Canal surgery in adult glaucomas

Historical and Contemporary Debates in Schlemm's Canal-Based MIGS

Glaucoma is one of the primary causes of blindness worldwide. Canal opening surgery, a type of minimally invasive glaucoma surgery (MIGS) applied in cases of mild to moderate glaucoma, has gained increasing popularity in recent years due to its efficacy in reducing the intraocular pressure, its safety profile, the simplicity of its technique, and the reduced likelihood of compromised vision. Nevertheless, the existing body of histopathological studies remains insufficient for a comprehensive understanding of post-surgical wound healing. Consequently, debates persist among researchers regarding the mechanism through which Schlemm's canal opening surgery reduces the intraocular pressure, as well as the surgical techniques that may impact the outcomes and the factors influencing surgical success. As the history of MIGS is relatively short and lacks sufficient systemic reviews or meta-analyses evaluating the influence of individual factors, this review was conducted to illuminate the disparities in researchers' opinions at the current stage of research.

A Review of Canaloplasty in the Treatment and Management of Glaucoma

Aim

To review the published literature evaluating the safety and efficacy outcomes of canaloplasty performed in the treatment of glaucoma.

Background

Canaloplasty is a nonpenetrating glaucoma procedure involving combined 360° circumnavigation and viscodilation of Schlemm's canal. The procedure may be performed under an ab externo (with tensioning suture) or ab-interno (conjunctiva-sparing) approach. Given the wide variety of glaucoma procedure types and approaches, further investigation into the role of canaloplasty in ophthalmological practice is warranted. The objectives of this narrative review are to synthesize the existing literature in order to investigate indications, safety and efficacy outcomes, and the optimal place of canaloplasty in glaucoma treatment and management.

Review of results

A total of 60 articles were included in this review. Both ab externo and ab-interno canaloplasty (ABiC) were found to be significantly effective at reducing intraocular pressure (IOP) and glaucoma medication burdens in patients with mild-to-moderate open-angle glaucoma (OAG). These findings remained consistent regardless of phacoemulsification status. ABiC was found to exhibit a safety profile favorable compared to trabeculectomy and comparable to minimally invasive trabecular bypass implants.

Conclusion

Canaloplasty is a nonpenetrating surgical intervention that is highly effective in treating patients with mild-to-moderate OAG across a large variety of clinical scenarios.

Clinical significance

These findings support the clinical use of canaloplasty in ophthalmological practice, clarify its patient profile, and compare procedural outcomes to other minimally invasive glaucoma surgery (MIGS) devices on the market.

How to cite this article

Wagner IV, Towne C, Saade MC, et al. A Review of Canaloplasty in the Treatment and Management of Glaucoma. J Curr Glaucoma Pract 2024;18(2):79-85.

Four-Year Efficacy and Safety of iTrack Ab-interno Canaloplasty as a Standalone Procedure and Combined with Cataract Surgery in Open-Angle Glaucoma

PURPOSE

To evaluate the long-term effectiveness of ab-interno canaloplasty (ABiC), performed with the iTrack microcatheter (Nova Eye Medical, Fremont, CA, USA), in reducing intraocular pressure (IOP) as well as the number of required glaucoma medications in patients with open-angle glaucoma (OAG).

METHODS

In this retrospective single-center consecutive case series, 27 eyes of 21 patients (mean age 77.3 ± 5.8 years) were treated with ABiC performed as a standalone procedure or combined with cataract surgery. Patients with uncontrolled IOP OAG or controlled IOP (≤ 18 mmHg) OAG with intolerance to medications or lack of compliance were included. Patients were followed for up to 4 years following the procedure. The iTrack microcatheter was used to perform a 360-degree circumferential intubation and viscodilation of Schlemm's canal. Primary efficacy endpoints included IOP and the number of glaucoma medications at 12, 24, 36, and 48 months after surgery.

