Safety and Efficacy of Microinvasive Glaucoma Surgery

Efficacy of gonioscopy-assisted transluminal trabeculotomy in advanced-age glaucoma patients

BACKGROUND

The prevalence and severity of many etiologies of glaucoma increase with age, often requiring surgery later in life. Surgery in the most aged demographic, however, poses multiple unique physiologic and psychosocial challenges with variable outcomes. In this study, we evaluate the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in an advanced-age population (>85 years of age).

METHODS

This is a single-centre retrospective cohort study of consecutive patients who underwent GATT at or above 85 years of age. This included patients with GATT of any circumferential extent (90°-360°) with or without concurrent phacoemulsification cataract surgery. The primary outcome measure was proportion of successful surgeries at 1 year by the "complete success" criteria (intraocular pressure [IOP] <17 mm Hg on no medications 3 months after surgery with no additional interventions). Secondary outcomes included proportion of successful surgeries by alternative criteria, cross-sectional analyses of IOPs and medication use, and analyses of postoperative complications and interventions.

RESULTS

Forty eyes of 31 patients were included in the study. Mean baseline IOP was 16.75 ± 7.33 mm Hg on 1.60 ± 1.43 classes of medication. At 1 year, the cumulative survival by Kaplan-Meier analysis was 46.6%. There was a statistically significant reduction in IOP at all postoperative time points to a mean of 11.78 ± 3.07 mm Hg at the last follow-up. There were postoperative complications in 18 eyes, with hyphema and corneal edema accounting for the majority.

CONCLUSIONS

This study provides evidence that GATT is a safe and effective intervention in advanced-age glaucoma populations.

Comparison between MIGS with trabeculectomy in the management of open-angle glaucoma with cataract: A systematic review

Age is an important risk factor for both glaucoma and cataract. As global life expectancy continues to rise, the prevalence of concomitant open-angle glaucoma (OAG) and cataracts is increasing. Currently, there is a lack of definitive consensus on the optimal management approach for such individuals. Conventionally, trabeculectomy (Trab) in combination with phacoemulsification is the preferred method. Recent developments in microinvasive glaucoma surgery (MIGS), which offer similar results with fewer complications, provide a new possible approach to this condition. This study aimed to assess the current knowledge of combination surgery in patients with cataract and OAG to provide a comprehensive understanding and help its implementation in clinical settings. A comprehensive systematic search was conducted in May 2021 on five databases (MEDLINE, Embase, SCOPUS, Proquest, EBSCO, and Cochrane Library). The results were filtered for English and human studies but not publication year. All studies published up to May 2021 were reviewed. Newcastle-Ottawa Scale and PEDro scale were used to screen studies for risk of bias where appropriate. Four studies satisfied the inclusion criteria and were subsequently added in this review. Study designs consisted of one RCT and three descriptive studies. Appropriate assessment tools were used; these studies demonstrated moderate to good quality. Postoperative mean IOP, IOP reduction, and qualified success rates were comparable in the Phaco-MIGS (Phaco-endoscopic cyclophotocoagulation (ECP), Phaco-ab interno trabeculectomy (AIT)) and Phaco-Trab group. Severe complication was reported only in the latter. Phaco-MIGS (in particular, trabectome) shows excellent promise as an option for individuals with OAG and concomitant cataract; further research through RCT is required to validate these findings.

Comparative Analysis of Surgical Durations and Fees Across Eight Types of Glaucoma Surgery Performed by a Single Surgeon

The duration of several types of glaucoma surgery and reimbursement amounts per minute of surgery remain unknown. This study compared the surgical duration of glaucoma procedures (ab interno trabeculotomy, PreserFlo, ab externo trabeculotomy, bleb revision, EXPRESS, trabeculectomy, Ahmed, and the Baerveldt implant) and their reimbursement amounts in Japan. We retrospectively analyzed 30 consecutive surgeries of each type of glaucoma surgery. The reimbursement amount per surgical hour was calculated by subtracting the implant cost from the total medical fees. Amounts were converted to dollars based on an exchange rate of 1 USD = 133 JPY. The average surgical time was as follows: ab interno trabeculotomy, 7.8 ± 2.1; PreserFlo, 13.5 ± 4.0; ab externo trabeculotomy, 15.2 ± 4.1; bleb revision, 15.6 ± 2.3; EXPRESS, 16.9 ± 2.7; trabeculectomy, 18.5 ± 3.1; Ahmed, 35.8 ± 8.2; and Baerveldt, 39.2 ± 6.2. The reimbursement amounts after implant deduction were as follows: ab interno trabeculotomy, $1,089; PreserFlo, $1,538; ab externo trabeculotomy, $1,430; bleb revision, $259; EXPRESS, $1,600; trabeculectomy, $1,774; Ahmed, $1,600; and Baerveldt, $1,765. Reimbursement amounts per minute varied, with the highest and lowest for ab interno trabeculotomy and bleb revision at $140 per minute and $17 per minute, respectively. Reimbursement amounts per minute of surgery for eight types of glaucoma surgery vary by up to eightfold.

The Evolution and Current Landscape of Minimally Invasive Glaucoma Surgeries: A Review

This review examines the evolution, current status, and future potential of minimally invasive glaucoma surgeries (MIGS), a significant advancement in the treatment of glaucoma, a leading cause of irreversible blindness. MIGS offer a less invasive alternative to traditional glaucoma surgeries, primarily aimed at reducing intraocular pressure, minimizing tissue trauma, and providing a safer profile. With the emergence of devices such as the Trabectome, iStent, and others, MIGS have expanded the surgical toolkit, allowing personalized, patient-centered care. Despite their advantages, MIGS face challenges such as efficacy in severe cases, long-term data, and accessibility. Ongoing research and technological innovations continue to refine their capabilities and applications, promising to further transform glaucoma management and patient outcomes. This paper provides an in-depth analysis of MIGS, reflecting on their impact and contemplating future directions in this dynamically evolving field.

First-in-Human Safety Study of Femtosecond Laser Image-Guided Trabeculotomy for Glaucoma Treatment: 24-month Outcomes

Purpose

Pilot study to evaluate adverse events and intraocular pressure (IOP)-lowering of a novel, noninvasive glaucoma procedure, femtosecond laser, image-guided, high-precision trabeculotomy (FLIGHT).

Design

Prospective, nonrandomized, single-center, interventional, single-arm clinical trial.

Participants

Eighteen eyes from 12 patients with open-angle glaucoma.

Methods

Eighteen eyes from 12 patients underwent FLIGHT, creating a single channel measuring 500-μm wide by 200-μm high through the trabecular meshwork and into Schlemm's canal. Adverse events, IOP, and other parameters were evaluated out to 24 months.

Main Outcome Measures

Outcomes were the rates and types of adverse events and the rate of postprocedure best-corrected visual acuity loss (≥ 2 lines) compared with baseline. Efficacy outcomes were reduction in mean intraocular pressure (IOP) with respect to baseline and the percentage of eyes with a ≥ 20% reduction in IOP.

Results

Eighteen eyes from 12 patients were enrolled in the study; 11 patients (17 eyes) returned at 24 months. There were no serious adverse events related to the laser treatment. Well-defined channels were clearly visible at 24 months by gonioscopy and anterior segment OCT, with no evidence of closure. At 24 months, the mean IOP was reduced by 34.6% from 22.3 ± 5.5 to 14.5 ± 2.6 mmHg (P < 5e-5), with an average of 2.0 ± 1.2 hypotensive medications compared with 2.2 ± 1.1 at baseline (P = 0.22). Fourteen out of the 17 study eyes (82.3%) achieved a ≥ 20% reduction in IOP at 24 months when compared with baseline.

