Novel glaucoma procedures: a report by the American Academy of Ophthalmology

Outcomes of bent ab interno needle goniectomy with phacoemulsification in moderate to severe primary open angle glaucoma

PURPOSE

To assess the safety and efficacy of bent ab interno needle goniectomy (BANG) in moderate to severe primary open angle glaucoma (POAG) eyes undergoing phacoemulsification (phaco).

DESIGN

Single-arm, prospective, interventional study.

METHODS

POAG patients with medically uncontrolled intraocular pressure (IOP), >15 mmHg for moderate and >12 mmHg for severe POAG, with visually significant cataract were recruited. All patients underwent BANG using a 26-gauge needle to excise 30° of the trabecular meshwork, along with phaco. Primary outcome was IOP. Secondary outcomes were success rate, percentage reduction in IOP/antiglaucoma medications (AGMs), and intraoperative complications. Success at 12 months was defined as: criterion A: IOP <15 mmHg for moderate glaucoma or <12 mmHg for severe glaucoma with or without AGMs OR criterion B: reduction in number of AGMs by >1.

RESULTS

Thirty-two eyes of 32 patients underwent BANG + phaco. Mean age of the participants was 62.7 ± 8.4 years and there were 25 males and seven females. At 12 months, a significant decrease was noted in both IOP (from 17.6 ± 3.6 to 12 ± 1.6 mmHg, 31.8%; P < 0.001) and AGMs (from 3.7 ± 0.9 to 2.8 ± 0.8, 24.3%; P < 0.001). Twenty percent or more reduction in IOP was achieved in 62.5% (20/32) of eyes. Overall success (meeting either of the criteria A or B) at 12 months was achieved in 87.5% eyes. Mild postoperative hyphema was noted in 10 (31.2%) eyes, and two eyes (6.2%) required additional filtration surgery at 7 months.

CONCLUSION

A 30-degree BANG with phaco in patients of POAG appears to be a safe, effective and affordable MIGS for developing countries.

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

Background

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

Methods

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

Results

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

Conclusions

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

Surgical Outcomes of Penetrating Canaloplasty in Patients with Uncontrolled Posner-Schlossman Syndrome: A Prospective Study

PURPOSE

To evaluate the surgical outcomes in patients with Posner-Schlossman syndrome (PSS) at one year.

METHODS

A prospective interventional study in PSS patients with penetrating canaloplasty. Main outcome measure was success rate (6 mmHg≤ intraocular pressure (IOP) ≤ 21 mmHg) with or without medications.

RESULTS

Thirteen eyes in 13 patients with PSS underwent complete catheterization. The mean IOP and medications (Meds) were reduced to 16.1 ± 4.8 mmHg on 0.5 ± 1.0 Meds at 12 months. Complete and qualified success rates were 61.5% and 84.6% at 12 months. The postoperative recurrent rate of PSS was 69.2%, the mean peak IOP during attacks and episodes were decreased to 26.7 ± 8.3 mmHg and 1.7 ± 2.0 times respectively. Transient IOP spike (61.5%) and hyphema (38.5%) were the two most common postoperative complications.

CONCLUSION

Penetrating canaloplasty achieves a high success rate in PSS without serious complications.

Direct Applications of Non-Thermal Atmospheric Pressure Plasma: An Emerging Therapeutic Era in Ophthalmology

This article explores the burgeoning role of cold atmospheric plasma (CAP) in ophthalmology. The versatile nature of CAP has transformed various facets of eye care, offering novel possibilities across different clinical domains. From sterilizing surgical instruments without compromising their integrity to effectively managing challenging corneal diseases like microbial keratitis and fungal infections, CAP has shown promising results. Moreover, its potential role in promoting corneal wound healing, facilitating corneal transplants, and enhancing outcomes in cataract surgeries deserves attention. The low-tension plasma blade (ie, the Fugo blade™, Medisurg Ltd. Norristown, PA), a controlled and precise form of CAP, has emerged as a game-changer in delicate eye surgeries. Its unmatched precision, minimal tissue damage, and surgeon-friendly nature have revolutionized ophthalmic procedures, including ptosis correction, dry eye treatment, and conjunctival cyst ablation. Despite conflicting findings on the efficacy of this technology in certain aspects, the extensive body of research on CAP underscores its potential for wider ophthalmic integration. Further investigation, including human trials, is crucial for understanding the in vivo safety profile of CAP for ophthalmic applications and optimizing its use, potentially revolutionizing ocular disease management and improving patient outcomes.

The effect of axial length on the short-term outcomes of cataract surgery combined with ab interno trabeculotomy

PURPOSE

Minimally invasive glaucoma surgery is safer and effective surgical modality for patients with glaucoma. To compare the effect of axial length (AL) on the surgical outcomes of combined cataract surgery and ab interno trabeculotomy (phaco-LOT), a retrospective, non-randomized comparative study was performed.

METHODS

In total, 458 eyes of 458 open-angle glaucoma patients who underwent phaco-LOT and were followed-up without any intervention for at least 6 months were enrolled. All were divided into a long-AL group (AL ≥ 26.0 mm, 123 eyes) and a not-long-AL group (AL < 26.0 mm, 335 eyes). The principal outcomes were the changes in intraocular pressure (IOP) and medication scores. We also sought a correlation between postoperative IOP spike and hyphema.

RESULTS

Significant postoperative reductions in IOP and medication scores were apparent in all subjects. The IOP reductions were significant at all timepoints in the not-long-AL group, but not until 1 month postoperatively in the long-AL group, and the IOP change was significantly lower in the long-AL group from postoperative day 1 to 3 months. On subanalysis of subjects by age, the microhook used, the pre-operative IOP, and the medication score, a significantly higher incidence of IOP spike was observed in the long-AL group in weeks 1 and 2 (both p < 0.05), but this did not correlate with hyphema status, implying that a different mechanism was in play.

CONCLUSION

Phaco-LOT was effective regardless of AL, but the postoperative IOP decrease was lower and the early postoperative incidence of IOP spike was higher in long-AL eyes.

Consistency in Standalone Canaloplasty Outcomes Using the iTrack Microcatheter

Purpose

To study the consistency in outcomes of standalone canaloplasty performed via an ab-interno surgical technique in reducing intraocular pressure (IOP) and number of medications in uncontrolled open-angle glaucoma (OAG) eyes over a 12-month period.

Methods

This retrospective multicenter case series included patients who underwent standalone canaloplasty via an ab-interno surgical technique using the iTrack microcatheter (Nova Eye, Inc., Fremont, USA) and had preoperative uncontrolled OAG (IOP≥18mmHg) along with no previous glaucoma surgery. The iTrack microcatheter is used to circumnavigate 360° and viscodilate Schlemm's canal. Consistency of IOP and medications reduction on an eye-by-eye basis were evaluated to understand the outcomes in each single eye.

Results

Sixty-four eyes of 60 patients (age 71.5±13.4 years) were included. Six eyes (9%) that underwent additional glaucoma surgery were considered a failure and were subsequently excluded from analysis. At 12 months, IOP was reduced in 57 of the 58 (89%) remaining eyes; one eye had the same IOP with a reduced number of medications. Of the 57/58 eyes with a reduced IOP: 44 eyes (69%) required fewer medications; 12 eyes (19%) required the same number of medications. Of these 58 eyes, 78% of eyes had a ≥20% reduction in IOP compared to baseline; 69% eyes had a postoperative IOP ≤15 mmHg, and 86% eyes ≤18 mmHg at 12 months. Forty percent of the eyes were medication-free at 12 months compared to none at baseline.

Conclusion

Canaloplasty performed via an ab-interno surgical technique as a standalone procedure consistently reduced IOP and glaucoma medications in almost all eyes.

Evaluation of ocular surface following PreserFlo Microshunt implantation: Functional outcomes and quality of life

BACKGROUND

This study aimed to evaluate the impact of PreserFlo Microshunt on the ocular surface, focusing on both objective and subjective parameters.

METHODS

Prospective-observational study on 48 eyes undergoing PreserFlo Microshunt implantation, standalone or combined with phacoemulsification. At baseline, 1-month, 6-months and 12-months post-operative follow-ups, we performed Ocular Surface Disease Index (OSDI) questionnaire, Schirmer's test (ST), Tear-film break-up time (TBUT), fluoresceine staining (FS), tear osmolarity and minimum corneal epithelial thickness (Epi-ThkMIN. ) measurements.

RESULTS

OSDI score improved from 37.43 ± 17.49 at baseline, to 24.13 ± 12.55 at 1-month (p = 0.003) and to 12.89 ± 8.54 and 13.09 ± 10.22 at 6-months and 12-months (p < 0.0001). TBUT and ST, in a similar way, non-significantly increased at 1-month, but then improved at 6-months and 12-months (p < 0.05 for both). Tear osmolarity significantly decreased from 308.2 ± 7.3 mOsm/L at baseline, to 303.3 ± 8.2 mOsm/L, 295.6.2 ± 7.0 mOsm/L and 297.6 ± 6.8 mOsm/L at 1-month, 6-months and 12-months (p < 0.05 for all). Epi-ThkMIN was stable when comparing baseline (44.9 ± 5.7 μm) and 1-month (p = 0.28), and successively increased in 6-months (47.8 ± 5.5 μm, p = 0.02) and 12-months (48.0 ± 3.6 μm, p = 0.01). In subgroup analysis, OSDI score and tear osmolarity were significantly higher at 1-month in combined group compared to standalone group (p = 0.03 and p = 0.02, respectively), but reaching comparable values in successive follow-ups. Further, Oxford scale grades for FS were significantly improved when comparing baseline-6-months and baseline-12-months.

