Early Results of Goniotomy with the Kahook Dual Blade, a Novel Device for the Treatment of Glaucoma

Minimally Invasive Direct Internal Cyclopexy in the Management of Goniotomy-Related Cyclodialysis Cleft with Hypotony Maculopathy

Introduction

Although ab-interno trabeculotomy-related (goniotomy-related) surgeries has a favorable safety profile, cyclodialysis cleft refractory to conservative management could occur, thereby requiring additional surgical treatment. External and, more recently, internal cycloplexy have been attempted to treat cyclodialysis clefts with hypotony maculopathy, however the traditional methods require conjunctival or scleral incisions and have been inappropriate for glaucoma patients who need to undergo future trabeculectomy. Therefore, we report two cases who underwent a novel reliable technique for suture fixation of the detached ciliary body onto the original scleral bed directly through the intraocular approach without conjunctival or scleral incision, minimally invasive direct internal cyclopexy, in the management of goniotomy-related cyclodialysis cleft with hypotony maculopathy.

Case Description

Goniotomy-related cyclodialysis cleft exceeded 45° and vision-threatening hypotony maculopathy was observed in two eyes in two patients with normal tension glaucoma and myopia gravis without a prior history of trauma who had undergone Kahook Dual Blade goniotomy combined with cataract surgery. The patients were followed conservatively for a while, however the cyclodialysis clefts and hypotony maculopathies did not resolve. Therefore, a 72-year-old man underwent minimally invasive direct internal cyclopexy on postoperative day 65 after the goniotomy, and another 67-year-old man underwent minimally invasive direct internal cyclopexy on postoperative day 149. In both cases, topical antibiotic and steroid eye drops were prescribed postoperatively. The cyclodialysis clefts were repaired successfully; however, the latter patient developed delayed-onset acute transient ocular hypertension 33 days after minimally invasive direct internal cyclopexy and required glaucoma medications. The hypotony maculopathies resolved approximately 3 months after suturing, and eventually visual acuity improved from preoperative levels and good intraocular pressure control was achieved in both. No further postoperative complications have been observed to date.

Conclusion

We successfully managed two cases of goniotomy-related cyclodialysis cleft with hypotony maculopathy using minimally invasive direct internal cyclopexy.

Twelve-month outcomes of Kahook dual blade goniotomy combined with cataract surgery in Latino patients

PURPOSE

To evaluate 12 month surgical outcome of Kahook Dual Blade (KDB) goniotomy in combination with cataract surgery in Latino patients with open angle glaucoma (OAG) and ocular hypertension (OHT).

METHODS

This retrospective study included 45 eyes of 40 patients who underwent KDB goniotomy combined with cataract extraction from January 2016 to September 2020 at two centers in South America. Primary outcome was surgical success defined as ≥ 20% intraocular pressure (IOP) reduction or ≥ 1 medication reduction from preoperative without additional IOP-lowering procedures and an IOP ≥ 5 mmHg or ≤ 21 mmHg. Additionally, we used 2 cutoffs values for success of IOP ≤ 18 and ≤ 15 mmHg. Secondary outcomes included: IOP, medication use, best corrected visual acuity, complications and failure-associated factors.

RESULTS

Success rates at 12 months with cutoff limits of 21, 18 and 15 mmHg were 84.3%, 75.6% and 58.7%, respectively. At 12 months, mean preoperative IOP significantly decreased from 19.23 ± 0.65 mmHg on 2.3 ± 1.0 medications to 14.33 ± 0.66 mmHg on 0.6 ± 0.9 medications (p < 0.001) , with 62% of eyes free of hypotensive medication. Eyes that developed postoperative IOP spikes showed a higher risk for failure using the cutoff limit of IOP ≤ 18 mmHg with a hazard ratio of 3.6 (95% confidence interval [CI], 1.80-7.13; p < 0.001). There were no serious ocular adverse events.

CONCLUSIONS

KDB combined with cataract extraction showed safety and efficacy for decreasing IOP in OAG and OHT Latino patients. Additionally, dependence on medications was reduced significantly after surgery.

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.

[Real-world outcomes of glaucoma surgical procedures for open-angle glaucoma]

This article provides an overview of real-world outcomes in glaucoma surgical procedures. While randomized clinical trials provide valuable insights, they do not fully reflect real-world clinical practice. Real-world studies enable the evaluation of outcomes in uncontrolled settings and play a crucial role in counselling and decision-making for glaucoma treatment. By examining real-world data the article aims to identify rare adverse events that may go unnoticed in controlled clinical trials. The focus is on assessing the effectiveness and safety of glaucoma surgical procedures beyond the controlled trial setting.

