Microinvasive Glaucoma Surgery Research Articles

Medical therapy for glaucoma: A review.

A number of pharmacological targets are exploited to modify the parameters in the Goldmann equation and reduce the intraocular pressure (IOP). This strategy constitutes the foundation for the medical management of glaucoma, the evolution of which, until only recently, has been in relative stagnation. A burst of innovation has produced new ocular hypotensive drugs and long-acting delivery methods, including intracameral delivery, which are expanding the clinician's medical armamentarium. A number of IOP-independent neuroprotection strategies have shown strong potential in animal models of glaucoma, but translational attempts have been surprisingly limited. However, while pharmacological options are expanding, the traditional role of topical medical therapy is being challenged by selective laser trabeculoplasty, micro-invasive glaucoma surgery, and sustained delivery methods. A scientifically rigorous assessment of new treatments will be critical to empower clinicians with evidence-based information to optimise vision preservation and quality of life outcomes for their patients.

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

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

Juvenile open angle glaucoma: current diagnosis and management.

The aim of this article is to summarize up-to-date research on the diagnosis and management of juvenile open-angle glaucoma (JOAG). JOAG can be subclassified into four clinical phenotypes, and faster myopic shift is a risk factor for disease progression. Vessel density is associated with structural damage and worsening visual acuity in JOAG and can be monitored with optical coherence tomography angiography. Genetic studies have revealed molecular causes of JOAG including variants in CPAMD8, MYOC, and CYP1B1. Tube shunt surgeries as well as gonioscopy-assisted transluminal trabeculotomy have been shown to be successful in JOAG. Although genetic advances may improve future screening, intraocular pressure monitoring and fundoscopic exam remain the current mainstay of diagnosis. Medical treatment alone for JOAG is typically insufficient with patients requiring surgical management. Selective laser trabeculoplasty may delay or decrease the need for surgery. Trabeculectomy has traditionally been shown to be effective in JOAG, but tube shunt surgery and microinvasive glaucoma surgery are effective alternatives.

Development and validation of a test facility for pivotal characterization of glaucoma drainage devices

Abstract Implant devices for micro invasive glaucoma surgery (MIGS) are gaining increasing acceptance in clinical ophthalmic use. The implant requirements are defined in international standards, such as ANSI Z80.27-2014 and the 2015 Guidance for Industry and Food and Drug Administration Staff “Premarket Studies of Implantable Minimally Invasive Glaucoma Surgical (MIGS) Devices”. The exact fluid-mechanical characterization represents a crucial part of the development and approval of innovative implant devices for MIGS. The current work describes the development and preliminary validation of a versatile test facility for pivotal characterization of glaucoma drainage devices. The test setup enables a pressurization of test specimens by means of two water columns. For measurement of pressure and volume flow, a pressure transducer and a total of three liquid flow meters were implemented into the test setup. Validation was conducted by experimental pressureflow characterization of standardized tubes and a comparison to theoretical results according to Hagen Poiseuille's law for stationary laminar flow of a Newtonian fluid in a tube with a circular cross section. Ultrapure water at (35 ± 2) °C was used for the analyses. The developed test setup potentially enables pressure-flow characterization of test specimens in a wide flow range of 0 μl min-1 ≤ Q ≤ 5.000 μl min-1. The preliminary test facility validation showed a good agreement of measured and theoretical volume flow characteristics as a function of the pressure difference, in the currently investigated flow range of Q < 80 μl min-1. The developed test facility is suitable for pivotal in vitro characterization of glaucoma drainage devices. Future investigations will focus on the final validation of the whole flow range and on the use of the test facility for fluid-mechanical characterization of self-developed prototypes of glaucoma microstents as well as commercially available glaucoma drainage devices.

