Kahook Dual Blade Excisional Goniotomy and Goniosynechialysis Combined With Phacoemulsification for Angle-closure Glaucoma: 6-Month Results

Canaloplasty and Trabeculotomy Combined With Phacoemulsification for Primary Angle-Closure Glaucoma: A Single-Surgeon Case Series

PURPOSE

To evaluate the outcomes of combined canaloplasty and trabeculotomy with phacoemulsification for primary angle-closure glaucoma (PACG).

METHODS

In this retrospective, consecutive, single-surgeon case series, we analyzed the pre- and postoperative measurements of PACG patients who had the procedure. Adverse events were recorded. The main outcomes were mean intraocular pressure (IOP) in each quartile of the follow-up year and the number of IOP-lowering medications the patients were on by the end of each quartile compared to their baseline values.

RESULTS

 A total of 46 eyes from 39 PACG patients were included. The preoperative IOP and glaucoma medications taken were 19.33±6.03 mm Hg and 1.80±1.39, respectively (N=46). Postoperative IOP means (mm Hg) in the subsequent four quartiles were 14.00±3.33 (N=44), 13.44±2.83 (N=32), 14.38±2.39 (N=16), and 14.92±2.90 (N=13) (p<0.0001). The mean number of meds was 0.32±0.80, 0.22±0.42, 0.59±0.80, and 0.08±0.28 in each respective quartile (p<0.0001), while the median was 0 across all quartiles.

CONCLUSIONS

Combining the OMNI surgical system with phacoemulsification led to substantial reductions in mean IOP and the number of IOP-lowering medications when compared to baseline measurements.

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.

Phacoemulsification with gonioscopy-assisted transluminal trabeculotomy versus phacoemulsification alone in primary angle closure glaucoma: A randomized controlled study

PURPOSE

To assess the safety and efficacy of combining phacoemulsification with gonioscopy-assisted transluminal trabeculotomy (GATT) compared to phacoemulsification alone in the management of primary angle closure glaucoma (PACG).

METHODS

Prospective, institutional study in which eyes requiring surgery for PACG were randomized to undergo phacoemulsification followed by GATT (phaco-GATT group) or phacoemulsification alone. Success was defined as having a final IOP of 6-20 mmHg with no subsequent glaucoma surgery or vision-threatening complications.

RESULTS

Thirty-six eyes underwent phaco-GATT with 360° angle incision and 38 eyes underwent phacoemulsification alone. IOP and glaucoma medications were significantly lower in the phaco-GATT group at 1, 3, 6, 9 and 12 months. The success rate in the phaco-GATT group was 94.4% after 12.16 ± 2.03 months, with 75% of eyes being off medications compared to 86.8% after 12.47 ± 4.27 months in the phaco group, with 42.1% off medications. (p = 0.008). Hyphema and fibrinous anterior chamber reaction were the most common complications in the phaco-GATT group and resolved with conservative treatment or required YAG capsulotomy. Although this delayed visual rehabilitation in the phaco-GATT group, it did not affect the final visual outcome with no significant difference in the final best-corrected visual acuity between both groups (p = 0.25).

CONCLUSION

Combining phacoemulsification with GATT in PACG yielded more favourable outcomes in terms of IOP, glaucoma medications and surgical success. Although the postoperative hyphema and fibrinous reaction may delay visual rehabilitation, GATT further lowers the IOP by breaking residual peripheral anterior synechiae and removing the dysfunctional trabeculum circumferentially, while avoiding the risks inherent in more invasive filtering procedures.

Early Outcomes of Combined Phacoemulsification and Ab Interno Tanito Microhook Trabeculotomy in Open-Angle Glaucoma

PURPOSE

To study the early postoperative efficacy and safety of an Ab Interno microhook trabeculotomy (microLOT) combined with cataract surgery in patients with open-angle glaucoma.

METHODS

This prospective, randomized, interventional study was conducted on consecutive patients with visually significant cataract and mild-moderate open-angle glaucoma. One hundred fourteen patients were included for analysis. The patients were randomized to undergo microhook trabeculotomy with phacoemulsification (group 1) or phacoemulsification alone (group 2). All patients were evaluated on postoperative day 1, 15, and 30, as well as 3, 6, and 12 months postoperatively. A P value < 0.05 was considered statistically significant. Baseline and follow-up visits were compared to determine significant differences in the number of antiglaucoma medications (AGMs), intraocular pressure (IOP), and best-corrected visual acuity.