Factors associated with 1-year outcomes and transient intraocular pressure elevation in minimally invasive glaucoma surgery using Kahook Dual Blades

In this retrospective case-control study, we aimed to investigate the mid- to long-term outcomes and factors involved in minimally invasive glaucoma surgery using the Kahook Dual Blade. Of the 229 cases since 2018 in which the dual blades were used for glaucoma surgery at the Tenri Hospital, 133 eyes of 98 patients who followed up for more than 3 months were included. Intraocular pressure (IOP), number of drops score, and need for reoperation were evaluated on day 1 and at 1, 3, 6, 9, and 12 months postoperatively. Intraocular pressure spikes occurred in 25 patients postoperatively (18.8%), occurring at approximately 4.5 days (1-10.25). The preoperative number of eye drops used and ocular axial length were found to be associated with the occurrence of spikes (OR = 1.45, 95% CI 1.02-2.06; P = 0.025 and OR = 1.41, 95% CI 0.98-1.25; P = 0.072, respectively). At the 12-month mark, no significant relationship was found between the presence of spikes or incisional extent scores and the amount of change in IOP and number of drops scores. Patients with severe visual field impairment, high preoperative IOP and drop scores, and long ocular axial length may require more frequent follow-ups after surgery to check for spikes.

Outcomes and risk factors for Kahook Dual Blade excisional goniotomy with concomitant phacoemulsification: a multicentre Canadian study

OBJECTIVE

To assess the outcomes and failure risk factors for Kahook Dual Blade (KDB) excisional goniotomy with cataract surgery (phaco-KDB) in eyes with various glaucoma subtypes and severities.

METHODS

This multisurgeon consecutive case series included glaucomatous eyes with cataract that underwent phaco-KDB and had a minimum follow-up of 12 months postoperatively. Efficacy was assessed by absolute and qualified surgical success (defined by different criteria) and changes in intraocular pressure (IOP) and antiglaucoma medication (AGM) at the last postoperative follow-up. Safety included best-corrected visual acuity, cup-to-disc ratio, visual field mean deviation, retinal nerve fibre layer thickness, and adverse events.

RESULTS

A total of 108 eyes of 89 patients with a median follow-up of 18 months (range, 12-47 months) were included. IOP decreased by 26% from 19.1 ± 5.0 mm Hg to 14.1 ± 3.5 mm Hg (p < 0.001), AGM use decreased by 29% from 2.4 ± 1.3 medications to 1.7 ± 1.3 (p < 0.001), and 25% of eyes became free of AGMs (vs 3% at baseline). Qualified success rates achieved for IOP cutoffs of 18, 15, and 12 mm Hg were 87%, 68%, and 46%, respectively. Higher baseline IOP and postoperative incidence of IOP spikes were associated with a higher risk of surgical failure. Best-corrected visual acuity improved postoperatively (p < 0.001), and visual field mean deviation, cup-to-disc ratio, and retinal nerve fibre layer thickness remained stable. Overall, safety was favourable, and adverse events were transient and not sight threatening.

CONCLUSION

This multicentre Canadian study provides real-world data that support the safety and efficacy of phaco-KDB in reducing IOP and AGM use with no evidence of disease progression during the follow-up period.

[Ab interno trabeculotomy without/with cataract operation-An alternative treatment before or instead of trabeculectomy in patients with high intraocular pressure?]

BACKGROUND

Trabeculotomy with the Kahook knife is a new ab interno minimally invasive glaucoma surgery (MIGS) procedure. The MIGS are usually performed in early to intermediate glaucoma eyes. In this retrospective study we analyzed the intraocular pressure (IOP) and topical glaucoma eye drop therapy (Meds) reduction achieved by the Kahook trabeculotomy (TO) without (n = 19) or with (n = 18) combined cataract operation (Cat-TO) as initial treatment before or to avoid filtering surgery.

MATERIAL AND METHODS

A total of 37 eyes of 37 patients were examined when IOP was > 21 mm Hg in at least 2 examinations despite the maximum tolerable Meds applied. Cat-TO was performed in 18 phakic eyes (primary open-angle glaucoma, POAG = 11, pseudoexfoliation glaucoma, PEX = 5, ocular hypertension, OHT = 2). In 19 pseudophakic eyes (POAG = 12, PEX = 6, OHT = 1) an isolated TO was executed. Complete success (no Meds) and relative success (irrespective of Meds) for IOP ≤ 21 mm Hg, ≤ 18 mm Hg, ≤ 16 mm Hg were evaluated 2, 6 and 12 months postoperatively.

