Using a Novel, Subconjunctival, Sustained-Release Mitomycin C Formulation in a Rabbit Model of Filtration Surgery with Gel Stent Implantation

Purpose: To investigate gel stent implantation with and without intraoperative sustained-release mitomycin C (MMC SR) in a rabbit model for gel stent implantation, and to examine aqueous humor outflow (AHO) postimplantation. Methods: Four groups of rabbits were included. Group 1 was untreated (control). Groups 2, 3, and 4 received the gel stent without MMC, with MMC solution (subconjunctival injection), and with MMC SR (subconjunctival injection), respectively. Intraocular pressure (IOP) and AHO were assessed via tonometry and indocyanine green-based angiography, respectively. The main efficacy measure was change in IOP from baseline. Results: Following gel stent implantation, Groups 2, 3, and 4 maintained ≥20% IOP reduction (response) for a median duration of 1 week, 6.5 weeks, and 30 weeks, respectively. Angiography showed normal aqueous humor drainage (Group 1) beginning at the perilimbal trabecular plexus and continuing posteriorly to episcleral outflow vessels. Following implantation, drainage occurred preferentially and directly into the subconjunctival bleb. Conclusions: Gel stent implantation with MMC SR was most effective in achieving sustained, long-term IOP reduction in the rabbit model, compared with implantation with or without MMC solution. Bleb presence and the postimplantation aqueous angiography results indicated redirection of the AHO to the subconjunctival vasculature and presumed lymphatics, suggesting efficient glaucoma filtration to lower IOP in this model. This rabbit model and aqueous angiography may help refine understanding of the mechanism of action of minimally invasive glaucoma surgeries and ultimately translate to improved surgical devices and procedures for patients with glaucoma.

Long-Term Efficacy of Successful Excisional Goniotomy with the Kahook Dual Blade

Purpose

To report clinical outcomes of successful excisional goniotomy with the Kahook Dual Blade (KDB), through 60 months.

Patients and methods

This was a noncomparative, single-surgeon, retrospective review of eyes receiving successful KDB goniotomy with or without concomitant phacoemulsification between October 2015 and January 2016 with five years of uninterrupted follow-up. Intraocular pressure (IOP), number of glaucoma medications, best corrected visual acuity (BCVA), and complications were recorded. Primary outcomes included changes from baseline in IOP, medication use, and BCVA, through five years.

Results

Fifty-two eyes of 28 patients were analyzed. Most eyes had mild primary open angle glaucoma (73%). Of the eyes analyzed, 41 underwent combined surgery and 11 underwent standalone surgery. With all eyes combined, mean (standard deviation) baseline IOP was 21.0 (4.1) mmHg and mean baseline medication use was 1.8 (1.1) medications per eye. Across time points at months 6, 12, 24, 36, 48, and 60, mean postoperative IOP ranged from 13.0 to 13.7 mmHg, representing mean reductions of 7.3-8.0 mmHg (34.7-38.3%; p <0.0001 at every time point). Similarly, mean medication use ranged from 0.4 to 0.6 medications per eye, representing mean reductions of 1.2-1.4 medications (66-75.5%; p <0.0001 at every time point). Mean logMAR BCVA improved from 0.321 (0.177) preoperatively to 0.015 (0.035) at month 60 (p < 0.0001).

Conclusion

In eyes not requiring secondary surgical procedures (eg, long-term surgical successes), excisional goniotomy provided clinically and statistically significant reductions in both IOP and the need for medications that were highly consistent through five years of follow-up. KDB goniotomy appears to be highly successful in Caucasian patients with open angle glaucoma on ≥1 IOP-lowering medications at baseline and with no history of prior ocular surgery. Successful excisional goniotomy with the KDB can be expected to improve long-term glaucoma-related visual outcomes through IOP reduction and to improve quality of life through medication reduction.

The gonio scratch study: methodology of a multicenter clinical trial establishing a new minimally invasive glaucoma surgery

There are numerous surgical procedures for glaucoma. Minimally invasive glaucoma surgery is becoming popular; however, the disadvantage is the high incidence of anterior chamber hemorrhage. Heavy bleeding can also lead to increased intraocular pressure (IOP) postoperatively. Gonio scratch is a surgical procedure that improves aqueous humor outflow by rubbing off deposits on the trabecular meshwork with a Diamond Dusted Sweeper. As the conjunctiva and trabecular meshwork are not incised, no postoperative bleeding is expected, and the IOP spike will be minimal. We designed this study to determine the efficacy and safety of gonio scratch. This is an on-going multicenter, prospective, clinical trial. Patients who are scheduled for glaucoma surgery with or without cataract surgery are being enrolled. A total of 80 eyes will be recruited in the Hiroshima University Hospital, Miyoshi Eye Clinic, Yokoyama Retina Clinic, and Kusatsu Eye Clinic. All patients will undergo gonio scratch. When combined with cataract surgery, gonio scratch is performed after the intraocular lens is inserted. The primary study endpoint is the change in IOP from baseline to 1 year after surgery. The secondary endpoints are complications, number of glaucoma medications, surgical time, and changes in visual acuity and the visual field. This study protocol was approved by the institutional review board of Hiroshima University. The trial results will be shared with the scientific community at international conferences and by publication in a peer-reviewed journal. Trial registration number is jRCTs062200003.

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

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

Changes to glaucoma surgery patterns during the coronavirus disease 2019 pandemic: a shift towards less invasive procedures

PURPOSE

The aim of the study was to compare the quantity, type of glaucoma surgeries, and the disease stage before and during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

This was a retrospective, single-centre consecutive case series that included medical records of patients who underwent glaucoma surgery at the University Hospital in Białystok between 4 September, 2018, and 3 March, 2020 (pre-pandemic group) and compared it with patients treated between 4 March, 2020, and 4 September, 2021 (pandemic group). Adult patients with primary or secondary open-angle or closed-angle glaucoma who underwent surgery were included in this study. Finally, 534 operated eyes (362 and 172 eyes operated on before and during the pandemic, respectively) were examined.

RESULTS

The number of glaucoma surgeries dropped by 50% during the pandemic compared to a similar pre-pandemic period, with a significant difference in the kind of procedure between the two groups (p < 0.001). The most common procedures in the pre-pandemic group were Ex-Press implantation (33.7%) and trabeculectomy (31.5%). Within the pandemic group, half of the eyes underwent trabeculectomy (50.0%), followed by Preserflo microshunt (11.6%), iStent (8.7%), and transscleral cyclophotocoagulation (TSCP) (8.7%). A significant difference in the average intraocular pressure was revealed among patients who qualified for surgery.

CONCLUSION

The COVID-19 pandemic is associated with a decrease in the number of extended antiglaucoma procedures and an increase in the number of short procedures performed, such as TSCP and minimally invasive glaucoma surgery.Key MessagesOur study has shown the negative impact of the COVID-19 pandemic in reducing the number of antiglaucoma procedures.The number of glaucoma surgeries dropped by 50% during the pandemic compared to those in a similar pre-pandemic period, and the type of performed procedures has changed.The COVID-19 pandemic is associated with a decrease in the number of combined antiglaucoma procedures, in opposite: the number of minimally invasive glaucoma surgeries increased due to safety reasons.

Fellow-Eye Comparison between Phaco-Tanito Microhook Trabeculotomy and Phaco-iStent Inject W

This study aims to compare the surgical efficacy and safety of the Tanito microhook trabeculotomy (TMH-CE) and iStent inject W (Inject-CE) when performed in combination with cataract surgery on the eyes of glaucoma patients. A total of 78 glaucomatous eyes from 39 participants were retrospectively analyzed. Intraocular pressure (IOP), the number of antiglaucoma medications, best-corrected visual acuity (BCVA), anterior chamber flare (ACF), and corneal endothelial cell density (CECD) were all evaluated preoperatively and at multiple postoperative time points. The preoperative IOP was significantly higher in the TMH-CE (19.6 ± 6.7 mmHg) than in the Inject-CE (15.7 ± 3.8 mmHg) (p < 0.0001). At the 12-month follow-up, reductions in IOP and the number of medications were more pronounced in the TMH-CE (6.6 mmHg, 27.6% and -1.1, respectively) group than Inject-CE (2.7 mmHg, 12.4% and -0.7, respectively) (p < 0.0001 and p = 0.0034), while the IOP and medication-number levels were identical between TMH-CE (13.0 ± 3.3 mmHg and 1.3 ± 0.9, respectively) and Inject-CE (12.9 ± 2.6 mmHg and 1.9 ± 0.9, respectively) (p = 0.88 and p > 0.99, respectively). The TMH-CE group exhibited a higher ACF, a higher frequency of layered hyphema, and a greater anterior chamber floating red blood cells score in the early postoperative periods. Despite these differences, the changes in BCVA, ACF, and CECD were equivalent between the two groups in later follow-up periods. TMH-CE provides a more significant IOP reduction and medication-number reduction compared to Inject-CE, while Inject-CE shows quicker BCVA recovery. This study provides valuable insights for ophthalmologists choosing the most suitable surgical approach for glaucoma and cataract patients.