RESULTS

There were 57 patients in each group. The baseline characteristics were similar between the 2 groups, except the number of AGMs, which was greater in group 2. The mean preoperative IOP for group 1 (phaco-microLOT) was 26.5 mmHg ± 5.2 and group 2 (phaco-alone group) was 25.3 mmHg ± 3.1 which decreased to 12.5 mmHg ±3.6 (P < 0.001) and 20.0 mmHg ± 2.7(P < 0.001) at 12 months, respectively. Logarithm of the minimum angle of resolution visual acuity improved from 0.48 (interquartile range [IQR], 0.30-0.60) preoperatively to 0.00 (0.00-0.18) postoperatively (P < 0001) in group 1 and improved from 0.30 (IQR, 0.30-0.48) to 0.00 (0.00-0.00) in group 2 (P < 0.001). In group 1, the mean (standard deviation [SD]) AGM used preoperatively was 0.6 (0.9) which was significantly reduced to 0.2 (0.5) at 12 months postoperatively, whereas in group 2, at 12 months, the mean (SD) AGM used was reduced from 1.4 (0.6) to 1.1 (0.9). In group 1, 90.3% of eyes achieved complete success at the end of 1 year. The most common complication was hyphema, noted in 4 patients with 1 eye requiring an anterior chamber washout.

CONCLUSION

Ab interno microhook trabeculotomy (microLOT) combined with phacoemulsification in patients with open-angle glaucoma is an efficacious procedure with relatively minimal complications.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

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.

The PreserFlo MicroShunt in the Context of Minimally Invasive Glaucoma Surgery: A Narrative Review

Recently, the quest for novel glaucoma surgical techniques and devices has been underway. Trabeculectomy remains the gold standard, but it requires the implantation of glaucoma drainage devices and frequent follow-ups, and it also carries a high risk of serious complications. The need for less invasive and safer procedures has led to the development of minimally invasive glaucoma surgery (MIGS), particularly for patients with mild-to-moderate disease. Among them, minimally invasive bleb surgery seems to be effective in classical glaucoma surgery, while maintaining MIGS benefits. The relatively new PreserFlo® MicroShunt (Santen, Osaka, Japan) is registered in Europe. It was released in 2019 for the treatment of patients with early-to-advanced open-angle glaucoma, where intraocular pressure (IOP) remains uncontrolled while on maximum tolerated medication and/or where glaucoma progression warrants surgery. This review focuses on the place of the PreserFlo MicroShunt, characterized by ab externo implantation, among MIGS procedures, discussing its advantages and disadvantages. The mechanisms of action, technical aspects, efficacy, and safety issues are summarized. The surgical technique, its efficacy, and safety profile are described, and directions for future studies are indicated. The PreserFlo MicroShunt ensures a high safety profile, minimal anatomical disruption, meaningful IOP-lowering effect, and ease of use for patients and physicians.

Risk factors of surgical failure in combined phacoemulsification and excisional goniotomy for angle-closure glaucoma

PURPOSE

To evaluate the therapeutic success, and risk factors for combined phacoemulsification and Kahook Dual Blade excisional goniotomy (Phaco/KDB) in primary angle-closure glaucoma (PACG).

METHODS

A retrospective review was conducted on glaucoma patients who underwent Phaco/KDB between September 2019 and August 2021 at 2 ophthalmology centers. Complete success was defined as unmedicated intraocular pressure (IOP) ≤ 18 mmHg with no further glaucoma surgery, while the medicated IOP ≤ 18 mmHg was defined as qualified success with lesser medications than at baseline.