RESULTS

The IOP was significantly reduced from preoperatively to 2 months after Cat-TO as well as after TO (Cat-TO: 26.8 ± 5.9 mm Hg to 16.0 ± 2.9 mm Hg, p < 0.001; TO: IOD 28.2 ± 5.6 mm Hg to 16.3 ± 3.5 mm Hg, p < 0.001). Meds reduction after Cat-TO as well as after TO was not significant (Cat-TO: 2.1 ± 1.3 to 1.3 ± 1.3, p = 0.11; TO: Meds 2.7 ± 1.1 to 2.2 ± 1.3, p = 0.23); however, Meds reduction after 6 and 12 months was significantly greater in the Cat-TO group compared to the TO group (p = 0.02). The IOP and Meds did not change significantly from 2 to 6 months. After Cat-TO, qualified success after 12 months for IOP ≤ 18 mm Hg was 61% (11/18) and for IOP ≤ 16 mm Hg 28% (5/18). After TO, qualified success after 12 months for TO was 47% (9/19) for IOP ≤ 18 mm Hg and 26% (5/19) for IOP ≤ 16 mm Hg. The intervention was not sufficient for 7 patients after TO and 2 patients after Cat-TO (IOP two times > 21 mm Hg).

CONCLUSION

The first year results show that TO as well as Cat-TO are effective minimally invasive interventions to delay or even avoid a filtrating operation. In case of Meds intolerance and target IOP ≤ 16 mm Hg Cat-TO is not sufficient.

12-month outcomes of ab interno excisional goniotomy combined with cataract surgery in primary open-angle glaucoma and normal tension glaucoma

PURPOSE

To evaluate the efficacy and safety of excisional goniotomy performed with the Kahook Dual Blade (KDB) combined with cataract surgery in patients with pimary open angle glaucoma (POAG) and Normal Tension Glaucoma (NTG) under topical therapy. Further sub-analysis was performed to compare between 90 and 120 degrees goniotomy.

METHODS

This was a prospective case series of 69 eyes from 69 adults (age 78 ± 5.9 years; male = 27, female = 42). Indications for surgery included insufficient IOP control with topical medication, glaucomatous damage progression under topical therapy and reduction of medication burden. Complete success was defined as IOP lowering below 21 mmHg without the need for topical medication. For NTG patients, complete success was defined as IOP lowering below 17 mmHg without the need for topical medication.

RESULTS

IOP was significantly lowered from 19.7 ± 4.7 to 15.1 ± 2.7 at 2 months, 15.8 ± 2.3 at 6 months and 16.1 ± 3.2 at 12 months (p < 0.05) for POAG and 15.1 ± 2.5 to 14.1 ± 2.4 at 2 months, 14.1 ± 3.1 at 6 months and 13.6 ± 1.8 at 12 months (p > 0.08) for NTG, respectively. Complete success was achieved in 64% of the patients. IOP lowering under 17 mmHg without the need for topical medication was achieved in 60% of the patients at 12 months. In NTG patients (14 eyes) IOP lowering under 17 mmHg without the need for topical medication was achieved in 71%. No significant difference was recorded in terms of IOP lowering at 12 months in-between 90° and 120° of treated trabecular meshwork (p > 0.7). No severe adverse reactions were recorded in this study.

CONCLUSION

One-year results show that KDB combined with cataract surgery is an effective treatment option for glaucoma patients. IOP lowering was successfully achieved in NTG patients with complete success in 70% of the patients. In our study, no significant differences were recorded in-between 90° and 120° of treated trabecular meshwork.

Risk Factors for Hyphema Following Kahook Dual Blade Goniotomy Combined With Phacoemulsification

PRCIS

Hyphema development after Kahook Dual Blade (KDB) excisional goniotomy was significantly associated with postoperative day 1 intraocular pressure (IOP) ≤12 mm Hg, male sex, and narrow iridocorneal angles, but not with continuation of anticoagulation or antiplatelet therapy.

PURPOSE

To identify risk factors of hyphema development after KDB goniotomy combined with phacoemulsification.

METHODS

In all, 202 eyes in 145 patients who received a KDB goniotomy combined with phacoemulsification between February 21, 2017 and February 18, 2020 were evaluated for preoperative factors that were predictive of postoperative hyphema. Hyphema was defined as the development of ≥1 mm layered blood in the anterior chamber. The primary outcome was the association between various preoperative factors and the development of postoperative hyphema. Binomial logistic regression was used to analyze risk factors of hyphema development while controlling for other variables.

RESULTS

Hyphema occurred in 8.4% (17/202) of patients on day 1 after KDB goniotomy combined with phacoemulsification. Male sex ( P =0.008), angle closure glaucoma ( P =0.036), and postoperative day 1 IOP ≤12 mm Hg ( P =0.049) were significantly correlated with hyphema development while controlling for other variables. Preoperative anticoagulation and antiplatelet therapy had no association with hyphema development ( P =0.538).

CONCLUSIONS

Postoperative hyphema was associated with male sex, narrow iridocorneal angles, and a postoperative day 1 IOP lower than typical episcleral venous pressure when controlling for other variables. Preoperative anticoagulation or antiplatelet therapy was not associated with developing postoperative hyphema in this study; however, further investigation is needed before recommendations can be made.

