.0% reduction, 14.8 mmHg to 13.7 mmHg, P<0.01) and inject W-treated eyes (11.9% reduction, 15.0 mmHg to 13.8 mmHg, P<0.01) (between-group comparison, P = 0.23). The mean medication burden decreased significantly from 2.5 to 1.1 for iStent (55.0% reduction, P<0.01) and 2.9 to 1.7 for iStent inject (46.8% reduction, P<0.01), with no significant differences between the two groups (P = 0.17). Both devices exhibited excellent safety.

CONCLUSIONS

Both devices significantly reduced IOP and glaucoma medication 12 months post-operatively. The outcome measures did not differ significantly between the two groups, and lower baseline IOP was predictive of surgical failure.

Biotissue stent for supraciliary outflow in open-angle glaucoma patients: surgical procedure and first clinical results of an aqueous drainage biostent

BACKGROUND/AIMS

To report a first-in-human trial in open-angle glaucoma (OAG) subjects treated with a new microinterventional biostent-reinforced cyclodialysis technique to enhance supraciliary aqueous drainage.

METHODS

Subjects (N=10; 74.1±7.9 years old) with OAG and cataracts underwent combined phacoemulsification cataract surgery with implantation of a permanent endoscleral supraciliary biostent to reinforce a controlled cyclodialysis cleft. The biostent comprised decellularised scleral allograft tissue microtrephined into a polymer tubular implant intraoperative/postoperative safety, intraocular pressure (IOP) and glaucoma medications were tracked through 12 months postimplantation.

RESULTS

Baseline medicated IOP averaged 24.2±6.9 mm Hg with subjects using 1.3±0.8 IOP-lowering medications. Successful biostent implantation was achieved in all individuals without significant complications. Immediate IOP lowering was sustained through 1 year. Twelve-month mean IOP was reduced 40% from baseline to 14.6±3.2 mm Hg (p=0.004; paired two-tailed t-test), and 80% of patients achieved >20% IOP reduction. Biostenting reduced glaucoma medication use 62%, from a baseline mean of 1.3 required medications to 0.5 medications (p=0.037) at postoperative 12 months. The biotissue implant was well tolerated and demonstrated good endothelial safety with only 11% endothelial cell loss at 12 months after combined phaco-biostenting surgery, similar to that expected after phacoemulsification alone. Mean BCVA increased from baseline 20/130 Snellen to 20/36 at postoperative 12 months (p=0.001).

CONCLUSION

Supraciliary biostenting in OAG patients is well tolerated, has a good safety profile and produces long-term IOP-lowering while reducing glaucoma medication requirements.

Does Cataract Extraction Significantly Affect Intraocular Pressure of Glaucomatous/Hypertensive Eyes? Meta-Analysis of Literature

BACKGROUND AND OBJECTIVES

This study aimed to evaluate the effect of cataract extraction on intraocular pressure at 6, 12, and 24 months and their difference compared to the baseline in diverse glaucoma subtypes.

MATERIALS AND METHODS

We carried out research in the MEDLINE, Cochrane Library and EMBASE databases, as of April 2022 for relevant papers, filtered according to established inclusion and exclusion criteria. The meta-analysis evaluated the Mean Reduction and relative Standard Error in these subpopulations at predetermined times. A total of 41 groups (2302 eyes) were included in the systematic review. Due to the significant heterogeneity, they were analysed through a Random Effects Model.

RESULTS

We obtained these differences from baseline: (1) Open Angle Glaucoma at 6, 12 and 24 months, respectively: -2.44 mmHg, -2.71 mmHg and -3.13 mmHg; (2) Angle Closure Glaucoma at 6, 12 and 24 months, respectively: -6.81 mmHg, -7.03 mmHg and -6.52 mmHg; (3) Pseudoexfoliation Glaucoma at 12 months: -5.30 mmHg; (4) Ocular Hypertension at 24 months: -2.27 mmHg.

CONCLUSIONS

Despite a certain variability, the reduction in ocular pressure was statistically significant at 6, 12 and 24 months in both Open Angle Glaucoma and Angle Closure Glaucoma, the latter being superior. Data for Pseudoexfoliation Glaucoma and for Ocular Hypertension are available, respectively, only at 12 months and at 24 months, both being significant.

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.

Short-term report of early glaucoma surgery with a clear lens extraction and an intraocular lens, OMNI canaloplasty, and a HYDRUS microstent: a case series in younger patients

Purpose

The purpose of this case series is to report the surgical outcomes from the combination of a clear lensectomy, OMNI® canaloplasty, and a HYDRUS® microstent with an adjacent goniotomy.

Methods

This is a retrospective non-comparative single-center case series of four black patients of African descent with glaucoma who were treated with a clear lensectomy, OMNI canaloplasty, and a HYDRUS microstent with an adjacent goniotomy. The surgeries were performed by an experienced cataract and glaucoma surgeon, Daniel Laroche, MD. The parameters investigated in this study were postoperative intraocular pressure (IOP) and the mean number of preoperative and postoperative medications needed.

Results

The mean age of the four patients was 44.5 years. All patients had a mean postoperative reduction in IOP of 17 mmHg to 12.7 mmHg. The mean number of preoperative medications was 2.2, while the mean number of postoperative medications was 0.3. Potential complications such as hyphema, IOP spikes, or corneal edema were not seen in this series. All patients achieved a lower IOP and stable vision with less refractive error. Patients also experienced improved visual fields, clearer vision, and more open angles.

