The Role of Minimally Invasive Glaucoma Surgery Devices in the Management of Glaucoma

A Comprehensive Review of Recent Advances in Minimally Invasive Glaucoma Surgery: Current Trends and Future Directions

Glaucoma, a leading cause of blindness globally, necessitates effective management strategies to prevent irreversible vision loss. Traditional glaucoma surgeries, while effective, are associated with significant risks and complications. Minimally invasive glaucoma surgery (MIGS) has emerged as a transformative approach, offering safer and less invasive alternatives. This review provides a comprehensive overview of recent advancements in MIGS, highlighting current trends, technological innovations, and future directions. MIGS procedures, characterized by smaller incisions and quicker recovery times, have expanded the therapeutic landscape, enabling earlier intervention and improved patient outcomes. The review evaluates various MIGS techniques, their efficacy, safety profiles, and clinical outcomes, drawing insights from comparative studies and meta-analyses. Technological innovations, including enhanced device designs and integration with digital health technologies, have further bolstered the field. Despite challenges in patient selection and long-term outcomes, the future of MIGS is promising, with ongoing research and development poised to enhance its impact. By synthesizing the latest research, this review aims to inform clinicians, researchers, and policymakers, ultimately contributing to improved management of glaucoma and patient care.

Neuroprotective effects of resveratrol on retinal ganglion cells in glaucoma in rodents: A narrative review

Glaucoma, an irreversible optic neuropathy, primarily affects retinal ganglion cells (RGC) and causes vision loss and blindness. The damage to RGCs in glaucoma occurs by various mechanisms, including elevated intraocular pressure, oxidative stress, inflammation, and other neurodegenerative processes. As the disease progresses, the loss of RGCs leads to vision loss. Therefore, protecting RGCs from damage and promoting their survival are important goals in managing glaucoma. In this regard, resveratrol (RES), a polyphenolic phytoalexin, exerts antioxidant effects and slows down the evolution and progression of glaucoma. The present review shows that RES plays a protective role in RGCs in cases of ischemic injury and hypoxia as well as in ErbB2 protein expression in the retina. Additionally, RES plays protective roles in RGCs by promoting cell growth, reducing apoptosis, and decreasing oxidative stress in H2O2-exposed RGCs. RES was also found to inhibit oxidative stress damage in RGCs and suppress the activation of mitogen-activated protein kinase signaling pathways. RES could alleviate retinal function impairment by suppressing the hypoxia-inducible factor-1 alpha/vascular endothelial growth factor and p38/p53 axes while stimulating the PI3K/Akt pathway. Therefore, RES might exert potential therapeutic effects for managing glaucoma by protecting RGCs from damage and promoting their survival.

Development and material characteristics of glaucoma surgical implants

Background

Glaucoma is the leading cause of irreversible blindness worldwide. The reduction of intraocular pressure has proved to be the only factor which can be modified in the treatment, and surgical management is one of the important methods for the treatment of glaucoma patients.

Main text

In order to increase aqueous humor outflow and further reduce intraocular pressure, various drainage implants have been designed and applied in clinical practice. From initial Molteno, Baerveldt and Ahmed glaucoma implants to the Ahmed ClearPath device, Paul glaucoma implant, EX-PRESS and the eyeWatch implant, to iStent, Hydrus, XEN, PreserFlo, Cypass, SOLX Gold Shunt, etc., glaucoma surgical implants are currently undergoing a massive transformation on their structures and performances. Multitudinous materials have been used to produce these implants, from original silicone and porous polyethylene, to gelatin, stainless steel, SIBS, titanium, nitinol and even 24-carat gold. Moreover, the material geometry, size, rigidity, biocompatibility and mechanism (valved versus nonvalved) among these implants are markedly different. In this review, we discussed the development and material characteristics of both conventional glaucoma drainage devices and more recent implants, such as the eyeWatch and the new minimally invasive glaucoma surgery (MIGS) devices.