RESULTS

In all eyes, mean IOP and number of glaucoma medications were significantly reduced from 19.8 ± 5.2 mmHg and 1.9 ± 1.00 at baseline to 14.6 ± 3 mmHg and 0.9 ± 0.8, respectively, at the 48-month follow-up (p < 0.001). IOP was stable from 12 months to 48 months (p > 0.005). After 48 months, 39% of the eyes required zero medications compared to 3.7% at baseline, and 72.2% of eyes required only one medication or less. Of all eyes, 77.8% recorded an IOP ≤ 17 mmHg. No serious complications were recorded.

CONCLUSION

iTrack ABiC performed as a standalone procedure or in combination with cataract surgery significantly reduced IOP and number of medications in patients with OAG up to 4 years after the procedure.

Efficacy of Endotrabeculectomy (Trabecula Ablation Ab Interno with the Forceps) for Open-angle Glaucoma

Aim

To investigate the efficacy of endotrabeculectomy (ETE) performed either alone or combined with phacoemulsification (phaco) in patients with primary open-angle glaucoma (POAG).

Materials and methods

Investigations were done in two groups. The first group (38 patients, 38 eyes) with POAG underwent ETE, and the second group of 126 patients (126 eyes) with POAG and cataracts underwent ETE and phaco. The hypotensive effect of the surgery was evaluated.

Results

In the ETE group, the mean intraocular pressure (IOP) was reduced from 20.25 ± 3.30 to 14.94 ± 1.95 mm Hg (26.2% reduction, p < 0.001) at 12 months. The number of medications was reduced from 2.8 ± 1.0 to 1.5 ± 1.0 (p < 0.001) at 12 months after the surgery. In the phaco-ETE group, the mean IOP was reduced from 18.24 ± 3.20 to 14.83 ± 1.71 mm Hg (18.7% reduction, p < 0.001) at 12 months. The mean number of medications was reduced from 2.2 ± 1.1 to 1.0 ± 1.0 (p < 0.001) at 12 months after the surgery. The success rate defined as a final IOP of <16 mm Hg using the Kaplan-Meier curve at 12 months was 73.8%. There were no complications that led to a constant visual decrease.

Clinical significance

Our study shows that ETE is technically simple, gives the ability to remove trabecula in any quadrant, and effectively reduces IOP in patients with POAG.

Conclusion

Endotrabeculectomy (ETE) is a safe and relatively simple procedure that significantly reduces IOP. The minimally invasive nature of the ETE allows expanding indications for combined treatment of glaucoma and cataract.

How to cite this article

Novytskyy IY, Novytskyy MI. Efficacy of Endotrabeculectomy (Trabecula Ablation Ab Interno with the Forceps) for Open-angle Glaucoma. J Curr Glaucoma Pract 2023;17(1):15-21.

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.

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.

Clinical outcomes of penetrating canaloplasty in patients with traumatic angle recession glaucoma: a prospective interventional case series

BACKGROUND/AIM

To evaluate the clinical outcomes of penetrating canaloplasty in traumatic angle recession glaucoma at 1 year.

METHODS

Patients with angle recession glaucoma underwent penetrating canaloplasty, a new Schlemm's canal-based internal drainage procedure, which creates a direct canal for flow of aqueous humour from the anterior chamber to the ostia of Schlemm's canal via a window created at the corneal scleral bed without use of antimetabolites. Postoperative intraocular pressure (IOP), number of glaucoma medications, and procedure-related complications were evaluated. Success was defined as an IOP ≤21 mm Hg without (complete) or with (qualified) use of glaucoma medication.

RESULTS

Forty eyes in 40 patients with angle recession glaucoma underwent successful circumferential catheterisation. The mean patient age was 42±13 years. In patients with penetrating canaloplasty that was deemed to be completely successful, the mean IOP decreased from a preoperative value of 37.8±12.3 mm Hg on 3.3±1.2 anti-glaucoma medications to 18.5±6.4 mm Hg on 1.2±1.4 medications, 14.9±4.6 mm Hg on 0.1±0.5 medications, 15.7±5.4 mm Hg on 0.1±0.4 medications and 14.8±3.6 mm Hg on 0.1±0.5 medications at 1, 3, 6 and 12 months postoperatively (p<0.05). Complete success was achieved in 35/40 eyes (87.5%) at 6 months and in 34/38 (89.5%) at 12 months. Hyphema (18/40, 45.0%) and transient IOP elevation (≥30 mm Hg, 9/40, 22.5%) were the most common postoperative complications.

