Efficacy and safety of a single-use dual blade goniotomy: 18-month results

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.

Surgical Outcomes of Ab Interno Trabeculotomy Without Phacoemulsification

Purpose

The aim of this study was to evaluate ab interno trabeculotomy outcomes without phacoemulsification.

Methods

This retrospective study evaluated 118 eyes of patients aged 18 and above who underwent ab interno trabeculotomy between December 2017 and August 2022. When surgeries were performed in both eyes, only the eye undergoing the initial surgery was evaluated. Prior to and after surgery, the intraocular pressure (IOP) and mean number of IOP-lowering medications were compared. An IOP of ≤21 mmHg (A) and ≤18 mmHg (B) along with a ≥20% reduction in the preoperative IOP was defined as survival. Cases that required reoperation for glaucoma were defined as surgical failure. The Kaplan-Meier method was used to evaluate the survival rates. A Cox proportional hazards model was used to analyze the preoperative factors that influenced survival rates.

Results

At 36 months postoperatively, the 13.4 ± 2.8 mmHg average IOP was significantly decreased from the preoperative 23.5 ± 9.8 mmHg value (P < 0.0001). Moreover, a significant decrease in the mean number of the IOP-lowering medications to 2.3 ± 1.4 at 36 months was found versus the initial 3.9 ± 1.1 preoperative value (P < 0.0001). The survival rates for criteria A and B at 36 months postoperatively were 28% and 25%, respectively. Only the preoperative IOP was identified by multivariate analysis as a factor influencing survival rates (P < 0.0001). Hyphema in 36 eyes (30.5%) and an IOP spike in 20 eyes (16.9%) were the only observed complications. Additional glaucoma surgery was required in 27 eyes (22.9%) during the follow-up period.

Conclusion

Utilization of ab interno trabeculotomy effectively lowered the IOP and reduced the number of IOP-lowering medications. Patients with higher preoperative IOP exhibited better postoperative outcomes.

A Retrospective Study of Risk Factors Affecting Long-Term Outcomes Following Ab Interno Trabeculotomy and Goniotomy Concomitant with Phacoemulsification

Purpose

To examine the potential risk factors affecting the long-term outcomes following a combination of phacoemulsification with ab interno trabeculotomy with the microhook (μLOT-Phaco) and goniotomy with the Kahook Dual Blade (KDB-Phaco).

Methods

For 12 months, we retrospectively examined a total of 100 eyes of 100 patients with primary open-angle glaucoma (POAG) and exfoliation glaucoma (EG) who had previously undergone surgery between December 2016 and December 2020. Patients with a preoperative intraocular pressure (IOP) ˂12 mmHg were excluded. Probability of success was calculated using the Kaplan-Meier method, with surgical failure defined as an IOP >18 mmHg, <20% IOP reduction or additional glaucoma surgery. The Cox proportional hazards model was used to examine the potential risk factors for failure, which included age, gender, type of glaucoma, surgical techniques, preoperative IOP, number and type of preoperative IOP-lowering medications, preoperative visual field mean deviation (MD) value, and axial length.

Results

For the 51 males and 49 females, mean preoperative age was 74.4 ± 9.0 years, with μLOT-Phaco performed in 44 and KDB-Phaco in 56 subjects. The type of glaucoma was POAG in 68 and EG in 32 eyes. Preoperative IOP was 20.5 ± 6.7 mmHg, while postoperative IOPs were 14.4 ± 4.2 mmHg, 13.7 ± 2.8 mmHg, and 14.6 ± 3.9 mmHg, respectively (P < 0.001). Significant decreases from the preoperative number of IOP-lowering medications (3.1 ± 1.2) were observed at 12, 24, and 36 months, respectively (1.2 ± 1.3, 1.6 ± 1.3, and 2.1 ± 1.4 (P < 0.001)). Probability of success at 12, 24, and 36 months postoperatively was 52.0%, 49.6%, and 47.7%, respectively. Lower preoperative IOP was shown to be a potential risk factor for surgical failure.

Conclusion

Long-term follow-ups showed IOP decreased in μLOT-Phaco and KDB-Phaco patients. Results suggest that patients with higher preoperative IOP may have better postoperative outcomes.

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.