Conclusions

Although different in design and materials, these delicate glaucoma surgical implants have widely expanded the glaucoma surgical methods, and improved the success rate and safety of glaucoma surgery significantly. However, all of these glaucoma surgical implants have various limitations and should be used for different glaucoma patients at different conditions.

Preventing Blindness with Early Cataract Surgery and Micro-Invasive Glaucoma Surgery in Patients Over 50: Guidance for Patients, Physicians and World Governments in Dealing with Glaucoma

Purpose

To offer clinical guidance and address safety and efficacy concerns regarding the growing use of micro-invasive glaucoma surgery (MIGS) as an initial treatment for glaucoma in adult patients.

Design

Narrative literature review.

Methods

A review was conducted to assess outcomes and complications of MIGS in the treatment of glaucoma, both alone and in combination with lens replacement. These outcomes were compared with those of standard glaucoma surgery and/or glaucoma management with medication.

Results

MIGS are effective at lowering intraocular pressure (IOP) over long periods of follow-up. These techniques share a similarly high safety profile between one another. MIGS were found to have lower complication rates and to be more effective in reducing the total amount of medication needed to maintain control of intraocular pressure than standard surgery approaches.

Conclusion

MIGS techniques are growing in popularity and have been demonstrated to be a safe and effective alternative to standard glaucoma surgery. Guidance in the implementation of these procedures has been outlined.

Magnetically actuated glaucoma drainage device for regulating intraocular pressure after implantation

The key risk factor for glaucoma is increased intraocular pressure (IOP). Glaucoma drainage devices implanted in the eye can reduce IOP and thus stop disease progression. However, most devices currently used in clinical practice are passive and do not allow for postsurgical IOP control, which may result in serious complications such as hypotony (i.e., excessively low IOP). To enable noninvasive IOP control, we demonstrate a novel, miniature glaucoma implant that will enable the repeated adjustment of the hydrodynamic resistance after implantation. This is achieved by integrating a magnetic microvalve containing a micropencil-shaped plug that is moved using an external magnet, thereby opening or closing fluidic channels. The microplug is made from biocompatible poly(styrene-block-isobutylene-block-styrene) (SIBS) containing iron microparticles. The complete implant consists of an SIBS drainage tube and a housing element containing the microvalve and fabricated with hot embossing using femtosecond laser-machined glass molds. Using in vitro and ex vivo microfluidic experiments, we demonstrate that when the microvalve is closed, it can provide sufficient hydrodynamic resistance to overcome hypotony. Valve function is repeatable and stable over time. Due to its small size, our implant is a promising, safe, easy-to-implant, minimally invasive glaucoma surgery device.

Impact of minimally invasive glaucoma surgery on the ocular surface and quality of life in patients with glaucoma

Background:

Minimally invasive glaucoma procedures are emerging as clinically effective and safe glaucoma management approaches; however, evidence regarding quality-of-life outcomes is limited.

Objectives:

To explore the impact of minimally invasive glaucoma surgery (MIGS) combined with phacoemulsification on patient-reported outcomes and clinical parameters related to ocular surface disease in people with glaucoma.

Design:

Retrospective observational study.

Methods:

Fifty-seven consecutive patients were examined prior to undergoing iStent combined with phacoemulsification with or without adjunctive endocyclophotocoagulation and at 4-month follow-up.

Results:

At follow-up, on average patients returned statistically significantly improved scores on glaucoma-specific (GQL-15, p < 0.001; GSS, p < 0.001), general health (EQ-5D, p = 0.02) and ocular surface PROMs (OSDI, p = 0.001). Patients were using fewer eye drops on average after MIGS compared with before surgery (1.1 ± 0.9 versus 1.8 ± 0.8; p < 0.001). Undergoing MIGS was associated with improved tear film break-up time ( p < 0.001) and reduced corneal fluorescein staining ( p < 0.001).

Conclusion:

This retrospective audit shows quality of life and clinical parameters related to the ocular surface are improved following MIGS combined with phacoemulsification in patients previously treated with anti-glaucoma therapy.