Factors Correlated With Mid-Term Morphology of Functional Blebs Following Implantation of Preserflo MicroShunt Using AS-OCT

Purpose

Evaluating bleb morphology is crucial after glaucoma filtering surgery. Advances in anterior segment optical coherence tomography (AS-OCT) allow for objective assessment. While various parameters differentiate functional from failed blebs, limited information exists regarding variations within functional blebs. This study aimed to identify factors influencing morphology of functional blebs following implantation of Preserflo MicroShunt.

Methods

Eyes with functional blebs after Preserflo were retrospectively included. Age, gender, lens status, preoperative intraocular pressure (pre-IOP) and number of glaucoma medications were documented along with biometric measurements as axial length (AL), white-to-white distance, and anterior chamber depth. Postoperative data included time elapsed since surgery (TaS) and postoperative IOP (post-IOP). Bleb dimensions were measured using AS-OCT including maximal bleb height (MBH), width, length (MBL), bleb wall thickness (BWT), and bleb distance to limbus (DtL) along with dimensions of episcleral lake (maximal height, width [MLW], and length). Linear regression models were applied to correlate these parameters with bleb dimensions.

Results

Included were 50 eyes from 50 patients. Mean IOP decreased from 25.3 ± 10.0 to 11.9 ± 3.0 mm Hg after 278.5 ± 221.9 days after surgery. MBH correlated negatively with age (unstandardized coefficients [uSC] = -0.012) and TaS (uSC = -0.001, P = 0.008 for both). BWT correlated negatively with age (uSC = -0.013, P = 0.02), MBL with AL (uSC = -0.566, P = 0.01) and MLW with pre-IOP (uSC = -0.073, P = 0.02). DtL exhibited a positive correlation with post-IOP (uCS = 0.136, P = 0.02).

Conclusions

Morphology of functional blebs might be influenced by multiple factors such as age, TaS, AL, and pre- and post-IOP.

Translational Relevance

Age, time after surgery, axial length, and preoperative and postoperative IOP could affect the morphology of a functional bleb; hence, these factors should be taken into consideration when making treatment decisions.

Effects of Schlemm's Canal Suture Implantation Surgery and Pilocarpine Eye Drops on Trabecular Meshwork Pulsatile Motion

The trabecular meshwork is an important structure in the outflow pathway of aqueous humor, and its movement ability directly affects the resistance of aqueous humor outflow, thereby affecting the steady state of intraocular pressure (IOP). (1) Objective: The purpose of this study was to preliminarily estimate the effects of pilocarpine eye drops and trabeculotomy tunneling trabeculoplasty (3T) on trabecular meshwork (TM) pulsatile motion via phase-sensitive optical coherence tomography (Phs-OCT). (2) Method: In a prospective single-arm study, we mainly recruited patients with primary open-angle glaucoma who did not have a history of glaucoma surgery, and mainly excluded angle closure glaucoma and other diseases that may cause visual field damage. The maximum velocity (MV) and cumulative displacement (CDisp) of the TM were quantified via Phs-OCT. All subjects underwent Phs-OCT examinations before and after the use of pilocarpine eye drops. Then, all subjects received 3T surgery and examinations of IOP at baseline, 1 day, 1 week, 1 month, 3 months, and 6 months post-surgery. Phaco-OCT examinations were performed at 3 and 6 months post-surgery, and the measurements were compared and analyzed. (3) Results: The MV of TM before and after the use of pilocarpine eye drops was 21.32 ± 2.63 μm/s and 17.00 ± 2.43 μm/s. The CDisp of TM before and after the use of pilocarpine eye drops was 0.204 ± 0.034 μm and 0.184 ± 0.035 μm. After the use of pilocarpine eye drops, both the MV and CDisp significantly decreased compared to those before use (p < 0.001 and 0.013, respectively). The IOP decreased from baseline at 22.16 ± 5.23 mmHg to 15.85 ± 3.71 mmHg after 3 months post-surgery and from 16.33 ± 2.51 mmHg at 6 months post-surgery, showing statistically significant differences (p < 0.001). The use of glaucoma medication decreased from baseline at 3.63 ± 0.65 to 1.17 ± 1.75 at 3 months and 1.00 ± 1.51 at 6 months post-surgery; the differences were statistically significant (p < 0.001). Additionally, there was no statistically significant difference in the MV between 3 and 6 months after surgery compared to baseline (p = 0.404 and 0.139, respectively). Further, there was no statistically significant difference in the CDisp between 3 and 6 months after surgery compared to baseline (p = 0.560 and 0.576, respectively) (4) Conclusions: After the preliminary study, we found that pilocarpine eye drops can attenuate TM pulsatile motion, and that 3T surgery may reduce IOP without affecting the pulsatile motion status of the TM.

Trends in the National Ophthalmological Healthcare Focusing on Cataract, Retina, and Glaucoma Over 15 Years in Japan

To assess the trends in ophthalmic healthcare, especially those of cataract, vitreo-retinal diseases, and glaucoma, the national data from the Japanese Ministry of Health, Labour and Welfare, which recorded medical practices for 126.1 million citizens, were studied for 15 years. The volume and expenses of cataract surgeries increased during this period; however, non-surgical expenses decreased. As a result, the total national cataract healthcare expenses decreased over the 15-year period. The volume of vitrectomies increased from 2007 to 2013. After introduction of anti-vascular endothelial growth factor (VEGF) injections, the number of injections increased 8.4 times from 2010 to 2021, while the volume of vitrectomy and retinal photocoagulation declined after 2019 and 2017, respectively. Minimally invasive glaucoma and long-tube shunt surgeries began to increase in 2015 and 2014, respectively. This trend contrasts with the decrease in trabeculectomies after 2019. The coronavirus disease-19 pandemic caused a 30.9% decrease in ophthalmological surgery expenses in 2020. The decreases in volume and expense were greater for cataract surgeries than for other surgeries. The pandemic had a stronger impact on ophthalmological healthcare than that on general medical healthcare. Advancements in technology and methodology have led to cost savings in national cataract healthcare, vitrectomy, and retinal photocoagulation while caused increase in the volume and expenditure of glaucoma surgeries and anti-VEGF injections over a span of 15 years in Japan.

Gonioscopy-Assisted Transluminal Trabeculotomy for the Treatment of Glaucoma in Uveitic Eyes

PURPOSE

To evaluate the outcomes of gonioscopy-assisted transluminal trabeculotomy (GATT) in adult eyes with uncontrolled uveitic glaucoma.

METHODS

We reviewed 16 eyes from 13 patients. Surgical success was defined as intraocular pressure (IOP) reduction >20% from baseline or IOP between 5 and 21 mmHg by the 3-month visit while on a stable number or fewer IOP-lowering agents and no need for additional glaucoma surgery.

RESULTS

At 12 months, the cumulative success rate was 81%. Mean IOP was 37.8 ± 13.0 mmHg at baseline and 12.2 ± 3.0 mmHg at 12 months (68% reduction; p < .0001). The average number of glaucoma medications was 4.6 ± 1.3 at baseline and 2.2 ± 0.7 at 12 months (52% reduction; p < .0001). Transient hyphema was seen in 44% of eyes at 1 week.

CONCLUSIONS

This small retrospective study suggests that GATT is effective and safe as an initial surgical treatment for medically refractory glaucoma in uveitic adult eyes.

Recent Advancements in Glaucoma Surgery-A Review

Surgery has long been an important treatment for limiting optic nerve damage and minimising visual loss in patients with glaucoma. Numerous improvements, modifications, and innovations in glaucoma surgery over recent decades have improved surgical safety, and have led to earlier and more frequent surgical intervention in glaucoma patients at risk of vision loss. This review summarises the latest advancements in trabeculectomy surgery, glaucoma drainage device (GDD) implantation, and minimally invasive glaucoma surgery (MIGS). A comprehensive search of MEDLINE, EMBASE, and CENTRAL databases, alongside subsequent hand searches-limited to the past 10 years for trabeculectomy and GDDs, and the past 5 years for MIGS-yielded 2283 results, 58 of which were included in the final review (8 trabeculectomy, 27 GDD, and 23 MIGS). Advancements in trabeculectomy are described in terms of adjunctive incisions, Tenon's layer management, and novel suturing techniques. Advancements in GDD implantation pertain to modifications of surgical techniques and devices, novel methods to deal with postoperative complications and surgical failure, and the invention of new GDDs. Finally, the popularity of MIGS has recently promoted modifications to current surgical techniques and the development of novel MIGS devices.