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.

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.

Stand-Alone Xen Gel Microstent Implantation Compared With Kahook Dual Blade Goniotomy

PRCIS

Both Xen gel Microstent implantation and Kahook Dual Blade (KDB) goniotomy are safe and effective as stand-alone procedures, but the Xen Gel Microstent was associated with more postoperative interventions and achieved higher success at a lower intraocular pressure threshold.

PURPOSE

To evaluate outcomes of stand-alone Xen Gel Microstent implantation compared with stand-alone KDB goniotomy for moderate to severe glaucoma.

METHODS

A retrospective, single-center, case-series analysis comparing outcomes of Xen Gel Microstent implantation and KDB goniotomy stand-alone cases in 75 eyes. Primary outcomes included intraocular pressure (IOP) reduction, glaucoma medication reduction, surgical success, and complications. Surgical success was defined using IOP<21 mm Hg and IOP<18 mm Hg thresholds, with or without glaucoma medications, and without further glaucoma surgery. Subjects were followed for at least 24 months after surgery.

RESULTS

Mean baseline IOP was comparable between the Xen Gel Microstent and KDB goniotomy groups (23.7±8.4 and 25.9±7.9 mm Hg, respectively, P =0.32). At 24 months after surgery, the mean IOP after Xen Gel Microstent was 14.7±3.2 mm Hg (32.7% reduction from baseline, P =0.018) and KDB goniotomy was 16.7±3.2 mm Hg (40.4% reduction from baseline, P =0.049). Although the mean IOP was significantly lower during the first month after Xen Gel Microstent implantation, no difference in mean IOP was observed between the 2 treatment groups at 24 months after surgery ( P =0.416). At 24 months after surgery, the percent reduction of IOP from baseline was not significantly different between the 2 groups. The mean reduction of glaucoma medications from baseline at 24 months was 1.69 drops after Xen Gel Microstent implantation ( P =.008) and 1.67 drops after KDB goniotomy ( P =0.038). Postoperative complications were nonvision-threatening and were not significantly different between the 2 groups ( P =0.550). Interventions not included with complications were needling performed in 21 (37%) of eyes in the Xen Gel Microstent group and Nd:YAG goniopuncture in 1 (5.6%) eye after KDB goniotomy. With an IOP threshold <21 mm Hg, surgical success was not significantly different between the 2 groups ( P =0.06). At a lower IOP threshold (<18 mm Hg), surgical success was higher after Xen Gel Microstent implantation compared with KDB goniotomy ( P =0.001).

CONCLUSIONS

Both stand-alone Xen Gel Microstent implantation and KDB goniotomy can effectively and safely reduce IOP for moderate to severe glaucoma. The Xen Gel Microstent was associated with a higher need for postoperative interventions and achieved greater success at a lower IOP threshold.

Minimally Invasive Glaucoma Surgery in Primary Angle-Closure Glaucoma

Primary angle-closure glaucoma (PACG) is responsible for half of the glaucoma-related blindness worldwide. Cataract surgery with or without trabeculectomy has been considered to be the first-line treatment in eyes with medically uncontrolled PACG. While minimally invasive glaucoma surgery has become an important surgical approach for primary open-angle glaucoma, its indications and benefits in PACG are less clear. This review summarizes the efficacy and safety profile of minimally invasive glaucoma surgery in PACG to unfold new insights into the surgical management of PACG.

Three-year clinical outcomes of phacoemulsification combined with excisional goniotomy using the kahook dual blade for cataract and open-angle glaucoma in Saudi Arabia

PURPOSE

The aim of this study was to describe the changes in intraocular pressure (IOP), IOP-reducing drugs, and visual acuity (VA) through up to 3 years of follow-up in patients undergoing combined phacoemulsification and excisional goniotomy with the Kahook Dual Blade (KDB-phaco) by a single surgeon in Saudi Arabia.

METHODS

The health records of 55 eyes of 47 patients undergoing KDB-phaco by a single surgeon were reviewed. Data were extracted from visits occurring preoperatively (n = 55), intraoperatively (n = 55), and 1-day (n = 55), 2 weeks (n = 55), 4-6 weeks (n = 49), 2-3 months (n = 55), and 6 (n = 55), 9 (n = 55), 12 (n = 55), 18 (n = 49), 24 (n = 46), and 36 months (n = 16) postoperatively. Data collection included IOP, IOP-lowering medications, and VA at each time point. Adverse events were also collected. Paired t-tests were used to compare IOP, medications, and VA at each time point to preoperative values.