Conclusion

The FLIGHT system demonstrated a favorable safety profile in this initial pilot study, with no device-related serious adverse events. The channels appeared patent at 24 months, indicating medium-term durability.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

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.

Real-World Outcomes of Canaloplasty and Trabeculotomy Combined with Cataract Surgery in Eyes with All Stages of Open-Angle Glaucoma

Purpose

To evaluate the long-term safety and efficacy of sequential canaloplasty and trabeculotomy combined with cataract surgery in patients with mild, moderate, and advanced open-angle glaucoma.

Patients and Methods

Case records of 171 consecutive patients (171 eyes) who had undergone cataract surgery followed by canaloplasty (≥180°) and trabeculotomy (≥90°) for mild, moderate, or advanced open-angle glaucoma (Shaffer grade ≥3) using the OMNI Surgical System (Sight Sciences, Inc., Menlo Park, CA) were analyzed retrospectively. Efficacy endpoints included change in mean IOP and number of medications from baseline to postoperative 12- and 24-months for the overall dataset and stratified by each stage of glaucoma. Kaplan-Meier survival analysis of success (eyes that did not require secondary surgical interventions (SSI)) by postoperative 24 months was also performed.

Results

Postoperatively, there was a statistically significant reduction in IOP (baseline of 17.2 mmHg on 1.3 medicines reduced to 14.3 on 0.8 medicines (12 months) and 14.0 on 0.9 medicines (24 months), p<0.001 for both time points). Eyes with advanced glaucoma (N=63) maintained significant IOP reduction (17.8 mmHg on 1.6 medicines at baseline reduced to 13.6 mmHg on 1.3 medicines (12 months) and 13.0 on 1.5 medicines (24 months), p<0.001). Kaplan-Meier analysis showed a 93.0% survival probability for the avoidance of SSI at 2 years after surgery.

Conclusion

Canaloplasty and trabeculotomy combined with cataract surgery provided effective IOP reduction for eyes with all stages of glaucoma at postoperative 12 and 24 months, and the procedure yielded a 93% survival rate for SSI avoidance at 2 years.

Minimally Invasive Glaucoma Surgery: A Review of the Literature

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

Gel Stent Versus Trabeculectomy: The Randomized, Multicenter, Gold-Standard Pathway Study (GPS) of Effectiveness and Safety at 12 Months

PURPOSE

To compare effectiveness and safety of the gel stent to trabeculectomy in open-angle glaucoma (OAG).

DESIGN

Prospective, randomized, multicenter, noninferiority study.

METHODS

Patients with OAG and intraocular pressure (IOP) 15 to 44 mm Hg on topical IOP-lowering medication were randomized 2:1 to gel stent implantation or trabeculectomy. Primary end point (surgical success): percentage of patients at month 12 achieving ≥20% IOP reduction from baseline without medication increase, clinical hypotony, vision loss to counting fingers, or secondary surgical intervention (SSI) in a noninferiority test with 24% margins. Secondary end points (month 12) included mean IOP and medication count, postoperative intervention rate, visual recovery, and patient-reported outcomes (PROs). Safety end points included adverse events (AEs).

RESULTS

At month 12, the gel stent was statistically noninferior to trabeculectomy (between-treatment difference [Δ], -6.1%; 95% CI, -22.9%, 10.8%); 62.1% and 68.2% achieved the primary end point, respectively (P=.487); mean IOP and medication count reductions from baseline were significant (P<.001); and the IOP change-related Δ (2.8 mm Hg) favored trabeculectomy (P=.024). The gel stent resulted in fewer eyes requiring in-office postoperative interventions (P=.024 after excluding laser suture lysis), faster visual recovery (P≤.048), and greater 6-month improvements in visual function problems (ie, PROs; P≤.022). The most common AEs were reduced visual acuity at any time (gel stent, 38.9%; trabeculectomy, 54.5%) and hypotony (IOP <6 mm Hg at any time) (gel stent, 23.2%; trabeculectomy, 50.0%).

CONCLUSIONS

At month 12, the gel stent was statistically noninferior to trabeculectomy, per the percentage of patients achieving ≥20% IOP reduction from baseline without medication increase, clinical hypotony, vision loss to counting fingers, or SSI. Trabeculectomy achieved a statistically lower mean IOP, numerically lower failure rate, and numerically lower need for supplemental medications. The gel stent resulted in fewer postoperative interventions, better visual recovery, and fewer AEs.

Subconjunctival filtration in evolution: current evidence on MicroShunt implantation for treating patients with glaucoma

BACKGROUND

Although traditional surgical procedures for glaucoma (such as trabeculectomy and tube-shunt implantation) can significantly reduce intraocular pressure (IOP), they are associated with numerous complications, some of which are vision-threatening, or involve prolonged recovery or a highly intensive postoperative course. Micro-invasive glaucoma surgery (MIGS) procedures have shown better safety but reduced efficacy in achieving target IOP. Combinations of these methods have led to the development of subconjunctival micro-invasive procedures with safety comparable to traditional surgery and greater efficacy than minimally invasive methods. This review describes the use of one of these devices, the poly(styrene-block-isobutylene-block-styrene) (SIBS)-based PreserFlo MicroShunt (Santen, Emeryville, CA), in the surgical treatment of patients with glaucoma.

MAIN TEXT

The MicroShunt is an 8.5-mm tube made of an inert polymer with no endplate, an internal diameter of 70 μm, and fins intended to prevent peritubular flow and anchor the device within the sclera to prevent proximal migration into the eye. Following ab externo implantation, the tube provides a conduit for flow of aqueous humor from the anterior chamber into the subconjunctival/sub-Tenon space. Clinical trials to date have shown that, when paired with mitomycin C (MMC) treatment, MicroShunt implantation significantly reduced both IOP and the number of glaucoma medications. These IOP-lowering results were found both when surgery was performed alone and with phacoemulsification. The MicroShunt also showed a safety profile comparable to that of traditional filtering surgery.

CONCLUSIONS

The MicroShunt and other novel subconjunctival procedures have shown substantial IOP reductions while mitigating hypotony-related complications. MMC, which modulates fibrosis and scarring postoperatively, is essential to surgical success. Randomized, long-term clinical trials will further clarify the role of controlled micro-incisional device-assisted ab externo glaucoma filtering surgery in long-term glaucoma management.

"Ab Interno" Surgery of the Schlemm's Canal in Postuveitic Glaucoma Patients

BACKGROUND

Patients with uveitis have a higher risk of developing glaucoma not only because of the disease by itself, but also because of the ongoing corticosteroid therapy. The pathogenesis of uveitic glaucoma is characterized by a complex of biochemical and cellular processes, as well as morphological changes in the trabecular meshwork. Treatment of secondary chronic glaucoma is challenging and often requires different approaches and solutions.

PURPOSE

To present the "ab interno" procedure of the Schlemm's canal (SC) performed with the help of TrabEx+ (MST, Redmond, WA, USA) in postuveitic glaucoma patients.

METHODS

The observed group included patients with postuveitic secondary glaucoma, which consisted of 12 pseudophakic patients (12 eyes). Patients are with intraocular pressure higher than 25 mmHg and on maximal local therapy. Due to insufficient conservative control on IOP, surgical solutions are needed. We describe a new, minimally invasive surgical procedure-the technique of the operation, the postoperative results and complications.