Minimally Invasive Glaucoma Surgery: A Review of the Literature

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

A Comparative Analysis of Morphology and Dimensions of Functional Blebs following PRESERFLO-Microshunt and XEN-Gel-Stent, a Study Using Anterior Segment OCT

Evaluation of bleb morphology is a vital part of successful filtration glaucoma surgery. The PRESERFLO-MicroShunt (PRESERFLO) and XEN-Gel-Stent (XEN) are drainage devices implanted using different surgical approaches (ab externo and ab interno, respectively), potentially resulting in distinct bleb morphology. Understanding these morphological differences is essential for postoperative care. In this study, we retrospectively examined functioning blebs following PRESERFLO and XEN implantation using high-resolution anterior segment OCT imaging. Qualitative assessment utilizing the Jenaer Bleb Grading System and quantitative assessment measuring 12 parameters representing bleb dimensions were conducted, and the results were compared between the two groups. A total of 80 eyes from 80 patients were included (41 after PRESERFLO, 39 after XEN). Functioning blebs following PRESERFLO exhibited a higher frequency of hyperreflective tenon changes compared to XEN (31.7% vs. 10.3%, respectively, p = 0.02) and a lower frequency of cavernous changes (17.1% vs. 35.9%, p = 0.05). Additionally, PRESERFLO blebs showed a higher frequency of visible episcleral lakes (92.7% vs. 30.8%, p < 0.001). Furthermore, PRESERFLO blebs demonstrated larger height (2.13 ± 0.5 vs. 1.85 ± 0.6 mm, p = 0.03), width (10.31 ± 2.3 vs. 9.1 ± 2.3 mm, p = 0.02), length (9.13 ± 1.8 vs. 8.24 ± 1.9 mm, p = 0.04), posterior location relative to the limbus (6.21 ± 1.2 vs. 5.21 ± 1.8 mm, p = 0.005), and a thicker bleb wall (1.60 ± 0.5 vs. 1.1 ± 0.4 mm, p = 0.004). Functioning blebs following PRESERFLO and XEN displayed morphological distinctions, likely attributed to variations in surgical techniques (ab externo vs. ab interno) and stent dimensions. These morphological differences should be taken into consideration when evaluating blebs, as they could impact assessments of bleb functionality and influence decisions regarding postoperative interventions.

The budget impact of introducing the OMNI® surgical system to a United States health plan for managing mild-to-moderate primary open-angle glaucoma

OBJECTIVES

Minimally invasive glaucoma surgery devices fill an unmet need in the treatment paradigm between topical intraocular pressure medicines and more invasive filtration procedures. This study evaluated the adoption of The OMNI® Surgical System with or without cataract surgery in primary open-angle glaucoma patients.

METHODS

A budget impact analysis estimated costs before and after adoption of OMNI® to a hypothetical US health plan with 1 million Medicare-covered lives over two years. Model input data were derived from published sources and development of the model included primary research with key opinion leaders and payers. The model compared total annual direct costs for OMNI® versus other treatment options (medications, other minimally invasive surgical procedures, selective laser trabeculoplasty) to calculate budget impact. A one-way sensitivity analysis was conducted to assess parameter uncertainty.

RESULTS

Increased adoption of OMNI® resulted in budget neutrality over the two years with a decrease in total costs of $35,362. Per member per month incremental costs were $0.00 when used without cataract surgery and yielded cost savings of -$0.01 when used with cataract surgery. Sensitivity analysis confirmed model robustness and identified surgical center fee variability as a key driver of costs.

CONCLUSION

OMNI® is budgetary efficient from a US payer perspective.

Nationwide Analysis of Glaucoma Surgeries in Fiscal Years of 2014 and 2020 in Japan

Nationwide trends in glaucoma surgical procedures were assessed by using the NDB Open Data 2014 and 2020. In Japan, 33,340 non-laser, 54,569 laser, and 88,019 total glaucoma surgeries were performed in 2014. In 2020, 60,108 non-laser, 60,547 laser, and 120,655 total glaucoma surgeries were performed. The rates from 2014 to 2020 were 180%, 111%, and 137%, respectively. In each procedure, angle surgery (326%), tube shunt surgery (383%), ciliary coagulation (489%), and gonio-laser (225%) were remarkably increased, while iridectomy (75%) and iris laser (77%) decreased during the same period. An increase in laser surgery was seen in young age groups, namely, 55-59 years old and younger, while non-laser surgery was increased in old age groups, namely, 45-49 years old and older. In 2020, 47.6 non-laser, 48.0 laser, and 95.6 total glaucoma surgeries were performed per 100,000 persons. None of the vital statistics, including prefectural population, mean age, and rate of ≥65-year-old people, were significantly associated with the number of glaucoma surgeries. Glaucoma practice patterns changed each time a new device or procedure was introduced. The results of the current study reflected the use of new procedures, such as minimally invasive glaucoma surgery, tube shunt, selective laser trabeculoplasty, and micropulse cyclophotocoagulation.

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.

One-Year Outcomes of PreserfloTM MicroShunt Implantation versus Trabeculectomy for Pseudoexfoliation Glaucoma

This retrospective, single-center study evaluates the safety and efficacy of Preserflo^TM MicroShunt (MicroShunt) implantations compared to trabeculectomies (TETs) in patients diagnosed with pseudoexfoliation glaucoma (PEXG). A total of 31 eyes from 28 patients received a MicroShunt implantation, and 29 eyes from 26 patients received a TET. Surgical success was defined as an intraocular pressure (IOP) between 5 mmHg and 17 mmHg at the end of the follow-up period, no need for surgical revisions or secondary glaucoma surgery, and no loss of light perception. In the MicroShunt group, the mean IOP dropped from 20.8 ± 5.9 mmHg at baseline to 12.4 ± 2.8 mmHg (p < 0.0001) after one year. In the TET group, the mean IOP dropped from 22.3 ± 6.5 mmHg to 11.1 ± 3.7 mmHg (p < 0.0001) after 12 months. In both of the groups, the mean number of medications was reduced significantly (MicroShunt from 2.7 ± 1.2 to 0.2 ± 0.7; p < 0.0001 vs. TET from 2.9 ± 1.2 to 0.3 ± 0.9; p < 0.0001). Considering the success rates, 83.9% of the MicroShunt eyes achieved complete success, and 90.3% qualified for success at the end of the follow-up period. In the TET group, the rates were 82.8% and 93.1%, respectively. The postoperative complications were comparable between both groups. In conclusion, the MicroShunt implantation demonstrated non-inferiority regarding its efficacy and safety profile compared to TET in PEXG at a follow-up of one year.

Systematic Preserflo MicroShunt Intraluminal Stenting for Hypotony Prevention in Highly Myopic Patients: A Comparative Study

Transient hypotony is the most common early complication after Preserflo MicroShunt (PMS) implantation. High myopia is a risk factor for the development of postoperative hypotony-related complications; therefore, it is advisable that PMS implantation in patients should be performed while employing hypotony preventive measures. The aim of this study is to compare the frequency of postoperative hypotony and hypotony-related complications in high-risk myopic patients after PMS implantation with and without intraluminal 10.0 nylon suture stenting. This is a retrospective, case-control, comparative study of 42 eyes with primary open-angle glaucoma (POAG) and severe myopia that underwent PMS implantation. A total of 21 eyes underwent a non-stented PMS implantation (nsPMS), while in the remaining eyes (21 eyes), PMS was implanted with an intraluminal suture (isPMS group). Hypotony occurred in six (28.57%) eyes in the nsPMS group and none in the isPMS group. Choroidal detachment occurred in three eyes in the nsPMS group; two of them were associated with the shallow anterior chamber and one was associated with macular folds. At 6 months after surgery, the mean IOP was 12.1 ± 3.16 mmHg and 13.43 ± 5.22 mmHg (p = 0.41) in the nsPMS and isPMS group, respectively. PMS intraluminal stenting is an effective measure to prevent early postoperative hypotony in POAG highly myopic patients.

Trends in operating room-based glaucoma procedures at a single eye center from 2016-2020

AIM

To evaluate trends in glaucoma procedures at the Peking University Eye Center in 2016-2020.

METHODS

A retrospective search of all glaucoma procedures performed at our institution were performed. Data were analyzed by calculating the absolute numbers and relative weightage of each procedure per year.

RESULTS

The average age of glaucoma patients undergoing surgical procedures was 62.33±17.87y, and 55% were women. From 2016 to 2019, the number of surgical procedures performed in glaucoma patients showed an overall upward trend from 749 to 1460, although it decreased slightly in 2020 (n=1393), probably due to the COVID-19 pandemic. The number of trabeculectomies did not change significantly in 2016 (n=161) to 2018 (n=164) but decreased in 2019 (n=139) to 2020 (n=121), indicating a reduction in its relative weightage among glaucoma procedures (from 21.50% to 8.69%). The number of glaucoma drainage device implantations and minimally invasive glaucoma surgeries both increased (50 and 58 respectively in 2019), except in 2020. The number of transscleral cyclophotocoagulation procedures was relatively stable, increasing until 2017 (n=218) and then decreasing. Cataract surgeries with or without glaucoma procedures accounted for a large number of the total surgeries, increasing from 247 (32.97%) in 2016 to 967 (69.42%), among which cataract extraction combined with goniosynechialysis was the most frequent.

CONCLUSION

The overall increase in the number of operating room-based surgical procedures is significant. Trabeculectomy is one of the most commonly performed procedures, despite the relative decline in its weightage. Other procedures, including use of glaucoma drainage devices and mini shunts and minimally invasive glaucoma surgeries, are gaining greater acceptance. Notably, lens-related surgery plays an important role in glaucoma management.

The Efficacy and Safety of the GATT Procedure in Open-Angle Glaucoma-6-Month Results

AIM

The aim of the study was to retrospectively evaluate the efficacy and safety of GATT during a 6-month observation period.

MATERIAL AND METHODS

The studied group consisted of 69 open-angle glaucoma patients treated with GATT as the only procedure or in combination with cataract surgery. Patients were assessed 1 day, 10 days, 1 month, 3 months, and 6 months after the surgery via standard ophthalmic examination including VF, IOP, and BCVA. The number of medications taken daily and possible complications were checked. Two criteria of success were established (S1: IOP decrease by 30% and S2: IOP lower than 18 mm Hg).