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

BackgroundGlaucoma is a disease characterized by progressive damage of the optic nerve. Several therapeutic options are available to lower intraocular pressure (IOP). In primary open-angle glaucoma (POAG) patients with inadequate IOP control (or controlled with multiple medical therapies or for whom medical therapy is contraindicated), the implantation of micro-invasive glaucoma surgery devices (MIGS) and concomitant cataract surgery has proved to be more effective in reducing intraocular pressure (IOP), as compared to cataract surgery alone. The objective of this study was to assess the cost-effectiveness of iStent inject® device with concurrent cataract surgery vs. cataract surgery alone, in patients with mild-to-moderate POAG, adopting the Italian National Health Service (NHS) perspective.MethodsSimulation of outcomes and costs was undertaken using a Markov model with 4 health states and one-month cycles, that is used to simulate the prognosis of these patients. Efficacy data were obtained from the randomized clinical trial (RCT). A lifetime horizon was adopted in the analysis. A discount rate of 3.5% was applied to both costs and effects. The Italian National Healthcare Service (NHS) perspective was considered, therefore only healthcare direct costs (acquisition of main interventions and subsequent procedures; medications; monitoring and follow-up; adverse events). Model robustness was tested through sensitivity analyses.ResultsResults of the base-case analysis showed that the total lifetime costs were higher in the iStent inject® + concurrent cataract surgery, compared with the cataract surgery alone group (€8368.51 vs. €7134.71 respectively). iStent inject® + concurrent cataract surgery was cost-effective vs. cataract surgery alone, with an incremental cost-effectiveness ratio of €13,037.01 per quality-adjusted life year (QALY) gained. Both one-way deterministic and probabilistic sensitivity analyses confirmed robustness of base-case results. The cost-effectiveness accessibility curve (CEAC) showed that iStent inject® + cataract surgery would have a 98% probability of being cost-effective, compared to cataract surgery alone, when the willingness to pay (WTP) is equal to €50,000 per QALY gained.ConclusionsThe results of the cost-utility analysis confirm that iStent inject® + cataract surgery is a cost-effective option for the treatment of patients affected by mild-to-moderate POAG, compared with cataract surgery alone, when evaluated from the Italian NHS perspective.

Microinvasive Glaucoma Surgery: An Evidence-Based Review

ABSTRACT Purpose: Interest in micro-invasive glaucoma surgery (MIGS) has exploded over the last 8 years with an increase in MIGS procedures of at least 400% in the United States, according to Medicare data. MIGS is an umbrella term that can cover many different types of surgeries. This review focuses on peer-reviewed evidence for Trabectome®, iStent inject ®, Kahook Dual Blade®, XEN® Gel Stent, and Hydrus®. Methods: We present key recent studies evaluating the efficacy and safety of MIGS in various types of glaucoma patients with different stages of disease. Conclusion: We conclude that MIGS is generally safe and efficacious, although only some MIGS have been studied through randomized clinical trials. When comparing and contrasting the different MIGS procedures, large prospective studies are not yet the norm. High-quality large prospective studies involving MIGS will be an important next step as ophthalmologists decide how to incorporate MIGS into their surgical armamentarium.

Survey of Microinvasive Glaucoma Surgery and Other Glaucoma Surgical Experience among United States Ophthalmology Residency Programs.

Purpose The aim of the study is to assess the state of glaucoma surgical training in United States ophthalmology residency programs, including experience with microinvasive glaucoma surgery (MIGS). Design The design of the study is anonymous, internet-based national survey. Participants Current United States ophthalmology residents of residency programs accredited by the Accreditation Council for Graduate Medical Education (ACGME). Methods An anonymous survey link was emailed to all 120 accredited United States ophthalmology residency programs inviting residents to participate in an assessment of residency glaucoma surgical experience. Survey responses were collected between January 21, 2019 and March 4, 2019 and analyzed using descriptive statistics. Main Outcome Measures The main outcomes of the study are demographic information, practice intentions, and anticipated primary surgical experience with ACGME-required glaucoma procedures and MIGS procedures, as self-reported by U.S. ophthalmology residents. Results Of the estimated 1,479 U.S. ophthalmology residents, 161 residents participated (10.9%). A total of 118 residents (73.2%) reported any degree of anticipated MIGS primary surgical experience during residency, with the iStent being the most familiar technique. The likelihood of any anticipated MIGS experience during residency was not significantly different by geographic region ( p = 0.16), however, anticipated volume varied significantly ( p = 0.037). Of the 113 respondents who reported an intention to manage glaucoma surgically in their eventual practice, 25 (22.1%) reported no anticipated primary MIGS experience during residency. 73.3% of residents anticipating MIGS experience anticipated 0 to 10 cases, with 42.9% anticipating less than 5 cases as primary surgeon. Conclusion MIGs are not a required component of the glaucoma surgical curriculum for U.S. ophthalmology residents. Although the majority of ophthalmology residents surveyed intend to manage glaucoma surgically in eventual practice, most receive minimal experience with these novel techniques during residency. Surgical training is variable by geographic region.