RESULTS

We present the achieved intraocular pressure (on the first day, 2 weeks, 1 month, 6, 8 12 and 18 months). The morphology of the trabecular area was demonstrated by gonioscopy. The effects of the therapy on the glaucoma progression, was evaluated with perimetry and OCT.

DISCUSSION

The following procedure is a minimally invasive procedure and provides good control of intraocular pressure. Aqueous veins in the conjunctiva are significantly preserved compared to conventional filtration trabeculectomy. This potentially modulates the physiological outflow pathways by ablating trabeculum strip the cause of increased outflow resistance-the inner wall of the SC.

CONCLUSION

Removal of the inner wall of the SC, using Trabex+ (MST, Redmond, WA, USA), demonstrates promising results in the selected patients with a minimally invasive nature.

Outcomes of Microhook ab Interno Trabeculotomy in Consecutive 36 Eyes with Uveitic Glaucoma

Microhook trabeculotomy (μLOT), recently developed by Tanito belongs to minimally invasive glaucoma surgery and contributes to intraocular pressure (IOP) control in eyes with glaucoma resistant to medical therapy. In this study, we aimed to investigate the effectiveness and safety of μLOT for uveitic glaucoma. The medical records of consecutive 36 eyes from 30 patients who underwent μLOT and were followed up over post-operative 1 year were reviewed. The surgical success (IOP = 5–20 mmHg and ΔIOP ≥ 20% with additional anti-glaucoma drugs) was achieved in 67% of eyes at post-operative 12 months. The median IOP significantly decreased from 30.5 mmHg pre-operatively to 15 mmHg at 12 months post-operatively (p = 0.001), and the median glaucoma drug score changed from 5 pre-operatively to 2.5 at 12 months post-operatively (p = 0.301). Intraocular inflammation scores at post-operative 6 weeks did not show a significant worsening as compared to pre-operatively, and 8 (22%) eyes exhibited exacerbation of inflammation during the 12-month follow-up period. Post-operative complications were confirmed in 58% of eyes, but most of them were mild and transient or successfully managed. With its favorable benefit–risk profile, μLOT would be an option worth considering as the first glaucoma surgery for uveitic glaucoma.

A Review of Excisional Goniotomy Performed with the Kahook Dual Blade for Glaucoma Management

Aim

To review the published literature describing clinical outcomes of excisional goniotomy using the Kahook Dual Blade (KDB) for the management of glaucoma.

Background

A family of less invasive glaucoma procedures—including excisional goniotomy with the KDB—has been developed to provide moderate reductions in intraocular pressure and/or medication burden in eyes with therapeutic needs that may not warrant the risks associated with more traditional procedures such as trabeculectomy and tube-shunt implantation. This review's goal is to synthesize the existing literature into a compendium of excisional goniotomy's indications, technique, efficacy and safety outcomes, and optimal place in glaucoma management.

Review results

Excisional goniotomy with the KDB effectively lowers IOP and reduces the medication burden in eyes with POAG and other forms of glaucoma across the spectrum of both baseline IOP and disease severity. The procedure exhibits a safety profile that is on par with other angle-based surgical interventions and enhanced safety compared to filtration procedures. It can be performed by comprehensive ophthalmologists as well as glaucoma specialists. This procedure as a standalone operation delivers IOP reductions consistent with filtration surgery, and in combination with cataract surgery delivers both IOP and medication reductions at least as great as other minimally invasive procedures.

Conclusion

Given the broad base of evidence supporting its use in a wide variety of clinical scenarios, excisional goniotomy with the KDB can play a meaningful role in the achievement of patient-specific glaucoma therapy goals.

Clinical significance

These aggregate findings support the efficacy and safety of excisional goniotomy with the KDB and clarify the patient profiles best suited for this procedure.

How to cite this article

Dorairaj S, Radcliffe NM, Grover DS, et al. A Review of Excisional Goniotomy Performed with the Kahook Dual Blade for Glaucoma Management. J Curr Glaucoma Pract 2022;16(1):59–64.

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.

A novel use of the endoscopic cyclophotocoagulative probe for the management of excisional goniotomy induced chronic recurrent hyphema

Purpose

To describe the management of a case of chronic, recurrent hyphema following excisional goniotomy with the Kahook Dual Blade.

Observations

One week following uncomplicated surgery, the patient presented with eye pain, elevated intraocular pressure, and layered hyphema. The hyphema resolved with conservative measures but recurred several times with similar symptoms over the next several months. An attempt to stenose the "oozing" collector channel using the argon laser was unsuccessful. Treatment of the angle with an endoscopic semi-conductor diode laser (endoscopic cyclophotocoagulative or ECP) probe successfully altered the angle preventing further episodes of recurrent hyphema. The primary glaucoma procedure failed necessitating a filtering procedure.

Conclusions and importance

Clinician should be aware of this potential complication, its treatment options, and outcomes.

Ocular benzalkonium chloride exposure: problems and solutions

Preservatives in multidose formulations of topical ophthalmic medications are crucial for maintaining sterility but can be toxic to the ocular surface. Benzalkonium chloride (BAK)-used in approximately 70% of ophthalmic formulations-is well known to cause cytotoxic damage to conjunctival and corneal epithelial cells, resulting in signs and symptoms of ocular surface disease (OSD) including ocular surface staining, increased tear break-up time, and higher OSD symptom scores. These adverse effects are more problematic with chronic exposure, as in lifetime therapy for glaucoma, but can also manifest after exposure as brief as seven days. Multiple strategies are available to minimize or eliminate BAK exposure, among them alternative preservatives, preservative-free formulations including sustained release drug delivery platforms, and non-pharmacological therapies for common eye diseases and conditions. In this paper, we review the cytotoxic and clinical effects of BAK on the ocular surface and discuss existing and emerging options for ocular disease management that can minimize or eliminate BAK exposure.

Outcomes of initial and repeat micro-pulse transscleral cyclophotocoagulation in adult glaucoma patients

BACKGROUND

Micro-pulse transscleral cyclophotocoagulation (MP-TSCPC) has continued to gain popularity as a treatment in adult glaucoma patients. Thus far there is limited evidence reporting the efficaciousness and safety of retreatment.

OBJECTIVE

To evaluate safety and efficacy of primary and repeat MP-TSCPC procedures.

METHODS

Thirty-four of 67 eyes who failed to achieve target IOP from initial MP-TSCPC underwent repeat MP-TSCPC and followed for a minimum of 6 months. All treatments were performed using the laser power of 2000 or 2250 mW, duration of 100-200 s, and a velocity 16-20 s per hemisphere swipe. Success criteria were defined as intraocular pressure (IOP) reduction of greater than 20% from baseline or any medication reduction without additional glaucoma procedures at 6 months after repeat MP-TSCPC. The 6-month success rate after repeat MP-TSCPC was also compared to that of initial MP-TSCPC in the same group of eyes.

RESULTS

Mean baseline IOP before the repeat MP-TSCPC was 23.0 + /- 5.3 on 3.0 + /- 1.4 medications. At 6 months, mean post-op IOP was 18.2 + /- 5.4 (21.9% reduction, p < 0.002), with mean medication staying relatively the same (p = .976). Success rate was increased from 23.5% to 44.1% with the repeat procedure compared to that of initial procedure (p = 0.123). Mean IOP reduction was also greater after repeat MP-TSCPC (18.7%, p < 0.002) when compared to initial MP-TSCPC (10.4%). No adverse events occurred.