RESULTS

Before the surgery, the mean IOP was 26.94 mmHg and significantly decreased after GATT to 15.59 mmHg at 6M. BCVA did not significantly differ between the visits. The mean MD did not change significantly within the 6-month observation period (-8.20 dB vs. -8.16 dB, p = 0.9824), similar to the mean VFI (64.31% vs. 63.05%, p = 0.8571). A 30% IOP decrease at 6M visit was obtained in 95.6% of patients, and 37.7% needed medications to stabilize IOP. An IOP lower than 18 mmHg at 6M was obtained in 91.3% of studied patients after the GATT procedure, and in 58.0% without additional medications. The mean number of medications received daily decreased significantly at 6M compared to preoperative results (2.59 at inclusion vs. 0.76 at 6M, p = 0.0004). The most frequent complication after surgery was hyphema, which resolved spontaneously within 10 days.

CONCLUSION

The 6-month observation showed that GATT is a minimally invasive glaucoma-surgery technique that enables an effective and safe IOP decrease.

Detailed intraocular pressure curve by telemetric tonometry with an implanted pressure sensor before and after PreserFlo® MicroShunt implantation: a case report

Continuous control of intraocular pressure (IOP) is crucial to preventing long-term damage to the optic nerve in glaucoma. Recently, a novel telemetric IOP sensor (EYEMATE-IO™, Implandata Ophthalmic Products GmbH, Hannover, Germany) has been developed that continuously records IOP. The patient can read the IOP measurements wirelessly using a hand-held reading device. We present the case of a 70-year-old patient with primary open-angle glaucoma who had been implanted with an EYEMATE-IO™ and recently underwent minimally invasive bleb-filtering surgery with the PreserFlo^® MicroShunt (Santen, Osaka, Japan). This case demonstrates both the benefits of continuous pressure measurement with EYEMATE-IO™ and the ability of the PreserFlo^® MicroShunt to significantly reduce IOP fluctuations.

Kahook Dual Blade versus Trabectome (KVT): Comparing Outcomes in Combination with Cataract Surgery

Purpose

To compare the safety and efficacy of Kahook Dual Blade (KDB) versus Trabectome with cataract surgery in reducing intraocular pressure (IOP) and medications used by patients with glaucoma.

Methods

Retrospective chart review comparing eyes after KDB or Trabectome with cataract surgery at 2 academic centers. Surgical success was defined as IOP <21 mmHg with ≥20% IOP reduction at post-operative month 12 (POM12). Changes in IOP, number of glaucoma medications, and adverse events were assessed.

Results

Ninety eyes in the KDB group and 125 eyes in the Trabectome group were included. Mean changes in IOP at POM12 were -1.9 ± 4.9 mmHg (11.2%, P = 0.002) in the KDB group and -3.5 ± 5.5 mmHg (19.1%, P < 0.001) in the Trabectome group, without a significant difference between the groups (P = 0.20). Mean change in glaucoma medications at POM12 was -0.8 ± 1.5 in the KDB group (58%, P < 0.001) and -0.3 ± 1.3 (38%, P = 0.003) in the Trabectome group, with KDB having a greater decrease in medications (P = 0.02). The percentage of eyes achieving success was 30% for the KDB group and 54% for the Trabectome group (P = 0.01). Hyphema was the most common complication, with an incidence of 3% for the KDB group and 14% for the Trabectome group (P = 0.01).

Conclusion

KDB or Trabectome with cataract surgery is safe and effective at lowering IOP and medication burden, with KDB resulting in a greater reduction in medications and Trabectome more frequently achieving success with an increased incidence of hyphema. Considering the study's limitations, the outcomes were similar.

Devices and Treatments to Address Low Adherence in Glaucoma Patients: A Narrative Review

Poor adherence to topical glaucoma medications has been linked to worse visual field outcomes in glaucoma patients. Therefore, identifying and overcoming the adherence barriers are expected to slow down the progression of disease. The most common barriers to adherence, in addition to the lack of knowledge, include forgetfulness, side effects of medications, difficulties with drop instillation and low self-efficacy. Symptoms and signs of ocular surface disease, which importantly reduce patients' quality of life, are decreased by using preservative-free topical medications. Sustained drug delivery systems using different vehicles seem promising for relieving the burden of drop administration. Currently, only the bimatoprost sustained-release intracameral implant is available for clinical use and single administration. In the era of digitalization, smart drug delivery-connected devices may aid adherence and, by sharing data with care providers, improve monitoring and adjusting treatment. Selective laser trabeculoplasty as first-line treatment delays the need for drops, whereas minimally invasive glaucoma procedures with and without devices combined with cataract surgery increase the likelihood of patients with early-to-moderate glaucoma to remain drop free or reduce the number of drops needed to control intraocular pressure. The aim of this narrative review is to present and discuss devices and treatments that may improve adherence by reducing the need for drops and side effects of medications and aiding in glaucoma monitoring. For the future, there is a need for studies focusing on clinically important outcomes, quality of life and the cost of intervention with longer post-interventional follow up.

Development and Application of a New T-shaped Internal Trabeculotomy Hook (T-hook)

PURPOSE

We introduce a newly designed T-shaped internal trabeculotomy hook and compare its surgical outcomes with those of Kahook dual blade (KDB) surgery.

PATIENTS AND METHODS

One eye each of seventeen and sixty-one patients underwent T-hook and KDB surgeries, respectively. Post-surgical intraocular pressure (IOP), medications, visual acuity, and prevalence of IOP spikes and hyphema were compared between the two cohorts.

RESULTS

The utility of the T-hook was excellent and enabled the easy opening of the Schlemm's canal. The pre-surgical IOP of 25.6 ±7.5 mmHg in the T-hook cohort decreased to 14.1 ± 4.3 (-41.2% reduction) and 15.0 ± 3.1mmHg (-39.3% reduction) at 3 (P<0.001) and 6 months (P=0.003), respectively. Pre-surgical medications of 2.8 decreased to 2.3 and 2.0 medications, respectively, at 3 and 6 months. The best-corrected visual acuity (BCVA) improved from the pre-surgical logarithm of the minimum angle resolution (logMAR) of 0.148 to -0.012 at three months (P=0.036,). While the pre-surgical IOP of 24.9±4.3 mmHg in the KDB cohort decreased to 16.5±5.7 mmHg (-35.5%, P<0.001) and 16.1±3.4 mmHg (-33.5%, P<0.001) at 3 and 6 months, respectively. Reduction in medications at 3- and 12-month timepoints (from 2.8 to 1.7 and 1.7, respectively; P<0.001) and improvement in BCVA at three months (from 0.106 to -0.025 logMAR, P<0.001) were also significant. There was no difference between the T-hook and KDB cohorts in terms of the pre-surgical IOP (P=0.15) and post-surgical IOP at 1 (P=0.27), 3 (P=0.17), 6 (P=0.47), and 12 months (P=0.11, Mann-Whitney U-test). The prevalence of a post-surgical IOP spike in the T-hook and KDB cohorts was 41.2% and 47.5%, and that of post-surgical hyphema was 17.6% and 26.2%, respectively.

CONCLUSION

The novel T-hook was easy to use and was as useful as the KDB device in performing internal trabeculotomy.

Minimally Invasive Glaucoma Surgery: Safety of Individual Devices

Primary open-angle glaucoma progression in those already on maximal medical therapy has traditionally been treated with trabeculectomy, a surgical procedure that carries a high degree of morbidity. In the last few decades, significant advances have been made in the field of minimally invasive glaucoma surgery (MIGS) devices, which aim to defer or prevent trabeculectomy via less arduous surgical techniques in certain types of glaucoma. Although reviews have been published examining the efficacy of various MIGS techniques, no article synthesises the comparative safety of all available devices. We performed a literature review examining the safety of MIGS devices. Fifteen devices were included, variously attempting to increase aqueous outflow through the trabecular meshwork or the suprachoroidal space, shunting into the subconjunctival space, or reducing aqueous production through ciliary body ablation. Notably, the earliest product attempting to increase outflow to the suprachoroidal space, Alcon's CyPass Micro-Stent, was withdrawn from the market due to concerns regarding increased corneal endothelial cell loss at five years post-implantation. All other devices were described as well-tolerated, with the most common adverse effects including hyphaema, intraocular pressure spikes, and device migration or obstruction. MIGS devices are purported to be uniformly safe, and many studies report no statistically significant increased complications beyond those associated with cataract surgery alone. It is important to note, however, the generally poor quality of current studies, with a dearth of randomised, or even prospective, data, and a large proportion of studies funded by device producers.

A comparison of iStent combined with phacoemulsification and endocyclophotocoagulation (ICE2) with the PreserFlo MicroShunt and XEN-45 implants

Background

Minimally invasive glaucoma surgery (MIGS), including minimally invasive bleb surgery (MIBS), is a rapidly evolving area of research and clinical interest in ophthalmology. The growing number of devices has necessitated evaluations to identify subtle differences in outcomes between treatments.

Objectives

To compare clinical effectiveness and safety outcomes of iStent combined with endoscopic cyclophotocoagulation (ICE2) with bleb forming PreserFlo MicroShunt (PMS) and XEN-45 gel implant in a 24-month retrospective review.

Design

A retrospective review of patient records.