CONCLUSION

PreserFlo implantation improved ocular surface subjective symptoms, increased TBUT and ST, and reduced FS, highlighting the potential benefits of this surgical intervention. Moreover, we reported significant improvements of tear osmolarity and corneal epithelium.

[Possibilities of physiotherapy in glaucomatous optic neuropathy after glaucoma surgery]

The current primary approach to the therapeutic and surgical management of glaucoma is limited to lowering intraocular pressure (IOP). While normalization of IOP stabilizes some functional parameters, there is still potential for further restoration of lost visual function in the post-operative period while maintaining the "therapeutic window". Neuroprotection refers to the modification of retinal ganglion cells and the neuronal microenvironment to promote their survival and function. Numerous studies have identified effective neuroprotective methods for glaucoma; however, their implementation into clinical practice remains a significant challenge. This review presents the most clinically significant treatment strategies, as well as the latest therapeutic advances in physiotherapy.

Clinical Outcomes of MicroPulse Transscleral Laser Therapy with the Revised P3 Delivery Device

Aim

To evaluate the success and safety of MicroPulse transscleral laser therapy (TLT) on intraocular pressure (IOP) reduction in adults with uncontrolled glaucoma using different total treatment durations, sweep velocities, and a number of sweeps utilizing the revised MicroPulse P3 delivery device.

Materials and methods

A single-center Institutional Review Board (IRB) approved multiple cohort studies of MicroPulse TLT with the revised MicroPulse P3 delivery device, which was conducted in 61 eyes from 40 adults with uncontrolled glaucoma. Eyes that received 50-second (GI, GII, and GIII) and 60-second (GIV, GV, and GVI) treatment applications between May and October 2020 were reviewed. Each hemisphere received a total of five, four, or three sweeps. The patient's IOP and glaucoma medications were monitored over 12 months follow-up. Qualified success was defined as an IOP of ≤21 mm Hg and/or reduction of ≥20% from baseline at 12 months, with no secondary glaucoma reinterventions. Complete success was defined as meeting the above criteria with no increase in glaucoma medications at 12 months. All eyes requiring a glaucoma surgical intervention were considered a failure.

Results

Qualified success was achieved in 83.6% of eyes, while complete success was achieved in 75.4% of eyes. In eyes receiving 50-second applications of five, four, or three sweeps (GI, GII, and GIII), 70, 90, and 91% achieved qualified success, respectively; in eyes receiving 60-second applications of five, four, or three sweeps (GIV, GV, and GVI), 78, 82, and 90% achieved qualified success, respectively. Within each subgroup, mean IOP reductions ranged from 32.8 to 49.4% and were statistically significant (p < 0.008). The failure rate was 16.4%, and at least one eye failed in each subgroup.

Conclusions

MicroPulse TLT with the revised MicroPulse P3 delivery device and relatively low total energy levels is safe and effective at lowering IOP. Efficacy appears to increase with longer treatment durations and slower sweep velocities, but statistical differences between age and clinical differences between baseline IOP measurements limit comparison between subgroups.

Clinical significance

There is a lack of literature evaluating the safety and IOP-lowering success of the revised MicroPulse P3 delivery device using different total treatment durations, sweep velocities, and number of sweeps.

How to cite this article

Checo LA, Dorairaj S, Wagner IV, et al. Clinical Outcomes of MicroPulse Transscleral Laser Therapy with the Revised P3 Delivery Device. J Curr Glaucoma Pract 2024;18(1):10-15.

European Glaucoma Society - A guide on surgical innovation for glaucoma

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

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

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.

Bleb Morphology on Anterior-Segment Optical Coherence Tomography after XEN Gel Stent Implantation

We investigated the internal morphology of filtration blebs after XEN gel stent implantation using anterior segment optical coherence tomography (AS-OCT) and identified factors related to intraocular pressure (IOP) postoperatively. Eighteen eyes of 18 patients who had undergone XEN gel stent implantation were analyzed. Blebs were imaged using Visante OCT (Carl Zeiss Meditec AG, Germany) at 6 months and 1 year after surgery and evaluated for quantitative parameters including bleb height, maximum height of internal cavity, maximum bleb wall thickness, and maximum bleb epithelial thickness. Subjects were classified into two groups according to the presence or absence of a definite internal cavity between the conjunctiva and sclera using AS-OCT imaging. Nine eyes (50%) were assigned to the internal cavity group and 9 (50%) to the uniform group. Postoperative IOP was significantly lower in the internal cavity group than in the uniform group both at 6 months and 1 year after surgery (p = 0.024 and p = 0.040). Postoperative IOP showed statistically significant negative correlations with bleb height and the height of the internal cavity (Spearman correlation coefficient r = -0.518, p = 0.028 and r = -0.453, p = 0.034, respectively). AS-OCT facilitates analysis of bleb morphology after XEN gel stent implantation. A larger height of the internal cavity of the bleb appeared to correlate with lower IOP after XEN implantation.

Case Report: Gonio-endoscopy: a novel approach to minimally invasive glaucoma surgery in a glaucomatous eye

Background

The gonio-endoscope is a novel device for use during minimally invasive glaucoma surgery (MIGS) to treat glaucomatous eyes with cloudy cornea. The MIGS procedure requires a surgical gonioprism lens for direct visualization of the angle, intraoperative manipulation of the surgical microscope and the patient's head position, and the patient's eye without a cloudy cornea. In cases with cloudy corneas or limitation of neck movement, MIGS cannot be safely performed. Gonio-endoscopy facilitates clear visualization of the trabecular meshwork (TM) to perform MIGS safely and easily even in a patient with corneal opacities or limitation of neck movement with no additional MIGS procedures. We report the first case in which we performed the newly developed a 10,000-pixel high-resolution 23-gauge gonio-endoscopic operation.

Case presentation

The patient was a 58-year-old man with Down syndrome who had secondary glaucoma bilaterally after cataract surgery and long-time use of a steroid for atopic dermatitis and allergic conjunctivitis. His left eye had a cloudy cornea after penetrating keratoplasty for keratoconus with severe corneal residual scarring after prior resolved corneal hydrops. When the intraocular pressure (IOP) in his left eye increased to 41 mmHg despite the maximum use of anti-glaucoma eyedrops, he was referred to our hospital. Anterior-segment optical coherence tomography showed an open angle. We developed a new gonio-endoscope (MACHIDA Endoscope Co., Ltd., Chiba, Japan and NIPRO CORPORATION, Osaka, Japan), the probe of which is bent appropriately to aid visualization of and access to the TM. After obtaining clinical approval from the government and our institution, we could safely perform a high-resolution 23-gauge gonio-endoscopy-assisted microhook ab interno trabeculotomy (μLOT). The IOP decreased to 10 mmHg and the visual acuity has been preserved with no major complications for 1 year postoperatively.

Conclusion

This new technique of clear gonio-visualization using a gonio-endoscope might be helpful for a safe and easy μLOT in patients with cloudy corneas. This device can apply to other types of MIGS procedures and cases with pathological diagnoses of glaucoma that are difficult to treat.

Ocular surface and glaucoma, a mutual relationship. Practical suggestions for classification and management

The chronic use of glaucoma medications could improve the development of an ocular comorbidity, the glaucoma therapy-related ocular surface disease. This could be related to the exposure of the conjunctiva to preservatives, but also active compounds such as prostaglandin analogues may improve the risk of ocular surface inflammation. Inflammation has a negative impact on tolerability and adherence to eyedrops and to the outcome of filtration surgery as well. A stratification of glaucoma patients based not only on visual field progression but also on glaucoma therapy-related ocular surface disease would be desirable for a strategic management. Early diagnosis, individualized treatment, and safe surgical management should be the hallmarks of glaucoma treatment. One of the main issues for the proper and successful management of patients is the right timing, effectiveness and safety for both medical and surgical treatment options leading to a precision medicine in glaucoma disease as the best modern treatment.