CONCLUSIONS

MP-TSCPC is a safe and effective non-invasive means to lower IOP in a variety of glaucoma patients. While over 50% (34/67) of eyes required repeat MP-TSCPC, repeat treatment resulted in greater success rates and IOP reduction without any adverse events when using the total energy between 112 and 150 J.

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.

Surgical Outcomes of Combined 2nd-Generation Trabecular Microbypass (iStent Inject) and Cataract Surgery for the Treatment of Primary Open-Angle Glaucoma in the Saudi Population

INTRODUCTION

To investigate the 24-month efficacy and safety of iStent inject trabecular microbypass system implantation combined with phacoemulsification in subjects with primary open-angle glaucoma (POAG) and concomitant cataract.

METHODS

This prospective, uncontrolled, interventional case series included 36 eyes (29 subjects) with POAG of mild to moderate severity and coexisting cataract that underwent combined phacoemulsification and implantation of a second-generation trabecular microbypass stent (iStent inject®). Main outcome measures involved mean intraocular pressure (IOP), number of antiglaucoma medications, and proportional analysis of eyes with IOP ≤ 18 mmHg or ≤ 15 mmHg, or with 0 or ≥ 2 glaucoma medications. Secondary outcome measures involved the cup-to-disc ratio, corrected distance visual acuity (CDVA), and adverse issues.

RESULTS

In 36 eyes, the mean IOP at baseline was 18.28 ± 2.87 mmHg, which decreased to 14.24 ± 1.36 (22.1%) and 14.46 ± 1.56 mmHg (20.9%) at 18 and 24 months, respectively (p < 0.001). At the last follow-up, 100% of eyes had an IOP ≤ 18 mmHg (vs. 50% preoperatively), and 75.7% of eyes had an IOP ≤ 15 mmHg (vs. 16.7% preoperatively); 58.3% of eyes achieved ≥ 20% IOP reduction from preoperative status. At baseline, eyes were treated with a mean of 2.35 ± 1.18 medications, which was reduced to 0.80 ± 1.04 (66% reduction) and 0.69 ± 0.95 medications (70.6% reduction) at 18 and 24 months, respectively (p < 0.001). At the last follow-up, 54.1% of eyes were medication-free (vs. 0% preoperatively) and 24.3% of eyes were treated with ≥ 2 medications (vs. 64.9% preoperatively). This combined procedure demonstrated an excellent safety profile with no reported intraoperative complications or adverse events; CDVA was maintained throughout the entire follow-up period.

CONCLUSIONS

This real-world series demonstrated that iStent inject device implantation at the time of phacoemulsification is a safe and effective method to decrease IOP and the necessity for antiglaucoma medications in patients with mild-to-moderate POAG and cataract; no associated vision-threatening complications were noted.

Standalone Trabeculotomy and Viscodilation of Schlemm's Canal and Collector Channels in Open-Angle Glaucoma Using the OMNI Surgical System: 24-Month Outcomes

Purpose

Intraocular pressure (IOP), medication outcomes at 24 months following trabeculotomy/viscodilation using the OMNI® surgical system as a standalone procedure in medically uncontrolled mild-moderate open-angle glaucoma (OAG).

Setting

Surgical center (Duesseldorf, Germany).

Design

Retrospective analysis. IOP and medication data were collected before surgery and through 24 months. Safety data included adverse events and the need for additional surgery.

Methods

Pre-op medication washout. Goldmann tonometry. Number of medications and adverse events (AE) at each time point. Primary outcomes: changes in IOP and medications. Two-sided paired t-tests compare values at each follow-up with baseline, significance p = 0.05. Secondary outcomes: proportion of eyes with IOP reduction of ≥20%, on fewer medications, and medication-free at each time point.

Results

This analysis included data from 38 eyes of 27 subjects. Mean (standard deviation) baseline IOP was 24.6 (3.0) mmHg and through 24 months ranged from 12.6 to 14.9 mmHg (p < 0.0001), representing reductions of 10.0-12.0 mmHg. Mean medications were 1.9 (baseline) and through 24 months ranged from 0.0 to 0.5 (70.6-100% reduction) (p < 0.0001). At Month 24, mean IOP was 14.9 mmHg (-10.0 mmHg), and 100% of eyes achieved IOP reduction >20% from baseline; mean medication use was 0.5 (-1.4 medications, p < 0.0001), 84.6% of eyes using >1 fewer medication, and 57.7% were medication-free. The most common adverse event was intraoperative hyphema (44.7%); all resolved spontaneously. There were two secondary procedures for IOP control.

Conclusion

The OMNI surgical system provides clinically relevant and statistically significant reductions in both IOP and medications with an excellent safety profile and should be considered in phakic or pseudophakic eyes with mild-moderate OAG requiring IOP or medication reduction, or both.

Long term outcome of combined phacoemulsification and excisional goniotomy with the Kahook Dual Blade in different subtypes of glaucoma

To characterize changes in intraocular pressure (IOP) and IOP-lowering medications through up to 2 years of follow-up in patients undergoing combined phacoemulsification and excisional goniotomy with the Kahook Dual Blade (phaco-KDB), with simultaneous goniosynechialysis in cases of angle-closure glaucoma. Prospective, non-comparative, interventional case series. Consecutive patients with medically-treated glaucoma and visually-significant cataract underwent combined surgery. Analysis was conducted on open-angle (OAG) and angle-closure (ACG) glaucoma groups separately. Thirty-seven patients with OAG (24 with primary OAG and 13 with pseudoexfoliation glaucoma) and 11 with ACG were enrolled. In OAG eyes, mean (standard error) baseline IOP was 21.1 (0.9) mmHg and through 24 months of follow-up was reduced by 6.4-7.7 mmHg (24.6-32.1%; p ≤ 0.0001 at all time points). In ACG eyes, mean baseline IOP was 20.8 (1.6) mmHg and was reduced by 6.1-8.77 mmHg (23.4-39.0%; p ≤ 0.0353). Mean medications were reduced by 61.9-89.1% (p ≤ 0.0001) in OAG eyes and by 56.3-87.3% (p ≤ 0.0004) in ACG eyes. Phaco-KDB significantly lowered IOP ~ 30% and medications by > 50% through 24 months. This combined procedure provides meaningful long-term reductions in IOP and need for IOP-lowering medication and does not adversely affect visual rehabilitation in eyes with cataract and glaucoma.

Aging, But Not Sex and Genetic Diversity, Impacts the Pathobiology of Bacterial Endophthalmitis

Purpose

Age, sex, and genetics are important biological variables in determining an individual's susceptibility or response to infectious agents; however, their role has not been evaluated in intraocular infections. In this study, we comprehensively examined the impact of these host biological factors in the pathogenesis of experimental bacterial endophthalmitis.

Methods

Endophthalmitis was induced by intravitreal injection of bacteria (Staphylococcusaureus) in the eyes of male and female C57BL/6 mice of different ages: group I (young, 6–8 weeks), group II (mid-age, 18–20 weeks), and group III (old, 1 year). Highly heterogeneous outbred J:DO mice were used for genetic diversity analysis. Eyes were subjected to clinical examination, retinal function testing using electroretinography (ERG), histopathological analysis (hematoxylin and eosin staining), and bacterial burden estimation. The levels of inflammatory mediators were measured using qPCR and ELISA, and the infiltration of neutrophils was determined by flow cytometry.