Conclusion

Clear lensectomy and combined microinvasive glaucoma surgery (MIGS) in patients with primary open-angle glaucoma (POAG) and narrow-angle glaucoma (NAG) results in the safe lowering of IOP. The limitations of this study include the small series size and the retrospective potential for bias. Further research with a larger series and a prospective trial with follow-up should be performed.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

European Glaucoma Society - A guide on surgical innovation for glaucoma

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

[Review by the French Glaucoma Society on the roles of new surgical techniques in glaucoma]

The surgical management of glaucoma has been enriched in recent years by the arrival of new surgical techniques as a group known as MIGS (minimally invasive glaucoma surgery). The objective of these new techniques is to reduce intraocular pressure (IOP) while limiting the risk of complications of conventional filtering surgery and allowing faster visual recovery. MIGS can be classified into three main categories depending on the route used to promote the outflow of aqueous humor: the trabecular route, the suprachoroidal route and the subconjunctival route. MIGS using the subconjunctival route are also called minimally invasive bleb surgery (MIBS). These new techniques do not replace conventional filtering surgery, which remains the gold standard technique, but now offer new alternatives for the surgical management of glaucoma patients in combination with cataract surgery or as stand-alone procedures.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Four-Year Efficacy and Safety of iTrack Ab-interno Canaloplasty as a Standalone Procedure and Combined with Cataract Surgery in Open-Angle Glaucoma

PURPOSE

To evaluate the long-term effectiveness of ab-interno canaloplasty (ABiC), performed with the iTrack microcatheter (Nova Eye Medical, Fremont, CA, USA), in reducing intraocular pressure (IOP) as well as the number of required glaucoma medications in patients with open-angle glaucoma (OAG).

METHODS

In this retrospective single-center consecutive case series, 27 eyes of 21 patients (mean age 77.3 ± 5.8 years) were treated with ABiC performed as a standalone procedure or combined with cataract surgery. Patients with uncontrolled IOP OAG or controlled IOP (≤ 18 mmHg) OAG with intolerance to medications or lack of compliance were included. Patients were followed for up to 4 years following the procedure. The iTrack microcatheter was used to perform a 360-degree circumferential intubation and viscodilation of Schlemm's canal. Primary efficacy endpoints included IOP and the number of glaucoma medications at 12, 24, 36, and 48 months after surgery.

RESULTS

In all eyes, mean IOP and number of glaucoma medications were significantly reduced from 19.8 ± 5.2 mmHg and 1.9 ± 1.00 at baseline to 14.6 ± 3 mmHg and 0.9 ± 0.8, respectively, at the 48-month follow-up (p < 0.001). IOP was stable from 12 months to 48 months (p > 0.005). After 48 months, 39% of the eyes required zero medications compared to 3.7% at baseline, and 72.2% of eyes required only one medication or less. Of all eyes, 77.8% recorded an IOP ≤ 17 mmHg. No serious complications were recorded.

CONCLUSION

iTrack ABiC performed as a standalone procedure or in combination with cataract surgery significantly reduced IOP and number of medications in patients with OAG up to 4 years after the procedure.

First-Generation iStent Bypass Implantation versus ab Externo Canaloplasty Combined with Phacoemulsification in Patients with Primary Open Angle Glaucoma-12-Month Follow-Up

This prospective, non-randomized, interventional clinical study evaluated the efficacy and safety profile of first-generation iStent bypass implantation versus ab externo canaloplasty, both combined with phacoemulsification, in patients with primary open-angle glaucoma (POAG) after 12-month follow-up. A total of 138 patients with POAG and their 138 eyes (69 phaco-iStent and 69 phacocanaloplasty) were included. Postoperatively at 12 months, the mean intraocular pressure (IOP) decreased from 18.44 ± 3.88 to 15.51 ± 2.50 mmHg and from 17.20 ± 4.04 to 14.97 ± 2.37 mmHg in the phaco-iStent (PiS) and phacocanaloplasty (PC) groups, respectively (p = 0.480). In both groups, 35.7% achieved >20% IOP reduction from baseline. A total of 86% and 71.4% of the eyes were medication-free at 12 months in the PiS and PC groups, respectively. In both groups, all eyes showed improvement in best-corrected visual acuity compared with baseline and demonstrated similar safety profiles throughout the 12-month follow-up period. This study showed equal hypotensive effects of PiS and PC. Both procedures significantly reduced the IOP and the requirement for IOP-lowering medications for at least 12 months postoperatively, with no significant differences between the groups.

Five-Year Visual Field Outcomes of the HORIZON Trial

PURPOSE

To compare visual field (VF) progression between glaucoma patients receiving cataract surgery alone (CS) or with a Hydrus microstent (CS-HMS).

DESIGN

Post hoc analysis of VF data from the HORIZON multicenter randomized controlled trial.

METHODS

A total of 556 patients with glaucoma and cataract were randomized 2:1 to either CS-HMS (369) or CS (187) and followed up for 5 years. VF was performed at 6 months and then every year after surgery. We analyzed data for all participants with at least 3 reliable VFs (false positives < 15%). Average between-group difference in rate of progression (RoP) was tested using a Bayesian mixed model and a 2-sided Bayesian P value <.05 (main outcome). A multivariable model measured the effect of intraocular pressure (IOP). A survival analysis compared the probability of global VF sensitivity dropping by predefined cutoffs (2.5, 3.5, 4.5, and 5.5 dB) from baseline.