Vision-Related Quality of Life following Combined Cataract and Minimally Invasive Glaucoma Surgery or Cataract Surgery Alone in Glaucoma Patients

This study examined glaucoma patients after undergoing combined cataract and minimally invasive glaucoma surgery (MIGS), microhook ab interno trabeculotomy and goniotomy with the Kahook Dual Blade (KDB), or cataract surgery alone, and it then evaluates their vision-related quality of life (VR-QOL) following the procedure. A total of 75 eyes of 75 consecutive glaucoma patients in this prospective cohort study underwent phacoemulsification (Phaco) or phaco and MIGS (Phaco-TLO) between October 2019 and March 2022. In all cases, the National Eye Institute Visual Function Questionnaire (VFQ-25) was used to evaluate the 20 eyes in the Phaco group and the 55 eyes in the Phaco-TLO group before and at 2 months after surgery. There was a significant increase in the visual acuity (logMAR) at 2 months post-operatively (Phaco group; 0.34 ± 0.10 to -0.07 ± 0.1, p < 0.0001, Phaco-TLO group; 0.37 ± 0.43 to 0.09 ± 0.32, p < 0.0001). The median (25-75th percentile) total VFQ scores in the Phaco group before and at 2 months after surgery were 71.1 (62.4-80.6) and 79.4 (69.0-84.0), respectively. (p = 0.006). The median (25-75th percentile) total VFQ scores in the Phaco-TLO group before and at 2 months after surgery were 69.8 (55.3-78.6) and 74.7 (65.1-83.3), respectively. (p = 0.005). Glaucoma patients who underwent not only cataract surgery alone but also combined cataract surgery and MIGS exhibited significant improvement in the VR-QOL.

Early post-operative anterior segment parameters modifications induced by PreserFlo MicroShunt in primary open-angle glaucoma

PURPOSE

The aim this study is to determine anterior chamber parameters variations induced by PreserFlo MicroShunt implantation, in the early post-operative days.

METHODS

This is a prospective observational study on 48 eyes undergoing PreserFlo MicroShunt implantation alone (n = 30) or combined with phacoemulsification (n = 18). Anterior chamber depth (ACD) and volume (ACV), central corneal thickness (CCT) and total corneal astigmatism (TCA) were evaluated pre-operatively, post-operatively at day-1 and at 1 week with the Pentacam tomography.

RESULTS

Intraocular pressure decreased significantly from 20.9 ± 4.0 to 8.0 ± 2.8 mmHg (p < 0.0001) and to 10.8 ± 3.7 mmHg (p = 0.0001) at day-1 and week-1, respectively. TCA varied significantly from baseline (1.5 ± 1.2 D) to both day 1 follow up (2.7 ± 1.9 D, p = 0.0003) and week 1 follow up (2.2 ± 1.6 D, p = 0.02). Nevertheless, only K1 showed a transient flattening at day 1, while K2 value didn't show any statistical variation in the early post-operative period. CCT value rose significantly at day 1 (547 ± 49 vs. 529 ± 32 µm at baseline, p = 0.04), but then returned toward pre-operative values at week 1 (537 ± 39 µm, p = 0.57). In contrast, ACD values changed insignificantly from 3.3 ± 0.9 to 3.7 ± 1.0 mm at day 1 (p = 0.21), and then stabilized at 3.4 ± 0.9 mm (p = 0.82) at week 1 follow up. ACV changed from 150.0 ± 36.2 to 159.5 ± 42.1 mm³ at day 1 (p = 0.58), and successively to 153.9 ± 37.9 mm³ at week 1 follow up (p = 0.96). The subgroup analysis in eyes undergoing standalone PreserFlo implantation didn't show significant changes in both ACD and ACV.

CONCLUSION

PreserFlo implantation minimizes the anterior chamber modifications generated by traditional filtering surgery, inducing low and transient corneal and biometric changes only in the very early postoperative period and insignificant changes to ACD and ACV, label of its safety and minimal invasiveness.

Complications and post-operative interventions in XEN45 gel stent implantation in the treatment of open angle glaucoma-a systematic review and meta-analysis

BACKGROUND

The XEN45 Gel Stent is a subconjunctival filtering device that has demonstrated promising efficacy. This meta-analysis quantitatively evaluates reported complications and interventions after XEN45 implantation in the treatment of open angle glaucoma (OAG).

METHODS

Pilot, cohort, observational studies, and randomised controlled trials that included at least ten patients undergoing ab interno or externo XEN45 surgery, with or without phacoemulsification were deemed eligible for inclusion. A meta-analysis of proportions with random-effect models was performed using the meta routine in R version 3.2.1. Outcomes included the rate of complications and post-operative interventions.

RESULTS

One hundred and fifty-two studies were identified on initial literature search and 33 were included in final analysis. Numerical hypotony was the most common post-operative complication, involving 20% of patients (95% CI: 10-31%). Post-operative gross hyphema occurred in 14% (95% CI: 7-22%) and transient intra-ocular pressure (IOP) spikes (>30 mmHg) in 13% (95% CI: 4-27%). Stent exposure occurred in 1% (95% CI: 0-2%). Stent migration occurred in 1% (95% CI: 0-3%). XEN45 revision and/or a second XEN45 implantation was performed in 5% of patients (95% CI: 3-7%). Stent relocation was performed in 3% (95% CI: 1-7%). A second glaucoma procedure was performed in 11% (95% CI: 8-15%). 26% underwent one (95% CI: 17-36%), 13% underwent two (95% CI: 5-24%) while 4% underwent three (95% CI: 2-6%) bleb needling procedures. 35% of patients (95% CI: 29-40%) required at least one needling. The average rate of needling per patient was 0.38 (95% CI: 0.20-0.59). However, there is a lack of high-quality data, with 8 of the 33 studies assessed to have a moderate to high risk of bias.

CONCLUSIONS

While literature suggests that XEN45 Gel Stent implantation is safe in the treatment of OAG, the overall current level of evidence is low and further studies are needed. More than a third of patients require at least one post-operative bleb needling procedure.

Device-modified trabeculectomy for glaucoma

BACKGROUND

Glaucoma is an optic neuropathy that leads to visual field defects and vision loss. It is the second leading cause of irreversible blindness in the world. Treatment for glaucoma aims to reduce intraocular pressure (IOP) to slow or prevent further vision loss. IOP can be lowered with medications, laser, or incisional surgery. Trabeculectomy is a surgical approach which lowers IOP by shunting aqueous humor to a subconjunctival bleb. Device-modified trabeculectomy techniques are intended to improve the durability and safety of this bleb-forming surgery. Trabeculectomy-modifying devices include the Ex-PRESS, the XEN Gel Stent, the PreserFlo MicroShunt, as well as antifibrotic materials such as Ologen, amniotic membrane, expanded polytetrafluoroethylene (ePTFE) membrane, Gelfilm and others. However, the comparative effectiveness and safety of these devices are uncertain.

OBJECTIVES

To evaluate the benefits and harms of different devices as adjuncts to trabeculectomy on IOP control in eyes with glaucoma compared to standard trabeculectomy.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search was August 2021.

SELECTION CRITERIA

We included randomized controlled trials in participants with glaucoma comparing device-modified trabeculectomy techniques with standard trabeculectomy. We included studies that used antimetabolites in either or both treatment groups.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. change in IOP and 2. mean postoperative IOP at one year. Our secondary outcomes were 3. mean change in IOP from baseline, 4. mean postoperative IOP at any time point, 5. mean best-corrected visual acuity (BCVA), 6. visual field change, 7. quality of life, 8. proportion of participants who are drop-free at one year, 9. mean number of IOP lowering medications at one year, and 10. proportion of participants with complications.

MAIN RESULTS

Eight studies met our inclusion criteria, of which seven were full-length journal articles and one was a conference abstract. The eight studies included 961 participants with glaucoma, and compared two types of devices implanted during trabeculectomy versus standard trabeculectomy. Seven studies (462 eyes, 434 participants) used the Ex-PRESS, and one study (527 eyes, 527 participants) used the PreserFlo MicroShunt. No studies using the XEN Gel Stent implantation met our criteria. The studies were conducted in North America, Europe, and Africa. Planned follow-up periods ranged from six months to five years. The studies were reported poorly, which limited our ability to judge risk of bias for many domains. None of the studies explicitly masked outcome assessment. We rated seven studies at high risk of detection bias. Low-certainty of evidence from five studies showed that using the Ex-PRESS plus trabeculectomy compared with standard trabeculectomy may be associated with a slightly lower IOP at one year (mean difference (MD) -1.76 mmHg, 95% confidence interval (CI) -2.81 to -0.70; 213 eyes). Moderate-certainty of evidence from one study showed that using the PreserFlo MicroShunt may be associated with a slightly higher IOP than standard trabeculectomy at one year (MD 3.20 mmHg, 95% CI 2.29 to 4.11). Participants who received standard trabeculectomy may have a higher risk of hypotony compared with those who received device-modified trabeculectomy, but the evidence is uncertain (RR 0.73, 95% CI 0.46 to 1.17; I² = 38%; P = 0.14). In the subgroup of participants who received the PreserFlo MicroShunt, there was a lower risk of developing hypotony or shallow anterior chamber compared with those receiving standard trabeculectomy (RR 0.44, 95% CI 0.25 to 0.79; 526 eyes). Device-modified trabeculectomy may lead to less subsequent cataract surgery within one year (RR 0.46, 95% CI 0.27 to 0.80; I² = 0%).

AUTHORS' CONCLUSIONS

Use of an Ex-PRESS plus trabeculectomy may produce greater IOP reduction at one-year follow-up than standard trabeculectomy; however, due to potential biases and imprecision in effect estimates, the certainty of evidence is low. PreserFlo MicroShunt may be inferior to standard trabeculectomy in lowering IOP. However, PreserFlo MicroShunt may prevent postoperative hypotony and bleb leakage. Overall, device-modified trabeculectomy appears associated with a lower risk of cataract surgery within five years compared with standard trabeculectomy. Due to various limitations in the design and conduct of the included studies, the applicability of this evidence synthesis to other populations or settings is uncertain. Further research is needed to determine the effectiveness and safety of other devices in subgroup populations, such as people with different types of glaucoma, of various races and ethnicity, and with different lens types (e.g. phakic, pseudophakic).