Results

Both inbred C57BL/6 and diversity outbred (J:DO) mice were equally susceptible to S. aureus endophthalmitis, as evidenced by a time-dependent increase in clinical scores, bacterial burden, intraocular inflammation, and retinal tissue damage, in addition to decreased retinal function. However, no significant differences were observed in disease severity and innate responses in male versus female mice. Older mice (group III) exhibited higher clinical scores coinciding with increased bacterial proliferation and intraocular inflammation, resulting in enhanced disease severity. Moreover, bone-marrow-derived macrophages from old mice exhibited reduced phagocytic activity but increased inflammatory response toward S. aureus challenge.

Conclusions

Age, but not sex, is an important biological variable in bacterial endophthalmitis. Identification of pathways underlying altered innate immunity and impaired bacterial clearance in aging eyes could provide new insights into the pathobiology of intraocular infections in elderly patients.

Risk factors leading to trabeculectomy surgery of glaucoma patient using Japanese nationwide administrative claims data: a retrospective non-interventional cohort study

BACKGROUND

Early recognition and management of baseline risk factors may play an important role in reducing glaucoma surgery burdens. However, no studies have investigated them using real-world data in Japan or other countries. This study aimed to clarify the risk factors leading to trabeculectomy surgery, which is the most common procedure of glaucoma surgery, of glaucoma patient using the Japanese nationwide administrative claims data associated with the diagnosis procedure combination (DPC) system.

METHODS

It was a retrospective, non-interventional cohort study. Data were collected from patients who were admitted to DPC participating hospitals, nationwide acute care hospitals and were diagnosed with glaucoma between 2012 to 2018. The primary outcome was the risk factors associated with trabeculectomy surgery. The association between baseline characteristics and trabeculectomy surgery was identified using multivariable logistic regression analysis by comparing patients with and without trabeculectomy surgery. Meanwhile, the secondary outcomes included the rate of comorbidities, the rate of concomitant drug use and the treatment patterns of glaucoma eye drops at the index admission. Among patients with trabeculectomy surgery, the risk factors leading to cataract surgery were also evaluated as subgroup analysis.

RESULTS

A total of 29,599 patients included in the analysis, 12,038 and 17,561 patients were in the glaucoma surgery and non-glaucoma surgery cohorts, respectively. The factors associated with the increase in trabeculectomy surgery were having allergies, taking concomitant drugs including cancer, depression, ischemic heart disease and peptic ulcer, being diagnosed with primary open-angle glaucoma and longer length of stay in hospital. In contrast, the factors associated with the decrease in trabeculectomy surgery were having hypertension, taking hypertension drug, age ≥ 80 and female.

CONCLUSIONS

Special focus on Japanese patients with glaucoma who have allergy-related comorbidities or take immune, nervous, circulatory or gastrointestinal system-related concomitant drugs seems to be desirable.

12-month interim results of a prospective study of patients with mild to moderate open-angle glaucoma undergoing combined viscodilation of Schlemm's canal and collector channels and 360° trabeculotomy as a standalone procedure or combined with cataract surgery

PURPOSE

To characterize clinical outcomes of combined viscodilation of Schlemm's canal and collector channels and 360° trabeculotomy as a standalone procedure or combined with cataract surgery in eyes with mild to moderate open-angle glaucoma (OAG).

METHODS

In this prospective case series, the OMNI glaucoma surgical platform (Sight Sciences, Menlo Park, CA) was utilized to perform the procedure either combined with phacoemulsification or as a standalone procedure. Changes from baseline in intraocular pressure (IOP) and IOP-lowering medications were evaluated through the first 12 months of a planned 24-month follow-up period.

RESULTS

Among 17 eyes of 15 subjects, mean IOP was reduced from 20.4 mmHg to 12.7-13.7 mmHg through 12 months of follow-up (p < 0.001 at every time point) and mean medications reduced from 2.5 to 0.1-0.6 (p < 0.001 at every time point). IOP reductions in eyes undergoing standalone surgery were approximately 2-4 mmHg greater at each time point compared to eyes undergoing surgery combined with phacoemulsification; this may be related to a higher baseline IOP in the former eyes (22.1 vs 18.5 mmHg). Six eyes developed hyphema, of which three required washout for elevated IOP on the first postoperative day; six additional eyes had IOP elevations that resolved with medical management.

CONCLUSION

Viscodilation of Schlemm's canal and collector channels paired with ab interno trabeculotomy performed with a single integrated instrument (OMNI), whether as standalone or combined with phacoemulsification, effectively lowers both IOP and the need for IOP-lowering medications through 12 months of follow-up.

Canaloplasty and Trabeculotomy Combined with Phacoemulsification in Open-Angle Glaucoma: Interim Results from the GEMINI Study

PURPOSE

To report interim 6-month safety and efficacy outcomes of 360° canaloplasty and 180° trabeculotomy using the OMNI® Surgical System concomitantly with phacoemulsification in patients with open-angle glaucoma (OAG).

SETTING

Fifteen multi-subspecialty ophthalmology practices and surgery centers located in 14 states (Alabama, Arizona, Arkansas, Florida, Georgia, Iowa, Kansas, Montana, Nebraska, North Dakota, Oklahoma, Pennsylvania, Texas, and Wisconsin).

DESIGN

Prospective, multicenter, IRB approved study of patients treated with canaloplasty (360°) and trabeculotomy (180°). Eligible patients had cataract and mild-moderate OAG with intraocular pressure (IOP) ≤33 mmHg on 1 to 4 hypotensive medications.

METHODS

Medication washout prior to baseline diurnal IOP (Goldmann). Effectiveness outcomes included mean IOP and medications. Safety outcomes included adverse events (AE), best corrected visual acuity (BCVA) and secondary surgical interventions (SSI). Analysis includes descriptive statistics and t-tests evaluating change from baseline.

RESULTS

A total of 137 patients were enrolled and treated. Mean diurnal IOP after washout was 23.8 ± 3.1 mmHg at baseline. At month 6, 78% (104/134) were medication free with IOP of 14.2 mmHg, a mean reduction of 9.0 mmHg (38%). 100% (104/104) had a ≥ 20% reduction in IOP and 86% (89/104) had IOP ≥6 and ≤18 mmHg. The mean number of medications at screening was 1.8 ± 0.9 and 0.6 ± 1.0 at month 6. AE included transient hyphema (4.6%) and IOP elevation ≥10 mmHg (2%). There were no AE for loss of BCVA or recurring hyphema. There were no SSI.

CONCLUSION

Canaloplasty followed with trabeculotomy and performed concomitantly with phacoemulsification has favorable intra and perioperative safety, significantly reduces IOP and anti-glaucoma medications through 6 months in eyes with mild-moderate OAG.

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.

Preclinical Investigation of Goniotomy Using Four Different Techniques

PURPOSE

To evaluate the tissue-level effects of goniotomy techniques on human trabecular meshwork (TM).

DESIGN

Laboratory investigation.

METHODS

The TM from human cadaveric corneal rim tissue was treated using 4 techniques: (1) microvitreoretinal (MVR) blade; (2) 360° trabeculotomy with 5-0 prolene suture; (3) the Kahook Dual Blade (KDB) Glide® device; (4) TrabEx™ device; tissue samples underwent standard histologic processing with H&E stain followed by comparative analyses.

RESULTS

The MVR blade exhibited incision of TM extending into the scleral wall. The TrabEx device removed a small portion of TM with large leaflet tissue remnants in all treated areas. 360° suture trabeculotomy resulted in incision of the TM proximate to Schwalbe's line with no excised tissue evident in all treated areas. Areas treated with the KDB Glide device resulted in nearly complete excision of TM without injury to surrounding tissues.