Budget impact analysis of the XEN®63 for the treatment of primary openangle glaucoma in Spain

BACKGROUND AND OBJECTIVE

To evaluate the economic impact in Spain derived from the introduction of the XEN®63 implant as a surgical alternative in the management of primary open angle glaucoma (POAG) with or without cataract in refractory patients.

MATERIALS AND METHODS

A budget impact analysis was designed to estimate the costs of surgical treatment of POAG from the perspective of the Spanish National Health System (NHS), over a time horizon of 1 year. The comparators considered (trabeculectomy, deep non-penetrating sclerectomy, Ahmed valve, iStent inject, Preserflo® microshunt and XEN®45) correspond to those used in Spanish public clinical practice. For the calculation of the target population, market shares and resource use in terms of follow-up visits, additional procedures and post-surgery complications, data from the literature were used and validated with a panel of 4 experts. Unit costs (€ 2021) were obtained from the ESALUD database.

RESULTS

The inclusion of XEN®63 could generate savings of €2,569,737 after one year since its introduction, derived from savings in the cost of the implant and procedure (-€423,120; -0.7%), follow-up visits (-€777,407; -4.5%), additional procedures (-€1,048,145; -20.6%) and post-surgery complications (-€321,065; -14.2%).

CONCLUSIONS

The incorporation of XEN63®in the surgical arsenal for the treatment of refractory POAG with and without cataracts could generate savings for the NHS.

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.

Anterior segment imaging in minimally invasive glaucoma surgery - A systematic review

Minimally invasive glaucoma surgery (MIGS) has grown in popularity over the past decade. This systematic review explores the peri-operative and intraoperative application of anterior segment imaging to maximize the efficacy and safety of MIGS. A review of the PubMed, EMBASE and CINAHL databases was conducted, with inclusion criteria restricted to MIGS that had received United States Food and Drug Administration (FDA) premarket approval, FDA 510(K) premarket notification, or were listed as a class 1 device exempt from FDA approval or notification. 21 manuscripts from 21 unique studies were identified pertaining to MIGS devices including the XEN Gel Stent, Trabectome, iStent Inject, 1st-generation iStent and the Kahook Dual Blade (KDB). Anterior segment imaging modalities included anterior segment optical coherence tomography (AS-OCT), ultrasound biomicroscopy (UBM), aqueous angiography, OCT volumetric scans and in vivo confocal microscopy. Identification and evaluation of aqueous outflow pathways before and after MIGS have potential for improving patient preoperative patient selection and postoperative outcomes. Intraoperative imaging potentially provides the resolution needed for good visualization of angle anatomy and accurate evaluation of surgical endpoints in angle-based MIGS. Anterior segment imaging has been used to identify procedural complications, provide objective information on implant location in relation to surrounding anatomy, assess the post-implantation structural impact of MIGS devices and manage bleb failure and scarring. Technical difficulties in incorporating imaging modalities into the surgical microscope, variable quality of images and optical interference from ocular structures or surgical instruments are remaining barriers, which discourage the widespread clinical use of this technology.

Reasons for choice of glaucoma surgery in eyes not treated with anti-glaucoma medications

Background

In the real world, some glaucoma patients can undergo an incisional glaucoma surgery without using medication. The rate of cases with no medication treatment at the time of surgery among those that underwent incisional glaucoma surgeries performed in our department was reported.

Methods

The department database of Shimane University Hospital for eyes that underwent incisional surgeries to manage glaucoma at the hospital between April 2018 and September 2020 were searched. By reviewing the medical charts of 1,417 consecutive eyes listed, 90 (6.4%) eyes of 67 subjects (mean age of 72 ± 16 years; 22 men, 29 eyes; 45 women, 61 eyes) who underwent a surgery without use of antiglaucoma medication were identified. The types of glaucoma, glaucoma procedures, and reasons for choosing the glaucoma surgeries rather than medical therapy were collected for the 90 eyes.