RESULTS

Data from 352 eyes in the CS-HMS arm and 165 in the CS arm were analyzed (2966 VFs). The mean RoP was -0.26 dB/y (95% credible interval -0.36, -0.16) for CS-HMS and -0.49 dB/y (95% credible interval -0.63, -0.34) for CS. This difference was significant (P = .0138). The difference in IOP only explained 17% of the effect (P < .0001). Five-year survival analysis showed an increased probability of VF worsening by 5.5 dB (P = .0170), indicating a greater proportion of fast progressors in the CS arm.

CONCLUSIONS

CS-HMS has a significant effect on VF preservation in glaucoma patients compared with CS alone, reducing the proportion of fast progressors.

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.

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.

The PreserFlo MicroShunt in the Context of Minimally Invasive Glaucoma Surgery: A Narrative Review

Recently, the quest for novel glaucoma surgical techniques and devices has been underway. Trabeculectomy remains the gold standard, but it requires the implantation of glaucoma drainage devices and frequent follow-ups, and it also carries a high risk of serious complications. The need for less invasive and safer procedures has led to the development of minimally invasive glaucoma surgery (MIGS), particularly for patients with mild-to-moderate disease. Among them, minimally invasive bleb surgery seems to be effective in classical glaucoma surgery, while maintaining MIGS benefits. The relatively new PreserFlo® MicroShunt (Santen, Osaka, Japan) is registered in Europe. It was released in 2019 for the treatment of patients with early-to-advanced open-angle glaucoma, where intraocular pressure (IOP) remains uncontrolled while on maximum tolerated medication and/or where glaucoma progression warrants surgery. This review focuses on the place of the PreserFlo MicroShunt, characterized by ab externo implantation, among MIGS procedures, discussing its advantages and disadvantages. The mechanisms of action, technical aspects, efficacy, and safety issues are summarized. The surgical technique, its efficacy, and safety profile are described, and directions for future studies are indicated. The PreserFlo MicroShunt ensures a high safety profile, minimal anatomical disruption, meaningful IOP-lowering effect, and ease of use for patients and physicians.

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.

'Microincisional trabeculectomy for glaucoma"

PURPOSE

To evaluate the short-term clinical outcomes of microincisional trabeculectomy (MIT), a new technique of ab-interno trabeculectomy.

METHODS

Consecutive patients with open-angle glaucoma identified from the hospital database that underwent MIT with or without cataract surgery between September 2021 to June 2022 at a tertiary eye centre in East India, were screened. Those with a follow-up of < 6 months or with incomplete data were excluded. MIT was done ab-interno using microscissors and microforceps in 2-4 clock hours of the nasal angle via a temporal incision. The intraocular pressure (IOP) reduction at 6 months, and reduction in the number of medications after surgery were analysed. Surgical success (IOP>6 and <22 mm Hg), complications, angle features on anterior segment optical coherence tomography (ASOCT), and the need for additional surgeries were analysed.

RESULTS

We included thirty-two eyes of 32 patients with open-angle glaucoma (including n = 9 eyes that underwent concurrent cataract surgery) with a preoperative mean IOP of 22 ±11.1 mm Hg and visual field index of 47±37.9%. All eyes achieved >30% IOP reduction, with a final IOP of 14±6.9 mm Hg at 6 months. Surgical success in 31 of 32 eyes with complete success seen in 28 eyes with none of the eyes requiring >1 medication for IOP control. Hyphema was seen in 4 eyes, while transient IOP spikes at 1 day-1 month were seen in 5 eyes, none of which required any additional interventions. One eye with persistent raised IOP at 1 month required incisional trabeculectomy for uncontrolled IOP with 2 medications.

CONCLUSION

MIT, a new technique of ab-interno trabeculectomy, is effective in terms of IOP control and reduction in the number of medications while having fewer complications. Long-term studies comparing the efficacy of MIT with incisional trabeculectomy, or other procedures are warranted in the future.

The place of endoscopic laser cyclodestruction in the system of microinvasive glaucoma surgery

Glaucoma is one of the leading causes of irreversible blindness in the world. Reducing intraocular pressure is the only way to slow down the progression of glaucomatous optic neuropathy. Minimally invasive glaucoma surgery aims to provide a safer way of reduction of intraocular pressure than traditional methods, and at the same time it is capable to reduce dependence on antihypertensive therapy. Cyclodestructive high-precision method of reducing the production of aquоeus humor occupies a confident position among modern minimally invasive glaucoma surgery methods. The data obtained as a result of studying the literature confirm our idea on the endoscopic laser cyclodestruction method as a minimally invasive, safe, reliable antiglaucomatous component of the combined surgical treatment of cataract and glaucoma.

Six year outcomes of combined phacoemulsification surgery and endoscopic cyclophotocoagulation in refractory glaucoma

PURPOSE

This study is to describe the 6-year results of combined phacoemulsification surgery and endoscopic cyclophotocoagulation (Phaco-ECP) surgery in patients with uncontrolled glaucoma and no previous glaucoma surgery.

METHODS

This is a retrospective case series of 84 eyes. The primary outcome measure was intraocular pressure (IOP) reduction 6 years postoperatively. Secondary outcome measures were the cumulative probability of failure of the surgical procedure at 6 years. Failure was defined as IOP higher than 21 mm Hg or lower than 6 mm Hg or IOP not reduced by 20% from baseline at the 1, 2, 3, 4, 5, or 6-year time points or further laser or other surgery to reduce IOP at any timepoint.