CONCLUSION

The various methods used for performing goniotomy or trabeculotomy resulted in varying degrees of incision or excision of TM. Only the KDB Glide device resulted in reliable excision of TM with the other devices producing incision or variable excision of tissue. Clinical correlation is required to better understand the implications of the current findings when using these methods to lower intraocular pressure in eyes with glaucoma.

A novel suprachoroidal microinvasive glaucoma implant: in vivo biocompatibility and biointegration

Background

A major challenge for any glaucoma implant is their ability to provide long-term intraocular pressure lowering efficacy. The formation of a low-permeability fibrous capsule around the device often leads to obstructed drainage channels, which may impair the drainage function of devices. These foreign body-related limitations point to the need to develop biologically inert biomaterials to improve performance in reaching long-term intraocular pressure reduction. The aim of this study was to evaluate in vivo (in rabbits) the ocular biocompatibility and tissue integration of a novel suprachoroidal microinvasive glaucoma implant, MINIject™ (iSTAR Medical, Wavre, Belgium).

Results

In two rabbit studies, no biocompatibility issue was induced by the suprachoroidal, ab-externo implantation of the MINIject™ device. Clinical evaluation throughout the 6 post-operative months between the sham and test groups were similar, suggesting most reactions were related to the ab-externo surgical technique used for rabbits, rather than the implant material itself. Histological analysis of ocular tissues at post-operative months 1, 3 and 6 revealed that the implant was well-tolerated and induced only minimal fibroplasia and thus minimal encapsulation around the implant. The microporous structure of the device became rapidly colonized by cells, mostly by macrophages through cell migration, which do not, by their nature, impede the flow of aqueous humor through the device. Time-course analysis showed that once established, pore colonization was stable over time. No fibrosis nor dense connective tissue development were observed within any implant at any time point. The presence of pore colonization may be the process by which encapsulation around the implant is minimized, thus preserving the permeability of the surrounding tissues. No degradation nor structural changes of the implant occurred during the course of both studies.

Conclusions

The novel MINIject™ microinvasive glaucoma implant was well-tolerated in ocular tissues of rabbits, with observance of biointegration, and no biocompatibility issues. Minimal fibrous encapsulation and stable cellular pore colonization provided evidence of preserved drainage properties over time, suggesting that the implant may produce a long-term ability to enhance aqueous outflow.

Predictors of Intraocular Pressure Lowering after Phacoemulsification and iStent Implantation

PURPOSE

To explore the demographic and clinical variables associated with intraocular pressure (IOP) lowering after cataract extraction (CE) alone or CE in combination with the iStent (Glaukos Corporation) placement (CE+IS).

DESIGN

Retrospective data extraction and survival analysis of consecutive patients identified over a 2-year period.

PARTICIPANTS

Patients with mild to moderate glaucoma who underwent CE (48 eyes of 32 patients) or CE+IS (61 eyes of 37 patients) were analyzed.

METHODS

Inability to reduce the number of medications or the IOP by at least 20% compared with baseline on 2 consecutive visits was considered surgical failure. Using Cox proportional hazards models, survival analysis was performed, and demographic and clinical variables were evaluated as risk factors.

MAIN OUTCOME MEASURES

Time to failure after surgical procedure.

RESULTS

CE+IS had lower odds of failure than CE alone (hazard ratio [HR], 2.01; P = 0.047). In White patients, CE+IS showed greater odds of success compared with CE alone (HR, 2.86; P = 0.007). For non-White patients, no difference was found in the outcomes for the 2 procedures (HR, 0.59; P = 0.48). In the multivariate analysis, non-White race (HR, 8.75; P = 0.0002) and longer axial length (HR, 1.61; P = 0.03) were associated with greater hazard of failure after CE+IS. In the CE group, greater odds of failure were associated with steeper corneal curvature (HR, 1.74; P = 0.008), shallower anterior chamber (HR, 0.22; P = 0.008), and longer axial length (HR, 1.58; P = 0.01).

CONCLUSIONS

Addition of the iStent to CE improved the duration of IOP lowering in White patients, but not in non-White patients. Associations between IOP lowering after CE and biometric parameters may allow for leveraging these clinical parameters for better case selection for these procedures.

Trabectome, trabecular aspiration and phacoemulsification in a triple procedure for treating exfoliation glaucoma: A long-term follow-up

PURPOSE

This study investigates the long-term intraocular pressure (IOP) lowering potential, risk profile and success rate of a triple procedure comprising phacoemulsification, trabecular aspiration and trabectome (Microsurgical Technology, Redmond, WA, USA) for treating exfoliation glaucoma.

METHODS

A total of 117 eyes of 117 patients with exfoliation glaucoma underwent a combination of phacoemulsification, trabectome and trabecular aspiration. They were followed up for up to 7 years. The success rates were designated according to criteria based on the Tube versus Trabeculectomy Study and the World Glaucoma Association guidelines: A (no resurgery); B/C (IOP < 21/18 mmHg, no resurgery, IOP reduction > 20%); D (IOP ⩽ 15 mmHg, no resurgery, IOP reduction ⩾ 40%).

RESULTS

The mean follow-up period was 46 months. IOP showed a 38% reduction from 24.5 ± 6.1 to 15.2 ± 3.6 mmHg (p < 0.0001). The Medication Score decreased by 23% from 2.2 ± 0.9 to 1.7 ±1.0 (p < 0.0001). The success rates were 87, 76, 74 and 38% according to criteria A, B, C and D. In eyes with an initial IOP of >30 mmHg, a 57% reduction from 34.2 ± 4.4 to 14.8 ± 3.2 mmHg (p < 0.0001) was observed, and the success rates were 91, 91, 82 and 59% for criteria A, B, C and D, respectively.

DISCUSSION

We conclude that the triple procedure may effectively lower IOP in patients with exfoliation glaucoma over a mean follow-up period of 46 months without significant side effects. Therefore, the triple procedure may serve as first-line surgery for patients with exfoliation and cataract, even with a high initial IOP.

Trends in Glaucoma Surgeries Performed by Glaucoma Subspecialists versus Nonsubspecialists on Medicare Beneficiaries from 2008 through 2016

PURPOSE

To characterize the use of laser and incisional glaucoma surgeries among Medicare beneficiaries from 2008 through 2016 and to compare the use of these surgeries by glaucoma subspecialists versus nonsubspecialists.

DESIGN

Retrospective, observational analysis.

PARTICIPANTS

Medicare beneficiaries (n = 1 468 035) undergoing ≥1 laser or incisional glaucoma surgery procedure during 2008 through 2016.

METHODS

Claims data from a 20% sample of enrollees in fee-for-service Medicare throughout the United States were analyzed to identify all laser and incisional glaucoma surgeries performed from 2008 through 2016. We assessed use of traditional incisional glaucoma surgery techniques (trabeculectomy and glaucoma drainage implant [GDI] procedure) and microinvasive glaucoma surgery (MIGS). Enrollee and procedure counts were multiplied by 5 to estimate use throughout all of Medicare. Linear regression was used to compare trends in use of glaucoma surgeries between ophthalmologists who could be characterized as glaucoma subspecialists versus nonsubspecialists.

MAIN OUTCOME MEASURES

Numbers of laser and incisional glaucoma surgeries performed overall and stratified by glaucoma subspecialist status.