Results

Among the 90 eyes, primary angle-closure disease (PACD) (60%) was the most frequent type of glaucoma followed by EXG (17%), POAG (16%), and others (8%). Among the reasons for the choice of incisional surgery, relief of angle closure (64%) was the most frequent, the second most frequent was the incidental diagnosis of glaucoma during the ocular examinations both for that eye’s cataract surgery or the contralateral glaucoma surgery (13%). Other reasons included poor medication adherence (10%), dementia (6%), multiple medication allergy (3%), and acute IOP elevation other than PACD (3%). Cataract extraction (CE) alone (33%) was the most frequent glaucoma procedures performed in these eyes, followed by CE combined with goniosynechialysis (27%), CE + iStent (16%), CE + goniotomy by Tanito microhook ab interno trabeculotomy or using the Kahook Dual Blade (11%), Ahmed Glaucoma valve implantation (11%), and trabeculectomy (2%).

Conclusion

In the real-world, 6.4% of incisional glaucoma surgeries were performed in the absence of medication use; of them, 32 eyes (2.3%) were with open angle glaucoma. In open angle glaucoma, the reasons can be classified into; 1) patients’ inability to instill the medication, 2) incidental diagnosis of glaucoma during the pre-surgical examinations, and 3) the eyes with acute IOP rise.

Conventional glaucoma implants and the new MIGS devices: a comprehensive review of current options and future directions

Glaucoma is a progressive optic neuropathy that is the second leading cause of preventable blindness worldwide, after cataract formation. A rise in the intraocular pressure (IOP) is considered to be a major risk factor for glaucoma and is associated with an abnormal increase of resistance to aqueous humour outflow from the anterior chamber. Glaucoma drainage devices have been developed to provide an alternative pathway through which aqueous humour can effectively exit the anterior chamber, thereby reducing IOP. These devices include the traditional aqueous shunts with tube-plate design, as well as more recent implants, such as the trabeculectomy-modifying EX-PRESS^® implant and the new minimally invasive glaucoma surgery (MIGS) devices. In this review, we will describe each implant in detail, focusing on their efficacy in reducing IOP and safety profile. Additionally, a critical and evidence-based comparison between these implants will be provided. Finally, we will propose potential developments that may help to improve the performance of current devices.

Short-term Outcomes and Prognostic Factors of Cataract-combined Surgery with iStent versus iStent Inject

Purpose: To analyze the therapeutic effects, prognostic factors, and complications that occurred after iStent^® or iStent inject^® implantation in South Korean glaucoma patients. Methods: We retrospectively analyzed 42 eyes of South Korean glaucoma patients, who were followed-up for more than 6 months after iStent^® or iStent inject^® implantation alone or combined with cataract surgery. Surgical success was defined as an intraocular pressure (IOP) ≤21 mmHg and an IOP reduction ≥20% from preoperative IOP levels. Results: The cumulative success rate at 6 months after surgery was 45.3 ± 8.1% for iStent inject^® alone (group A), 28.6 ± 13.1% for iStent^® alone (group B), 81.2 ± 6.8% for iStent inject^® combined with cataract surgery (group A-1), and 27.3 ± 21.8% for iStent^® combined with cataract surgery (group B-1). Group A-1 showed a higher success rate than group B-1 (<i>p</i> = 0.007); the difference in success rates between groups A and B was not statistically significant (<i>p</i> = 0.579). When the success prognostic factors were analyzed by Cox regression analysis, the results showed that a higher preoperative IOP was associated with a higher surgical success rate (hazard ratio 0.80, <i>p</i> = 0.02). Conclusions: In our patient group, iStent inject^® was more effective than iStent^® in combination with cataract surgery. The higher the preoperative IOP, the higher the surgical success rate; the results were significant.

The Hydrus Microstent in Pseudophakic Patients With Medically Refractory Open-angle Glaucoma

PURPOSE

Minimally invasive glaucoma surgery (MIGS) is an emerging therapy for glaucoma. The Hydrus Microstent is a MIGS device that stents Schlemm's canal, thereby increasing aqueous drainage and lowering intraocular pressure (IOP). This article describes the use of the microstent in pseudophakic patients with medically refractory glaucoma, a patient population undocumented in the current literature.