Methods

We compared outcomes of 247 patients undergoing one of three glaucoma procedures (ICE2 = 162; PMS = 48; XEN-45 = 37) at a single facility in the United Kingdom. Clinical records were reviewed retrospectively between July 2016 and May 2020. Pairwise comparisons and within group analyses were performed to assess intraocular pressure (IOP), best-corrected LogMAR visual acuity (BCVA), the Humphrey visual fields and antiglaucoma medication outcomes across the three treatment groups.

Results

No statistically significantly differences in IOP between the groups at day 7, 6 months, 12 months and 24 months. PMS had statistically significantly change in IOP between baseline and day 7 compared with ICE2 (p = 0.003). BCVA was statistically significant different at 24 months between the ICE2 compared with PMS group (0.12 versus 0.33 LogMAR; p = 0.002). PMS group achieved the largest decline in medication usage between baseline a 24-month follow-up (2.9 versus 0.9; p < 0.001), with no statistically significant difference in the number of antiglaucoma medications being used between groups at 24 months. Postoperative complications in all three groups were transient and could be resolved with office-based interventions.

Conclusion

Real-world outcomes after 24 months were similar between patients undergoing MIGS and MIBS procedures.

Outcomes of ab-interno irrigating goniectomy with trabectome in primary and secondary glaucoma from a single center in India

Purpose

This study was done to report intermediate-term outcomes of irrigating goniectomy with trabectome (trabectome) surgery among different types of glaucoma eyes from a single center in India using a cross-sectional, longitudinal, observational study design.

Methods

Fifty-three patients (58 eyes) with glaucoma who underwent irrigating goniectomy with trabectome between January 2019 and February 2020 were included. Pre-operative data included age, gender, eye laterality, specific diagnosis, number of anti-glaucoma medications (AGMs), prior glaucoma surgeries, visual acuity, and intraocular pressure (IOP) on medical treatment. Post-operative data included IOP changes during the follow-up till 1-year, number of AGMs, any complications, or additional surgical intervention required. Success was defined as IOP ≤ 21 mmHg and ≥ 20% reduction of IOP from pre-operative IOP with no additional glaucoma surgery.

Results

The cohort included 58 eyes (male 53.4% and female 46.6%) ranging from 0.6 to 81 years of age. The average baseline IOP was 23.4 ± 10.2 mmHg and reduced significantly with surgery to 14.1 ± 5.3 mmHg at 1-year follow-up. The AGMs reduced from 2.4 ± 1.4 pre-surgery to 1.6 ± 1.4 at 1-year follow-up. Four eyes required additional glaucoma surgeries for IOP control. The success rate of trabectome with phacoemulsification (88%) was discernibly higher than with trabectome alone (67%). Intra-operatively, significant blood reflux was noticed in 27 eyes, of which only one required tamponading with a viscoelastic agent.

Conclusion

This study concludes that irrigating goniectomy with trabectome has good efficacy and safety in both pediatric and adult cases of glaucoma in terms of IOP control, reduction in AGMs, and low incidence of complications in the Indian population.

XEN45 Gelstent Implantation in the Treatment of Glaucoma Secondary to Fuchs Uveitis Syndrome

PURPOSE

Evaluation of treatment efficacy of XEN45 gelstent for glaucoma secondary to Fuchs uveitis syndrome (FUS).

METHODS

This retrospective case series evaluated patients with glaucoma secondary to FUS, who underwent XEN45 implantation. Complete success was defined as IOP lowering of ≥ 20% and cutoff IOP at ≤18 mmHg. Success was qualified if additional glaucoma medication was necessary. Additional glaucoma surgery except for needling and open bleb revision was regarded as failure.

RESULTS

Twelve eyes of 12 patients were included. Qualified and complete success rates were 50% after one year (n = 10). Qualified success was achieved in 66.6% of patients with 33.3% of patients achieving complete success after two years (n = 6).

CONCLUSIONS

XEN45 implantation had some success in the treatment of glaucoma secondary to FUS, but needling was frequently necessary to improve outcome.

Gonioscopy-assisted transluminal trabeculotomy: Passing the right way decoding suture

Background

Trabeculectomy is still the most frequently performed glaucoma surgery. But being an invasive procedure, it has numerous vision-threatening complications along with bleb-related complications like cystic bleb, overhanging bleb blebitis, or endophthalmitis. The choice of therapy between medical laser and filtering surgery is now bridged by minimally invasive glaucoma surgeries (MIGS), which are conjunctiva-sparing procedures with adequate intraocular pressure (IOP)-lowering effects and good safety profiles. Among the armamentarium of MIGS procedures, gonioscopy-assisted transluminal trabeculotomy (GATT) is a frontrunner safe procedure. The procedure is a blebless and sutureless procedure in which a readily available Prolene suture is used to cleave the entire trabecular meshwork. An ab interno approach also allows direct visualization of a so-called trabecular shelf that, when present, indicates an open, cleaved collector system commonly associated with a positive postoperative outcome. Thus, it not only saves the eye from various postoperative complications of other previous penetrating procedures, but is also an effective glaucoma surgery that can be performed with very low costs, which would have big economic implications for glaucoma care in developing countries.

Purpose

The purpose of this video is to illustrate transluminal novel trabeculotomy technique and video-based skill transfer to a novice surgeon.

Synopsis

This video depicts detailed steps of GATT surgery in a patient with primary open angle glaucoma and in a case of silicon oil induced secondary open angle glaucoma. The authors also share their experience regarding possible intraoperative problems and solutions with some tips and tricks to make the surgery easy.

Highlights

GATT can be performed with cataract surgery with minimal patient morbidity and a short recovery time with preserving healthy conjunctiva. There is no risk of post op hypotony or bleb related complications, with a short surgical learning curve.

Online Video Link

https://youtu.be/gk1of38EX1g.

Outcomes of Deep Sclerectomy following Failed XEN Gel Stent Implantation in Open-Angle Glaucoma: A Prospective Study

Background: The purpose of this study is to evaluate the outcome of deep sclerectomy (DS) as a secondary procedure following failed ab-interno XEN gel stent implantation in patients with open-angle glaucoma. Methods: Prospective, single-center, non-randomized, interventional study. Consecutive eyes that underwent mitomycin C (MMC) augmented XEN gel stent surgery, with uncontrolled intraocular pressure (IOP) or signs of disease progression, were included to undergo MMC-augmented DS. Primary efficacy outcome was surgical success, defined as complete when the unmedicated IOP was 12 mmHg or less, or 15 mmHg or less and 20% lower than at the timing of XEN failure and defined as qualified when the IOP fulfilled the same conditions with fewer medications than before deep sclerectomy. Secondary measures were mean reduction in IOP and in the number of medications, and the rates of complications. Results: Seventeen eyes were enrolled with a mean age of 72.1 ± 8.2 years (66.7% women). The mean follow-up was 20.1 ± 4.9 months, with more than 12-month data available from 15 eyes. Following DS, IOP decreased significantly from 22.6 ± 5.3 mmHg to 12.3 ± 5.5 (45.6%; p < 0.001). Antiglaucoma medications dropped from 1.1 ± 0.9 to 0.3 ± 0.7. Complete success was obtained in 40% of eyes using the threshold of 12 mmHg or less and a 20% decrease of IOP, and in 60% using the 15 mmHg or less threshold. Adverse events were observed in 20% of eyes (bleb leakage (13.3%); hypotony (6.7%)). No cases of choroidal detachment or hypotony maculopathy were reported. Conclusions: Failed XEN gel stent implantation does not seem to negatively affect the safety and efficacy of subsequent deep sclerectomy surgery.

Comparison of minimally invasive glaucoma surgery with trabecular micro-bypass stent and microhook ab interno trabeculotomy performed in conjunction with cataract surgery

AIM

To evaluate the effectuality and safety of cataract surgery combined with either ab interno trabeculotomy by the microhook (µLOT) or a single iStent^® trabecular bypass implantation (iStent) in eyes with cataract and mild-to-moderate glaucoma.

METHODS

This study enrolled subjects with mild-to-moderate open angle glaucoma with visually significant cataract who used two or more ophthalmic antiglaucoma agents between 60 and 90y of age. Patients underwent cataract surgery cooperated with either implantation of an iStent (iStent-phaco) or excisional goniotomy with the µLOT (µLOT-phaco). Patients underwent µLOT-phaco in the eye with lower the mean deviation, according to the Humphrey field analyzer, while iStent-phaco was carried out on the other eye. Intraocular pressure (IOP) pre- and post-surgery, alterations in anterior chamber flare (ACF), and corneal endothelial cell density (ECD) were estimated.

RESULTS

Twenty subjects were enrolled (mean age: 73.6±7.3y). The mean medicated preoperative IOP was 16.7 mm Hg in the µLOT and 16.2 mm Hg in the iStent eyes. The mean final IOP at 12mo was 13.6 mm Hg in the µLOT eyes and 13.6 mm Hg in the iStent eyes, representing a 17.8% and 17.2% reduction, respectively. The preoperative ACF in the µLOT eyes was 9.5 pc/ms and it returned to normal in 30d postoperatively, with a value of 11.4 pc/ms. In the iStent eyes, ACF was 9.6 pc/ms preoperatively and it returned to normal by 7d postoperatively (11.2 pc/ms at day 7), demonstrating that postoperative inflammation was less in the iStent eyes. The corneal ECD in both groups was not significantly decreased.