RESULTS

The number of Medicare beneficiaries undergoing any glaucoma therapeutic procedure increased by 10.6%, from 218 375 in 2008 to 241 565 in 2016. The total number of traditional incisional glaucoma surgeries decreased by 11.7%, from 37 225 to 32 885 (P = 0.02). The total number of MIGS procedures increased by 426% from 13 705 in 2012 (the first year MIGS codes were available) to 58 345 in 2016 (P = 0.001). Throughout the study period, glaucoma subspecialists performed most of the trabeculectomies (76.7% in 2008, 83.1% in 2016) and GDI procedures (77.7% in 2008, 80.6% in 2016). Many MIGS procedures were performed by nonsubspecialists. The proportions of endocyclophotocoagulations, iStent (Glaukos; San Clemente, CA) insertions, goniotomies, and canaloplasties performed by glaucoma subspecialists in 2016 were 22.0%, 25.2%, 56.9%, and 62.8%, respectively.

CONCLUSIONS

From 2008 through 2016, a large shift in practice from traditional incisional glaucoma surgeries to MIGS procedures was observed. Although glaucoma subspecialists continue to perform most traditional incisional glaucoma surgeries, many MIGS procedures are performed by nonsubspecialists. These results highlight the importance of training residents in performing MIGS procedures and managing these patients perioperatively. Future studies should explore the impact of this shift in care on outcomes and costs.

Transscleral cyclophotocoagulation and its histological effects on the conjunctiva

Micropulse transscleral cyclophotocoagulation (MP-TCP) is increasingly being used as an initial procedure prior to conjunctival filtration surgeries. However, it is uncertain whether MP-TCP may cause inflammation and scarring of the bulbar conjunctiva. Thus, we aimed to study the histological effects of MP-TCP (compared to controls and continuous wave [CW]-TCP) on the conjunctiva. Our study included 10 Dutch Belted Rabbits that underwent TCP in their right eyes (n = 5, MP-TCP; n = 5, CW-TCP), while their left eyes served as controls. The rabbits were euthanised at 4 weeks, and their dissected globes underwent histopathological and immunohistochemical examination. We observed greater conjunctival inflammation in MP-TCP or CW-TCP-treated eyes compared to controls, but not between each other. The majority of the lymphocytic infiltrates were CD4 T-cells. Increased conjunctival fibrosis was evident in MP-TCP or CW-TCP-treated eyes, to similar extents, compared to controls. However, the increased staining for myofibroblasts was not statistically significant in TCP-treated eyes. We concluded that MP-TCP causes significantly greater overall conjunctival inflammation and scarring compared to controls, similar to CW-TCP. As these are risk-factors for fibrosis and failure of the conjunctival bleb, further studies are required to explore the effect, if any, of post-TCP conjunctival changes on future bleb morphology and survival.

12-Month Retrospective Comparison of Kahook Dual Blade Excisional Goniotomy with Istent Trabecular Bypass Device Implantation in Glaucomatous Eyes at the Time of Cataract Surgery

PURPOSE

To compare the efficacy and safety of combined cataract extraction and either excisional goniotomy performed with the Kahook Dual Blade (KDB; phaco-KDB group) or single iStent trabecular bypass implantation (phaco-iStent group) in eyes with mild to moderate glaucoma and visually significant cataract.

METHODS

This was a retrospective analysis of 315 eyes from 230 adults with mild or moderate glaucoma treated with one or more intraocular pressure (IOP)-lowering medications (190 eyes of 134 subjects in the phaco-KDB group and 125 eyes of 96 subjects in the phaco-iStent group) that required no subsequent surgical intervention for IOP control through 12 months of follow-up. Data included best-corrected visual acuity (BCVA), IOP, and IOP-lowering medications, collected preoperatively and at 1 week and 1, 3, 6, and 12 months postoperatively as well as intraoperative and postoperative adverse events. The primary efficacy outcomes were the proportion of subjects in each group achieving ≥ 20% IOP reduction and ≥ 1 medication reduction at month 12. Subgroup analysis by baseline IOP (≤ 18 mmHg vs. > 18 mmHg) was also performed.

RESULTS

Mean (standard error) baseline IOP was 18.2 (0.3) mmHg in the phaco-KDB group and 16.7 (0.3) mmHg in the phaco-iStent group (p = 0.001). Statistically significant mean IOP and mean IOP medication reductions from baseline were achieved at all time points in both groups. Mean IOP reductions were significantly greater in the phaco-KDB group than in the phaco-iStent group at all time points including month 12 [- 5.0 (0.3) mmHg vs. - 2.3 (0.4) mmHg, p < 0.001], while mean medication reductions were similar between groups at all time points except week 1, when greater mean medication reduction was seen in the phaco-iStent group (- 1.23 vs. - 0.60 medications, p < 0.001). At month 12, IOP reductions ≥ 20% were achieved by 64.2% and 41.6% (p < 0.001) in the phaco-KDB and phaco-iStent groups, respectively, and IOP medication reductions of ≥ 1 medication were achieved by 80.4% and 77.4% (p = 0.522), respectively. Intraocular pressure subgroup analysis revealed significant reductions in IOP-lowering medications without compromise of IOP control in lower IOP subgroups and significant reductions in both IOP and IOP-lowering medications in the higher IOP subgroups. The most common adverse events were transient IOP elevations and transient anterior chamber inflammation, which occurred with similar frequency in both groups and resolved spontaneously.

CONCLUSION

Goniotomy with the KDB lowered IOP significantly more than iStent implantation, with few adverse events in both groups. In eyes with mild to moderate glaucoma undergoing combined cataract extraction and glaucoma surgery, goniotomy with the KDB can safely deliver statistically significant and clinically meaningful reductions in both IOP and IOP medication burden through 12 months of follow-up.

FUNDING

New World Medical, Inc., provided funding for the study, medical writing assistance, Rapid Service Fees, and the open access fee.

Outcome of phacoemulsification combined with excisional goniotomy using the Kahook Dual Blade in severe glaucoma patients at 6 months

Purpose

The aim of this study was to describe 6-month rates of achieving target IOP without requiring additional glaucoma surgery after excisional goniotomy using the Kahook Dual Blade combined with phacoemulsification (phaco-KDB) in patients with severe-stage glaucoma.

Methods

Retrospective review of 42 eyes from 36 patients with severe glaucoma who received phaco-KDB. Primary and secondary open-angle and combined-mechanism glaucoma were included. Preoperative, intraoperative, and postoperative data were collected through the 6-month follow-up period. The primary outcome was proportion of patients achieving IOP ≤15 mmHg without additional glaucoma procedures. Secondary outcomes were mean change in IOP, reduction of glaucoma medications, additional glaucoma procedures needed, and adverse events.

Results

Preoperative baseline mean IOP was 17.1±4.8 mmHg (mean ± SD) and number of medications was 2.4±1.3. At 6 months, 64.3% (27/42) of eyes had achieved IOP ≤15 mmHg without additional glaucoma procedures, 45.2% (19/42) reached this target IOP on fewer medications, and 31.0% (13/42) on no medications. Mean IOP reduction was 2.1±4.67 mmHg (P=0.022) and mean medication reduction was 1.2±1.4 (P≤0.001). Visually significant complications were experienced by 7.1% (3/42) of eyes, and 7.1% (3/42) required additional IOP-lowering procedures within 6 months of surgery.