Effectiveness of Microinvasive Glaucoma Surgery in the United States: Intelligent Research in Sight Registry Analysis 2013-2019

PURPOSE

To evaluate the effectiveness of microinvasive glaucoma surgery (MIGS) with and without concurrent phacoemulsification.

DESIGN

Multicenter, retrospective cohort study.

PARTICIPANTS

Patients in the Intelligent Research in Sight (IRIS®) Registry who underwent Xen gel stent (ab interno) implantation, endoscopic cyclophotocoagulation (ECP), or goniotomy or canaloplasty from 2013 through 2019.

METHODS

Kaplan-Meier survival analysis was used to assess reoperation rates. We defined reoperation as any subsequent glaucoma surgery occurring 1 month to 3 years after the initial procedure. Multivariable Cox proportional hazard models were used to determine factors predictive of reoperation.

MAIN OUTCOME MEASURES

Reoperation rate, mean intraocular pressure (IOP) and visual acuity (VA), postoperative complications, predictors of reoperation, and reoperation procedure type.

RESULTS

A total of 79 363 eyes from 57 561 patients were included, with 15 118 eyes (19%) receiving stand-alone MIGS and 64 245 eyes (81%) receiving MIGS concurrent with phacoemulsification. Overall, patients who underwent MIGS concurrently with phacoemulsification showed lower reoperation rates compared with stand-alone MIGS, most pronounced in ECP and goniotomy or canaloplasty. At postoperative year 2, the cumulative reoperation rate for stand-alone procedures was 15% for ECP, 24% for Xen implantation, and 24% for goniotomy or canaloplasty compared with 3% for ECP, 19% for Xen implantation, and 6% for goniotomy or canaloplasty concurrent with phacoemulsification (P < 0.001 for each stand-alone MIGS vs. MIGS with phacoemulsification). Black race, older age, moderate and severe glaucoma, higher baseline IOP, and glaucoma subtype were associated with higher reoperation risk. Although IOP decreased in all groups, stand-alone MIGS showed a more substantial decrease in mean IOP. Complication rates from MIGS were low overall: 1% for ECP, 1% for Xen implantation, and 2% for goniotomy or canaloplasty.

CONCLUSIONS

In current United States clinical practice, MIGS has substantially lower reoperation rates when performed with phacoemulsification, especially for ECP and goniotomy or canaloplasty. Approximately one-sixth of patients undergoing stand-alone ECP and one-quarter of patients undergoing stand-alone Xen implantation or goniotomy or canaloplasty require reoperation by 2 years. Black race, diagnosis coding of moderate to severe glaucoma, and higher baseline IOP were associated with higher risk of reoperation after MIGS procedures.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

PreserFlo™ MicroShunt Versus Ab Externo Canaloplasty in Patients With Moderate to Advanced Open-Angle Glaucoma: 12-Month Follow-Up of a Single-Center Retrospective Study

Purpose To evaluate and compare the efficacy and safety of the PreserFlo MicoShunt and the canaloplasty in patients with moderate to advanced glaucoma. Methods In this retrospective study, 300 patients with moderate to advanced glaucoma underwent either the implantation of the PreserFlo™ MicroShunt (group A) or a canaloplasty (group B). All patients underwent regular follow-up examinations in our department every two days, every two weeks, and every three, six, and 12 months postoperatively. Examinations included measurement of the best corrected visual acuity (BCVA), slit-lamp biomicroscopy of the anterior and posterior segments, intraocular pressure (IOP) measurement using Goldmann applanation tonometry, visual field perimetry, and measurement of the endothelial cell density (ECD). Efficacy was shown by the absolute and qualified success rates calculated with the Kaplan-Meyer analysis. Results  In group A, IOP was significantly reduced at 12 months (13.37 ± 3.94 mmHg, p≤ 0.01) postoperatively in comparison to baseline (23.47 ± 8.39 mmHg). In group B, there was also a reduction in IOP at 12 months (14.32 ± 3.59 mmHg, p≤ 0.01) in comparison to the baseline (18.86 ± 5.82 mmHg). Comparing both groups, the IOP of patients who received the PreserFlo™ MicroShunt was significantly lower than the IOP of patients receiving canaloplasty after 12 months (p=0.049). Patients in both groups were treated with significantly fewer topical agents after 12 months (group A: baseline = 2.53±1.56; 12 months: 0.43 ± 0.83, p≤0.01; group B: baseline 2.62 ± 0.87; 12 months: 1.52 ± 0.99, p≤0.01). Patients receiving the PreserFlo™ MicroShunt applied significantly fewer topical agents than patients who underwent canaloplasty (p≤ 0.01). One year after surgery, the cumulative probability of absolute success was 81.33% in group A and 14.67% in group B. After one year, the cumulative probability of qualified success was 93.33% in group A and 82.00% in group B. Conclusion The PreserFlo™ as well as the canaloplasty offer many advantages and only a few disadvantages for patients with glaucoma. However, the respective patient's history and individual risk profile play an important role in the decision of the glaucoma specialist regarding the most appropriate surgical treatment for each patient. Patients with a high risk of conjunctival scarring and postoperative complications may benefit more from a canaloplasty, whereas patients who need a lower average IOP and show intolerance to any topical agents may require the PreserFlo™ implantation.

Comparison of Mid-Term Outcomes between Microhook ab Interno Trabeculotomy and Goniotomy with the Kahook Dual Blade

This study retrospectively examined the mid-term surgical outcomes between microhook ab interno trabeculotomy (μLOT) and goniotomy when one was using the Kahook Dual Blade (KDB) in combination with phacoemulsification in primary open-angle glaucoma and exfoliation glaucoma patients. Between December 2016 and December 2020, the current study examined 47 μLOT and 52 KDB eyes that underwent surgery. When there was a < 20% reduction in the preoperative intraocular pressure (IOP) or when the IOP was > 18 mmHg (criterion A), the IOP was > 14 mmHg (criterion B) at two consecutive follow-up visits, or when there was a requirement for reoperation, these were all considered to indicate that the surgery failed. A genetic algorithm that used the preoperative IOP was used to determine the score matching. After score matching, a total of 27 eyes were evaluated. In the μLOT and KDB groups, the mean postoperative follow-up periods were 31.2 ± 13.3 and 37.2 ± 16.3 months, respectively. The results for both of the groups show there were significant postoperative reductions in the IOP (p < 0.05) and medication scores (p < 0.05) at 6, 12, 24 and 36 months. At 12, 24, and 36 months, the probabilities of success in the μLOT and KDB groups for criterion A were 70.4% and 48.2%, 61.9% and 48.2%, and 55.0% and 48.2% (p = 0.32; log-rank test), respectively. For criterion B, the results for the two groups were 55.6% and 33.3%, 44.4% and 33.3%, and 44.4% and 33.3% (p = 0.15; log-rank test), respectively. Similar postoperative complications were found between the groups. Comparable mid-term surgical outcomes were found for the uses of μLOT and KDB.

Efficacy of Endotrabeculectomy (Trabecula Ablation Ab Interno with the Forceps) for Open-angle Glaucoma

Aim

To investigate the efficacy of endotrabeculectomy (ETE) performed either alone or combined with phacoemulsification (phaco) in patients with primary open-angle glaucoma (POAG).

Materials and methods

Investigations were done in two groups. The first group (38 patients, 38 eyes) with POAG underwent ETE, and the second group of 126 patients (126 eyes) with POAG and cataracts underwent ETE and phaco. The hypotensive effect of the surgery was evaluated.

Results

In the ETE group, the mean intraocular pressure (IOP) was reduced from 20.25 ± 3.30 to 14.94 ± 1.95 mm Hg (26.2% reduction, p < 0.001) at 12 months. The number of medications was reduced from 2.8 ± 1.0 to 1.5 ± 1.0 (p < 0.001) at 12 months after the surgery. In the phaco-ETE group, the mean IOP was reduced from 18.24 ± 3.20 to 14.83 ± 1.71 mm Hg (18.7% reduction, p < 0.001) at 12 months. The mean number of medications was reduced from 2.2 ± 1.1 to 1.0 ± 1.0 (p < 0.001) at 12 months after the surgery. The success rate defined as a final IOP of <16 mm Hg using the Kaplan-Meier curve at 12 months was 73.8%. There were no complications that led to a constant visual decrease.

Clinical significance

Our study shows that ETE is technically simple, gives the ability to remove trabecula in any quadrant, and effectively reduces IOP in patients with POAG.

Conclusion

Endotrabeculectomy (ETE) is a safe and relatively simple procedure that significantly reduces IOP. The minimally invasive nature of the ETE allows expanding indications for combined treatment of glaucoma and cataract.