CONCLUSION

In this study, iStent and µLOT are both effective through 12mo of follow-up. Safety is more favorable in the iStent eyes, based on early anterior chamber inflammation.

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.

Transconjunctival XEN45 Implantation for Glaucoma Performed at the Slit Lamp: A Pilot Study

PRCIS

This pilot study of ab externo implantation of a gel microstent is a novel, minimally invasive glaucoma surgery performed at the slit lamp that is effective for lowering intraocular pressure in patients with uncontrolled glaucoma.

PURPOSE

To evaluate the intraocular pressure (IOP)-lowering effect of gel microstent (XEN Gel Stent, Allergan, Irvine, CA) implantation using an ab externo approach in an office setting.

PATIENTS AND METHODS

This retrospective, multicenter chart review examined outcomes in patients with uncontrolled glaucoma receiving maximally tolerated medical therapy, who underwent slit lamp ab externo gel stent implantation. At postoperative visit, the IOP, the number of glaucoma medications, the final position of the stent, and the needling rate were analyzed. Assessments were conducted 1 day, 1 week and 1, 3, 6, and 12 months after the implantation. Treatment success was defined as IOP ≥6 mm Hg and ≤18 mm Hg with ≥20% reduction from presurgical IOP, with or without medications.

RESULTS

Thirty-four eyes from 28 patients were included. Mean preoperative IOP was 24.1±8.0 mm Hg on 3.2±0.9 glaucoma medications. At 12 months postoperative, IOP was reduced to 15.4±4.7 mm Hg on 0.6±1.0 medications; 46.9% and 81.3% of eyes achieved complete and partial success, respectively. The gel stent was properly positioned in 94.1% of eyes after 1 attempt at implantation and in 100% of eyes after a second attempt. In addition to malpositioning, observed complications included occlusion, erosion, and endophthalmitis following anterior chamber reformation. Adjunctive needling was required in 21% of implanted eyes.

CONCLUSION

Slit-lamp-based transconjunctival XEN45 implantation reduced intraocular pressure in glaucoma patients in the first year of this pilot study and was most commonly associated with wound leak and hypotony among other adverse events.

Early Complications and Results of Preserflo MicroShunt in the Management of Uncontrolled Open-Angle Glaucoma: A Case Series

We analyze the surgical outcomes and early complications with their management of the Preserflo MicroShunt (Santen Pharmaceutical Co., Ltd., Osaka, Japan) at six-month follow-up. The study is conducted between March 2021 and May 2022. Best-corrected visual acuity (BCVA) logMAR, intraocular pressure (IOP), and changes in glaucoma medications are assessed. Thirty eyes of 30 patients (22 women [73.3%] and 8 men [26.7%]) are included. They are augmented with mitomycin C (MMC) 0.5 mg/mL (8 subjects) or MMC 0.2 mg/mL (22 subjects) intraoperatively. BCVA is significantly higher one day after the treatment than before the treatment (MD with 95% CI = 0.05 (<0.01; 0.30); p = 0.045) when analyzing all patients. Such dependency is not observed when analyzing only patients treated with MMC 0.2 or 0.5 mg/mL (p > 0.050 for both analyses). No other statistically significant differences are detected in the level of BCVA before and after treatment. Among the patients, overall IOP is significantly lower at each time point after treatment than before surgery (p < 0.001 for all analyses). Among patients augmented with MMC 0.2 mg/mL, the IOP level is also significantly lower at each time point after treatment than before treatment (p ≤ 0.001 for all analyses). The same differences are observed among patients with MMC = 0.5—the IOP level is significantly lower at each time point after treatment than before treatment (p < 0.050 for all analyses). Five subjects (16.7%) require anti-glaucoma medications three months after the procedure. Early complications (hypotony, choroidal effusion, keratitis, hyphema, and bleb fibrosis) are observed in 46.7% of cases. Our early results show that Preserflo MicroShunt is safe and effective for lowering IOP; however, it is not free from transient complications.

Outcomes of XEN 63 Device at 18-Month Follow-Up in Glaucoma Patients: A Two-Center Retrospective Study

Background: Glaucoma surgery has significantly evolved over the last years. This paper aims to evaluate the midterm clinical outcomes of the XEN63 device in a real-world scenario. Methods: A retrospective clinical study was conducted on consecutive patients who underwent an XEN63 implant insertion, either alone or in combination with phacoemulsification. The primary endpoint was the mean intraocular pressure (IOP) at the month 18 visit. Results: Twenty-three eyes (23 patients) were included in the analysis. The preoperative IOP was significantly lowered from 27.0 ± 7.8 mmHg to 14.1 ± 3.4 mmHg at month 18 (p < 0.0001). At month 18, 14 (77.8%) and 11 (61.1%) eyes had an IOP ≤ 16 mmHg and ≤ 14 mmHg, respectively, without ocular hypotensive medication. The mean number of ocular hypotensive medication taken was significantly reduced from 2.3 ± 0.9 drugs at baseline to 1.0 ± 1.4 drugs at month 18 (p = 0.0020). Four (17.4%) eyes had hypotony at postoperative day 1, which was successfully resolved without sequelae. Four (17.4%) eyes underwent a needling procedure and four (17.4%) eyes underwent additional surgeries. Conclusions: The XEN63, either alone or in combination with cataract surgery, significantly lowered the IOP and reduced the need for ocular hypotensive drugs over a period of 18 months.

Corneal Endothelial Cell Loss in Patients After Minimally Invasive Glaucoma Surgery: Current Perspectives

Minimally invasive glaucoma surgery (MIGS) is a rapidly expanding category of surgical glaucoma treatment options that offer a superior safety profile compared with traditional approaches for reducing intraocular pressure. However, MIGS may cause corneal endothelial cell loss; therefore, it has been receiving increasing attention. This systematic review aimed to evaluate and compare the rate and degree of corneal endothelial loss after MIGS. First, this paper presents an overview of the theoretical effectiveness of MIGS, the fundamental aspects regarding the roles of endothelial cells, and the effect of cataract surgery on the quality and count of endothelial cells. Further, we detail the various surgical techniques involved in MIGS, the development of these techniques over the time, and clinical aspects to consider with respect to the endothelial cell count. We discuss in detail the COMPASS-XT study, which was based on data collected over 5 years, reported that withdrawal of the CyPass Micro-Stent (Alcon Laboratories) yielded increased corneal endothelial cell loss. Generally, MIGS procedures are considered safe, with the incidence of complications ranging from 1% to 20% depending on the surgery type; however, there is still need for studies with longer follow-up. Thus, an adequate count of endothelial cells in the central cornea portion is recommended as necessary for candidate patients for MIGS.

Optical coherence tomography-guided early postoperative management of XEN Gel implant

This interventional case series demonstrates the usefulness of anterior segment optical coherence tomography (AS-OCT) in guiding early postoperative management following XEN45 Gel Stent implantation, in conjunction with intraocular pressure (IOP) readings and slit lamp findings. Three primary open-angle glaucoma patients undergoing XEN45 Gel Stent implantation were included. Two patients received early postoperative needling because the IOP was not low enough and AS-OCT revealed that the XEN stent orifice was trapped by the Tenon's capsule. Immediately after needling, the distal tip of the XEN stent was freed and connected to a cystic space with significant IOP reduction. The third patient suffered from abrupt bleb flattening on the 5^th postoperative day following XEN stent implantation. AS-OCT revealed internal occlusion of the XEN stent with exudative material, which resolved spontaneously after intensifying topical steroids with improved bleb functioning 2 days later. AS-OCT provides in-depth microscopic evaluation of the XEN stent and its relationship with surrounding tissue. This information is helpful in identifying causes of impaired outflow, determining the timing, and effect of needling intervention in eyes with inadequate bleb functioning or IOP control, especially during the early postoperative period.

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

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

Early Results of Irrigating Goniectomy With TrabEx+: A Novel Device for the Treatment of Open-angle Glaucoma

PRCIS

Irrigating goniectomy with the TrabEx+ device can lower intraocular pressure (IOP) in patients with glaucoma, as a standalone procedure or combined with cataract surgery.

PURPOSE

The aim was to describe the efficacy and safety of irrigating goniectomy performed using the TrabEx+ device, either as a standalone procedure or combined with cataract surgery, in eyes with medically treated open-angle glaucoma.

METHODS

A retrospective case series of eyes treated by a single surgeon at a single UK teaching hospital. Data was collected at follow-up visits at 1 week, 3, 6, 12, 18, and 24 months postoperatively. Primary outcomes included IOP and glaucoma medication reduction after surgery. Proportion of eyes achieving >20% IOP reduction, IOP <21 mm Hg, and no reoperation were classified as surgical success.

RESULTS

Seventy-three consecutive eyes of 64 patients (mean age 68.4±13.7 y) were enrolled. 62% were treated as combined procedures with cataract surgery. Overall, mean IOP decreased from 31.3±7.3 to 20.9±10.4 mm Hg at the latest follow-up (34% reduction) (P<0.001) at the latest follow-up (16.1±10.3 mo) with mean preoperative medications decreased from 2.9±1.2 to 1.9±1.3 (P<0.001). 73% met the definition of success at latest follow-up. Postoperative complications were recorded including hyphaema (17%), uveitis (3%), hypotony (1%), and persistent vitreous hemorrhage (1%). Eighteen percent required reoperation because of treatment failure.