Surgical outcomes of excisional goniotomy using the kahook dual blade in severe and refractory glaucoma: 12-month results

OBJECTIVES

To describe the efficacy and safety of goniotomy with trabecular meshwork excision using the Kahook Dual Blade (KDB, New World Medical Inc., Rancho Cucamonga, CA) in patients with severe or refractory glaucoma.

METHODS

This retrospective multicentre case series reports on 40 eyes with severe or refractory open-angle glaucoma that underwent standalone or combined KDB goniotomy and were followed for 12 months post-operatively in the United-States, Mexico and Switzerland. Surgical success was defined as an intraocular pressure (IOP) reduction ≥20% from baseline at 12 months, with fewer medications than preoperatively. Mean IOP and antiglaucoma medication reduction, probabilities of achieving an IOP ≤16 or 18 mmHg, and adverse events were also analysed.

RESULTS

Mean IOP decreased from 18.1 ± 5.0 mmHg at baseline to 14.8 ± 3.7 mmHg at 12 months (18.2% reduction, P < 0.001). Concomitantly, the mean number of glaucoma medications decreased from 2.5 ± 1.4 to 1.7 ± 1.2 (32% reduction, P = 0.002). The proportion of eyes achieving an IOP reduction of more than 20% from baseline was 37.5% (n = 15) at 12 months. At 12 months, 67.5% and 82.5% achieved a medicated IOP ≤ 16 and ≤18 mmHg, respectively. No severe complications were reported.

CONCLUSION

Excisional goniotomy with KDB achieves a statistically significant IOP and antiglaucoma medication reduction in severe or refractory glaucoma over a period of 12 months. While its efficacy decreases with time, its favourable safety profile makes it a potentially useful primary or adjunctive procedure in high-risk eyes.

Kahook Dual-Blade Goniotomy with and without Phacoemulsification in Medically Uncontrolled Glaucoma

Purpose

To evaluate the 2-year efficacy and safety of Kahook dual-blade (KDB) goniotomy in patients with medically uncontrolled glaucoma.

Methods

This was a retrospective case-series study of 90 consecutive patients with primary open-angle glaucoma (POAG) or pseudoexfoliation glaucoma (PEXG) that underwent KDB goniotomy alone (KDB-alone group) or KDB goniotomy in combination with phacoemulsification (KDB-phaco group) during 2019-2020. All patients were uncontrolled on three or more medications. Surgical success was defined as an IOP reduction ≥20% and/or a reduction of one or more medications at 24 months. We also report IOP levels and number of medications from baseline to 24 months, as well as the need for further glaucoma interventions.

Results

At 24 months, mean IOP had reduced from 24.8±8.3 to 15.0±5.3 mmHg in the KDB-alone group (P<0.001) and from 22.3±5.8 to 13.9±3.0 mmHg in the KDB-phaco group (P<0.001). Medications had reduced from 3.5±0.6 to 3.1±0.9 in the KDB-alone group (P=0.047) and from 3.3±0.5 to 2.3±1.1 in the KDB-phaco group (P<0.001). An IOP reduction ≥20% and/or a reduction with one or more medications was achieved by 47% of eyes in the KDB-alone group and by 76% of eyes in the KDB-phaco group. Eyes with PEXG and POAG responded equally well to the success criteria. During the 24-month follow-up, additional glaucoma surgery or transscleral photocoagulation was performed in 28% of eyes in the KDB-alone group and in 12% of eyes in the KDB-phaco group.

Conclusion

In patients with medically uncontrolled glaucoma, KDB had a significant IOP-lowering effect after 24 months, but success rates were higher when KDB was performed in combination with cataract surgery compared to stand-alone treatment.

Minimally Invasive Glaucoma Surgery: Safety of Individual Devices

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

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.

Long-Term Outcomes of a Kahook Dual Blade Procedure Combined with Phacoemulsification in Japanese Patients with Open-Angle Glaucoma