How to cite this article

Novytskyy IY, Novytskyy MI. Efficacy of Endotrabeculectomy (Trabecula Ablation Ab Interno with the Forceps) for Open-angle Glaucoma. J Curr Glaucoma Pract 2023;17(1):15-21.

Efficacy of the PRESERFLO MicroShunt and a Meta-Analysis of the Literature

Background: Recent studies on the PRESERFLO MicroShunt suggest that it may be effective in lowering intraocular pressure (IOP); however, the number of studies on this device remains limited. Therefore, we assessed the efficacy of the PRESERFLO MicroShunt in patients with glaucoma and performed a meta-analysis of published results. Methods: Prospective study including all patients that underwent PRESERFLO MicroShunt surgery from 2018 onwards. Sub-analyses were performed for cataract-combined procedures. To compare our results, we performed a systematic review and meta-analysis. IOP, IOP-lowering medication and surgical complications reported in the retrieved studies were assessed. Results: A total of 72 eyes underwent PRESERFLO-implant surgery (59 as standalone procedure and 13 as cataract-combined procedure). No significant differences were found in IOP and IOP-lowering medication between both groups. The mean ± standard deviation IOP and IOP-lowering medications of both groups taken together declined from 21.72 ± 8.35 to 15.92 ± 8.54 mmHg (p < 0.001, 26.7% reduction) and 3.40 to 0.93 (p < 0.001, 72.6% reduction) at 1 year follow-up, respectively. Secondary surgeries were required in 19.4% of eyes, the majority (71.4%) within 6 months. The meta-analysis including 14 studies (totaling 1213 PRESERFLO MicroShunt surgeries) from the systematic review showed a mean preoperative IOP and IOP-lowering medication of 22.28 ± 5.38 and 2.97 ± 1.07, respectively. The three-years postoperative pooled mean was (weighted mean difference, 95% CI) 11.07 (10.27 [8.23−12.32], p < 0.001) mmHg and 0.91 (1.77 [1.26−2.28], p < 0.001) for IOP and IOP-lowering medication, respectively. The most common reported complication was hypotony (2−39%). Conclusion: The PRESERFLO MicroShunt is effective and safe in lowering IOP and the number of IOP-lowering medications.

Transient ciliochoroidal detachment after microhook ab interno trabeculotomy: Its frequency and potential risk factors

Purpose

To investigate ciliochoroidal detachment (CCD) frequency and risk factors after performing microhook ab interno trabeculotomy (μLOT).

Methods

A retrospective evaluation of 62 eyes of 62 patients who underwent μLOT and were subsequently examined by anterior-segment optical coherence tomography (AS-OCT) found CCD at 1 day, and 1 and 2 months after surgery.

Results

In the 62 patients (mean age 67.3 ± 13.9 years), AS-OCT detected CCD in 18 eyes (29%) at 1 day after surgery, which disappeared within 1 month. Comparisons between the CCD vs. the non-CCD group showed the mean IOPs were 11.7 ± 1.5 mmHg vs. 14.4 ± 1.0 mmHg at day 1 (P = 0.13), 12.2 ± 1.1 mmHg vs. 14.8 ± 0.7 mmHg at day 7 (P = 0.06), 12.2 ± 0.7 mmHg vs. 12.9 ± 0.5 mmHg at 1 month (P = 0.48), and 11.3 ± 0.7 mmHg vs. 12.7 ± 0.5 mmHg at 2 months (P = 0.09). For postoperative IOP, there were no significant differences observed. After undergoing μLOT, multiple regression analysis demonstrated that the CCD development might be influenced by the presence of a thinner central corneal thickness.

Conclusion

Approximately one-third of all patients exhibited CCD after μLOT. A thinner central corneal thickness was found to be a risk factor for developing CCD.

Topical Anesthesia Offers Sufficient Pain Control for MicroPulse Transscleral Laser Therapy for Glaucoma

Introduction

The aim of this study was to evaluate patient pain during and after MicroPulse Transscleral Laser Therapy (TLT) and vision-related quality of life using two different anesthesia protocols: “Topical Plus” anesthesia without standby anesthesia (study group), and analgosedation with standby anesthesia (control group).

Methods

A retrospective, comparative chart review was conducted to evaluate patient pain between the two groups based on an analog pain scale at baseline and postoperatively (1 hour, 6 hours, 1 day, 1 week, and 1 month). Furthermore, vision-related quality of life at baseline was compared at 1 month postoperatively.

Results

Four eyes underwent MicroPulse TLT under Topical Plus anesthesia and 4 eyes underwent analgosedation. The mean age at the time of the MicroPulse TLT was 78.3 ± 6.4 years. In the study group, the reported pain level increased significantly immediately after the treatment (from 0.5 to 2.8, p=0.003; mild pain); however, no difference was found at any later time point compared to baseline. The vision-related quality of life was similar in both groups and was not negatively impacted by the MicroPulse TLT at 1 month after the treatment. Discussion/Conclusion. The Topical Plus anesthesia protocol provides adequate pain control for the patient to remain comfortable during and post-MicroPulse TLT treatment, with no changes in vision-related quality of life. Although the sample size was small and, thus, the results cannot be generalized, this case series showed that it is possible to perform MicroPulse TLT under topical anesthesia.

Intracanalicular Dexamethasone Insert or Topical Prednisolone Following iStent and Hydrus Surgery for Glaucoma

PRCIS

Using an intracanalicular dexamethasone insert or topical prednisolone following iStent and Hydrus surgery provided similar short-term control of postoperative inflammation.

PURPOSE

The purpose of this study was to compare postoperative inflammation in patients who received an intracanalicular dexamethasone insert or topical prednisolone after iStent or Hydrus insertion during cataract surgery.

PATIENTS AND METHODS

Patients receiving a dexamethasone insert after iStent or Hydrus insertion were included and compared with age-matched controls who received topical prednisolone. Preoperative data were recorded. Postoperative inflammatory cell and the proportion of patients with zero anterior chamber cells was recorded at month 1. Postoperative intraocular pressure (IOP) and rate of cystoid macular edema were recorded at months 1 and 3.

RESULTS

Forty eyes receiving topical prednisolone were compared with 35 eyes receiving a dexamethasone insert after iStent or Hydrus insertion. The mean postoperative inflammatory cell for the topical group at month 1 was 0.2±0.3, and the dexamethasone group, 0.3±0.5 ( P =0.816). Overall, 70% of patients in the topical group had zero anterior chamber cell at postoperative month 1 compared with 75.8% in the dexamethasone group ( P =0.583). The mean preoperative IOP for the topical group was 18.8±5.5 and the dexamethasone group was 17.1±4.1 ( P =0.064). Mean postoperative IOP for the topical group at months 1 and 3 was 17.6±6.4 and 15.1±3.1, respectively and the dexamethasone group, 17.5±4.8 and 15.0±3.4, respectively ( P =0.772 and 0.884). One patient developed cystoid macular edema in each group.

CONCLUSION

There was no statistically significant difference in the proportion of patients who had zero anterior chamber cell at postoperative month 1 between groups receiving intracanalicular dexamethasone insert or topical prednisolone.

Usage Patterns of Minimally Invasive Glaucoma Surgery (MIGS) Differ by Glaucoma Type: IRIS Registry Analysis 2013-2018

PURPOSE

To examine patterns of standard (trabeculectomy or glaucoma drainage devices, GDDs) vs novel (minimally invasive glaucoma surgery, MIGS) surgical techniques in the US.

METHODS

We used the American Academy of Ophthalmology (AAO) IRIS® Registry (Intelligent Research in Sight) queried between 2013 and 2018 (inclusive) to calculate the cumulative proportion of stand-alone, concurrent (same day) or sequential (subsequent day) glaucoma surgical techniques performed in each glaucoma diagnosis type. Secondary analyses of adjusted proportions of concurrent and sequential surgeries stratified by glaucoma diagnosis were also performed.

RESULTS

Of 203,146 eyes receiving glaucoma surgeries, open angle glaucoma (OAG) was most likely to undergo all types of intervention. The iStent was the most commonly performed MIGS, primarily for those with normal tension glaucoma (NTG) or OAG (p < .001). Conversely, GDD was the most commonly performed procedure in secondary glaucoma or other (specified) glaucoma (p < .001). ECP and iStent were the most common concurrent procedures performed; most often for OAG and NTG (p < .001). After an initial standard surgery, most eyes underwent recurrent standard interventions (90.3%). ECP was the most common MIGS performed after an initial standard surgery; particularly in primary angle-closure (PACG) and secondary glaucoma eyes (p < .001).

CONCLUSION

Glaucoma type may influence the choice of glaucoma procedures and the decision to perform concurrent as well sequential surgical procedures. Given the poorly understood long term safety and effectiveness of MIGS, and with substantially increasing use of MIGS procedures in recent years, future studies comparing their safety and effectiveness vs standard interventions, for a variety of glaucoma types, is needed.

3-year Outcomes of XEN Implant Compared to Trabeculectomy, With or Without Phacoemulsification for Open-angle Glaucoma

PRCIS

Trabeculectomy surgery reduces the intraocular pressure (IOP) more than the XEN45 implant over 3 years. There is no difference in the number of antiglaucoma medications between the two procedures. The decision to perform either trabeculectomy or XEN45 implantation must be evaluated on a case-by-case basis, taking into account the high rate of needling of the XEN45.