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.

Incidence of steroid response in microinvasive glaucoma surgery with trabecular microbypass stent and ab interno trabeculectomy

ObjectiveTo determine the incidence and risk factors for steroid response in patients undergoing combined phacoemulsification cataract extraction (PCE) and microinvasive glaucoma surgery with either trabecular microbypass stent implantation (iStent) or ab interno trabeculectomy (Trabectome). DesignRetrospective, noncomparative, single-institutional observational chart review. ParticipantsConsecutive patients with open-angle glaucoma who underwent PCE with iStent or Trabectome with 3 months of follow-up. MethodsData were collected from patient charts, including pre- and postoperative intraocular pressure (IOP) following application of topical corticosteroid on postoperative visits for at least 3 months. A steroid response was defined as an IOP rise of greater than 5 mm Hg beginning at least 3 days after surgery with no other obvious explanation and with IOP < 20 mm Hg following rapid tapering or withdrawal of the steroid. ResultsA total of 118 eyes from 89 patients, average age of 71.4 ±12.1 years, were included. Overall, a steroid response was seen in 12.7% of eyes (n = 15), and no difference was noted between Trabectome (11.8%) and iStent (13.6%, p = 0.782) eyes. Axial length (AL; p = 0.01), younger age (p = 0.009), traumatic glaucoma (p = 0.004), and normal-tension glaucoma (NTG; p = 0.0048) were significant predictors of steroid response in a multivariate analysis. In eyes with AL ≥ 25 mm, the steroid response rate was 40%, in contrast to eyes with AL < 25 mm, where it was 10.2%. ConclusionA steroid response develops in approximately 1 in 8 patients undergoing PCE with Trabectome or iStent. Young age, AL > 25 mm, traumatic glaucoma, and NTG were found to be significant predictors of steroid response.

Safety and efficacy of microinvasive glaucoma surgery with cataract extraction in patients with normal-tension glaucoma

This study assesses the safety and efficacy of microinvasive glaucoma surgery (MIGS) with cataract extraction in patients with normal-tension glaucoma (NTG). In our sample of 45 NTG patients, mean intraocular pressure (IOP) decreased from 13.7 to 12.3 mmHg at 2.5 years, and mean medication burden decreased from 2.0 to 1.1 at 1.5 years. For success defined as IOP reduction ≥ 30% from baseline IOP with medication burden reduction from preoperative levels, success probability was 5.4% at 1.5 years. For success defined as medication burden reduction with an IOP reaching goal IOP as determined by the glaucoma specialist, success probabilities were 67.2% at 1.5 years and 29.4% at 2.5 years. At the last follow-up visit, eyes with two MIGS procedures with different mechanisms of action achieved successful medication reduction 68.8% of the time versus 35.7% achieved by a single MIGS procedure (p = 0.052). At their last visit, visual acuity was unchanged or improved in all eyes (100%). MIGS with cataract surgery results in modest reductions in IOP and medication burden in NTG patients, which may lead to lower costs and better therapeutic compliance. A combination of two MIGS procedures with different mechanisms of action may potentially be more effective in reducing medication burden than a single MIGS procedure in NTG patients. Further research is necessary to ascertain whether MIGS for NTG patients may help decrease medication burden while helping achieve goal IOP.