Conclusion

Patients with severe-stage open-angle glaucoma achieved significant IOP and medication reductions following phaco-KDB. Notably, about two-thirds of eyes achieved an IOP of ≤15 mmHg at 6 months without additional glaucoma procedures. Complications and need for additional procedures were rare. Phaco-KDB may be an effective and safe alternative to more invasive filtering surgery in many patients with severe glaucoma.

Efficacy of Cataract Surgery With Trabecular Microbypass Stent Implantation in Combined-Mechanism Angle Closure Glaucoma Patients

PURPOSE

To evaluate the effectiveness of trabecular microbypass stent (iStent) implantation in combined mechanism glaucoma (CMG).

DESIGN

Retrospective cohort study.

METHODS

We reviewed the medical charts of patients with the following scenarios: (1) primary open-angle glaucoma (POAG) undergoing phacoemulsification (PE), (2) POAG undergoing PE with iStent (POAG-PE/iStent), (3) CMG undergoing PE (CMG-PE), and (4) CMG undergoing PE with iStent (CMG-PE/iStent). CMG was defined as narrow-angle glaucoma patients whose angle had opened after iridotomy. Linear mixed-effects models were performed to determine the effect of iStent on postoperative 1-year success rate (intraocular pressure [IOP] ≤ 18 without medication), IOP, and number of medications.

RESULTS

Data from 301 eyes were available. The number of eyes (subjects) was 61 (45) in the POAG-PE, 60 (50) in POAG-PE/iStent, 93 (76) in CMG-PE, and 87 (70) in CMG-PE/iStent group. Success criteria were achieved in 13.1% for POAG-PE, 33.3% for POAG-PE/iStent (POAG-PE vs POAG-PE/iStent B 3.01; P < .001), 37.6% for CMG-PE, and 43.7% for CMG-PE/iStent (CMG-PE vs CMG-PE/iStent B 2.25; P < .001). There was no difference in the IOP between POAG-PE and POAG-PE/iStent, and between CMG-PE and CMG-PE/iStent. The iStent significantly reduced number of medications in the POAG (B -0.70; P < .001) and CMG group (B -0.52; P < .001). Comparing the effect of iStent on POAG and CMG, the analysis showed similar iStent efficacy in terms of the success rate, IOP, and number of medications (P > .05).

CONCLUSIONS

Combined PE/iStent significantly increased success rate and reduced number of medications in CMG patients compared to PE alone. The effects of iStent were comparable between POAG and CMG groups.

Incidence and causes of visual impairment in Japan: the first nation-wide complete enumeration survey of newly certified visually impaired individuals

PURPOSE

To investigate the visual impairment certification status in Japan.

STUDY DESIGN

Observational cross-sectional study.

METHODS

We asked all welfare offices throughout Japan to submit data concerning age, sex, causative diseases, and visual impairment grades for newly certified visually impaired individuals aged ≥ 18 years in the fiscal year of 2015. The certification was based on criteria of the Act on Welfare of Physically Disabled Persons.

RESULTS

In total, data were collected for 12,505 newly certified visually impaired individuals. The most common age group for these individuals was 80-89 years (29.6%), followed by 70-79 (26.3%) and 60-69 (17.3%) years. The most common causative disease was glaucoma (28.6%), followed by retinitis pigmentosa (14.0%), diabetic retinopathy (12.8%), and macular degeneration (8.0%). Glaucoma was the most common causative disease in both sexes (30.2% in men and 27.0% in women). The most common impairment grade was grade 2 (31.8%), followed by grades 5 (24.3%) and grade 1 (16.1%). The number of visually impaired individuals with underlying glaucoma had increased in comparison with the number in the most recent surveys (from fiscal years 2007 to 2009), whereas the number of individuals with underlying diabetic retinopathy and macular degeneration had decreased.

CONCLUSION

To our knowledge, this is the first nation-wide complete enumeration survey of newly certified visually impaired individuals in Japan. These findings may contribute to administrative activities concerning medical welfare as well as educational activities for preventing visual impairment.

Systematic Literature Review of Clinical and Economic Outcomes of Micro-Invasive Glaucoma Surgery (MIGS) in Primary Open-Angle Glaucoma

INTRODUCTION

Primary open-angle glaucoma is estimated to affect 3% of the population aged 40-80 years. Trabeculectomy is considered the gold standard in surgical management of glaucoma; however, it is a technically complex procedure that may result in a range of adverse outcomes. Device-augmented, minimally invasive procedures (micro-invasive glaucoma surgeries, MIGS) have been developed aiming for safer and less invasive intraocular pressure (IOP) reduction compared with traditional surgery.

METHODS

This paper presents results from a systematic literature review conducted in accordance with National Institute for Health and Care Excellence requirements for the Medical Technology Evaluation Programme via multiple databases from 2005 to 2016. For clinical outcomes, randomized clinical trials (RCTs) comparing MIGS with trabeculectomy or other therapies, observational studies, and other non-RCTs were included. Clinical outcomes reviewed were the change from baseline in mean IOP levels and change in topical glaucoma medication. Safety was assessed by reported harm and adverse events. For economic evidence, trials on cost-effectiveness, cost-utility, cost-benefit, cost-consequences, cost-minimization, cost of illness, and specific procedure costs were included. Risk of bias was assessed for clinical studies using the Cochrane Risk of Bias tool.

RESULTS

A total of nine RCTs (seven iStents^®, one Hydrus^®, and one CyPass^®), seven non-RCTs (three iStent^®, three CyPass^®, and one Hydrus^®), and 23 economic studies were analyzed. While various forms of trabeculectomy can achieve postoperative IOP of between 11.0 and 13.0 mmHg, MIGS devices described in this review were typically associated with higher postoperative IOP levels. In addition, MIGS devices may result in increased hypotony rates or bleb needling in subconjunctival placed devices, requiring additional medical resources to manage. There is limited available evidence on the cost-effectiveness of MIGS and therefore it remains unclear whether the cost of using MIGS is outweighed by cost savings through decreased medication and need for further interventions.

CONCLUSION

Larger randomized trials and real-world observational studies are needed for MIGS devices to better assess clinical and economic effectiveness. Given the shortage of published data and increasing use of such procedures, living systematic reviews may help to provide ongoing and timely evidence-based direction for clinicians and decision makers. This review highlights the current unmet need for treatments that are easy to implement and reduce long-term IOP levels without increasing postoperative aftercare and cost.

FUNDING

Santen GmbH, Germany.

Changes in Glaucoma Medication during the Past Eight Years and Future Directions in Japan Based on an Insurance Medical Claim Database

Purpose

To investigate changes in the status of glaucoma care between 2006 and 2013 and to predict future directions of glaucoma care in Japan.

Subjects and Methods

Japanese subjects registered in the largest national insurance claim database in Japan from 2006 to 2013 were analyzed. Estimations of the number of glaucoma patients during the past eight years and of the number of future patients were calculated. Changes in prescription trends among the same patients in the three-year period after initiating antiglaucoma medication were also investigated.

Results

There was a total of 3,016,000 subjects in the database. The proportion of glaucoma patients increased consistently from 2.5% in 2006 to 4.5% in 2013. This trend was predicted to continue until 2025, followed by a constant decrease with age. The most frequently prescribed antiglaucoma medications were prostaglandin analogues (PGs); however, in recent years, fixed combination therapy has emerged as a major treatment. Among 2856 newly diagnosed glaucoma patients; 94.7% of the patients initially received a single medication, but 25% of the patients received additional medications within 3 years.

Conclusions

The prevalence of glaucoma patients has significantly increased during the past eight years. The number of antiglaucoma medications continuously increased during the treatment period.