RESULTS

Seventy-two eyes (64 patients) with a mean age of 67.1 ± 8.1 years were included in this study, and 70.2% were female. The mean medicated baseline IOP decreased from 23.4 ± 8.1 to 16.6 ± 3.9 mmHg at an average of 11.6 ± 3.7 months of follow-up (- 29.1%; P < 0.00). Medications decreased from 2.6 ± 1.3 to 0.4 ± 0.9 (- 82.6%; P < 0.001). Complete success and qualified success were achieved in 65.3% and 79.2% of eyes, respectively. Male gender [hazard ratio (HR): 6.00 (1.57-22.9); P = 0.009] was observed a risk factor for surgical failure, whereas higher axial length (HR:0.37 (0.16-0.86); P = 0.021), and a combined circumferential goniosynechialysis procedure (HR: 0.13 (0.02-0.74); P = 0.022) lowered the risk of surgical failure. Hyphema, postoperative shallowing anterior chamber, and IOP spike were the most common complications. The cumulative survival proportion for qualified success at 12 months was 82.5% ± 0.05 (95% CI, 0.70-0.90).

CONCLUSION

Phaco/KDB provided acceptable therapeutic success rate and may, therefore, be recommended in patients with coexisting cataract and PACG. Identifying patients with risk factors preoperatively may help clinicians predict surgical success.

One-Year Results of a Multicenter Study: Intraocular Pressure-Lowering Effect of Combined Phacoemulsification, Goniosynechialysis, and Goniotomy for Cases of Advanced Primary Angle-Closure Glaucoma With Cataract

PURPOSE

To evaluate the intraocular pressure (IOP)-lowering effect of the combination of phacoemulsification with intraocular lens implantation (PEI), goniosynechialysis (GSL), and goniotomy (GT) in eyes of advanced primary angle-closure glaucoma (PACG) with cataract.

DESIGN

Multicenter observational study.

METHODS

We enrolled 83 eyes of 83 patients with advanced PACG who received combined PEI+GSL+GT at 8 ophthalmic institutes. Each patient was assessed before treatment and at 1, 7 days, 1, 3, 6, and 12 months postsurgery. The criteria for complete success were IOP within 6 to 18 mm Hg and at least 20% of reduction in IOP from baseline without ocular hypotensive medications or reoperation. The definition of qualified success was similar to that of complete success, except for the need for ocular hypotensive medications. The potential prognostic factors for surgical success were investigated using a multivariate logistic model.

RESULTS

All participants completed 1 year of follow-up. Complete and qualified success were achieved in 74 (89.1%) and 79 (95.2%) of 83 eyes, respectively. The mean preoperative and postsurgical IOPs were 27.4±7.3 and 14.2±2.6 mm Hg, respectively. Participants used an average of 2.0 and 0.3 types of ocular hypotensive medications before and after surgery, respectively. The chief complications included hyphema (n=9), IOP spike (n=9), and corneal edema (n=8). None of the eyes required reoperation or developed vision-threatening complications. Multivariate analysis showed that older age was associated with a higher probability of complete success (odds ratio=1.13; 95% CI: 1.02-1.25; P=0.020).

CONCLUSIONS

The 1-year results of combination of PEI+GSL+GT in treating advanced PACG cases with cataract appear to be safe and effective. Further large-scale multination and multicenter studies are warranted.

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.

Risk factors for intraocular pressure elevation in a six-month period after ab interno trabeculotomy using a Kahook Dual Blade

BACKGROUND

To examine the risk factors for an early postoperative intraocular pressure (IOP) increase after ab interno trabeculotomy using a Kahook Dual Blade (KDB trabeculotomy).

METHODS

A retrospective study was performed in 76 exfoliation glaucoma (EXG) eyes and 56 primary open angle glaucoma (POAG) eyes that underwent KDB trabeculotomy, with or without cataract surgery at Kumamoto University Hospital. Postoperative high IOP was classified as IOP≥20 mmHg (within three months after surgery, whether persistent or temporary), transient IOP≥20 mmHg (IOP≥20 mmHg after surgery, then dropped below 20 mmHg), and the presence of IOP spikes (≥ 10 mmHg from baseline). Risk factors were examined using logistic regression analysis.

RESULTS

The preoperative mean IOP (SD) was 24.98 (7.23) mmHg in patients with EXG and 21.28 (6.58) mmHg in patients with POAG. IOP was reduced by 32.1% in patients with EXG and by 17.7% in patients with POAG at 6 months after surgery. Postoperative IOP≥20 mmHg was observed in 56.6% of EXG patients and in 51.8% of POAG patients. IOP spikes occurred in 15.8% of EXG patients and in 14.3% of POAG patients. Logistic regression analysis showed that factors with significant odds ratios (ORs) were age (OR = 0.866, 95% CI = 0.793-0.945), preoperative medication use (OR = 2.02, 95% CI = 1.17-3.49), trabeculotomy in combination with cataract surgery (OR = 0.0674, 95% CI = 0.015-0.303), and IOP at day 1 (OR = 1.41, 95% CI = 1.18-1.68) for postoperative IOP≥20 mmHg, the IOP at day 1 (OR = 1.1, 95% CI = 1.03-1.17) for transient IOP≥20 mmHg, and age (OR = 0.948, 95% CI = 0.901-0.997) and preoperative IOP (OR = 0.83, 95% CI = 0.736-0.936) for IOP spikes.