Microinvasive Glaucoma Surgery in US Ophthalmology Residency: Surgical Case Log Cross-sectional Analysis and Proposal for New Glaucoma Procedure Classification.

A cross-sectional sample of the US ophthalmology residency graduating class of 2018 revealed that 18.4% of residents logged <5 traditional glaucoma surgeries, and 63.4% logged at least 1 microinvasive glaucoma surgery (MIGS). Describe the state of MIGS in US ophthalmology residency training and propose a glaucoma procedure classification system for residents' surgical case logs. Deidentified case logs from residents graduating in 2018 were requested from US residency program directors. Case logs were received for 152/488 (31%) residents from 36/115 (31%) programs. The mean number of traditional glaucoma surgeries per resident was 9.0±5.9 (range: 0 to 31). The mean number of MIGS per resident was 5.2±8.9 cases (range: 0 to 58). There were 28/152 (18.4%) residents from 16/36 (44.4%) programs who logged <5 traditional glaucoma surgeries as primary surgeon, and 3/152 (2.0%) residents from 3/36 (8.3%) programs who logged zero traditional glaucoma surgeries as primary surgeon. There were 98/152 (64.5%) residents from 32/36 (88.8%) programs who logged <5 MIGS as primary surgeon, and 48/152 (31.6%) residents from 25 of 36 (69.4%) programs who logged zero MIGS as primary surgeon. There were 104/152 (63.4%) residents from 33/36 (91.6%) programs who logged at least 1 MIGS as primary surgeon; there were 3/36 (8.3%) residency programs where no resident logged any MIGS as primary surgeon. US ophthalmology residents' MIGS experience varies widely. Residents can satisfy glaucoma surgery requirements with some MIGS, even in the absence of adequate traditional glaucoma surgeries. We propose a residency case log classification system that better reflects the growing role of MIGS in clinical practice and helps ophthalmic educators more accurately track procedures requiring related skills.

Microinvasive Glaucoma Surgery: A Review of Schlemm's Canal-Based Procedures.

Microinvasive glaucoma surgery has gained popularity over the past decade. It can be performed using three different mechanisms. In the present review, we focused on Schlemm’s canal (SC)-based surgery, which increases aqueous humor (AH) outflow into the aqueous veins by either removal of the trabecular meshwork (TM) or an increase in the tension in the TM. In primary open-angle glaucoma (POAG), the TM is the most likely region for increased AH outflow resistance. Theoretically, removal of the TM can improve the AH outflow; hence, glaucoma specialists focus on microsurgical dissection of the TM. In this review, we analyzed the available literature to examine SC-related microsurgical modalities based on the histopathological proofs of the localization of resistance of the AH outflow. First, we considered the role, anatomy, and physiology of the TM and SC. We referred to studies that describe the mechanisms and potential pathways, related to increased intraocular pressure in the POAG, that are targeted using the SC-related microsurgical interventions. Next, we took a closer look at the gonioscopic tools necessary for an ab-interno approach and explored incision canal surgery: ab-interno trabeculectomy using different instrumentation (Trabectome®, Kahook Dual Blade) and variations of the technique. Thereafter, we discussed ab-interno canaloplasty, explaining the technique and reviewing its effectiveness. Finally, we presented the scope for future research in the field. Although the iStent also targets SC by bypassing it, this device has been reviewed extensively elsewhere.

Mid-term evaluation of the safety and efficacy of the iStent trabecular micro-bypass system combined with phacoemulsification.