RESULTS

There was a statistically significant decrease in mean IOP from 18.9 mmHg pre-operatively to 13.7, 12.8, 13.0, 12.7, 12.5, and 12.3 mmHg at the 1, 2, 3, 4, 5, and 6 years post-operatively respectively (p < 0.001). Fifty-seven (68%) reached criteria for failure by 6 years. In 36% of cases, this was due to inadequate IOP control, whereas 32% required further laser or surgery. When we excluded patients who only had selective laser trabeculoplasty rather than further surgery, the failure rate reduced to 51%. Eleven percent had a post-operative complication, 2.4% requiring further surgical intervention.

CONCLUSIONS

At 6 years postoperatively, combined phaco-ECP achieved a significant reduction in IOP in patients with uncontrolled glaucoma and no previous drainage surgery. Significant complications were uncommon, but 68% was classified as surgical failures by the six year point.

Treatment Outcomes in the Primary Tube Versus Trabeculectomy Study after 5 Years of Follow-up

PURPOSE

To report 5-year treatment outcomes in the Primary Tube Versus Trabeculectomy (PTVT) Study.

DESIGN

Multicenter randomized clinical trial.

PARTICIPANTS

A total of 242 eyes of 242 patients with medically uncontrolled glaucoma and no previous incisional ocular surgery, including 125 patients in the tube group and 117 patients in the trabeculectomy group.

METHODS

Patients were enrolled at 16 clinical centers and randomly assigned to treatment with a tube shunt (350-mm2 Baerveldt glaucoma implant) or trabeculectomy with mitomycin C (MMC) (0.4 mg/ml for 2 minutes).

MAIN OUTCOME MEASURES

The primary outcome measure was the rate of surgical failure, defined as intraocular pressure (IOP) > 21 mmHg or reduced < 20% from baseline, IOP ≤ 5 mmHg, reoperation for glaucoma, or loss of light perception. Secondary outcome measures included IOP, glaucoma medical therapy, and visual acuity.

RESULTS

The cumulative probability of failure after 5 years of follow-up was 42% in the tube group and 35% in the trabeculectomy group (P = 0.21; hazard ratio = 1.31; 95% confidence interval = 0.86-2.01). At 5 years, IOP (mean ± standard deviation) was 13.4 ± 3.5 mmHg in the tube group and 13.0 ± 5.2 mmHg in the trabeculectomy group (P = 0.52), and the number of glaucoma medications (mean ± standard deviation) was 2.2 ± 1.3 in the tube group and 1.3 ± 1.4 in the trabeculectomy group (P < 0.001).

CONCLUSIONS

Trabeculectomy with MMC and tube shunt surgery produced similar IOPs after 5 years of follow-up in the PTVT Study, but fewer glaucoma medications were required after trabeculectomy. No significant difference in the rate of surgical failure was observed between the 2 surgical procedures at 5 years.

A Multicenter 12-Month Retrospective Evaluation of Canaloplasty and Trabeculotomy in Patients with Open-Angle Glaucoma: The ROMEO 2 Study

Purpose

Twelve-month safety and effectiveness results for canaloplasty combined with trabeculotomy using the OMNI surgical system in pseudophakic eyes or combined with cataract surgery in mild-to-moderate open-angle glaucoma (OAG).

Setting

Sixteen centers in 11 US states (AL, AR, CA, CT, KS, LA, MO, NY, SD, TN, TX).

Design

Retrospective, case series, open-label.

Methods

A total of 136 eligible patients from 20 surgeons: mild-to-moderate OAG (visual field mean deviation (MD) not worse than −12 dB), 12-month follow-up, preoperative medicated IOP >18 mmHg and ≤36 mmHg on ≤5 medications. One eye per patient enrolled. Endpoints included proportion with ≥20% reduction in IOP or IOP between 6 and 18 mmHg (inclusive) and on the same or fewer medications without secondary surgical intervention (SSI) (primary success), mean IOP, change in IOP, ocular hypotensive medication use, and proportion of patients with a 20% or greater reduction in IOP at 12 months. Safety: adverse events (AE) and best corrected visual acuity (BCVA).

Results

Primary success was met by 71%. Mean IOP was reduced (22.3–15.9 mmHg, p < 0.0001). Medications went from 1.9 ± 1.3 to 1.3 ± 1.2 (p < 0.001). AE were mild and as expected for angle surgery. The most frequent AE were BCVA loss (6%), mild inflammation (4%), IOP elevation (3%), and clinically significant hyphema (3%). There were 4 (3%) SSI.

Conclusion

The OMNI system provides effective IOP reduction, sustained IOP control, and meaningful medication reduction for up to 12 months postoperative. The present study confirms and extends the results from ROMEO.

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.

Minimally Invasive Glaucoma Surgery in Primary Angle-Closure Glaucoma

Primary angle-closure glaucoma (PACG) is responsible for half of the glaucoma-related blindness worldwide. Cataract surgery with or without trabeculectomy has been considered to be the first-line treatment in eyes with medically uncontrolled PACG. While minimally invasive glaucoma surgery has become an important surgical approach for primary open-angle glaucoma, its indications and benefits in PACG are less clear. This review summarizes the efficacy and safety profile of minimally invasive glaucoma surgery in PACG to unfold new insights into the surgical management of PACG.

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

Introduction

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

Methods

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

Results

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

Conclusions

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

Supplementary Information

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

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.