CONCLUSION

Although KDB trabeculotomy is an effective treatment for patients with EXG and POAG, patients who take multiple preoperative medications and have a high IOP on day 1 require careful follow-up to prevent postoperative IOP elevation.

Efficacy and safety of trabeculectomy versus peripheral iridectomy plus goniotomy in advanced primary angle-closure glaucoma: study protocol for a multicentre, non-inferiority, randomised controlled trial (the TVG study)

INTRODUCTION

Primary angle-closure glaucoma (PACG) is a major subtype of glaucoma that accounts for most bilateral glaucoma-related blindness globally. Filtering surgery is a conventional strategy for PACG, yet it has a long learning curve and undesirable disastrous complications. Minimally invasive glaucoma surgery (MIGS) plays an increasing role in the management of glaucoma due to its safer and faster recovery profile; cataract surgery-based MIGS is the most commonly performed such procedure in PACG. However, for patients with a transparent lens or no indications for cataract extraction, incorporation of MIGS into PACG treatment has not yet been reported. Therefore, this multicentre, non-inferiority, randomised controlled clinical trial aims to compare the efficacy and safety of trabeculectomy versus peripheral iridectomy plus an ab interno goniotomy in advanced PACG with no or mild cataracts.

METHODS AND ANALYSIS

This non-inferiority, multicentre, randomised controlled trial will be conducted at seven ophthalmic departments and institutes across China. Eighty-eight patients with no or mild cataracts and advanced PACG will be enrolled and randomised to undergo trabeculectomy or peripheral iridectomy plus ab interno goniotomy. Enrolled patients will undergo comprehensive ophthalmic examinations before and after surgery. The primary outcome is intraocular pressure (IOP) at 12 months postoperatively. The secondary outcomes are cumulative success rate of surgery, surgery-related complications and number of IOP-lowering medications. Participants will be followed up for 36 months postoperatively.

ETHICS AND DISSEMINATION

The study protocol was approved by the ethical committees of the Zhongshan Ophthalmic Center, Sun Yat-sen University, China (ID: 2021KYPJ191) and of all subcentres. All participants will be required to provide written informed consent. The results will be published in peer-reviewed journals and disseminated in international academic meetings.

TRIAL REGISTRATION NUMBER

NCT05163951.

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.

The surgical management of glaucoma: A review

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

Efficacy and safety of phacotrabeculectomy versus phacogoniotomy in advanced primary angle-closure glaucoma: study protocol for a multicentre non-inferiority randomised controlled trial (PVP Study)

INTRODUCTION

Primary angle-closure glaucoma (PACG) has a high prevalence and blinding rate across Asia. The first-line treatment of PACG is surgery, and phacotrabeculectomy remains the mainstream surgery for advanced PACG. However, it may cause vision-threatening complications with long learning curve. Minimally invasive glaucoma surgery has been gradually used in PACG combined with cataract surgery and achieved efficacy without excessive injury, of which goniotomy is the most commonly performed. Therefore, this study aimed to conduct a multicentre, non-inferiority randomised controlled clinical trial to compare the efficacy and safety of phacotrabeculectomy versus phacogoniotomy in advanced PACG.

METHODS AND ANALYSIS

This is a non-inferiority multicentre randomised controlled trial and will be conducted at eight ophthalmic departments and institutes in China. 124 patients with advanced PACG will be enrolled and randomised to undergo phacotrabeculectomy or phacogoniotomy. Comprehensive ophthalmic examinations will be performed before and after the surgery. The primary outcome is the change of intraocular pressure at 12 months after surgery compared with the baseline intraocular pressure. An extended follow-up period of 36 months will be required. Cumulative success rate of surgery, intraoperative and postoperative complications, and number of anti-glaucomatous medications will also be compared between the groups as secondary outcomes.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the ethical committee of Zhongshan Ophthalmic Center, Sun Yat-sen University, China (ID: 2021KYPJ090) and all subcentres. All the participants will be required to provide written informed consent. The results will be disseminated through scientific meetings and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04878458.