Micro-invasive glaucoma surgery (MIGS) and MIGS devices have been gaining increasing attention in recent years. One such device is the trabecular micro-bypass stent, or iStent® (Glaukos Corporation, Laguna Hills, USA). To evaluate the safety and efficacy of the minimally invasive ab interno surgical implantation of a trabecular bypass during cataract surgery in reducing intraocular pressure (IOP) in patients with mild and moderate open-angle glaucoma and cataracts. The study was a prospective, uncontrolled, interventional case series (a prospective study of a case series), including 54 patients with a mean age of 72 years. All subjects underwent ab interno implantation of a single iStent together with cataract surgery. The corrected distance visual acuity (CDVA), IOP, anti-glaucoma medications, visual field, and number and type of complications were investigated after surgery. The patients were followed up at 1, 7, and 30 days, and 3, 6, 12, 24 and 36 months after the operation. The mean observation time was 20 months. At baseline, CDVA was 0.5 or better in 65% of the eyes; this improved to 0.5 or better in all eyes (0.8 or better in 79%) at the end of the observation. The mean baseline IOP was 17.1 mm Hg, which fell to a mean of 15.1 mm Hg. The mean number of medicinal eye drops prescribed preoperatively was 1.7, which decreased to 0.26 at the end of the observation. Cataract surgery combined with iStent implantation seems to be an effective procedure in patients with mild to moderate open-angle glaucoma and cataracts. The insertion of 1 stent resulted in a significant decrease in IOP and a reduction in the number of topical anti-glaucoma medications needed. Based on the characteristics of the observed complications, iStent implantation can be considered a safe method.

Changes in Performance of Glaucoma Surgeries 1994 through 2017 Based on Claims and Payment Data for United States Medicare Beneficiaries

To evaluate trends in glaucoma procedures in the United States Medicare population and to evaluate which physicians are performing newer procedures. Analysis of publicly available claims and payment data. Surgeons and beneficiaries enrolled in United States Medicare between 1994 and2017. Data regarding payments to physicians by the Centers for Medicare and Medicaid Services (CMS) were downloaded for the years 2012 through 2017. Data regarding claims to CMS by physicians were requested and processed between 1994 and 2017. Procedure counts from both data sets then were normalized for changes in the Medicare population, with 1995 as the baseline. The normalized volumes of procedures over time were visualized, as were geographic distributions of surgeons and their volume of procedures. Trends in procedure counts over time, geographic distribution of surgeons, and their volume of procedures. The number of trabeculectomies continues to decline and now is similar to the number of tubes. Use of the relatively new trabecular bypass shunts has increased rapidly. Surgeons performing these procedures are less likely to be performing traditional glaucoma surgeries as well. The number of laser-based cyclodestruction procedures increased after introduction of the endoscopic technique and again with the introduction of so-called micropulse procedures. The procedure counts obtained with physician payment data consistently are lower than those from claims data given the limitations of the payment data. Glaucoma practice patterns change each time a new device or procedure is introduced. Collectively, the use of new microinvasive glaucoma surgery procedures has increased rapidly such that they now account for a significant majority of glaucoma surgeries. Given the almost complete lack of comparative data to inform surgeon choices regarding these procedures, it will be important that randomized studies are carried out to fill this gap.

Phaco-UCP; combined phacoemulsification and ultrasound ciliary plasty versus phacoemulsification alone for management of coexisting cataract and open angle glaucoma: a randomized clinical trial

BackgroundVarious surgical techniques have been described, to be combined with cataract surgery in glaucoma patients, aiming for an additional reduction of intraocular pressure (IOP), hence minimizing the burden of anti-glaucoma medication (AGM). Ultrasound ciliary plasty (UCP) is a recent microinvasive glaucoma surgery (MIGS) recommended for primary and refractory glaucoma. This study was conducted to evaluate the safety and efficacy of a new technique; combined phacoemulsification and ultrasound ciliary plasty (Phaco-UCP) as a primary surgical treatment for coexisting cataract and open angle glaucoma.MethodsA randomized clinical trial, including 61 eyes of 61 patients with visually significant cataract and open angle glaucoma, randomized to either Phaco-UCP (study group; 31 eyes) or phacoemulsification alone (Phaco-alone) (control group; 30 eyes). Primary outcomes included reduction in IOP and/or the number of AGM. Secondary outcomes included visual acuity improvement and complications. Qualified Success was defined as an IOP reduction ≥ 20% from baseline value, with an IOP 6–21 mmHg, with no additional AGM or glaucoma surgery. Failure was defined as either < 20% IOP reduction, despite AGM use, the need of glaucoma surgeries or serious complications.ResultsAt 18 months postoperatively, Phaco-UCP group had a median IOP reduction of 7 mmHg (Q1, Q3 = 3, 10) compared to 2 mmHg (Q1, Q3 = 2, 3) in Phaco-alone group (P < 0.001). Phaco-UCP group had significantly higher success rate at all time points reaching 67.7% at the last follow-up versus 16.7% only in Phaco-alone group (P< 0.001). The median number of AGM significantly decreased from [3 (Q1, Q3 = 2, 4), 3 (Q1, Q3 = 2,3)] respectively, (P =0.3)] at baseline to [1 (Q1,Q3 = 1, 2), 2 (Q1,Q3 = 2, 2)] respectively, (P < 0.001)] at 18 months postoperatively. No serious intraoperative or postoperative complications were encountered in either group.ConclusionPhaco-UCP is a simple, safe and effective procedure for management of coexisting cataract and open angle glaucoma.Trial registrationClinicalTrials.gov identifier, NCT04430647; retrospectively registered. June 12, 2020.