CONCLUSION

TrabEx+ appears to be effective in lowering IOP and medication with or without cataract surgery. However, long-term safety and efficacy will be better understood in a prospective study with longer follow-up.

Comparative study of 2-year outcomes for Hydrus or iStent inject microinvasive glaucoma surgery implants with cataract surgery

BACKGROUND

To compare real-world 24-month outcomes of phacoemulsification combined with either iStent inject or Hydrus Microstent.

METHODS

Analysis of data from the Fight Glaucoma Blindness (FGB) international registry. Anonymized data from 344 eyes with mild-to-moderate open-angle glaucoma, normal-tension glaucoma or ocular hypertension that underwent phacoemulsification combined with either iStent inject (224) or Hydrus Microstent (120) were included. Data were adjusted for baseline characteristics using linear regression and propensity score matching. The primary endpoint was a comparison of mean intraocular pressure (IOP) at 24 months.

RESULTS

At 24 months, there was no significant difference in IOP reduction between the two groups, consistent across all analyses. The matched cohort showed iStent inject achieved 3.1 mmHg reduction and Hydrus a 2.3 mmHg reduction (p = 0.530) and a mean medication reduction of 1.0 for iStent inject versus 0.5 for Hydrus (p = 0.081). 5.4% of eyes in the iStent inject group and 7.5% of eyes in the Hydrus group required subsequent procedures to improve IOP control within 24 months. Complications were rare with no significant differences between the groups.

CONCLUSIONS

Twenty-four-month outcomes showed sustained IOP reduction with a good safety profile for both groups. There was no significant difference in IOP outcomes between the groups. There may be a small additional reduction in glaucoma medication usage following cataract surgery with iStent inject compared to Hydrus.

Corneal endothelial cell density loss following glaucoma surgery alone or in combination with cataract surgery: A systematic review and meta-analysis

TOPIC

Corneal endothelial cell density (ECD) loss following glaucoma surgery with or without cataract surgery.

CLINICAL RELEVANCE

Corneal ECD loss may occur due to intraoperative surgical trauma in glaucoma surgery or postoperatively with chronic endothelial cell trauma or irritation.

METHODS

Trabeculectomy, glaucoma filtration surgery or microinvasive glaucoma surgery in participants with ocular hypertension, primary and secondary open angle glaucoma, normal tension glaucoma and angle-closure glaucoma were included. Pediatric populations and participants with pre-existing corneal disease were excluded. Laser treatments and peripheral iridotomy were excluded. Electronic databases searched in December 2021 included MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov and The International Prospective Register of Systematic Reviews (PROSPERO), FDA PMA and FDA 510(k).

RESULTS

39 studies were included in quantitative synthesis. 12 months following suprachoroidal MIGS mean ECD loss was 282 cells/mm² (95% Confidence Interval (CI) 220 to 345; p <0.00001; Chi² = 0.06; I² = 0%; 2 studies; very low certainty). Mean ECD loss after Schlemm's canal implantable devices was 338 cells/mm² (95% CI 185 to 491; p<0.0001; Chi² = 0.08; I² = 0%; 2 studies; low certainty) at 12 months. When compared to phacoemulsification alone, Schlemm's canal implants combined with phacoemulsification showed statistically significant mean ECD reduction at 24 months; mean difference of ECD was -19% (95% CI -37% to -2%; p=0.03; Chi² = 3.04; I² = 34%; 3 studies; low certainty). Mean ECD loss was 64 cells/mm² (95% CI 21 to 107; p=0.004; Chi² = 4.55; I² = 0%; 6 studies; low certainty) following Schlemm's canal procedures (without implantable devices) at 12 months. At 12 months the mean ECD loss after trabeculectomy was 33 cells/mm² (95% CI -38 to 105, p=0.36, Chi² = 1.17; I² = 0%; moderate certainty). At 12 months mean ECD loss was 121 cells/mm² (95% CI 53 to 189; p=0.0005; Chi² = 3.00; I² = 0%; 5 studies; low certainty) after Express implantation. When compared to control fellow eye, aqueous shunt surgery reduced ECD by 5.75% (95% CI -0.93 to 12.43; p=0.09 Chi² = 1.32; I² = 0%; low certainty) and 8.11% ECD loss (95%CI 0.06 to 16.16 p=0.05; Chi²= 1.93; I²=48%) at 12 and 24 months, respectively.

CONCLUSIONS

Overall there is low certainty evidence to suggest that glaucoma surgery involving long-term implants has a greater extent of ECD loss than glaucoma filtration surgeries without the use of implants. The results of this review support long-term follow-up (beyond 36 months) to assess ECD loss and corneal decompensation following implantation of glaucoma drainage implants.

36-month effectiveness of ab-interno canaloplasty standalone versus combined with cataract surgery for the treatment of open-angle glaucoma

PURPOSE

To report the 36-month effectiveness of ab-interno canaloplasty performed with the iTrack microcatheter (Nova Eye Medical, Fremont, USA) as a standalone procedure or combined with cataract surgery.

DESIGN

A single-center, retrospective case series PARTICIPANTS: Eyes diagnosed with primary open-angle glaucoma (POAG).

METHODS

Eyes with POAG were treated with either ab-interno canaloplasty as a standalone procedure (iTrack-alone) or in conjunction with phacoemulsification (iTrack+phaco).

MAIN OUTCOME MEASURES

The main outcome was mean reduction in intraocular pressure (IOP) and number of glaucoma medications at 12, 24, and 36 months postoperatively. Secondary endpoints consisted of visual acuity and the rate of complications.

RESULTS

44 eyes of 44 patients with open-angle glaucoma were included: 23 eyes in the iTrack-alone group and 21 eyes in the iTrack+phaco group. When both groups were analyzed together, both IOP and the number of medications were significantly reduced at 12 months (p<0.0001) and remained stable at 24 and 36 months. IOP decreased from 20.5±5.1 mmHg preoperatively to 13.3±2.1, 13.1±2.4 and 13.3±2.1 mmHg at 12-24-36 months respectively; the number of medications was reduced from 2.8±0.9 preoperatively to 1.1±1.1, 1.0±1.1 and 1.3±1.3 at 12-24 and 36 months postoperatively. Comparable results were observed in the iTrack-alone and iTrack+phaco groups, from a baseline 20.9±6.1 and 20.0±3.9 to 13.2±2.1 and 13.5±2.2 at 36-month respectively. At 36 months, 95.5% of eyes had IOP ≤17 mmHg and 68.2% of eyes were on ≤1 medication. No serious intra-operative or postoperative complications were reported.

CONCLUSION

Ab-interno canaloplasty performed with the iTrack microcatheter was found to be effective in reducing IOP and medication dependence. Comparable results were observed when employed as a standalone procedure or when combined with cataract surgery.

Updates on the utility of anterior segment optical coherence tomography in the assessment of filtration blebs after glaucoma surgery

The formation of filtration blebs is the main drainage mechanism for reducing intraocular pressure after traditional incisional glaucoma surgery such as trabeculectomy and non-penetrating deep sclerotomy. Early and short-lasting blebs may also occur after canaloplasty. Bleb formation also plays an important role after the implantation of glaucoma drainage devices, including Minimally Invasive Glaucoma Surgery devices. Anterior segment optical coherence tomography (AS-OCT) is a rapid and non-invasive high-resolution imaging technique that has evolved in recent years to become a routine examination. Anterior segment optical coherence tomography (AS-OCT) provides key information in the assessment and follow-up of glaucoma surgery, especially in the assessment of filtration blebs. Thus, bleb morphology can be qualitatively classified into diffuse, cystic, encapsulated and flattened, and AS-OCT imaging can also provide several quantitative parameters of the bleb, such as total bleb height, bleb fluid-filled cavity height, bleb wall thickness, number of microcysts and trabeculectomy opening size. These parameters could have an impact on clinical management during follow-up because they may predict the success or failure of the surgery in the early and late postoperative periods. Additionally, they may also guide the procedures used to increase filtration and reduce intraocular pressure, such as bleb needling and laser suture lysis.

Association of the prolonged use of anti-glaucoma medications with the surgical failure of ab interno microhook trabeculotomy

PURPOSE

This study examined the perioperative factors affecting surgical success in ab interno microhook trabeculotomy (μTLO).

METHODS

A total of 146 consecutive patients who underwent μTLO were included in this retrospective study. We performed Cox proportional hazard modelling by setting surgical success at 1 year as an objective variable. The explanatory variables included age, sex, glaucoma type, preoperative intraocular pressure (IOP), glaucoma drug score, mean deviation (MD) of the Humphrey visual field test, duration of glaucoma drug use, antithrombotic drug use, combined cataract surgery, incision range and diabetes mellitus. Additionally, we performed 1:1 matching using propensity score analysis and compared the perioperative parameters between durations of glaucoma drug use of <4.5 years and ≥ 4.5 years (50 patients each). We defined surgical success as satisfaction of all three criteria: IOP 5-21 mmHg, IOP reduction of ≥20% from the preoperative IOP and no additional glaucoma surgery.