RESULTS

Mean (standard error) baseline IOP was 20.4 (0.7) mmHg and through up to 36 months of follow-up (minimum 12 months, mean 26.1 [1.0] months) ranged from 13.6 to 14.1 mmHg; significant reductions (P < 0.0007) of 5.7-7.0 mmHg (23.0%-29.5%) were achieved at every time point. Medications were reduced from 3.2 (0.1) to 0.2-2.0 (reductions of 1.2-3.1 medications [50.0%-94.9%]; P < 0.0001 at every time point). At months 24 and 36, the mean IOP was 13.9 (0.3) and 13.9 (0.5) mmHg and mean medications were 1.4 (0.2) and 2.0 (0.4). Mean logMAR VA improved from 1.0 (0.1) preoperatively to (0.2 [0.0]; P < 0.001) by month 6 and remained stable thereafter through the duration of follow-up.

CONCLUSION

KDB-phaco significantly lowered IOP approximately 30% by day 1 with consistency and durability through 3 years. Medication use was reduced by >50% through 36 months. Mean logMAR VA improved from 1.0 to 0.2 (Snellen equivalent 20/200-20/32). This procedure provides meaningful long-term reductions in IOP and the need for IOP-lowering medications without compromising visual rehabilitation in Saudi Arabian eyes with cataract and glaucoma.

Predictive Factors of Outcomes in Kahook Dual Blade Excisional Goniotomy Combined with Phacoemulsification

Aim

To identify factors that were significant predictors of Kahook Dual Blade (KDB) excisional goniotomy outcomes.

Materials and methods

One hundred and thirty-two eyes from 99 adult glaucoma patients who underwent combined KDB and phacoemulsification (KDB-phaco) with a minimum 6-month follow-up were assessed for baseline patient characteristics to determine correlation to the success of KDB-phaco at 6 and 12 months postoperatively. Success was defined as ≥20% intraocular pressure (IOP) reduction or ≥1 medication reduction as well as IOP ≤18 mm Hg without any additional IOP-lowering procedures after KDB-phaco.

Results

63.6% (84/132) and 46.1% (41/89) of cases were successful at the 6- and 12-month follow-ups, respectively. KDB-phaco reduced patient's preoperative IOP (in mm Hg) from 17.6 ± 4.6 to 14.9 ± 3.2 at 6 months (15.3%, p < 0.001) and 15.4 ± 4.7 at 12 months (12.5%, p = 0.001). KDB-phaco reduced patient's preoperative IOP-lowering medications from 2 ± 1.2 to 1.1 ± 1.2 at 6 months (45%, p < 0.001) and 1.32 ± 1.3 at 12 months (34%, p < 0.001). At 6 months, patients on >1 IOP lowering medication had a greater chance of meeting our success criteria (p = 0.037). Visually significant postoperative hyphema was not associated with the use of anticoagulation (p = 0.943) but was significantly associated with postoperative day 1 IOP ≤ 10 mm Hg (p = 0.011).

Conclusion

Patients who underwent KDB-phaco significantly reduced their IOP and medication burden at both 6 and 12 months compared with their baseline preoperative values. KDB-phaco outcome was associated with higher baseline IOP-lowering medications and increased rate of hyphema was associated with lower postoperative day 1 IOP, regardless of anticoagulation status. Age, ethnicity, prior laser trabeculoplasty, type and severity of glaucoma, and baseline preoperative IOP were not associated with surgical success.

Clinical significance

Patients with a higher number of baseline medications may experience a greater probability of success following KDB-phaco.

How to cite this article

Pratte EL, Cho J, Landreneau JR, et al. Predictive Factors of Outcomes in Kahook Dual Blade Excisional Goniotomy Combined with Phacoemulsification. J Curr Glaucoma Pract 2022;16(1):47-52.

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

Aim

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

Background

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

Review results

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

Conclusion

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

Clinical significance

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

How to cite this article

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

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.

Outcomes of combined single-use dual blade goniotomy and cataract surgery

Purpose

Single-use dual blade goniotomy (SBG) is a novel ab interno procedure that removes three to five clock hours of trabecular meshwork (TM). We analysed the reduction of intraocular pressure (IOP) and topical glaucoma medication (Meds) in eyes following combined cataract surgery and SBG (Cat-SBG).

Methods

IOP and Meds were evaluated retrospectively in 55 eyes of 38 patients. 44 eyes had high tension glaucoma (HTG) and eleven eyes had normal tension glaucoma (NTG). Complete success (no Meds) and qualified success (with Meds) for IOP levels ≤ 21, ≤ 18 , ≤ 16 mmHg or ≥ 20% IOP reduction at the two- and six-month follow-up were evaluated.