PATIENTS AND METHODS

We present a retrospective case series of 11 pseudophakic eyes using 3 or more pressure lowering medications daily for open-angle glaucoma who underwent Hydrus Microstent insertion. Patients were followed up at 1, 3, 6, 12, 24, 36, 48, and 60 months postoperatively and assessed for reductions in IOP and medication burden.

RESULTS

At intervals 12 and 24 months, medication burden reduced by 75.6% at both junctures, and IOP reduced by 43.8% and 34.1%. Complications included 4 hyphaemas and 1 corneal epithelial defect, each of which resolved.

DISCUSSION

This case series demonstrated effective pressure and medication reduction in medically refractory open-angle glaucoma patients using the Hydrus Microstent. Use of this device in this population is thus far undocumented in the literature and may represent an optimal therapeutic modality in the future.

Trends in Surgical Glaucoma Treatment in Germany Between 2006 and 2018

Background/Aims

Surgical procedures in ophthalmology underlie variations over different time periods and are strongly dependent on the technical process and the invention of innovative surgical techniques. Especially, in glaucoma surgery a lot of surgical devices and techniques have been introduced during the last years. Until now, the use of these newer techniques has not been shown on a robust data basis. We herein present the numbers of different types of glaucoma surgeries performed at German hospitals between 2006 and 2018.

Methods and Design

The quality reports of hospitals in Germany from 2006 to 2018 were analyzed concerning all procedural codes for glaucoma surgery and intervention. Especially, the change in usage of "classical" and "modern" surgical techniques (MIGS: "minimally invasive glaucoma surgery") or devices was compared.

Results

The number of glaucoma procedures performed increased by 75% from 27,811 in 2006 to 48,794 in 2018. Absolute numbers of trabeculectomies, goniotomies, ab externo trabeculotomies and to a certain level cyclodestructive procedures decreased during the examined years while use of MIGS has increased in absolute and relative numbers since 2012. From 2015 a strong increase in the usage of XEN implants could be seen. Drainage implants (such as Baerveldt/Ahmed) showed stable absolute numbers over the time period covered. Absolute numbers of laser trabeculoplasty peaked in 2014 and decreased afterwards. Iridotomies and iridectomies increased by 120%/248% over the whole period.

Conclusion

Our data show a trend towards the modern surgical options and especially MIGS during the recent years. Classical procedures showed a decrease in total numbers emphasized from 2013. These numbers confirm the assumption that modern glaucoma surgery is becoming more and more popular and established in German hospitals.

A review of glaucoma surgical therapy

Glaucoma is a disorder of all species due to a rise of intraocular pressure (IOP) beyond which is compatible with ganglion cell and axon function, often resulting in optic nerve degeneration and irreversible blindness. Glaucoma treatment with surgical intervention aimed at either reducing aqueous production, or increasing or altering aqueous outflow has evolved over preceding decades, but there remains no cure. The present article is intended to provide a concise review of glaucoma surgical therapies in veterinary ophthalmology.

Intraocular Pressure Reduction After Real-world Cataract Surgery

PRéCIS:: A large cohort undergoing cataract extraction was retrospectively analyzed to ascertain the degree of real-world intraocular pressure (IOP) reduction in normal eyes and those with glaucoma, and a predictive formula was developed.

PURPOSE

The purpose of this study was to define the real-world degree of IOP reduction after cataract extraction to guide its role as an isolated intervention for glaucoma.

MATERIALS AND METHODS

A retrospective analysis was carried out of clinical data collected in 8 clinical sites in the United Kingdom from an electronic medical record system between January 2006 and May 2015. A total of 20,508 eyes without known pathology and 2251 eyes from patients with glaucoma undergoing phacoemulsification and intraocular lens insertion were included. Eyes with intraoperative complications, undergoing additional procedures, axial lengths outside 22 to 26.5 mm, preoperative IOP under 6 mm Hg or over 30 mm Hg, and copathology, except for amblyopia or glaucoma, were excluded. The main outcome measure was the change in preoperative IOP compared with the next recorded visit for up to 12 weeks.