PURPOSE

The aim of this study was to compare the differences between the efficacy and safety of the XEN45 implant and trabeculectomy (TRAB), either alone or in combination with phacoemulsification (PHACO), in patients with open-angle glaucoma (OAG) at 36 months.

METHODS

A retrospective, single-center and comparative study conducted on OAG patients that underwent XEN45 implantation or trabeculectomy from 2016 to 2018. Patients were divided into four groups: group 1 (XEN45 alone); group 2 (XEN45+PHACO); group 3 (TRAB alone); group 4 (TRAB+PHACO). For statistical purposes, groups 1 and 2 were combined (XEN45 implant), while groups 3 and 4 were also combined (TRAB surgery). Intraocular pressure (IOP), number of antiglaucoma medications (NOAM) and adverse events were evaluated. The main outcome measure was the reduction in IOP at 36 months postoperatively.

RESULTS

One hundred and thirty-four patients (134 eyes; 63 XEN45 and 71 TRAB) were included. The mean (95% CI) IOP reduction at the end of the study follow-up was-6.3 (-11.0 to -1.6 mmHg, P=0.025, XEN45 alone),-8.9 (-11.0 to-6.8 mmHg, P<0.001, TRAB alone),-2.5 (-4.5 to -0.4 mmHg, P=0.019, XEN45+PHACO), and-5.6 (-7.7 to-3.4 mmHg, P<0.001, TRAB±PHACO). The proportion of patients achieving an IOP≥6 and≤16 mmHg without treatment at the end of the 36-month follow-up were 50.8% (32/63) in the XEN45 implant and 49.3% (35/71) in the TRAB surgery group, P=0.863. The mean number of antiglaucoma medications was significantly reduced in all the study groups. The needling rate was 19% in XEN45 versus 5.6% in the TRAB group (P=0.030), and 2.81% and 36.6% of eyes in the TRAB group presented anterior chamber (AC) flattening and hyphema, respectively.

CONCLUSIONS

Trabeculectomy surgery lowered IOP significantly more than XEN45 implant with or without phacoemulsification over 3 years and had a significantly lower need for additional needling surgery. Both procedures reduce the number of antiglaucoma medications to a similar rate. These findings are relevant to the informed consent process and patient decisions for one procedure over the other.

Evaluation of a Novel Αb Εxterno MicroShunt for the Treatment of Glaucoma

The surgical management of glaucoma has been revolutionized by the introduction of minimally invasive glaucoma surgery (MIGS). The various MIGS options aim to meaningfully lower intraocular pressure with a better safety profile than traditional glaucoma surgery. The key clinical attributes and the emerging potential of an ab externo MicroShunt (PreserFlo™) are reviewed in the context of published evidence and clinical experience. This novel MicroShunt consists of an 8.5-mm-long tube that is implanted in the eye via an ab externo approach enabling aqueous humor drainage into the sub-Tenon’s space through the formation of a bleb, similar in appearance to that created by trabeculectomy. The efficacy and safety of this procedure, the concomitant use of antimetabolites, the impact of tube positioning, and its future value in clinical practice are critically reviewed. Recent evidence has demonstrated the MicroShunt to be less effective than traditional filtration surgery, but with a significant improvement in safety. Cumulative data suggest that the new implant provides tangible clinical benefits to selected patients with glaucoma in need of further intraocular pressure (IOP) lowering. Future research should delineate the precise role of this and other MIGS options in the rapidly evolving glaucoma treatment algorithm.

Anterior Segment-Optical Coherence Tomography Bleb Morphology Comparison in Minimally Invasive Glaucoma Surgery: XEN Gel Stent vs. PreserFlo MicroShunt

Background: The purpose of this study is to compare the morphology of six-month follow-up blebs created by a subconjunctival glaucoma surgical device (XEN45) to those created by a PreserFlo MicroShunt with a sub-Tenon insertion, utilizing AS-OCT. Methods: A retrospective study of 29 eyes who underwent XEN45 implantation and 29 eyes who underwent PreserFlo MicroShunt implantation. The patients were analyzed at 24 h, 1 week, 1 month, 3 months and 6 months. At each visit, the maturation and morphological alterations of the blebs were observed, as well as connections with the IOP. Results: In both groups, IOP showed significant reduction at all follow ups (p < 0.0001). In XEN group, the most common bleb morphology in the immediate postoperative was the subconjuntival separation type (42%) followed by the uniform type (34%), with a trend inversion at 6 month follow up (51% of uniform type). On the contrary, the most common morphology after PreserFlo was the multiple internal layer (55%), which showed a tendency to reduce over time and was substituted by the microcystic multiform, whose percentage increased over time (17% at day 1 vs. 44% at month 6). Uniform appearance was associated by the posterior episcleral fluid (PEF) lake presence. Both horizontal and vertical diameters significantly increased over time. Conclusion: XEN and PreserFlo implantation resulted in the production of diffuse blebs with different characteristics, which may influence IOP lowering capacity and bleb revisions necessity over time.

The surgical management of glaucoma: A review

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

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

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

Selective laser trabeculoplasty following failed combined phacoemulsification cataract extraction and excimer laser trabeculotomy can control intraocular pressure for a limited time

PURPOSE

To assess the efficacy of selective laser trabeculoplasty (SLT) following failed phacoemulsification cataract extraction combined with excimer laser trabeculotomy (phaco-ELT).

METHODS

Retrospectively, the medical records of patients with primary or secondary open-angle glaucoma or ocular hypertension who underwent SLT between January 2001 and February 2015 by one surgeon at a single center after a failed phaco-ELT were evaluated. Exclusion criteria were: angle-closure glaucoma, optic nerve atrophy due to disease other than glaucoma, and additional glaucoma procedures between phaco-ELT and SLT. The main outcome measures were time to failure and Kaplan-Meier survival. Complete success was defined as a reduction of intraocular pressure (IOP) of  > 3 mmHg and  > 20% compared to baseline, and the number of AGM ≤ baseline.

RESULTS

A total of 23 eyes of 21 subjects were included. Baseline IOP was 19.7 (range, 19.1-22.7) mmHg, and the number of AGM at baseline was 2.5 (range, 1.9-2.9). Median time to failure after SLT was 7.2 (range, 6.6-7.8) months. The number of antiglaucoma medications did not change during that time.

CONCLUSIONS

In eyes in which the IOP is no longer controlled following phaco-ELT, SLT could be an option to slow disease progression or prolong time until incisional filtration surgery. However, time to failure after SLT is limited. Thus, close follow-up visits are necessary in order to not delay an incisional surgery.

Anterior-segment optical coherence tomography of filtering blebs in the early postoperative period of ab externo SIBS microshunt implantation with mitomycin C: Morphological analysis and correlation with intraocular pressure reduction

PURPOSE

To analyse the morphological evolution of filtering blebs with anterior-segment OCT (AS-OCT) and its correlation with intraocular pressure after ab externo SIBS microshunt implantation with mitomycin C (MMC) during a 3-month follow-up period.

METHODS

Twenty-eight filtering blebs of 28 patients with open-angle glaucoma were measured horizontally and vertically in the sub-Tenon space with AS-OCT after ab externo SIBS microshunt implantation with MMC. The intraocular pressure (IOP) was monitored simultaneously at each visit. Maturation of and morphological changes in the blebs and correlations with the IOP were recorded.

RESULTS

The average median preoperative IOP of 20.7 (range, 12-30) mmHg decreased to 8.5 (range, 4-17), 8.9 (range, 5-17), 10.4 (range, 8-16) and 10.9 (range, 9-15) mmHg at 24 hr, 1 week, 1 month and 3 months, respectively (p < 0.001). A multiform morphology on AS-OCT prevailed at all time points, with a 3.5% rate of a uniform bleb morphology at the first week. The horizontal and vertical diameters of the blebs increased from baseline to the third month. The horizontal expansion (406 ± 127 μm on day 7, p = 0.04, 712 ± 211 μm on day 30, p = 0.02 and 952 ± 218 μm on day 90, p < 0.001) was greater than the vertical expansion (16 ± 18 μm, p = 0.3 on day 1, 63 ± 27 μm, p = 0.02 on day 30 and 137 ± 34 μm, p < 0.001 on day 90) without correlation with the IOP (r = -0.3, p = 0.2).

CONCLUSION

Anterior-segment OCT (AS-OCT) of the filtering blebs formed after ab externo SIBS microshunt implantation showed progressive horizontal and vertical expansion of the blebs in the sub-Tenon space, with a significant peak at the first month not significantly correlated with the decrease in the IOP.