Minimally Invasive Glaucoma Surgery-to Remove or Preserve the Trabecular Meshwork: That is the Question?

How to cite this article: Dada T, Mahalingam K, Bhartiya S. Minimally Invasive Glaucoma Surgery—to Remove or Preserve the Trabecular Meshwork: That is the Question? J Curr Glaucoma Pract 2021;15(2):47–51.

Excisional goniotomy vs trabecular microbypass stent implantation: a prospective randomized clinical trial in eyes with mild to moderate open-angle glaucoma

PURPOSE

To compare reduction in intraocular pressure (IOP) and IOP-lowering medication in eyes undergoing excisional goniotomy with Kahook Dual Blade (KDB) vs iStent microbypass implantation, both combined with phacoemulsification, in eyes with mild to moderate open-angle glaucoma (OAG).

SETTING

Nine practices in the United States.

DESIGN

Prospective, randomized, active-controlled, parallel-group clinical trial.

METHODS

Eyes were randomized to KDB-Phaco or iStent-Phaco group. Demographics, corrected distance visual acuity, IOP, IOP-lowering medications, and adverse events were collected at baseline and at day 1, week 1, and months 1, 3, 6, and 12 postoperatively. The primary outcome measure was the proportion of eyes at 12 months with IOP reduction of 20% or greater or IOP medication reduction of 1 or more compared with baseline.

RESULTS

For this study, 164 eyes of 164 patients were analyzed (82 in each group). Mean IOP was reduced at 12 months compared with baseline from 18.5 (standard of error 0.4) to 15.4 (0.4) mm Hg in the KDB-Phaco group and from 18.5 (0.3) to 16.1 (0.4) mm Hg in the iStent-Phaco group (P = .24). Mean IOP-lowering medications were reduced from 1.3 (0.1) to 0.3 (0.1) in the KDB-Phaco group and from 1.4 (0.1) to 0.4 (0.1) in the iStent-Phaco group (P = .17). Among study completers, the primary outcome was attained in 74 (93.7%) of 79 patients of KDB-Phaco eyes and 65 (83.3%) of 78 patients of iStent-Phaco eyes (P = .04). Both procedures had similar safety profiles.

CONCLUSIONS

Both procedures lowered both IOP and the need for IOP-lowering medications effectively and safely in eyes with mild to moderate OAG and cataract. Significantly, more KDB-Phaco eyes than iStent-Phaco eyes met the primary outcome of 20% or greater IOP reduction or 1 or more medication reduction at 12 months.

Minimally Invasive Glaucoma Surgery: A Critical Appraisal of the Literature

Micro- or minimally invasive glaucoma surgeries (MIGS) have been the latest addition to the glaucoma surgical treatment paradigm. This term refers not to a single surgery, but rather to a group of distinct procedures and devices that aim to decrease intraocular pressure. Broadly, MIGS can be categorized into surgeries that increase the trabecular outflow [Trabectome, iStent (first and second generations), Hydrus microstent, Kahook Dual Blade and gonioscopy-assisted transluminal trabeculotomy], surgeries that increase suprachoroidal outflow (Cypass microstent and iStent Supra), and conjunctival bleb-forming procedures (Xen gel stent and InnFocus microshunt). Compared to traditional glaucoma surgeries, such as trabeculectomy and glaucoma drainage device implantation (Ahmed, Baerveldt, and Molteno valves), MIGS are touted to have less severe complications and shorter surgical time. MIGS represent an evolving field, and the efficacy and complications of each procedure should be considered independently, giving more importance to high-quality and longer-term studies.

Microinvasive Glaucoma Surgery: An Evidence-Based Review

PURPOSE

Interest in micro-invasive glaucoma surgery (MIGS) has exploded over the last 8 years with an increase in MIGS procedures of at least 400% in the United States, according to Medicare data. MIGS is an umbrella term that can cover many different types of surgeries. This review focuses on peer-reviewed evidence for Trabectome^®, iStent inject^®, Kahook Dual Blade^®, XEN^® Gel Stent, and Hydrus^®.

