Consistency in Standalone Canaloplasty Outcomes Using the iTrack Microcatheter

Purpose

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

Methods

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

Results

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

Conclusion

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

Ab-externo canaloplasty with and without suture in highly myopic eyes

PURPOSE

To evaluate the effectiveness of ab-externo canaloplasty using the iTrack canaloplasty microcatheter (Nova Eye Inc, Fremont, California), with or without suture, in glaucoma patients with high myopia.

METHODS

This was a prospective, single-center, single-surgeon, observational study comparing the outcomes of ab-externo canaloplasty performed with a tensioning suture (suture group) and without a tensioning suture (no-suture group) in mild to severe glaucoma patients with high myopia. Twenty-three eyes received canaloplasty as a standalone procedure, 5 in combination with phacoemulsification. Primary efficacy endpoints included intraocular pressure (IOP) and the number of glaucoma medications. Safety was assessed based on reported complications and adverse events.

RESULTS

Twenty-nine eyes of 29 patients with a mean age of 61.2 ± 12.3 years; 19 eyes in the no-suture group and 10 eyes in the suture group. All eyes demonstrated a significant reduction in IOP 24 months postoperatively, from 21.9 ± 7.22 to 15.4 ± 4.86 mmHg in the suture group and from 23.8 ± 7.58 to 19.7 ± 3.68 mmHg in the no-suture group. The mean number of anti-glaucoma medications reduced from 3.1 ± 0.6 to 0.4 ± 0.7 in the suture group and 3.3 ± 0.9 to and 0.2 ± 0.6 in the no-suture group at 24 months. IOP was not significantly different at baseline between the 2 groups, but it was statistically different at 12 and 24 months. There was no statistically significant difference in the number of medications between the groups at baseline, 12 and 24 months. No serious complications were reported.

CONCLUSION

Ab-externo canaloplasty performed either with or without a tensioning suture demonstrated good effectiveness in highly myopic eyes with a significant reduction in IOP and number of anti-glaucoma medications. The suture group achieved a lower postoperative IOP. However, the no-suture modification provides a similar reduction in medications with reduced tissue handling.

Alternative application of an iTrack microcatheter and canaloplasty: case report and literature review

INTRODUCTION

Glaucoma is the leading cause of irreversible blindness worldwide. Schlemm's canal surgery using an iTrack flexible microcatheter has become popular because of its high quality-of-life issues and the growing demand for less invasive but effective procedures. The unique design of the microcatheter makes it a multimodal tool, which can be used not only in the field of antiglaucoma surgery but also as a drug delivery system to treat various conditions.

AREAS COVERED

This review presents an update on the selected aspects of a drug delivery system using the iTrack microcatheter, including glaucoma gene therapy and posterior-segment diseases, both in animal models and human patients. The authors also report the case of a patient with branch retinal vein occlusion treated with suprachoroidal bevacizumab in the submacular region administered with the iTrack catheter.

EXPERT OPINION

The findings presented in this study may indicate that the application of a microcatheter in open-angle glaucoma gene therapy is reasonable and can be combined with full or partial surgical canaloplasty procedures. Translation of this potential into a treatment modality would require overcoming multiple barriers.

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

PURPOSE

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

DESIGN

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

METHODS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSION

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

Long-term medication reduction in controlled glaucoma with iTrack ab-interno canaloplasty as a standalone procedure and combined with cataract surgery

Purpose:

To evaluate the long-term effectiveness of iTrack (Nova Eye Medical, Fremont, USA) ab-interno canaloplasty performed as a standalone procedure, or combined with cataract surgery, in reducing antiglaucoma medication dependence and maintaining intraocular pressure within target range in patients with controlled primary open-angle glaucoma.

Methods:

This is a retrospective, single-center, case series study of patients who underwent iTrack ab-interno canaloplasty as a standalone procedure (n = 34) or in combination with cataract surgery (n = 11). Eyes with controlled mild or moderate glaucoma (intraocular pressure ⩽17 mmHg) were included; those with prior glaucoma surgeries were excluded. The primary outcome was the mean reduction in glaucoma medication and the secondary outcome was the maintenance of controlled intraocular pressure postoperatively.

Results:

A total of 35 patients (45 eyes) with a mean age of 73 ± 9.7 years were included in the study. For all eyes, a significant decrease (61%) in the mean number of medications was seen at 36 months (1.89 ± 0.93 versus 0.60 ± 0.82; p < 0.001), with 56% (14/25) of eyes medication free. No significant difference was observed in the reduction of medication use whether iTrack was performed with or without cataract surgery at 12 and 36 months. Mean baseline intraocular pressure of 14.42 ± 2.2 mmHg for all eyes was maintained at the 12-, 24-, and 36-month follow-up visits (14.6 ± 3.65, 15.06 ± 2.26, and 14.19 ± 2.91, respectively), with no significant difference between the two groups (p = 0.08).

Conclusion:

The iTrack ab-interno canaloplasty significantly reduced medication dependency and maintained intraocular pressure within target range in patients with controlled mild or moderate primary open-angle glaucoma, while showing a good safety profile, both as a standalone procedure or in combination with cataract surgery.