Comparison of Different Procedures in a Combination of Ab Interno Microhook Trabeculotomy and Cataract Surgery

The purpose of this study was to compare the clinical outcomes of ab interno microhook trabeculotomy (µLOT) before and after cataract surgery for the combination of µLOT and cataract surgery. This retrospective case series included 40 eyes that underwent µLOT combined with cataract surgery at Kochi University Hospital. Groups 1 (20 eyes) and 2 (20 eyes) included eyes that underwent µLOT before and after cataract surgery, respectively. The patient characteristics and clinical outcomes were also analyzed. The mean preoperative intraocular pressure (IOP) in Groups 1 and 2 (26.1 ± 12.2 mmHg and 20.6 ± 8.8 mmHg) was reduced significantly to 14.1 ± 3.3 mmHg and 12.9 ± 3.2 mmHg, respectively, at 5–7 months postoperatively. The median preoperative number of antiglaucoma medications in Groups 1 and 2 (4.0 and 3.5) also decreased significantly, to 2.5 and 1.0, respectively, at 5–7 months postoperatively. Postoperative hyphema with niveau formation in Groups 1 and 2 was observed in one eye (5.0%) and six eyes (30.0%), respectively. For the combination of µLOT and cataract surgery, performing µLOT before cataract surgery may be less likely to result in postoperative hyphema with niveau formation.

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

PRCIS

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Micropulse Transscleral Cyclophotocoagulation as Primary Surgical Treatment for Primary Open Angle Glaucoma in Taiwan during the COVID-19 Pandemic

Glaucoma is the leading cause of irreversible blindness worldwide, with primary open angle glaucoma (POAG) accounting for the greatest number of total glaucoma cases. This study aimed to evaluate the efficacy and safety of micropulse transscleral cyclophotocoagulation (MP-TSCPC) as a primary procedure in POAG during the COVID-19 pandemic. We retrospectively analyzed 60 eyes of 52 patients, who were diagnosed with mild-to-end-stage POAG without previous glaucoma surgery and received MP-TSCPC between 1 January 2020 and 31 August 2020. The mean preoperative intraocular pressure (IOP) significantly decreased from 27.8 mm Hg to 19.8, 20.1, 20.3, 20.4, and 20.2 mm Hg at 1, 3, 6, 9, and 12 months, respectively (all p < 0.05). The mean number of IOP-lowering medications used significantly decreased from 3.3 at the baseline to 1.6, 1.8, 1.8, 1.9, and 1.9 at 1, 3, 6, 9, and 12 months, respectively (all p < 0.001). Total withdrawal of antiglaucoma medications was fulfilled in five patients. The main outcome was achieved in 81.7% at postoperative month 12. The most common adverse effect was transient mydriasis (28.3%). No major complications were encountered. MP-TSCPC seems to be an effective and safe treatment to reduce IOP and the medication burden with minimal vision-threatening complications in mild-to-end-stage POAG patients without previous glaucoma surgery.

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

PURPOSE

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

DESIGN

Retrospective analysis.

PARTICIPANTS

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

METHODS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

Minimally Invasive Glaucoma Surgical Techniques for Open-Angle Glaucoma: An Overview of Cochrane Systematic Reviews and Network Meta-analysis

IMPORTANCE

Glaucoma affects more than 75 million people worldwide. Intraocular pressure (IOP)-lowering surgery is an important treatment for this disease. Interest in reducing surgical morbidity has led to the introduction of minimally invasive glaucoma surgeries (MIGS). Understanding the comparative effectiveness and safety of MIGS is necessary for clinicians and patients.

OBJECTIVE

To summarize data from randomized clinical trials of MIGS for open-angle glaucoma, which were evaluated in a suite of Cochrane reviews.

DATA SOURCES

The Cochrane Database of Systematic Reviews including studies published before June 1, 2021.

STUDY SELECTION

Reviews of randomized clinical trials comparing MIGS with cataract extraction alone, other MIGS, traditional glaucoma surgery, laser trabeculoplasty, or medical therapy.

DATA EXTRACTION AND SYNTHESIS

Data were extracted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines by one investigator and confirmed by a second. Methodologic rigor was assessed using the AMSTAR 2 appraisal tool and random-effects network meta-analyses were conducted.

MAIN OUTCOMES AND MEASURES

The proportion of participants who did not need to use medication to reduce intraocular pressure (IOP) postsurgery (drop-free). Outcomes were analyzed at short-term (<6 months), medium-term (6-18 months), and long-term (>18 months) follow-up.

RESULTS

Six eligible Cochrane reviews were identified discussing trabecular bypass with iStent or Hydrus microstents, ab interno trabeculotomy with Trabectome, subconjunctival and supraciliary drainage devices, and endoscopic cyclophotocoagulation. Moderate certainty evidence indicated that adding a Hydrus safely improved the likelihood of drop-free glaucoma control at medium-term (relative risk [RR], 1.6; 95% CI, 1.4 to 1.8) and long-term (RR, 1.6; 95% CI, 1.4 to 1.9) follow-up and conferred 2.0-mm Hg (95% CI, -2.7 to -1.3 mm Hg) greater IOP reduction at long-term follow-up, compared with cataract surgery alone. Adding an iStent also safely improved drop-free disease control compared with cataract surgery alone (RR, 1.4; 95% CI, 1.2 to 1.6), but the short-term IOP-lowering effect of the iStent was not sustained. Addition of a CyPass microstent improved drop-free glaucoma control compared with cataract surgery alone (RR, 1.3; 95% CI, 1.1 to 1.5) but was associated with an increased risk of vraision loss. Network meta-analyses supported the direction and magnitude of these results.

CONCLUSIONS AND RELEVANCE

Based on data synthesized in Cochrane reviews, some MIGS may afford patients with glaucoma greater drop-free disease control than cataract surgery alone. Among the products currently available, randomized clinical trial data associate the Hydrus with greater drop-free glaucoma control and IOP lowering than the iStent; however, these effect sizes were small.

A review of additive manufacturing applications in ophthalmology

Additive Manufacturing (AM) capabilities in terms of product customization, manufacture of complex shape, minimal time, and low volume production those are very well suited for medical implants and biological models. AM technology permits the fabrication of physical object based on the 3D CAD model through layer by layer manufacturing method. AM use Magnetic Resonance Image (MRI), Computed Tomography (CT), and 3D scanning images and these data are converted into surface tessellation language (STL) file for fabrication. The applications of AM in ophthalmology includes diagnosis and treatment planning, customized prosthesis, implants, surgical practice/simulation, pre-operative surgical planning, fabrication of assistive tools, surgical tools, and instruments. In this article, development of AM technology in ophthalmology and its potential applications is reviewed. The aim of this study is nurturing an awareness of the engineers and ophthalmologists to enhance the ophthalmic devices and instruments. Here some of the 3D printed case examples of functional prototype and concept prototypes are carried out to understand the capabilities of this technology. This research paper explores the possibility of AM technology that can be successfully executed in the ophthalmology field for developing innovative products. This novel technique is used toward improving the quality of treatment and surgical skills by customization and pre-operative treatment planning which are more promising factors.

Ab interno supraciliary microstent surgery for open-angle glaucoma

BACKGROUND

Glaucoma is the leading cause of global irreversible blindness, often associated with raised intraocular pressure (IOP). Where medical or laser treatment has failed or is not tolerated, surgery is often required. Minimally-invasive surgical approaches have been developed in recent years to reduce IOP with lower surgical risks. Supraciliary microstent surgery for the treatment of open-angle glaucoma (OAG) is one such approach.

OBJECTIVES

To evaluate the efficacy and safety of supraciliary microstent surgery for the treatment of OAG, and to compare with standard medical, laser or surgical treatments.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2020, Issue 8); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 27 August 2020.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) of supraciliary microstent surgery, alone or with cataract surgery, compared to other surgical treatments (cataract surgery alone, other minimally invasive glaucoma device techniques, trabeculectomy), laser treatment or medical treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts from the database search to identify studies that met the selection criteria. Data extraction, analysis, and evaluation of risk of bias from selected studies was performed independently and according to standard Cochrane methodology.

MAIN RESULTS

One study met the inclusion criteria of this review, evaluating the efficacy and safety of the Cypass supraciliary microstent surgery for the treatment of OAG, comparing phacoemulsification + supraciliary microstent surgery with phacoemulsification alone over 24 months. This study comprised 505 eyes of 505 participants with both OAG and cataract, 374 randomised to the phacoemulsification + microstent group.  In this study, the perceived risk of bias from random sequence generation, allocation concealment and selective reporting was low. However, we considered the study to be at high risk of performance bias as surgeons/investigators were unmasked. Attrition bias was unclear, with 448/505 participants contributing to per protocol analysis. Insertion of a Cypass supraciliary microstent combined with phacoemulsification probably increases the proportion of participants who are medication-free (not using eye-drops) at 24 months compared with phacoemulsification alone (85% versus 59%, risk ratio (RR) 1.27, 95% confidence interval (CI) 1.09 to 1.49, moderate-certainty evidence). There is high-certainty evidence that a greater improvement in mean IOP occurs in the phacoemulsification + microstent group - mean (SD) change in IOP from baseline of -5.4 (3.9) mmHg in the phacoemulsification group, compared to -7.4 (4.4) mmHg in the phacoemulsification + microstent group at 24 months (mean difference -2.0 mmHg, 95% CI -2.85 to -1.15). There is moderate-certainty evidence that insertion of a microstent is probably associated with a greater reduction in use of IOP-lowering drops (mean reduction of 0.7 medications in the phacoemulsification group, compared to a mean reduction of 1.2 medications in the phacoemulsification + microstent group). Insertion of a microstent during phacoemulsification may reduce the requirement for further glaucoma intervention to control IOP at a later stage compared to phacoemulsification alone (RR 0.26, 95% CI 0.07 to 1.04, low-certainty evidence). There is no evidence relating to the rate of visual field progression, or proportion of participants whose visual field loss progressed in this study. There is moderate-certainty evidence showing little or no difference in the proportion of participants experiencing postoperative complications over 24 months between participants in the microstent group compared to those who received phacoemulsification alone (RR 1.1, 95% CI 0.8 to 1.4). Five year post-approval data regarding the safety of the Cypass supraciliary microstent showed increased endothelial cell loss, associated with the position of the microstent in the anterior chamber. There were no reported health-related quality of life (HRQoL) outcomes in the included study.