METHODS

We present key recent studies evaluating the efficacy and safety of MIGS in various types of glaucoma patients with different stages of disease.

CONCLUSION

We conclude that MIGS is generally safe and efficacious, although only some MIGS have been studied through randomized clinical trials. When comparing and contrasting the different MIGS procedures, large prospective studies are not yet the norm. High-quality large prospective studies involving MIGS will be an important next step as ophthalmologists decide how to incorporate MIGS into their surgical armamentarium.

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 and efficacy of incisional goniotomy as an adjunct with phacoemulsification in primary angle-closure glaucoma

PURPOSE

To evaluate the intraocular pressure (IOP)-lowering efficacy and safety of incisional goniotomy as an adjunct to phacoemulsification in primary angle-closure glaucoma (PACG) patients.

METHODS

Consecutive patients with PACG (high or borderline IOP) deemed fit for phacoemulsification were enrolled. After phacoemulsification, incisional goniotomy was performed with or without goniosynechialysis. Patient demographic profile, clinical data, and adverse events, if any, were analyzed during at least a 6-month follow-up period. Success was defined as IOP of 18 mm Hg or lesser with or without medications.

SETTING

Tertiary care Ophthalmic hospital.

DESIGN

Prospective interventional case series.

RESULTS

Of 46 eyes (38 patients) included, 69.6% eyes were classified as having advanced glaucoma. The mean treated IOP decreased by 7.3 ± 1.0 (SE) mm Hg (95% CI, 5.2-9.3) from 21.4 ± 6.6 to 14.2 ± 3.7 mm Hg at a mean duration of 11.7 ± 5.5 months (6-22 months) postoperatively (P < .001, paired t test). There was 66.6% reduction in median number of hypotensive medications (P < .001, Wilcoxon signed-rank test). Observed complications included hyphema (13 eyes [28%]), IOP spike (3 eyes [6.5%]), and cyclodialysis (1 eye [2.17%]). High treated IOP and number of medications were significantly associated with failure in univariate analysis (P < .05, Fisher exact test). The cumulative survival probability for qualified success at 22 months was 87.8% ± 0.07 (95% CI, 0.65-0.96).

CONCLUSIONS

Incisional goniotomy as an adjunct with phacoemulsification resulted in a significant and sustained reduction in IOP along with decrease in number of glaucoma medications in chronic PACG eyes, irrespective of the disease stage.

Two-Year Clinical Outcomes of Combined Phacoemulsification, Goniosynechialysis, and Excisional Goniotomy For Angle-Closure Glaucoma

PURPOSE

The aim of this study was to describe changes in intraocular pressure (IOP) and IOP medications after phacoemulsification with Kahook Dual Blade-assisted goniosynechialysis and excisional goniotomy in eyes with angle-closure glaucoma and cataract.

DESIGN

Retrospective case series.

METHODS

Data were collected retrospectively through 24 months of follow-up in 42 eyes of 24 subjects.

RESULTS

Preoperative mean (SE) IOP was 25.5 (0.7) mm Hg using a mean of 2.3 (0.1) medications per eye. At month 24, mean IOP had decreased to 13.5 (0.4) mm Hg [a reduction of 12.0 mm Hg (47.1%); P < 0.0001]. Medication use declined to a mean of 0.6 (0.2) medications per eye [a reduction of 1.7 medications per eye (76%); P < 0.0001]. At month 24, 40 of 42 eyes (95.2%) achieved IOP ≤18 mm Hg, 42 of 42 eyes (100%) achieved IOP reduction of ≥20%, 36 of 42 eyes (85.7%) required ≥1 fewer medications for IOP control, and 29 of 42 (69.0%) were medication-free. No eyes required additional glaucoma surgery throughout 24 months of follow-up.

CONCLUSIONS

Phaco plus Kahook Dual Blade-assisted goniosynechialysis/excisional goniotomy provides statistically and clinically meaningful reductions in both IOP and medications in eyes with angle-closure glaucoma throughout 2 years of follow-up. These findings are consistent with our previously reported outcomes in this cohort at months 6 and 12 postoperatively, demonstrating a significant and sustained benefit of this procedure in eyes with angle-closure glaucoma and cataract.