Microstent Implantation with Phacoemulsification Versus Phacoemulsification Alone for Patients with Open Angle Glaucoma: A Systematic Review and Meta-Analysis of Randomised Clinical Trials

PURPOSES

The purpose of this meta-analysis is to systematically compare the IOP-lowering effect of different microstents combined with phacoemulsification versus phacoemulsification for patients with OAG and cataract.

METHODS

This work was done through the data searched from PubMed, EMBASE, and the Cochrane Library. The Cochrane Handbook was also used to evaluate the quality of the included studies. In addition, this meta-analysis was performed using Revman 5.4 software.

RESULTS

A total of 8 randomized controlled trials (RCTs) were included. Compared with phacoemulsification alone, microstent implantation with phacoemulsification resulted in significant reduction in the postoperative IOP (MD = -1.66, 95%CI: [-2.25 to -1.06]). Patients with medication free and patients with beyond 20% IOP reduction were significantly increased in the microstent implantation with phacoemulsification group compared with phacoemulsification alone group (RR = 1.54, 95%CI: [1.34 to 1.77]; RR = 1.34, 95%CI: [1.24 to 1.45]).

CONCLUSION

Both microstent implantation with concurrent phacoemulsification and phacoemulsification alone result in a significant reduction in IOP. In terms of both reductions, microstent implantation with phacoemulsification significantly outperforms phacoemulsification alone.

Intraocular Pressure and Medication Burden With Cataract Surgery Alone, or Cataract Surgery Combined With Trabecular Bypass or Goniotomy

PRCIS

When compared with cataract surgery in glaucoma patients, trabecular micro-bypass and goniotomy resulted in a large decrease in the incidence of intraocular pressure (IOP) spikes, a modest effect on IOP, and a minimal effect on medication burden.

PURPOSE

To compare changes in IOP and ocular hypotensive medications in 3 surgical cohorts: cataract surgery, cataract surgery with trabecular micro-bypass (cataract/trabecular), and cataract surgery with goniotomy (cataract/goniotomy).

MATERIALS AND METHODS

We included 138 eyes diagnosed with open-angle glaucoma: (1) 84 eyes with cataract surgery alone, (2) 25 eyes with cataract/trabecular surgery, and (3) 29 eyes with cataract/goniotomy surgery. We compared the groups for postoperative IOP and the number of ocular hypotensive medications. We adjusted for preoperative IOP, and preoperative and postoperative number of ocular hypotensive medications. We defined an IOP spike as IOP ≥21 mm Hg and 10 mm Hg higher than preoperative on postoperative day 1.

RESULTS

All 3 surgeries showed a decrease in IOP (P≤0.004) and medication burden (P≤0.001) at 3 and 6 months postoperatively when compared with their own preoperative baselines. When compared with cataract surgery alone, cataract/trabecular and cataract/goniotomy had similar IOP lowering at 1 month postoperatively, and variable results at 3 and 6 months. The change in ocular hypotensive medications was not statistically different between the surgical groups at any postoperative visit. Cataract/trabecular and cataract/goniotomy decreased IOP on postoperative day 1, and had relative risk reduction of ~70% for IOP spikes (P≤0.001 for both).

CONCLUSION

Trabecular micro-bypass and goniotomy when added to cataract surgery resulted in a large decrease in IOP spikes, a modest effect on IOP, and a minimal effect on medication burden when compared with cataract surgery alone in glaucoma patients.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Outcomes of combined single-use dual blade goniotomy and cataract surgery

Purpose

Single-use dual blade goniotomy (SBG) is a novel ab interno procedure that removes three to five clock hours of trabecular meshwork (TM). We analysed the reduction of intraocular pressure (IOP) and topical glaucoma medication (Meds) in eyes following combined cataract surgery and SBG (Cat-SBG).

Methods

IOP and Meds were evaluated retrospectively in 55 eyes of 38 patients. 44 eyes had high tension glaucoma (HTG) and eleven eyes had normal tension glaucoma (NTG). Complete success (no Meds) and qualified success (with Meds) for IOP levels ≤ 21, ≤ 18 , ≤ 16 mmHg or ≥ 20% IOP reduction at the two- and six-month follow-up were evaluated.

Results

IOP and Meds were significantly reduced from before to two months after Cat-SBG in HTG- and NTG-patients (HTG: IOP 19.4 ± 3.3 to 15.1 ± 3.3 mmHg; p < 0.001; Meds 2.1 ± 1.3 to 0.8 ± 1.3; p < 0.001; NTG: IOP 14.0 ± 2.3 to 11.5 ± 2.3 mmHg; p = 0.004; Meds 1.6 ± 0.7 to 0.3 ± 0.7; p < 0.001). IOP and Meds did not change significantly from two to six months after Cat-SBG.

In HTG, complete and qualified success rates were 43% (19/44) and 93% (41/44) for IOP ≤ 18 mmHg, 36% (16/44) and 64% (28/44) for IOP ≤ 16 mmHg and 30% (13/44) and 43% (19/44) for ≥ 20% IOP reduction six months after surgery. In NTG, complete and qualified success was 81% (9/11) and 100% (11/11) for IOP ≤ 18 and ≤ 16 mmHg, and 27% (3/11) for IOP reduction ≥ 20%.

IOP and Meds reduction were comparable between HTG and NTG eyes.

Only minor postoperative complications occurred.

Conclusion

Cat-SBG is an efficient method to significantly lower IOP in patients with HTG and NTG.