Adverse Events Associated with Microinvasive Glaucoma Surgery Reported to the Food and Drug Administration

Adverse Events Associated with Microinvasive Glaucoma Surgery Reported to the Food and Drug Administration

European TiO2 prices drop to early 2017 levels

To evaluate trends in glaucoma procedures in the United States Medicare population and to evaluate which physicians are performing newer procedures.Analysis of publicly available claims and payment data.Surgeons and beneficiaries enrolled in United States Medicare between 1994 and 2017.Data regarding payments to physicians by the Centers for Medicare and Medicaid Services (CMS) were downloaded for the years 2012 through 2017. Data regarding claims to CMS by physicians were requested and processed between 1994 and 2017. Procedure counts from both data sets then were normalized for changes in the Medicare population, with 1995 as the baseline. The normalized volumes of procedures over time were visualized, as were geographic distributions of surgeons and their volume of procedures.Trends in procedure counts over time, geographic distribution of surgeons, and their volume of procedures.The number of trabeculectomies continues to decline and now is similar to the number of tubes. Use of the relatively new trabecular bypass shunts has increased rapidly. Surgeons performing these procedures are less likely to be performing traditional glaucoma surgeries as well. The number of laser-based cyclodestruction procedures increased after introduction of the endoscopic technique and again with the introduction of so-called micropulse procedures. The procedure counts obtained with physician payment data consistently are lower than those from claims data given the limitations of the payment data.Glaucoma practice patterns change each time a new device or procedure is introduced. Collectively, the use of new microinvasive glaucoma surgery procedures has increased rapidly such that they now account for a significant majority of glaucoma surgeries. Given the almost complete lack of comparative data to inform surgeon choices regarding these procedures, it will be important that randomized studies are carried out to fill this gap.

&lt;p&gt;Mid-Term Evaluation of iStent Inject&lt;sup&gt;®&lt;/sup&gt; Trabecular Micro-Bypass Stent Implantation with or without Phacoemulsification: A Retrospective Study&lt;/p&gt;

IntroductionThis study evaluated the 6-month performance and safety of micro-invasive glaucoma surgery (MIGS) with iStent inject either with or without cataract surgery.Material and MethodsLongitudinal retrospective study of 86 surgeries in 49 patients with inadequately controlled open-angle glaucoma (OAG) or ocular hypertension who underwent iStent inject trabecular micro-bypass implantation either alone (isolated group) or combined with cataract surgery (combined group). The two primary outcomes included an intraocular pressure (IOP) drop of ≥20% versus preoperative values (adequate drop) and IOP maintenance between 6 and 18 mmHg (adequate Range). For both outcomes, we determined “complete” and “qualified” success if patients did not require or did require glaucoma medications, respectively, at the end of follow-up. Safety outcomes included best-corrected visual acuity, adverse events, and secondary surgeries.ResultsIn the adequate drop analysis, 30.2% achieved “complete success,” and 37.2% achieved “qualified success.” For adequate range, 40.7% achieved “complete success” and 39.5% achieved “qualified success.” There was no difference in medication decrease (p=0.77) nor IOP reduction (p=0.46) between the isolated and combined groups. Safety was generally favorable and similar between groups, with mild transient adverse events that resulted in no sequelae.Discussion/ConclusioniStent inject implantation either with or without cataract surgery was able to safely decrease IOP and medication requirements through 6 months after surgery.