Results

IOP and Meds were significantly reduced from before to two months after Cat-SBG in HTG- and NTG-patients (HTG: IOP 19.4 ± 3.3 to 15.1 ± 3.3 mmHg; p < 0.001; Meds 2.1 ± 1.3 to 0.8 ± 1.3; p < 0.001; NTG: IOP 14.0 ± 2.3 to 11.5 ± 2.3 mmHg; p = 0.004; Meds 1.6 ± 0.7 to 0.3 ± 0.7; p < 0.001). IOP and Meds did not change significantly from two to six months after Cat-SBG.

In HTG, complete and qualified success rates were 43% (19/44) and 93% (41/44) for IOP ≤ 18 mmHg, 36% (16/44) and 64% (28/44) for IOP ≤ 16 mmHg and 30% (13/44) and 43% (19/44) for ≥ 20% IOP reduction six months after surgery. In NTG, complete and qualified success was 81% (9/11) and 100% (11/11) for IOP ≤ 18 and ≤ 16 mmHg, and 27% (3/11) for IOP reduction ≥ 20%.

IOP and Meds reduction were comparable between HTG and NTG eyes.

Only minor postoperative complications occurred.

Conclusion

Cat-SBG is an efficient method to significantly lower IOP in patients with HTG and NTG.

Ab-interno trabeculotomy with Kahook dual blade in secondary traumatic glaucoma in a child

Purpose

To report a successful ab-interno trabeculotomy with Kahook Dual Blade (KDB) in secondary traumatic angle recession glaucoma in a child and discuss the possible mechanisms of action.

Observations

A 7 years-old boy presented, after a blunt trauma in the left eye, with angular recess surroundings 110° and concomitant intra-ocular pressure (IOP) elevation around 35 mmHg, despite the maximum topical and systemic ocular hypotensive therapy. As there was no glaucomatous neuropathy yet, a KDB ab-interno trabeculotomy was performed. After KDB's surgery, oral and topical hypotensive medications were gradually withdrawn until complete suspension with IOP levels around 11 mmHg, which has remained the same in the last 2 years. Both functional and structural assessment of glaucoma have maintained stable throughout the follow-up until the present moment.

Conclusion and Importance

The KDB has demonstrating a favorable safety profile and a useful surgical technique that should be considered mainly in trabecular glaucomas, as well as those secondary to trauma. Studies are still needed to define which patient and glaucoma profile are the most suitable for the procedure and for how long it is effective.

12-month clinical outcomes of combined phacoemulsification and ab interno trabeculectomy for open-angle glaucoma in the United Kingdom

BACKGROUND/OBJECTIVES

To describe intraocular pressure (IOP) and ocular hypotensive medication outcomes of combined phacoemulsification and ab interno trabeculectomy with the Kahook Dual Blade (KDB; New World Medical, Inc, Rancho Cucamonga, CA) in adults with cataract and open-angle glaucoma (OAG).

SUBJECTS/METHODS

Retrospective chart review of existing medical records. Data collected included intraocular pressure (IOP) and IOP-lowering medication use preoperatively and through up to 24 months postoperatively. Paired t-tests were utilized to compare preoperative to postoperative mean IOP and mean medications used.

RESULTS

Data from 32 eyes of 26 subjects were analyzed. Subjects were predominantly Caucasian (25/26) had mean (standard error) age of 79.3 (1.2) years, and eyes had moderate-advanced OAG (mean visual field mean deviation -8.3 [1.3] dB). Mean IOP was 19.8 (0.8) mmHg at baseline and 15.5 (0.6) mmHg (p<0.0001) after mean follow-up of 11.5 (1.0) months; IOP reductions of ≥20% were achieved in 20/32 eyes (62.5%). Mean medication use declined from 2.4 (0.2) medications per eye at baseline to 0.5 (0.2) at last follow-up (p<0.0001); 23/32 eyes (71.9%) were medication-free at last follow-up. No vision-threatening complications were observed.

CONCLUSIONS

Combined phacoemulsification and ab interno trabeculectomy with the KDB safely provided mean IOP reductions of 21.7% and mean IOP medication reductions of 83% after mean follow-up of 12 months in eyes with moderate to advanced OAG. This procedure provides medication-independence in most eyes with statistically and clinically significant IOP reductions.

Kahook Dual Blade Ab-interno Trabeculectomy Compared With Conventional Goniotomy in the Treatment of Primary Congenital Glaucoma: 1-Year Results

INTRODUCTION

Kahook dual blade (KDB) removes a strip of the trabecular meshwork from the angle, which may make it superior to simple goniotomy in treating the angle anomaly in primary congenital glaucoma (PCG). This prospective study compares KDB ab-interno trabeculectomy to conventional goniotomy in PCG.

METHODS

Forty-two eyes of 29 patients with PCG underwent ab-interno trabeculectomy using a KDB or conventional goniotomy using a 25-G irrigating needle, targeting 100 to 120 degrees of the nasal iridocorneal angle. Patients were seen at 1, 3, 6, and 12 months postoperatively. Success was defined as intraocular pressure (IOP) ≤21 mm Hg at 1-year follow-up visit, with no evidence of glaucoma progression.