The surgical management of glaucoma: A review

After a long period of little change, glaucoma surgery has experienced a dramatic rise in the number of possible procedures in the last two decades. Glaucoma filtering surgeries with mitomycin C and glaucoma drainage devices remain the standard of surgical care. Other newer surgeries, some of which are minimally or microinvasive glaucoma surgeries, target existing trabecular outflow, enhance suprachoroidal outflow, create subconjunctival blebs, or reduce aqueous production. Some require the implantation of a device such as the iStent, Hydrus, Ex-PRESS, XEN and PRESERFLO, whilst others do not-Trabectome, Kahook dual blade, Ab interno canaloplasty, gonioscopy-assisted transluminal trabeculotomy, OMNI and excimer laser trabeculotomy. Others are a less destructive variation of an established procedure, such as micropulse transscleral cyclophotocoagulation, endoscopic cyclophotocoagulation and ultrasound cycloplasty. Cataract surgery alone can be a significant glaucoma operation. These older and newer glaucoma surgeries, their mechanism of action, efficacy and complications are the subject of this review.

Microinvasive glaucoma surgery: a review and classification of implant-dependent procedures and techniques

The aim of this article is to discuss how physiology and anatomical background affect the effectiveness of implant‐dependent microinvasive glaucoma surgery (MIGS). First, we provide a micro view of aqueous outflow and tissue behaviour. Second, we review studies exploring the mechanisms of the pressure‐lowering effect of MIGS, as well as tissue behaviour during aqueous flow and tissue motion. We also describe and classify microinvasive surgical procedures and the most important types of implants, as well as their mechanisms of action, implantation techniques and efficacy. Further, we summarize the indications and surgical results presented in recent studies, providing an evidence‐based update on novel and emerging MIGS techniques for the treatment of open‐angle glaucoma. These data can help surgeons to personalize the management of glaucoma and to choose the best MIGS option for individual glaucoma patients.

Corneal Endothelial Cell Loss in Glaucoma and Glaucoma Surgery and the Utility of Management with Descemet Membrane Endothelial Keratoplasty (DMEK)

The corneal endothelium has a crucial role in maintaining a clear and healthy cornea. Corneal endothelial cell loss occurs naturally with age; however, a diagnosis of glaucoma and surgical intervention for glaucoma can exacerbate a decline in cell number and impairment in morphology. In glaucoma, the mechanisms for this are not well understood and this accelerated cell loss can result in corneal decompensation. Given the high prevalence of glaucoma worldwide, this review aims to explore the abnormalities observed in the corneal endothelium in differing glaucoma phenotypes and glaucoma therapies (medical or surgical including with new generation microinvasive glaucoma surgeries). Descemet membrane endothelial keratoplasty (DMEK) is increasingly being used to manage corneal endothelial failure for glaucoma patients and we aim to review the recent literature evaluating the use of this technique in this clinical scenario.

Recent trends in glaucoma surgery: a nationwide database study in Japan, 2011-2019

PURPOSE

To clarify recent trends in glaucoma surgery in Japan, including minimally invasive glaucoma surgery.

STUDY DESIGN

Retrospective cohort study.

METHODS

We used the Diagnostic Procedure Combination database, a nationwide administrative database in Japan. Patients who underwent glaucoma-related procedures were included. We calculated the number of surgeries stratified by procedures and age categories. We also investigated the number of glaucoma-related procedures in combination with cataract surgery.

RESULTS

From fiscal years 2011 to 2019, we identified 134,331 glaucoma-related procedures at 720 hospitals. The total number of glaucoma-related procedures increased by 215% from 6516 in 2011 to 20,569 in 2019. The numbers of filtering surgeries, trabeculotomies, and glaucoma drainage devices with plates [GDD(p +)] procedures significantly increased (P = 0.002, 0.002, and 0.006, respectively), whereas the number of cyclocryotherapy procedures significantly decreased (P = 0.002). The number of iStent procedures increased by 49% from 371 in 2018 to 551 in 2019. The ≥ 65 year age group accounted for > 80% of the iStent procedures. In the 0 to 14 year age group, trabeculotomy accounted for about 70% of the procedures, and the GDD(p +) procedure became the second most common procedure after trabeculotomy because of the decrease in filtering surgeries. Among combination surgeries, trabeculotomy was most frequently performed. The proportion of combination surgery increased, especially in trabeculotomy.

CONCLUSIONS

The total number of glaucoma-related procedures increased throughout the observation period. Before 2017 filtering surgery was the most common procedure, whereas trabeculotomy was most common after 2018. The proportion of trabeculotomies performed in combination with cataract surgery continuously increased.

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.

Gonioscopy-assisted transluminal trabeculotomy versus goniotomy with Kahook dual blade in patients with uncontrolled juvenile open-angle glaucoma: a retrospective study

Background

To compare the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) and Kahook Dual Blade (KDB) excisional goniotomy in patients with uncontrolled juvenile open-angle glaucoma (JOAG).

Methods

Thirty-three patients (46 eyes) were included in this single-center, retrospective, comparative study and treated with GATT (36 eyes) or KDB goniotomy (13 eyes). Intraocular pressure (IOP), number of glaucoma medications, adverse events, and additional anti-glaucoma procedures were collected during pre- and postoperative visits. Surgical success was defined as 6 mmHg ≤ IOP ≤ 18 mmHg and ≥ 20% IOP reduction from baseline with (partial success) or without (complete success) IOP-lowering medications.