RESULTS

The Cox proportional hazard model revealed that a longer duration of anti-glaucoma medication was significantly associated with surgical failure. Propensity score matching analysis showed that the <4.5-year users of anti-glaucoma drugs had significantly higher success rates than the ≥4.5-year users (72% versus 52%; p = 0.04).

CONCLUSIONS

The prolonged use of multiple glaucoma drugs adversely affected the outcome of μTLO at least at 1 year postoperatively.

Short-Time Changes of Intraocular Pressure and Biomechanics of the Anterior Segment of the Eye during Water Drinking Test in Patients with XEN GelStent

Purpose: Little is known about short-term changes in intraocular pressure (IOP) following minimally invasive glaucoma surgeries, such as post-XEN GelStent implantation. Although the importance of corneal biomechanics in glaucoma diagnostics has been reported, little work has been conducted on postoperative description of changes when the structure of the anterior segment is altered. The aim of presented study was to evaluate the changes in the biomechanical parameters of the anterior segment of the post-XEN GelStent implantation eyes. Patients and Methods: This investigator-initiated, open-label, prospective, single-center study recruited patients. Patients with primary open-angle glaucoma (POAG) after XEN GelStent implantation versus matched POAG controls (considered as control group/CG) treated pharmacologically were screened. Water loading was conducted using 10 mL of water per kilogram of body weight for ≤5 min. Goldmann applanation tonometry (GAT), corneal hysteresis (CH), and corneal resistance factor (CRF) were performed before water loading and after every 15 min up to 1 h. Results: The water drinking test (WDT) was positive in 3.7% (1 out of 27) of patients in the post-XEN group compared with 22.7% (5 out of 22) of patients in the control group (CG; p < 0.05). Mean fluctuations in GAT during the WDT were higher in the CG group (3.6 ± 2.5 mmHg vs. 2.9 ± 1.3 mmHg, p < 0.001). CRF and CH changed significantly only in the post-XEN group. The mean peak of CH and CRF occurred at 15 and 30 min of the test in the post-XEN group (p = 0.001). Conclusion: WDT is important to assess the ability of compensation mechanisms to reduce fluctuations in IOP after water upload. The relationship between biomechanics of the anterior segment and glaucoma may have substantial impact on surgical outcome evaluation.

Comparison of efficacy and early surgery-related complications between one-quadrant and two-quadrant microhook ab interno trabeculotomy: a propensity score matched study

PURPOSE

We compared the 1-year outcomes and early surgery-related complications between 1-quadrant and 2-quadrant microhook ab interno trabeculotomy (TLO).

METHODS

Medical chart extraction was performed on 47 consecutive patients with 1-quadrant incision and 37 consecutive patients with 2-quadrant incision of trabecular meshwork. Logistic regression analysis was conducted to calculate the propensity score to create a 1:1 match for a comparative analysis of 1-year postoperative success. Success was defined as postoperative intraocular pressure (IOP) between 5-21 mmHg, >20% IOP reduction from baseline, and no additional glaucoma surgery. Outcome-related covariates were age, glaucoma type, mean deviation of visual field tests, preoperative IOP, the number of preoperative glaucoma eye drops and the presence of combined cataract surgery. Thirty eyes from each group were compared.

RESULTS

The median preoperative IOP was not different between the 1-quadrant and 2-quadrant groups (28.5 mmHg, quartile range 23-33.5 versus 27 mmHg, 23.3-30.0, p = 0.47). There was no difference in median postoperative IOP at 1 year (15 mmHg versus 16 mmHg, p = 0.80). The success rate was 73% in the 1-quadrant group versus 70% in the 2-quadrant group (p = 1.00). The 2-quadrant group had a significantly higher proportion of patients with transiently elevated IOP (47%) than the 1-quadrant (17%; Fisher's exact test, p = 0.02). There was no difference of hyphema formation (Fisher's exact test, p = 0.18).

CONCLUSION

The 1-year success rate was not significantly different between 1- and 2-quadrant incisions of microhook TLO. However, the 2-quadrant TLO showed significantly higher proportion of post-surgical transient IOP elevation.

Non-inferiority of Microhook to Trabectome: Trabectome vs. ab interno Microhook Trabeculotomy Comparative Study (TramTrac Study)

PURPOSE

To elucidate the non-inferiority of ab interno microhook trabeculotomy (μTLO) using a recently developed reusable stainless spatula-type microhook device to incise the trabecular meshwork to trabectome (TOM) in terms of the 1-year postoperative outcomes of Japanese patients with glaucoma by means of propensity score analyses.

DESIGN

A multicenter retrospective cohort study.

PARTICIPANTS

We enrolled 553 and 392 patients who underwent TOM and μTLO, respectively, between January 2014 and March 2020 at 10 facilities.

METHODS

Logistic regression analysis was conducted to calculate the propensity score, which indicates the likelihood of treatment assignment (TOM or μTLO). We set the following factors as outcome-related covariates: age, sex, facility, glaucoma disease types, preoperative intraocular pressure (IOP), glaucoma drug score, mean deviation of the Humphrey visual field test and antithrombotic drug use, the presence or absence of combined cataract surgery, and incision range of trabecular meshwork (one or two quadrants). We analyzed four different methods (matching, inverse probability of treatment weighting (IPTW), stratification, and regression adjustment) using the propensity score. We set 15% as the non-inferiority margin based on previous trabectome meta-analysis results.

MAIN OUTCOME MEASURES

The primary outcome was surgical success at 1 year postoperatively. We defined surgical success as satisfying all three criteria: (1) IOP within 5-21 mmHg; (2) IOP reduction of ≥20% from preoperative IOP; and (3) no additional glaucoma surgery.

RESULTS

The 95% confidence interval of risk difference of surgical failure in μTLO in reference to TOM was -12.1 to +9.5% in matching, -12.7 to +11.1% in IPTW, -12.2 to +7.0 in stratification, and -9.7 to +8.1% in regression adjustment, all of which fell within the predetermined non-inferiority margin of 15%.

CONCLUSIONS

Surgical success of μTLO at 1-year postoperatively was not inferior to that of TOM.

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

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

XEN Glaucoma Implant for the Management of Glaucoma in Naïve Patients versus Patients with Previous Glaucoma Surgery

This retrospective study analyzed the surgical and refractive outcomes of a XEN Gel Implant (Allergan, Abbvie Company, Irvine, CA, USA) in naïve patients versus those with previous glaucoma surgery. We evaluated the efficacy of XEN implantation in 86 glaucoma patients during a long-term follow-up period. Patients were divided into two groups: naïve patients (Group 1) and patients with previous glaucoma surgery (Group 2). Eyes that received a XEN Gel Stent placement from December 2014 to October 2019 were included. Intraocular pressure (IOP) change, corrected distance visual acuity (CDVA), change in glaucoma medications, frequency of slit lamp revision procedures, and frequency of secondary glaucoma surgeries were the primary outcomes. In Group 1, the mean IOP before surgery was decreased significantly from 25.00 ± 7.52 mmHg to 16.83 ± 5.12 mmHg by the end of the study. In Group 2, the mean IOP decreased significantly from 25.35 ± 7.81 mmHg to 17.54 ± 5.34 mmHg. The mean IOP decrease from baseline was 29% in Group 1 and 27% in Group 2 (p = 0.567). There were no significant differences between the groups in the IOP baseline level, the final level, or the change between preoperative and final levels. The qualified success rate for Group 2 was 68.7% versus 76.5% for Group 1 for the initial procedure and 15.4% vs. 20.2%, respectively, for complete success rate (p > 0.05). However, at the end of the follow-up, more patients achieved an IOP < 18 mmHg in Group 1 than in Group 2. Despite the need for more anti-glaucoma medications, repeat XEN Gel implantation appears to show promising results in patients with previously failed anti-glaucoma procedures, owing to its minimal invasiveness.

Evaluation of the Effect of the First Generation iStent on Corneal Endothelial Cell Loss-A Match Case-Control Study

Glaucoma is the leading cause of irreversible blindness worldwide. The only proven factor in slowing the progression of glaucomatous neuropathy is lower intraocular pressure (IOP), which can be achieved with pharmacology, laser therapy, or surgery. However, these treatments are associated with various adverse effects, including corneal endothelial cell loss (CECL). In recent years, several novel surgeries for reducing the IOP, collectively referred to as minimally invasive glaucoma surgery (MIGS), have been developed, one of which is the iStent. However, the long-term effects of such surgeries remain unknown. We compared a group of patients with open-angle glaucoma and cataract who underwent phacoemulsification alone with a group of patients with similar demographic and clinical characteristics who underwent simultaneous phacoemulsification and iStent implantation. Overall, 26 eyes of 22 subjects who underwent a combined phacoemulsification-iStent procedure and 26 eyes of 24 subjects who underwent cataract surgery were included. Before surgery, endothelial cells accounted to 2228.65 ± 474.99 in iStent group and 2253.96 ± 404.76 in the control group (p = 0.836). After surgery, their number declined to 1389.77 ± 433.26 and 1475.31 ± 556.45, respectively (p = 0.509). There was no statistically significant difference in CECL between the two groups 18–24 months after surgery, despite increased manipulation in the anterior chamber and the presence of an implant in the trabecular meshwork in those with an iStent implant. Thus, iStent bypass implantation is a safe treatment in terms of CECL for mild-to-moderate open-angle glaucoma.