AUTHORS' CONCLUSIONS

Data from this single RCT show superiority of supraciliary microstent surgery when combined with phacoemulsification compared to phacoemulsification alone in achieving medication-free control of OAG. However, there are long-term safety concerns with the device used in this trial, relating to the observed significant loss of corneal endothelial cells at five years following device implantation. At the time of this review, this device has been withdrawn from the market. This review has found that few high-quality studies exist comparing supraciliary microstent surgery to standard medical, laser or surgical glaucoma treatments. This should be addressed by further appropriately designed RCTs with sufficient long-term follow-up to ensure robust safety data are obtained. Consideration of health-related quality of life outcomes should also feature in trial design.

XEN® Gel Stent compared to PRESERFLO™ MicroShunt implantation for primary open-angle glaucoma: two-year results

Purpose

To evaluate the long‐term efficacy and safety of two minimally invasive glaucoma surgery implants with a subconjunctival drainage approach: the XEN45 Gel Stent^® (Xen) implant and the PRESERFLO™ MicroShunt (MicroShunt).

Methods

Retrospective comparative case series of primary open‐angle glaucoma (POAG) patients with at least 6 months of follow‐up after a MicroShunt or Xen implantation augmented with mitomycin C.

Results

Forty‐one eyes of 31 patients underwent Xen implantation, and 41 eyes of 33 patients, MicroShunt implantation. Baseline characteristics were similar, except for more combined surgeries with phacoemulsification in the Xen group (37% vs. 2%). Mean baseline IOP ± standard deviation dropped from 19.2 ± 4.4 to 13.8 ± 3.8 mmHg (n = 26) in the Xen group and from 20.1 ± 5.0 to 12.1 ± 3.5 (n = 14) in the MicroShunt group at 24 months of follow‐up (p = 0.19, t‐test). The number of IOP‐lowering medications dropped from 2.5 ± 1.4 to 0.9 ± 1.2 in the Xen group and from 2.3 ± 1.5 to 0.7 ± 1.1 in the MicroShunt group. The probability of qualified success was 73% and 79% at 24 months of follow‐up for the Xen and MicroShunt groups, respectively. Postoperative complications were usually mild and self‐limiting. The number of bleb needling and secondary glaucoma surgery procedures was similar in both groups; however, in the Xen group more additional MicroPulse^® transscleral cyclophotocoagulation procedures were performed.

Conclusion

Xen Gel Stent and PreserFlo MicroShunt implantations achieved comparable results in POAG eyes in terms of IOP‐lowering and surgical success, with a similar high safety profile.

Standalone XEN45 Gel Stent implantation versus combined XEN45-phacoemulsification in the treatment of open angle glaucoma-a systematic review and meta-analysis

PURPOSE

The XEN45 Gel Stent is currently the only FDA-approved sub-conjunctival minimally invasive glaucoma surgery (MIGS) procedure. It has been used worldwide either as a standalone implantation procedure or in combination with phacoemulsification surgery. Concomitant phacoemulsification is understood to influence outcomes of traditional subconjunctival filtering surgery. However, the comparative efficacy between standalone XEN45 Gel Sent implantation ("Standalone XEN45") and combined XEN-phacoemulsification surgery ("XEN45-Phaco") remains unclear. This study aims to appraise current literature to compare the efficacy of Standalone XEN45 and XEN45-Phaco in open-angle glaucoma.

METHODS

A comprehensive search of PubMed, CINAHL, CENTRAL databases was performed with the terms "Xen surgery" followed by selective vetting. Pilot, cohort, observational studies and randomised controlled trials that included at least 10 patients undergoing either Standalone XEN45 or XEN45-Phaco surgeries for the treatment of open-angle glaucoma were deemed eligible for inclusion after independent assessment by 2 authors. The search workflow was reported according to the PRISMA guidelines. Data was pooled using random-effects model. A meta-analysis of continuous outcome and proportions was performed using the meta routine in R v3.2.1.

RESULTS

Ten studies were included. There was a statistically significant difference in IOP reduction favouring Standalone XEN45 at post-operative day 1, week 1, months 1, 3 and 6. There was a statistically significant difference in decrease in IOP-lowering medications favouring Standalone XEN45 at post-operative week 1 and month 1.

CONCLUSION

Standalone XEN45 has superior IOP-lowering outcomes compared to XEN45-Phaco in the early post-operative period, up to 6 months after surgery.

Ab interno trabecular bypass surgery with Trabectome for open-angle glaucoma

BACKGROUND

Glaucoma is the leading cause of irreversible blindness. Minimally invasive surgical techniques, such as ab interno trabecular bypass surgery, have been introduced to prevent glaucoma from progressing.   OBJECTIVES: In light of the potential benefits for people with open-angle glaucoma and the widespread uptake of the technique, it is important to critically evaluate the evidence for whether treatment with ab interno trabecular bypass surgery with Trabectome is both efficacious and safe.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2020, Issue 7); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 17 July 2020.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) of ab interno trabecular bypass surgery with Trabectome compared to other surgical treatments (other minimally invasive glaucoma device techniques, trabeculectomy), laser treatment, or medical treatment. We also included trials in which these devices were combined with phacoemulsification compared to phacoemulsification in combination with other glaucoma surgery or alone.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. Our primary outcome was proportion of participants who were medication-free (not using eye drops). Secondary outcomes included mean change in intraocular pressure (IOP), proportion of participants who required further glaucoma surgery, mean change in quality of life, proportion of participants who achieved an IOP of 21 mmHg or less, 17 mmHg or less, or 14 mmHg or less and rate of visual field progression. Adverse effects were the proportion of participants experiencing intra- and postoperative complications. All outcomes were measured in the short term (6 to 18 months), medium term (18 to 36 months), and long term (36 months or longer).

MAIN RESULTS

In this update, we included one RCT which had previously been identified as an ongoing study in our 2016 publication. This trial was a single-centre, single-surgeon RCT set in Canada with 19 participants. Participants were adults who had open-angle glaucoma, open angles, and had inadequately controlled IOP that required surgical intervention. The study was terminated before the intended sample size was reached 'due to slow recruitment and increasing lack of clinical equipoise over time'. This reduced the power of the study to detect clinically important effects. We assessed the trial as being at high risk of attrition, reporting, and other potential sources of biases. The risks of performance and detection bias are unclear. The intervention group of 10 people had Trabectome ab interno trabeculotomy combined with cataract extraction (phaco-AIT) and the comparator group of 9 people had trabeculectomy with mitomycin C combined with cataract extraction (phaco-Trab), one of whom was lost to follow-up. Seven of 10 participants in the phaco-AIT group and 4 of 8 in the phaco-Trab group were medication-free (not using drops) at 12 months (odds ratio (OR) 2.33, 95% confidence interval (CI) 0.34 to 16.2; very low-certainty evidence). At 12 months, the mean change in IOP was worse for phaco-AIT than for phaco-Trab, but this evidence was very uncertain (mean difference (MD) 3.70 mmHg, 95% CI -1.44 to 8.84; very low-certainty evidence) in the phaco-AIT group, as was the difference in the mean number of IOP-lowering drops taken per day (MD -0.41, 95% CI -1.22 to 0.40; very low-certainty evidence). Only one participant in the phaco-AIT group required further glaucoma surgery. The study protocol declared that quality of life and visual field progression were measured, but they were not reported All 8 participants with complete data in the phaco-Trab group and 8 of 10 in the phaco-AIT had at least one early or late postoperative complication (e.g. day 1 IOP spike, hypotony, choroidal effusion, bleb leak or encapsulation, uveitis, or peripheral anterior synechiae). The evidence was very low-certainty due to high risk of bias for several domains for this study and for large imprecision of all estimates. We also identified one ongoing study, identified from the International Clinical Trials Registry Platform (ICTRP): a multicentre, open, RCT comparing Trabectome to ab interno trabeculectomy using microhook. The study investigators plan to recruit 120 adults between 20 and 90 years of age. The primary outcome is duration of treatment success. Secondary outcomes include postoperative IOP, number of anti-glaucoma medications, and adverse events.

AUTHORS' CONCLUSIONS

There is currently no high-quality evidence for the outcomes of ab interno trabecular bypass surgery with Trabectome for open-angle glaucoma. Properly designed RCTs are needed to assess the long-term efficacy and safety of this technique.