Results

The mean ± SD preoperative IOP was 30.48 ± 12.9 mmHg and 26.08 ± 13.1 mmHg (P = 0.164) on 3.71 ± 0.46 and 3.08 ± 0.86 (P = 0.023) glaucoma medications in GATT and KDB group, respectively. At 3 months, the mean ± SD IOP was 15.48 ± 5.93 mmHg and 20.0 ± 10.8 mmHg after GATT and KDB, respectively (P = 0.072). The percentage of IOP lowering from baseline was 44.4 in the GATT group and 14.1 in the KDB group (P = 0.011). The mean reduction in medications was 2.6 ± 1.7 and 0.8 ± 1.2 three months after GATT and KDB, respectively (P < 0.001). Cumulative proportion of partial and complete success were 65.6 and 44.7% in the GATT group, 30.8 and 15.4% in the KDB group at 6 months. Additional procedures were required in 13.9% of cases after GATT and in 61.5% after KDB (P = 0.001). Patients in the GATT group with prior anti-glaucoma procedures and postoperative IOP spikes were more likely to fail, while those with complete trabeculotomy had a better prognosis.

Conclusions

Reduction of IOP and medications were greater after GATT in uncontrolled JOAG eyes. Whereas, more additional IOP-lowering procedures were required after KDB goniotomy.

Trial registration

This study was registered under the Chinese Clinical Trial Registry (ChiCTR2000034172, 27/06/2020).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02159-z.

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

Background

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

Methods

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

Results

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

Conclusions

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

Supplementary Information

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

Trends and Usage Patterns of Minimally Invasive Glaucoma Surgery in the United States: IRIS® Registry Analysis 2013-2018

PURPOSE

Understanding trends and patterns in the use of minimally invasive glaucoma surgery (MIGS) and patient profiles undergoing each procedure is important given their relative expense and unknown long-term safety and effectiveness.

DESIGN

Retrospective analysis.

PARTICIPANTS

Minimally invasive glaucoma surgeries and standard glaucoma surgeries recorded in the American Academy of Ophthalmology Intelligent Research in Sight (IRIS®) Registry.

METHODS

We used the data from IRIS Registry between 2013 and 2018 (inclusive) to measure the annual number of MIGS and standard surgical techniques (trabeculectomy or glaucoma drainage device [GDD] placement) performed in the United States, stratified by demographic characteristics. Secondary analyses of concurrent surgeries and of subsequent surgeries for MIGS and standard surgical technique also were conducted.

MAIN OUTCOME MEASURES

Trends and sociodemographic characteristics of MIGS use in the United States.

RESULTS

Two hundred three thousand three hundred thirty-two eyes and 232 537 unique procedures had associated, documented International Statistical Classification of Diseases and Related Health Problems (ICD), Ninth or Tenth Revision, codes for glaucoma and were included in final analyses. Among eyes with documented glaucoma diagnoses, a substantial increase in annual MIGS procedures occurred over the study period (from 7586 in 2013 to 39 677) and a smaller decrease in standard glaucoma procedures (from 16 215 to 13 701). The proportion of iStent procedures almost tripled during the study period (from 14% to 40%), and by 2017 accounted for almost half (43.7%) of all glaucoma surgeries in the United States. Twenty-one thousand twenty-five of all eyes (10.3%) underwent multiple procedures: 7638 (36.3%) on the same day and 13 387 (63.7%) on subsequent days. Endocyclophotocoagulation and iStent placement were the most common concurrent procedures (55.4% of all concurrent procedures). Trabeculectomy and GDD placement were most commonly followed by another standard glaucoma surgery, but when followed by sequential MIGS, endocyclophotocoagulation and goniotomy were the most common procedures performed (33.0% and 21.9%, respectively).

CONCLUSIONS

A significant increase in MIGS use occurred over the recent 6-year period, despite limited evidence of their long-term safety or effectiveness, highlighting the need for trials comparing safety and outcomes of novel MIGS versus traditional surgical treatments for glaucoma.

Parylene-C Microbore Tubing: A Simpler Shunt for Reducing Intraocular Pressure

OBJECTIVE

Current minimally-invasive glaucoma surgery (MIGS) devices promise to control elevated levels of intraocular pressure (IOP) while avoiding many of the downsides of traditional glaucoma surgery. However, there remains room for improvement in performance metrics, including drainage efficacy, device longevity, and time to implant, as outlined by benchmarks set forth by the Audacious Goals Initiative. We introduce a better shunt, which achieves similar or improved pre-clinical safety and efficacy outcomes to commercial MIGS devices, while reducing surgical profile and implantation time.

METHODS

We developed a parylene-based microbore glaucoma drainage device capable of modulating IOP via a minimally-invasive implantation procedure. We surgically implanted microbore tubing in five healthy New Zealand White rabbits and measured IOP levels biweekly using handheld applanation tonometry to assess device efficacy in lowering and maintaining IOP. After 6 weeks, the rabbits were euthanized and eyes were enucleated to evaluate inflammatory and histologic response to a foreign-body implant.

RESULTS

This device is the only one that fulfills the 10-minute benchmark for implantation time compared to other commercial MIGS devices. In 4 of 5 animals implanted, post-op IOP in the experimental eye dropped by an average of 16.17%. Histopathologic evaluation revealed localized evidence of minor inflammatory reaction and tissue irritation, as well as minimal fibrosis along the tube-tissue interface.

CONCLUSION AND SIGNIFICANCE

Based on these findings, this device stands as a promising platform to lowering IOP, particularly in patients with mild to moderate glaucoma requiring no need for cataract intervention, without eliciting a severe biological response.