Combined Ab interno viscocanaloplasty (ABiC) in open-angle glaucoma: 12-month outcomes

PURPOSE

The aim of this study was to analyse the safety profile and efficacy of ab interno viscocanaloplasty (ABiC) through to 12 months post-operatively.

METHODS

In this retrospective study, the medical records of all patients who underwent ABiC between September 2015 and December 2019 were analysed. Complete success was defined as a 12-month reduction in intraocular pressure (IOP) ≥ 20% from baseline with no concomitant medications. Qualified success criteria were identical, with no more medications than at baseline.

RESULTS

In all, 54 eyes of 41 patients were analysed. Mean IOP decreased from 23.6 ± 7.4 mmHg preoperatively to 14.2 ± 2.9 mmHg (-39.8%; p < 0.001) after 12 months. Concomitantly, the number of anti-glaucoma treatment dropped from 2.9 ± 1.0 to 0.6 ± 1.1 (-79.3%; p < 0.001). Amongst patients with a baseline MD < -12.0 dBs, mean IOP decreased from 22.8 ± 9.8 mmHg to 13.8 ± 4.4 mmHg (p = 0.049), with a concomitant reduction of medications from 2.8 ± 1.3 to 1.2 ± 1.3 (p < 0.001). Complete success at 12 months was achieved in 46% of eyes, and qualified success was achieved in 65% of eyes. Amongst eyes with a baseline MD < -12.0 dBs, 50% achieved complete success, and 83.3% achieved qualified success. A total of 19 eyes (35.2%) were considered surgical failure, all due to uncontrolled IOP. Of them, 7 eyes (13.0%) required further filtering surgery. Twelve post-operative adverse events were observed, with early post-operative IOP spikes being the most common (22.2%).

CONCLUSIONS

ABIC achieved a statistically significant reduction in IOP and anti-glaucoma medications through 12 months, while maintaining a favourable safety profile in mild-to-severe open-angle glaucoma.

24-Month Efficacy of Viscodilation of Schlemm's Canal and the Distal Outflow System with iTrack Ab-Interno Canaloplasty for the Treatment of Primary Open-Angle Glaucoma

PURPOSE

This study aimed to evaluate the 24-month efficacy of viscodilation of Schlemm's canal and the distal outflow system with iTrack ab-interno canaloplasty in reducing intraocular pressure (IOP) and antiglaucoma medication use in patients with primary open-angle glaucoma (POAG).

PATIENTS AND METHODS

This retrospective, comparative, and consecutive case series assessed the 24-month outcomes of iTrack as a standalone procedure (iTrack-alone) or in conjunction with cataract surgery (iTrack+phaco), in cases of mild, moderate or severe POAG. Data were collected at baseline and the 12- and 24-month follow-up visits.

RESULTS

The study included 53 patients (60 eyes) with a mean age of 73.6±9 years. For all eyes, a significant reduction in mean IOP was seen at 12 and 24 months, reducing from 20±4.9 mmHg at baseline to 13.6±1.9 mmHg and 13.5±2.6 mmHg, respectively (P<0.001). The reduction in medications was also significant, reducing to 1.12±1.09 and 1.7±1.29 medications at 12 months and 24 months, respectively, from a baseline of 2.77±0.91 (P<0.001). Similar results were achieved whether iTrack was performed as a standalone procedure, or in conjunction with cataract surgery. While the iTrack-alone group started with a higher IOP at baseline, both groups experienced similar and stable IOP reduction of more than 30% from baseline. The reduction in medication use was also significant in both groups, decreasing from 3±0.7 for iTrack-alone and 2.5±1.1 for iTrack+phaco at baseline to 2.1±1.3 and 1.3±1.2 at 24 months, respectively (P<0.001). The 24-month efficacy outcomes were similar in cases of mild-moderate versus severe glaucoma. No serious adverse events were recorded.

CONCLUSION

Twenty-four-month follow-up data demonstrate that iTrack ab-interno canaloplasty can effectively reduce IOP and medication dependence, with a good safety profile. These results also demonstrate that iTrack can be effectively performed as a standalone procedure or in combination with cataract surgery, and in all grades of glaucoma severity.

Canaloplasty in the Treatment of Primary Open-Angle Glaucoma: Patient Selection and Perspectives

Canaloplasty is a surgical procedure that has undergone a number of developments since its introduction in 2005. Many thousands of canaloplasties have been performed around the world since then and is, by definition, a blebless procedure. It does not necessitate the use of any antifibrotic agents and results in safe and effective IOP reductions in patients with open-angle glaucoma (OAG) with minimal complications and no bleb-related adverse events. When considering the surgical management of patients with early and medium stages of the disease, canaloplasty can be considered as a first line option. This paper will overview the theoretical effectiveness of canal surgery, the fundamental aspects of aqueous outflow resistance with particular emphasis on the role of the trabecular meshwork, Schlemm's canal, and the collector channels, and the methods available for the clinical evaluation of the outflow pathways in relation to the ocular anatomy. Further, the paper will detail the surgical technique itself and how this has developed over time together with the clinical aspects that should be accounted for when selecting patients for this surgery.