CONCLUSION

Penetrating canaloplasty significantly reduces IOP and has a high success rate in angle recession glaucoma.

TRIAL REGISTRATION NUMBER

ChiCTR1900020511.

Microcatheter-Assisted Trabeculotomy Combined With Deep Sclerectomy and Trabeculectomy in Young to Middle-Aged Adults With Advanced Primary Open-Angle Glaucoma: 1-Year Result

Objective: We aimed to evaluate the safety and clinical efficacy of ab externo microcatheter-assisted trabeculotomy combined with deep sclerectomy and trabeculectomy (MATT-DS-Trab) in the surgical management of advanced primary open-angle glaucoma (POAG).

Methods: According to the inclusion criteria, we retrospectively collected and analyzed 37 POAG cases in advanced stage who received MATT-DS-Trab. The intraocular pressure (IOP), best corrected visual acuity (BCVA), use of anti-glaucoma drugs, shape of the filtering bleb, size of the scleral lake, complications, and the surgical success rate were recorded.

Results: The mean IOP was 37.50 ± 8.11 mmHg before the operation, while it depleted to 10.08 ± 2.01 and 11.43 ± 2.07 mmHg at 1 week and 12 months after the operation, respectively (both P < 0.001 compared to preoperative IOP). From none to two kinds of anti-glaucoma drugs were used 12 months after surgery on the patients, which were significantly reduced compared with that preoperatively (P < 0.001). An L-type filtering bleb was the main form at all time points after the operation. At 12 months following surgery, an F-type filtering bleb accounted for 5.41% and no E-type filtering bleb was recorded. The length and height of the scleral lake shrunk with time, but there was no statistical significance (P > 0.05). Also, there was no correlation between the size of the scleral pool and the IOP (P > 0.05). At 12 months after the operation, the complete success rates were 94.59, 83.78, and 72.97% according to standards A (≤18 mmHg), B (≤15 mmHg), and C (≤12 mmHg), respectively. Intraoperative complications were mainly anterior chamber hemorrhage, and no complications related to the filtration bleb were observed after the operation.

Conclusion: Based on multichannel mechanisms, MATT-DS-Trab is able to effectively reduce IOP in advanced POAG patients, with few serious complications and a high success rate.

Gonioscopy-assisted transluminal trabeculotomy in primary angle-closure glaucoma

PURPOSE

This study aims to report on outcomes of gonioscopy-assisted transluminal trabeculotomy (GATT) in eyes with primary angle-closure glaucoma (PACG).

METHODS

This study is a prospective, interventional, non-comparative case series. A total of 103 eyes from 88 patients with PACG underwent an ab interno trabeculotomy, using either a 5.0 polypropylene suture or an illuminated microcatheter, with up to 24 months of follow-up. The main outcome measures were intraocular pressure (IOP), number of antiglaucoma medications, success rate (IOP reduction ≥ 20% from baseline or IOP between 6 and 21 mmHg, without further glaucoma surgery) and complication rate.

RESULTS

The mean preoperative IOP was 21.4 (SD 7.4) mmHg using 2.5 (SD 1.1) glaucoma medications. These decreased postoperatively to 12.1 (SD 2.4) mmHg and 0.8 (SD 1.2) medications, at 24 months (P < 0.05). Success rate was 78% at 24 months of follow-up, and complication rate was 4.8%.

CONCLUSION

At 24 months of follow-up, our results for GATT in PACG demonstrate that this procedure effectively lowers IOP in this subtype of glaucoma, with a low complication rate.