Evaluation of the Efficacy and Safety of Canaloplasty and iStent Bypass Implantation in Patients with Open-Angle Glaucoma: A Review of the Literature

The aim of the paper was to evaluate the efficacy and safety of minimally invasive antiglaucoma procedures: Canaloplasty and iStent bypass implantation with and without phacoemulsification in patients with primary open-angle glaucoma (POAG). A systematic review of the recent literature was performed based on the PubMed, Google Scholar, Web of Science and Scopus databases. The effectiveness of the procedures was evaluated based on the reduction of intraocular pressure (IOP) and the amount of antiglaucoma medication used before and after surgery. Safety of the treatments was evaluated based on the number of incidences of certain intraoperative and postoperative complications. Independent prospective randomized controlled trials (PRCTs) have demonstrated that both procedures, canaloplasty and iStent implantation, are effective in reducing IOP and the amount of antiglaucoma medication. Considering the safety profile of these procedures, both canaloplasty and iStent implantation are associated with low rates of postoperative complications and have similar safety profiles. Further studies are needed to confirm the results of our analysis, including a high-quality randomized controlled trial comparing canaloplasty and iStent bypass implantation

5-year outcomes of single iStent (G1) trabecular microbypass implantation with phacoemulsification in moderately advanced primary open angle glaucoma

Purpose

To evaluate the safety and efficacy of combined phacoemulsification and single iStent (G1) (iStent, Glaukos Corp. San Clemente, USA), implantation in moderately advanced primary open angle glaucoma (POAG) with 5-years follow-up.

Methods

Retrospective, interventional case series. All subjects had POAG and underwent single iStent implantation+ phaco+IOL by a single surgeon, with 5 years follow-up. Primary outcome measures: reduction in intraocular pressure (IOP) and proportion of eyes achieving at least 20% reduction of IOP at 5 years. Secondary outcome measures: number of glaucoma drops at 1 through to 5 years; change in visual field mean deviation (MD) at year 5 compared to baseline.

Results

35 eyes of 26 patients were included. Mean (sd) medicated pre-op IOP was 18.5 (3.2) mm Hg on mean (sd) 2.3 (1.0) medications. Mean IOP was reduced to 15.9 (4.5) mm Hg on 2.2 (0.9) drops, 15.0mm (4.5) mm Hg on 2.3 (0.9) drops, 15.6 (3.6) mm Hg on 2.5 (1.0) drops, 15.7 (4.43) mmHg on 2.6 (1.0) drops and 14.7 (3.02) mmHg (P<0.001) on 2.7 (1.14) drops (P = 0.06) from 1 through to 5 years. At year 5, 62% of eyes had achieved at least 20% reduction in IOP. MD reduced from -8 (8.1) dB to -10.7 (13.4) dB over 5 years (p = 0.8) at 0.54dB/ annum. One eye required filtering surgery. There were no sight-threatening complications.

Conclusion

This study showed sustained IOP reduction and excellent safety profile for single iStent implantation. Uniquely it provides data for a more severe stage of glaucoma, and also visual field data, which indicated no significant change through 5 years.

Three-Year Outcomes of Second-generation Trabecular Micro-bypass Stents (iStent inject) With Phacoemulsification in Various Glaucoma Subtypes and Severities

PRECIS

This longitudinal case series provides valuable long-term data on the safety and efficacy of iStent inject with concomitant cataract surgery. Patients experienced significant and durable reductions in both intraocular pressure (IOP) and medication burden through 3 years postoperative.

PURPOSE

The purpose of this study was to examine the 3-year effectiveness and safety of iStent inject second-generation trabecular micro-bypass stent implantation with concomitant phacoemulsification cataract surgery in eyes with various glaucoma subtypes and severities.

METHODS

This was a single-center consecutive case series. Three-year outcomes included mean IOP and medications, the proportions of eyes with IOP ≤18, ≤15, and ≤12 mm Hg, and success (absence of secondary glaucoma interventions). Safety included best-corrected visual acuity (BCVA), cup-to-disc ratio, visual field (VF) mean deviation, retinal nerve fiber layer (RNFL), and ganglion cell-inner plexiform layer (GCIPL) thickness, and adverse events.

RESULTS

A total of 124 eyes with different glaucoma subtypes and severities were included. At 3 years postoperative, mean IOP reduced from 16.90±3.85 mm Hg preoperatively to 13.17±2.83 mm Hg (22% reduction, P<0.001) and mean medication burden decreased from 2.38±1.29 medications preoperatively to 1.16±1.22 medications (51% reduction, P<0.001). At 3 years, 96% of eyes achieved IOP ≤18 mm Hg (vs. 69% preoperatively), 80% of eyes achieved IOP ≤15 mm Hg (vs. 40% preoperatively), and 42% of eyes achieved IOP ≤12 mm Hg (vs. 7% preoperatively) with 76% of eyes eliminating ≥1 medication and 37% of eyes eliminating ≥2 medications versus preoperative medication burden. The 3-year cumulative survival rate was 74%. Postphacoemulsification BCVA improvement was preserved, and cup-to-disc ratio, VF mean deviation, and RNFL and GCIPL thickness remained stable. A favorable safety profile included no intraoperative complications and few, transient, postoperative adverse events.

CONCLUSION

Significant and sustained IOP and medication reductions were achieved through 3 years after iStent inject implantation with cataract surgery in a real-world clinical population with mild-to-severe glaucoma, along with favorable safety including stable BCVA, VF, and RNFL and GCIPL thickness.