RESULTS

The KDB group included 21 eyes of patients with a median age of 6 months (interquartile range: 4 to 8.5 mo) and the goniotomy group included 21 eyes of patients with a median age of 5 months (interquartile range: 3 to 9.5 mo). There was a significant reduction in IOP in both groups at all follow-up visits. The reduction in the number of glaucoma medications was significant at 1, 3, and 6 months postoperatively in the KDB group, and at 1 month in the goniotomy group. There was no significant difference in IOP or glaucoma medications between both groups at any follow-up visit. Success was achieved in 12 eyes (57.1%) in each group, with no eyes developing any serious complications.

CONCLUSION

One-year results show that KDB ab-interno trabeculectomy is at least as effective as goniotomy in the treatment of PCG. Eyes with bilateral glaucoma had a tendency to fail both procedures.

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

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

Safety profile of minimally invasive glaucoma surgery

PURPOSE OF REVIEW

This article reviews the safety profile of trabecular meshwork/Schlemm's canal-based, subconjunctival, and suprachoroidal minimally invasive glaucoma surgery (MIGS).

RECENT FINDINGS

Prospective randomized clinical trials and metaanalyses published during the 2019-2020 review period provided important data regarding the safety profile of trabecular meshwork/Schlemm's canal-based MIGS. Transient hyphema and intraocular pressure spikes are among the most common complications associated with this category of MIGS, but more serious adverse events such as cyclodialysis cleft formation may also occur. Trabecular bypass microstents and the intracanalicular scaffold are further subject to device-related complications, including malposition and obstruction. Recent case reports and retrospective case series have further characterized the safety profile of the subconjunctival gel stent, with adverse events ranging from self-limited hypotony to visually devastating endophthalmitis and suprachoroidal hemorrhage. Five-year results of the COMPASS XT study demonstrated significantly greater endothelial cell loss in patients randomized to receive CyPass Micro-Stent (Alcon Laboratories, Fort Worth, TX, USA) in combination with cataract surgery versus those who underwent cataract surgery alone, and ultimately led to a Food and Drug Administration Class I recall of the device.

SUMMARY

Trabecular meshwork/Schlemm's canal-based procedures are generally among the safest MIGS, with mostly self-limited and nonvision-threatening complications. Subconjunctival gel stent insertion is associated with both bleb-related and stent-specific adverse events, which are similar to those observed with trabeculectomy and tube shunt surgery, respectively. Removal of the CyPass Micro-Stent from the market underscores the need for high-quality, long-term safety data regarding MIGS.

Kahook Dual Blade Goniotomy vs iStent inject: Long-Term Results in Patients with Open-Angle Glaucoma

Purpose

Efficacy and safety evaluation of Kahook Dual Blade (KDB) goniotomy vs iStent inject implantation.

Materials and Methods

Retrospective study in patients that underwent goniotomy with KDB or iStent inject implantation, stand-alone or combined with cataract surgery. Main outcome parameters were intraocular pressure (IOP), number of glaucoma medications, proportion of eyes achieving >20% IOP reduction and number of eyes with postoperative IOP <19 mmHg at last follow-up.

Results

A total of 29 patients (30 eyes) were included in the iStent inject group and 30 patients (32 eyes) in the KDB group. Mean follow-ups were 20.9±6.5 (KDB-alone) to 29.5±7.6 (phaco-iStent inject) months. Pre- and post-operative IOPs were 22.2±5.8 mmHg and 15.9±4.3 mmHg (P=0.004) in the KDB-alone, 24.2±6.8 mmHg and 16.2±6.7 mmHg (P=0.001) in the phaco-KDB, 20.6±5.4 mmHg and 20.9±6.8 mmHg (P=0.598) in the iStent inject-alone as well as 20.9±5.5 mmHg and 15.6±3.4 mmHg (P=0.003) in the phaco-iStent inject subgroups. No major complications occurred.

Conclusion

All KDB and iStent subgroups except the stand-alone iStent inject subgroup showed a clinically significant IOP-lowering effect as a stand-alone procedure or combined with cataract surgery. Goniotomy with KDB in this setting seems to offer an advantageous IOP reduction compared to iStent inject.