Treatment Complexity in Primary Open-Angle Glaucoma (POAG): Perspectives on Patient Selection in Micro-Invasive Glaucoma Surgery (MIGS) Using Stents.

Primary open-angle glaucoma (POAG) is still one of the most common causes of impaired vision worldwide, despite the further development of therapy options, and can lead to blindness. Micro-invasive glaucoma surgery (MIGS) using stents aims at reducing intraocular pressure (IOP), as it is the main risk factor. With regard to adherence and adverse drug reactions it also aims at reducing the drug burden on patients. The study investigates under everyday conditions the criteria according to which ophthalmologists in Germany select patients for MIGS using stents. In addition, it will be investigated which patients (could) benefit most from the therapy. In this qualitative study, 11 narrative interviews were conducted between May 2017 and July 2018 with ophthalmologists working in the hospital or in a private practice. They were interviewed on their experiences in the treatment of POAG with microstents. The interviews were analysed by an interdisciplinary team using the qualitative content analysis. The stages of therapy escalation form the frame of reference for patient selection in MIGS using stents. Only if the IOP cannot be sufficiently reduced by drop therapy or when this causes drug-related side effects that are intolerable for the patients, stents are apparently used as the next higher escalation stage. The intensive post-operative medication and the frequent check-up appointments are perceived as barriers by the interviewees, especially for people with or without disabilities, who are dependent on external help and/or those living in rural areas. The active cooperation of the patients in the demanding aftercare seems to be indispensable for the ophthalmologists. In addition, necessary revisions are sometimes stressful for patients (physical/psychological) and doctors (work organisation/therapy). Against the background of the organisational and economic challenges in the outpatient spectrum of tasks, especially physicians in private practice seem to weigh up carefully for which patients microstent therapy would be reasonable. In view of the therapeutic requirements, the current microstent therapy seems to be used in a selected, adherent patient group. Further qualitative and quantitative studies (in other health care regions and structures) are necessary to verify and extend the available results.

The association between corneal hysteresis and surgical outcomes from trabecular meshwork microinvasive glaucoma surgery.

To assess whether an association exists between pretreatment corneal hysteresis (CH) and the magnitude of intraocular pressure (IOP) and medication burden reduction following microinvasive glaucoma surgery (MIGS). Retrospective chart review of 84 eyes from 57 patients with CH measurements who underwent trabecular meshwork MIGS in a glaucoma practice in New York City with follow-up visits at 3-6 and 9-12 months. MIGS included canaloplasty, goniotomy, microbypass stents, or a combination thereof. The lowest and middle CH tertiles experienced significantly reduced mean IOP at 3-6-month follow-ups (p = .007, < .001), whereas the highest tertile did not (p = .06). At 9-12-month follow-ups, a significant mean IOP reduction only persisted in the middle tertile (p = .001). For medication burden reduction, only the highest CH tertile experienced significant mean reductions at both 3-6- and 9-12-month follow-ups (p = .015, .028). Notably, 7 patients in the lowest CH tertile failed MIGS and required an additional surgical or laser procedure within 24 months of MIGS, whereas only 3 patients failed in the other tertiles (likelihood ratio < .05). Multivariate analysis excluding MIGS failures demonstrated an inverse association between CH and the magnitude of post-operative IOP reduction at both 3-6- and 9-12-month follow-ups when controlling for baseline IOP and medication changes (p = .002, .026). There was an inverse association between pretreatment CH and the magnitude of IOP reduction following surgery. There is also evidence of an increased need for repeat surgery or other intervention in patients with lower CH who undergo MIGS.