RESULTS

In eyes without pathology, the mean reduction in IOP was 1.40 mm Hg (±3.74) compared with 1.03 (±5.02), P-value <0.001, in eyes with a diagnosis of glaucoma. A multiple linear regression model identified preoperative IOP, a glaucoma diagnosis, preoperative corrected visual acuity, age, and axial length as determinants of IOP reduction. The model was validated against an independent cohort.

CONCLUSIONS

We quantify mean IOP reduction achieved in a real-world setting from cataract surgery alone. In glaucomatous eyes where angle closure is not differentiated, phacoemulsification alone yields only a modest reduction of IOP.

XEN gel implant with or without phacoemulsification for glaucoma: a systematic review and meta-analysis

Background

XEN gel implant is an alternative method of treating glaucoma by connecting the anterior chamber and the subconjunctival space. The efficacy of the XEN gel implant and whether to combine with phacoemulsification is what most concerned. This review aims to test the efficacy and safety of the XEN gel implant compared with trabeculectomy and to test the efficacy between XEN combined with phacoemulsification and XEN alone.

Methods

The PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov were searched through July 8, 2020. Studies comparing XEN and trabeculectomy or comparing XEN + phacoemulsification and XEN alone were included. The standard mean differences (SMD) were calculated to analyze the lowered intraocular pressure (IOP) and the number of anti-glaucoma medications. All data were measured from baseline to endpoint. The I2 statistic quantified heterogeneity ranged from 0% to 100%, and a random effects model was used in this meta-analysis. Review Manager 5.3 performed all analyses. The t-test calculated all P values, and P values were regarded as statistically significant at P<0.05. The methodological index for non-randomized studies was used to find and test bias in the literature.

Results

Twelve studies with 1,602 eyes were included. Five studies compared the XEN gel implant with trabeculectomy. Eight compared XEN + phacoemulsification with XEN alone. There was no significant correlation between XEN and trabeculectomy groups in lowering IOP (SMD 0.30, 95% CI, 0.00 to 0.60, I²=60%) and reduced the number of IOP lowering drugs (SMD 0.01, 95% CI, –0.16 to 0.17, I²=0%). There was a significant difference between XEN + phacoemulsification and XEN alone in lowering IOP (1,034 eyes, SMD 0.22, 95% CI, 0.05 to 0.40, I²=38%) and reducing the number of medications (729 eyes, SMD 0.20, 95% CI, –0.06 to 0.46, I²=62%).

Conclusions

XEN gel implant, although not effective as trabeculectomy, is a safe operation for open-angle and some other types of glaucoma. Meanwhile, XEN alone is more effective than XEN combined with phacoemulsification within 1 week after operations. After three months, the two groups are similar in lowering IOP. More extensive, better-designed, strictly blinded, multicenter randomized clinical trials are needed to confirm our findings.

Microinvasive glaucoma surgery: A review of 3476 eyes

Microinvasive glaucoma surgery (MIGS) is a potentially safer and more efficacious method studied in patients with mild-to-moderate open-angle glaucoma requiring less invasive treatment goals; however, the literature on MIGS must be thoroughly evaluated. We conducted a review of MIGS by searching MEDLINE, EMBASE, and Cochrane CENTRAL. Primary efficacy indicators were reductions in intraocular pressure and topical medication use postoperatively. While all comparative randomized controlled trials assessing MIGS in English peer-reviewed journals were included, only observational studies with a target follow-up of at least one year and a high priority score were analyzed, resulting in a total of 3476 eyes across 20 trials. The mean age was 69.5 ± 2.9 years, 53.7% were female, and 77.4% were Caucasian. One study had last follow-up at less than one year, fifteen studies had follow-up extending 1-2 years, and four had longer than two years of follow-up. A pattern of more significant intraocular pressure and medication reduction was observed in patients who underwent MIGS (n = 2170) relative to control (n = 1306) interventions. iStent had the most literature supporting its efficacy, followed by Hydrus. The most common adverse events after MIGS implantation included stent obstruction, inflammation, and subsequent surgical intervention. Surgical complication rates and efficacy are favorable after MIGS. This review helps to consolidate the high-quality evidence that exists for various MIGS procedures and to identify gaps where further research is needed.