Twelve-month surgical outcome and prognostic factors of stand-alone ab interno trabeculotomy in Japanese patients with open-angle glaucoma

The purpose of the study was to evaluate the 12-month surgical outcome and prognostic factors of stand-alone ab interno trabeculotomy. The changes in the intraocular pressure (IOP) and medication score and the success rate of the surgery were analyzed. Thirty-four eyes of 29 patients with primary open-angle glaucoma (POAG; n = 16) or pseudoexfoliation glaucoma (PEG; n = 18) with a 12-month follow-up period were included in the study. The decreases in IOP and medication score from the baseline to the all-time-point were statistically significant (P < 0.001). The surgical success rates were 97.1%, 76.5%, and 44.0% at 3 months (90 days), 6 months (180 days), and 12 months (365 days), respectively. A mixed effect Cox model revealed that the type of glaucoma (POAG) was significantly associated with surgical failure (P = 0.044). Furthermore, the surgical success rate was significantly higher in eyes with PEG than it was in those with POAG (P = 0.019). Stand-alone ab interno trabeculotomy significantly lowered both the IOP and the medication score in patients with glaucoma, although almost one quarter of the cases needed additional glaucoma surgeries. The surgical success rate was significantly higher in eyes with PEG than it was in those with POAG.

Excisional Goniotomy in Latino Patients with Open-Angle Glaucoma: Outcomes Through 24 Months

Purpose

To characterize the efficacy of combined phacoemulsification and excisional goniotomy with the Kahook Dual Blade (KDB-phaco) in eyes of Latino adults with cataract and open-angle glaucoma (OAG).

Methods

Health records of consecutive Latino patients undergoing KDB-phaco were retrospectively reviewed. Intraocular pressure (IOP) and IOP-lowering medication use were recorded at baseline and each postoperative visit through up to 24 months. Primary outcomes were reductions in IOP and medication use from baseline; secondary outcomes were the proportions of eyes achieving IOP reductions of ≥20% and medication reductions ≥1 medication from baseline. Subgroup analysis was conducted in eyes with high and low baseline IOP.

Results

Data from 44 eyes of 32 Latino patients with OAG were analyzed. Mean IOP was 17.8 (0.7) mmHg at baseline and postoperatively ranged from 12.4 to 13.8 mmHg (p≥0.0003), representing mean IOP reductions of 4.2–4.6 mmHg (19.7–23.1%). Mean medication was 1.5 (0.2) medications per eye at baseline and postoperatively ranged from 0.2 to 1.0 (p≥0.0061), representing mean medication reductions of 0.7–1.2 medications per eye (47.1–87.2%). In the low baseline IOP group (<18 mmHg), mean IOP was significantly reduced through Month 24 and medications through Month 12; in the high baseline IOP group (≥18 mmHg), IOP and medications were significantly reduced through Month 24. From Months 1–24, IOP reductions of ≥20% were achieved by 48.4–56.2% of eyes in the full cohort, by 20.0–33.3% in the low IOP group, and by 66.7–100% in the high IOP group; medication reductions of ≥1 medication were achieved by 72.0–95.6%, 64.7–94.2%, and 87.5–100% of eyes, respectively.

Conclusion

Combined KDB-phaco in eyes of Latino patients with glaucoma and cataract significantly lowers IOP and the need for IOP-lowering medications for up to 24 months and should be considered for such patients who warrant IOP reduction, medication reduction, or both.

Minimally Invasive Glaucoma Surgery: Where Is the Evidence?

PURPOSE

The last decade has witnessed an unprecedented growth in glaucoma treatment options through the introduction of minimally invasive glaucoma surgeries (MIGS). The aim of the present review is to provide an understanding of the currently available MIGS and to examine what data are currently available to guide treatment choice.

DESIGN

Meta-analysis and systematic review of randomized and non-randomized control trials.

METHODS

Out of 2567 articles identified, a total of 77 articles were retained for analysis, including 28 comparative studies and 12 randomized control trials. Overall, 7570 eyes were included. When data permitted, the weighted mean difference in intraocular pressure reduction was calculated for comparison purposes.

RESULTS

Weighted mean intraocular pressure reductions from all analyzed studies were: 15.3% (iStent), 29.1% (iStent inject), 36.2% (ab interno canaloplasty), 34.4% (Hydrus), 36.5% (gonioscopically-assisted transluminal trabeculotomy), 24.0% (trabectome), 25.1% (Kahook dual blade), 30.2% (Cypass), 38.8% (XEN), and 50.0% (Preserflo).

CONCLUSIONS

One of the advantages of the heterogenous range of available MIGS options is the chance to tailor therapy in an individualized manner. However, high-quality data are required to make this choice more than an educated guess. Overall, this review confirms the efficiency of assessed MIGS compared with standalone phacoemulsification, but it highlights that only few studies compare different MIGS techniques and even fewer assess MIGS against criterion standard treatments. Current evidence, while non-negligible, is mostly limited to heterogenous nonrandomized studies and uncontrolled retrospective comparisons, with few quality randomized control trials. We suggest that future research should be comparative and include relevant comparators, standardized to report key outcome features, long-term to assess sustainability and late complications, and ideally randomized.