We retrospectively evaluated the long-term surgical outcomes of phacoemulsification combined with a Kahook dual blade (KDB) procedure in Japanese patients with open-angle glaucoma. The primary outcome was surgical success or failure. Surgical failure was indicated by a <20% reduction in preoperative intraocular pressure (IOP) or IOP > 18 mmHg (criterion A), IOP > 14 mmHg (criterion B), or requirement for reoperation. Glaucoma medications after surgery and postoperative complications were recorded. Surgical outcomes were compared between primary open-angle glaucoma (POAG) and exfoliation glaucoma (ExG) groups. The probability of success at 36 months postoperation was 52.5% using criterion A and 36.9% using criterion B. Mean IOP decreased significantly from 19.5 ± 6.9 mmHg preoperatively to 11.9 ± 2.7 mmHg at 36 months, and the mean number of glaucoma medications from 2.4 ± 1.4 to 1.6 ± 1.4 (both p < 0.01). IOP spikes were significantly more common in the ExG group (23.7% vs. 9.1%; p = 0.045), as was the need for additional glaucoma surgery (10.5% vs. 1.8%; p = 0.038). A KDB procedure combined with cataract surgery resulted in significant long-term decreases in IOP and the number of glaucoma medications. The complication rate was higher in eyes with ExG. Therefore, these eyes require more careful management after a KDB procedure.

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.

Initial experience with phacoemulsification and goniotomy using the Kahook dual blade in advanced open-angle glaucoma: Six-month outcomes in Indian eyes

Purpose:

The aim of this study was to report our initial experience on the outcomes of phacoemulsification in combination with goniotomy using the Kahook Dual Blade (KDB) in eyes with advanced open-angle glaucoma (OAG).

Methods:

The outcomes of phaco-goniotomy with KDB in advanced OAG in Indian eyes were retrospectively analyzed. Based on the Hodapp-Anderson-Parrish criteria of visual field defects, severe glaucoma (mean deviation on standard automated perimetry worse than 12 dB) was considered as advance glaucoma. Preoperative, intraoperative, and postoperative data were collected through 6 months of follow-up. Outcome measures included antiglaucoma medications (AGM), the proportion of eyes achieving >1AGM reduction, intraocular pressure (IOP), and visual acuity.

Results:

Median (interquartile range) number of AGM in eyes that underwent phaco-KDB goniotomy reduced from 2 (2,3) at baseline to 1 (0,1) at 6 months (P = 0.002). Median IOP reduced from 20 (20,26) mmHg at baseline to 14 (12,15) mmHg at 6 months (P = 0.02). The proportion of eyes achieving >1 medication reduction was 88% eyes (8/9). Adverse events noted were IOP spike (22 mmHg) in 2 eyes and intra-op hyphema in 1 eye on postoperative day-1, both resolved in a week with conservative management. Except one eye with central corneal scar due to prior pterygium surgery, 8 eyes had 20/20 vision at 1 week which was maintained till last follow-up.

Conclusion:

Phacoemulsification with KDB Goniotomy significantly lowered the need for AGM with moderate IOP reduction in advanced OAG eyes. There were no serious complications and the visual recovery was good and early.

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.

Canaloplasty ab interno (AbiC) - 2-Year-Results of a Novel Minimally Invasive Glaucoma Surgery (MIGS) Technique

PURPOSE

The aim of this study is to evaluate the long-term efficacy of a novel minimally invasive glaucoma surgery technique (MIGS), Ab interno Canaloplasty (AbiC).

MATERIAL AND METHODS

For this retrospective cohort study, we analysed the data of 25 eyes of 23 patients with open angle glaucoma who underwent an AbiC (6 eyes) or in case of an additional cataract, a combined cataract-AbiC procedure ("phacocanaloplasty ab interno", 19 eyes), respectively. Postoperatively, we investigated the intraocular pressure (IOP) and the number of still required IOP-lowering medication, as well as surgery-related complications.

RESULTS

Overall, the mean baseline IOP of 20.24 mmHg ± 5.92 (n = 25) was reduced to 10.64 mmHg ± 2.77 (n = 25, p < 0.001), 12.55 mmHg ± 3.33 (n = 22, p < 0.001) and 13.67 mmHg ± 2.15 (n = 21, p < 0.001) at 1 day, 1 year and 2 year follow-up visit, respectively. Compared to baseline, this implies a reduction in IOP of 47.4, 37.9 and 32.5%. An average glaucoma medication usage of 1.92 ± 1.04 was registered at baseline visit and was reduced to 0,05 ± 0,23 after 2 years of follow-up. 80% of patients were off medication. In 5 eyes (20%) further antiglaucomatous eye drops or surgical treatment were administered. The only surgical complications were hyphema in 5 eyes (20%) and a localized peripheral detachment of the Descemet's membrane in one eye (4%) with no late sequelae.

CONCLUSION

AbiC performed independently or combined with cataract surgery seems to be a safe and effective MIGS-technique with good long-term regulation of IOP and low risk profile.

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.