Outcomes of effective goniosynechialysis under an endoscopic view combined with phacoemulsification in residual angle-closure glaucoma with lens opacity: 6-month results

PURPOSE

We aimed to evaluate the efficacy and safety of effective goniosynechialysis (GSL) under an endoscopic view combined with phacoemulsification in residual angle-closure glaucoma with lens opacity.

METHODS

This was a retrospective study. Patients with residual angle-closure glaucoma, lens opacity, and uncontrolled intraocular pressure (IOP) who were receiving anti-glaucoma medications were selected to undergo effective GSL under an endoscopic view combined with phacoemulsification. Follow-up examinations were conducted until 6 months postoperatively.

RESULTS

Twenty-five eyes of 24 patients diagnosed with residual angle-closure glaucoma and lens opacity and peripheral anterior synechiae (PAS) at least ≥ 270° were included. Their mean age was 61.32 ± 6.11 years. Preoperatively, the mean (standard error) IOP was 29.69 (11.22) mmHg, and the median number of IOP-lowering medications used was 3.0. The decreases in the rates of IOP of the patients were 44.29%, 52.17%, 46.95%, 48.37%, and 47.29% at 1 day, 1 week, 1 month, 2.5 months, and 6 months after the surgery, respectively. At 6 months, the median number of IOP-lowering medications used decreased from 3 to 0 and the range of PAS compared to the baseline decreased from 312° to 107° (P < 0.001). We also found that 21/25 eyes achieved improved or stable visual acuity after surgery. Postoperative complications included transiently elevated IOP (12.0%), exudation (8.0%), and hyphema (4.0%).

CONCLUSIONS

Phacoemulsification combined with effective GSL under an endoscopic view may reopen residual angle-closure glaucoma and reduce the number of IOP-lowering medications for up to 6 months. It is an effective and safe method for patients with residual angle-closure glaucoma and lens opacity.

Twelve-Month Outcomes of Stand-Alone Excisional Goniotomy in Mild to Severe Glaucoma

PURPOSE

To describe 12-month intraocular pressure (IOP) and medication use outcomes following excisional goniotomy (EG) as a stand-alone procedure in eyes with medically uncontrolled glaucoma.

METHODS

This was a retrospective analysis of data from surgeons at 8 centers (6 US, 2 Mexico). Eyes with glaucoma undergoing standalone EG with a specialized instrument (Kahook Dual Blade, New World Medical, Rancho Cucamonga, CA) for IOP reduction and followed for 12 months postoperatively were included. Data were collected preoperatively, intraoperatively, and 1 day, 1 week, and 1, 3, 6, and 12 months postoperatively. The primary outcome was reduction from baseline in IOP, and key secondary outcomes included IOP-lowering medication reduction as well as adverse events.

RESULTS

A total of 42 eyes were analyzed, of which 36 (85.7%) had mild to severe primary open-angle glaucoma (POAG). Mean (standard error) IOP at baseline was 21.6 (0.8) mmHg, and mean number of medications used at baseline was 2.6 (0.2). At 3, 6, and 12 months postoperatively, mean IOP reductions from baseline were 4.6 mmHg (22.3%), 5.6 mmHg (27.7%), and 3.9 mmHg (19.3%) (p≤0.001 at each time point). At the same time points, mean medications reductions of 0.7 (25.8%), 0.9 (32.6%), and 0.3 (12.5%) medications were seen (p<0.05 at months 3 and 6, not significant at month 12). Six eyes (14.3%) underwent additional glaucoma surgery during the 12-month follow-up period.

DISCUSSION

Standalone EG with KDB can reduce IOP, and in many cases reduce medication use, through up to 12 months in eyes with mild to severe glaucoma. Statistically significant and clinically relevant reductions in IOP were seen at every time point. While the goal of surgery was not to reduce medication burden, mean medication use was significantly reduced at all but the last time point. In the majority of eyes, the need for a bleb-based glaucoma procedure was delayed or prevented for at least 12 months.

An Update on Microinvasive Glaucoma Surgery Concurrent With Cataract Extraction

Purpose of Review

In this article, we review the current options for microinvasive glaucoma surgery (MIGS) combined with cataract extraction in the USA and the efficacy of the various approaches.