Outcomes of phacoemulsification combined with two iStent inject trabecular microbypass stents with or without endocyclophotocoagulation

AIM

Comparing outcomes after combined phacoemulsification, two iStents insertion and endocyclophotocoagulation (ECP) versus phacoemulsification-iStents alone.

METHODS

This is a longitudinal retrospective 12 months study in eyes with ocular hypertension or early-to-moderate open angle glaucoma. Level of disease, intraocular pressure (IOP) and tolerance of glaucoma medication were considered before planning surgery. Best-corrected visual acuity (BCVA-logMAR), IOP (mm Hg), number of medications were assessed at baseline, week 1, week 5, month 3, 6, 12 postop.

MAIN OUTCOME

percentage (%) in IOP reduction at 12 months vs medicated baseline.

SECONDARY OUTCOMES

absolute values of IOP/medication reduction, BCVA and postop complications.

RESULTS

The ICE2 (two iStents-cataract extraction-ECP) group included 63 eyes and Phaco-iStent group included 46 eyes. Baseline IOP was higher in the ICE2 than phaco-iStent group (19.97±4.31 mm Hg vs 17.63±3.86 mm Hg, p=0.004) and mean deviation was lower (-7.20±2.58 dB vs -4.94±4.51 dB, p=0.037). Number of medications were comparable at baseline: 2.22±1.06 (ICE2) vs 2.07±1.02 (phaco-iStent), p=0.442. At month 12 postop, IOP in the ICE2 group decreased 35% from baseline vs 21% in the phaco-iStent group (p=0.03); absolute IOP reduction was significantly lower than baseline in each group (p<0.001), yet final IOP was lower in the ICE2 group than phaco-iStent group (13.05±2.18 mm Hg vs 14.09±1.86 mm Hg, p=0.01). Similar results were found for glaucoma medication (1.24±1.05 in ICE2 group vs 1.39±1.03 in phaco-iStent group, p=0.01). Final BCVA was 0.11±0.18 (phaco-iStent group) vs 0.08±0.08 (ICE2 group), p=0.309. Safety outcomes were comparable between groups.

CONCLUSION

ICE2 procedure offers better results in IOP/medication reduction at 12 months than phacoemulsification-iStents alone.

The cost burden of falls in people with glaucoma in National Health Service Hospital Trusts in the UK

Aims: Falls have devastating consequences in older people with a considerable cost burden. Glaucoma is a risk factor for falls, and patients with glaucoma who fall are at high risk of hospital admission. The aim was to quantify the cost burden of falls to NHS Trusts in people with glaucoma in the UK.Methods: Financial data were used to identify non-elective episodes and associated costs from 2012 to 2018, for all admissions where glaucoma was recorded as a secondary diagnosis and admissions for falls (all, with and without a glaucoma secondary diagnosis). A secondary diagnosis is only recorded by the admitting clinician if it is clinically relevant; therefore, a secondary diagnosis of glaucoma was used as a proxy for glaucoma as a contributory factor to falls.Limitations: Use of financial records means that data on other falls risk factors was unavailable and we cannot be certain that glaucoma was the only relevant factor in all falls. Although this methodology is imperfect, case capture was biased towards cases with clinically significant glaucoma, and financial data is robust. Potential coding errors mean that we may have excluded patients in whom glaucoma was a factor in their fall.Results: At Maidstone and Tunbridge Wells (MTW) NHS Trust, 11.7% (95% confidence intervals [CI] = 10.7-12.8) of admissions for falls were in patients with a secondary diagnosis of glaucoma. This extrapolates to an estimated annual 10,056 admissions at a cost of £28.6 million across the UK. This is an under-estimate of cost, as A&E attendance without admission and outpatient appointments are excluded.Conclusions: At MTW, glaucoma potentially plays a part in around one in eight falls resulting in hospital admission, at considerable personal and financial cost. It is suggested that further work should explore early diagnosis of glaucoma, treatment, and mitigation of falls risk.