Recent Findings

MIGS is a rapidly growing area of research and clinical interest. Available surgeries aim to reduce intraocular pressure by improving aqueous outflow through the trabecular or subconjunctival pathways or by reducing aqueous production.

Summary

Multiple approaches to MIGS are utilized in clinical practice. On average, these surgeries are safe and modestly effective in reducing intraocular pressure. Future research will demonstrate which surgical approaches are most efficacious, whether and how to combine MIGS, and the role of MIGS in improving patient quality of life.

Comparison Of Surgical Outcomes Between Excisional Goniotomy Using The Kahook Dual Blade And iStent Trabecular Micro-Bypass Stent In Combination With Phacoemulsification

PURPOSE

To compare 6-month surgical outcomes of patients who underwent phacoemulsification (Phaco) combined with iStent implantation (iStent) versus excisional goniotomy using Kahook Dual Blade (KDB).

METHODS

Retrospective comparative case series of 58 iStent-Phaco eyes and 44 KDB-Phaco eyes operated upon by a single surgeon between 2016 and 2018. Preoperative, intraoperative, and postoperative intraocular pressure (IOP) and IOP-lowering medication data were collected. The primary outcome was the proportion of eyes using ≥1 fewer IOP-lowering medication at Month 6 while maintaining IOP ≤ 18 mmHg.

RESULTS

Baseline IOP was 17.2 (standard error 0.7) in the KDB-Phaco group using a mean of 1.9 (0.2) medications; at Month 6, mean IOP was 14.8 mmHg P=0.002) on 1.0 (0.2) medications (P<0.002). Baseline IOP was 16.7 (0.4) in the iStent-Phaco group using a mean of 1.4 (0.1) medications; at Month 6, mean IOP was 14.2 mmHg (P<0.002) on 1.4 (0.1) medications P=0.374). Changes in IOP and medications were not significantly different between groups (P>0.05). Significantly more KDB-Phaco eyes than iStent-Phaco eyes (43.2% vs 17.2%, P=0.004) were using ≥1 fewer medications while maintaining IOP ≤18 mmHg at Month 6. Adverse events were uncommon and similar in nature and frequency between groups with the exception that more KDB-Phaco eyes than iStent-Phaco eyes (8 [18.2%] versus 1 [1.7%]) experienced an IOP elevation presumed to be related to steroid use.

CONCLUSION

KDB-Phaco and iStent-Phaco provided comparable IOP and medication reductions. The proportion of eyes able to discontinue 1 or more medications while maintaining IOP ≤ 18 mmHg was significantly greater in eyes undergoing KDB-Phaco.

Twelve-month outcomes of excisional goniotomy using the Kahook Dual Blade® in eyes with angle-closure glaucoma

Purpose

To characterize clinical outcomes following Kahook Dual Blade^® (KDB)-assisted goniosynechialysis and excisional goniotomy combined with phacoemulsification in eyes with angle-closure glaucoma and cataract.

Setting

Two clinical practices.

Methods

In this retrospective analysis of existing health records, data were collected from 42 eyes of 24 subjects from preoperative, operative, and postoperative encounters through 12 months of follow-up. Outcomes included changes in mean IOP, IOP-lowering medications, and logMAR best-corrected visual acuity (BCVA), as well as the proportions of patients achieving IOP reductions ≥20%, IOP ≤18 mmHg, and a reduction of ≥1 medication.

Results

Preoperative, mean (standard error) IOP was 25.5 (0.7) mmHg and at Month 12 was reduced by 12.3 (0.73) mmHg (−47.2%; p<0.0001). The mean number of IOP-lowering medications used was 2.3 (0.1) preoperatively and was reduced at Month 12 by 2.2 (0.12) (−91.7%; p<0.0001). At Month 12, 92.9% of eyes achieved IOP ≤18 mmHg, 100% achieved IOP reduction of ≥20%, 95.2% required ≥1 fewer medications for IOP control, and 85.7% (36/42) were medication-free. Mean LogMAR BCVA improved from 0.547 (0.06) at baseline to 0.159 (0.07) at Month 12.

Conclusion

KDB-assisted goniosynechialysis and excisional goniotomy at the time of phacoemulsification safely provide significant reductions in both IOP and IOP-lowering medication burden in eyes with angle-closure glaucoma, while simultaneously improving visual acuity.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

FUNDING

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