The future of canine glaucoma therapy

Canine glaucoma is a group of disorders that are generally associated with increased intraocular pressure (IOP) resulting in a characteristic optic neuropathy. Glaucoma is a leading cause of irreversible vision loss in dogs and may be either primary or secondary. Despite the growing spectrum of medical and surgical therapies, there is no cure, and many affected dogs go blind. Often eyes are enucleated because of painfully high, uncontrollable IOP. While progressive vision loss due to primary glaucoma is considered preventable in some humans, this is mostly not true for dogs. There is an urgent need for more effective, affordable treatment options. Because newly developed glaucoma medications are emerging at a very slow rate and may not be effective in dogs, work toward improving surgical options may be the most rewarding approach in the near term. This Viewpoint Article summarizes the discussions and recommended research strategies of both a Think Tank and a Consortium focused on the development of more effective therapies for canine glaucoma; both were organized and funded by the American College of Veterinary Ophthalmologists Vision for Animals Foundation (ACVO-VAF). The recommendations consist of (a) better understanding of disease mechanisms, (b) early glaucoma diagnosis and disease staging, (c) optimization of IOP-lowering medical treatment, (d) new surgical therapies to control IOP, and (e) novel treatment strategies, such as gene and stem cell therapies, neuroprotection, and neuroregeneration. In order to address these needs, increases in research funding specifically focused on canine glaucoma are necessary.

Miniaturization in Glaucoma Monitoring and Treatment: A Review of New Technologies That Require a Minimal Surgical Approach

In the management of glaucoma, recent and upcoming innovations have the potential to contribute to both the efficacy of intraocular pressure (IOP) monitoring and the number of available treatment options. These new devices and procedures have two things in common: they are part of the trend in medicine towards miniaturization, and they require a limited surgical procedure to become effective. This review focuses on the Eyemate (Argos) intraocular sensor, which offers a new way to reliably measure 24 h IOP, and on intraocular sustained release systems for pharmacological glaucoma therapy. It also briefly reflects on the miniature implants currently used in minimally invasive glaucoma surgery (MIGS).

Supraciliary Microstent in Refractory Open-Angle Glaucoma: Two-Year Outcomes from the DUETTE Trial

PURPOSE

The aim of the study was to report longer term (24-month) outcomes for primary open-angle glaucoma (POAG) patients refractory to medical therapy implanted with a supraciliary microstent (CyPass Micro-Stent, Alcon) in the DUETTE clinical study.

METHODS

Sixty-five eyes were enrolled in this multicenter single-arm trial. Enrolled patients had POAG and intraocular pressure (IOP) >21 mmHg at baseline on 1-4 ocular hypotensive medications. Microstent implantation was performed as stand-alone surgery in these phakic or pseudophakic patients through a standard clear corneal approach. IOP and the use of IOP-lowering medications were monitored in this 1-year extension beyond the 12-month primary endpoint.

RESULTS

Two-year follow-up visits were scheduled to confirm the 12-month results; safety data were obtained for 37 eyes of 35 patients. IOP at the end of the 24-month follow-up was 16.8 mmHg (n = 32), with a mean reduction of 7.7 mmHg from the baseline IOP of 24.5 mmHg (n = 65). Medication use was decreased from an average of 2.1 (baseline) to 1.5 at 24 months. The IOP and medication use at 24 months were consistent with the 12-month results (16.4 mmHg, 1.4 medications) reported previously. The adverse event profile remained as described for the first 12 months postimplantation.

CONCLUSIONS

Placement of a supraciliary microstent provides up to 24 months of effective IOP lowering for medication-refractory POAG patients while, on average, decreasing the requirement for ocular hypotensive medications.