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.

Ab Interno Canaloplasty in Open-angle Glaucoma Patients Combined With In Vivo Trypan Blue Aqueous Venography

PURPOSE

To demonstrate canalogram patterns observed when trypan blue tracer is combined with oculoviscoelastic device during ab interno canaloplasty, and discuss surgical results and potential implications for diagnosis, prognosis, and treatment.

METHODS

This is a retrospective small case series study.

RESULTS

The authors performed this procedure on 5 patients with informed consent with 4 to 18 months of follow-up. All procedures have been complication free. The average preoperative intraocular pressure was 16.4 mm Hg with an average number of topical glaucoma medications being equal to 3.6. Postoperatively, the average intraocular pressure for the group was reduced to 13 mm Hg with a concurrent drop in the average number of topical medications used equaling 1.8.

CONCLUSIONS

Currently, there are limited practical options to evaluate the patency of the aqueous outflow system in our patients. The primary purpose of this paper is to describe canalogram patterns observed during ab interno canaloplasty with trypan blue. This technique may allow us to further our understanding of the aqueous outflow system and its role in the underlying pathophysiology of glaucoma. Further research is required to evaluate the prognostic and diagnostic significance of this technique.

Comparison of Ab Externo and Ab Interno 360-degree Suture Trabeculotomy in Adult Open-angle Glaucoma

PRECIS

Ab interno (gonioscopy-assisted transluminal trabeculotomy) and ab externo 360-degree suture trabeculotomy (ST) achieved similar success rates for reducing intraocular pressure (IOP) without serious complications threatening visual acuity.

PURPOSE

We aimed to compare the efficacy of ab externo and ab interno 360-degree ST in reducing IOP, decreasing the number of antiglaucoma medications required, and decreasing the rates of intraoperative/postoperative complications in adults with open-angle glaucoma (OAG).

PATIENTS AND METHODS

This retrospective study included 33 eyes of 33 patients who underwent ab externo 360-degree ST (group 1) and 23 eyes of 23 patients who underwent ab interno 360-degree ST for OAG (group 2). We analyzed demographics as well as preoperative and postoperative (1, 3, 6, and 12 mo) data related to IOP, the number of antiglaucoma medications, complications, and surgical success rates.

RESULTS

In group 1, the mean IOP was 26.2±10.4 mm Hg, and the mean number of antiglaucoma medications was 3.2±1.0 preoperatively, decreasing to 11.2±3.0 mm Hg and 0.1±0.4 at 12 months, respectively (P<0.001, <0.001). In group 2, the mean IOP was 28.3±10.4 mm Hg, and the mean number of antiglaucoma medications was 3.5±0.9 preoperatively, decreasing to 13.3±6.5 mm Hg and 0.8±1.0 at 12 months, respectively (P<0.001, <0.001). Decreases in IOP at 6 and 12 months were similar in groups 1 and 2 (50% vs. 47%, P=0.6; and 51% vs. 49%, P=0.7, respectively). At 12 months, complete and qualified success rates were 88% and 97% for group 1 and 57% and 87% for group 2, respectively. The most common complications in both groups were hyphema and transient IOP spikes.

CONCLUSION

Ab interno 360-degree ST is similar to ab externo 360-degree ST in terms of safety and efficacy in patients with OAG.

XEN Gel Stent Implantation Following Encircling Scleral Buckle Surgery

Scleral buckling procedures create a challenge for intraocular pressure (IOP) control in the glaucoma patient. The encircling band is believed to compress vortex veins, causing increased episcleral venous pressure, a proposed mechanism for secondary glaucoma. Glaucoma drainage device implantation is preferred over trabeculectomy when medical management fails, but often involves modification of the glaucoma implant and manipulation of the fibrotic capsule surrounding the scleral buckle. This case demonstrates that ab externo XEN gel stent implantation may successfully reduce IOP without interfering with the previous scleral buckle, a major limitation of previous glaucoma filtering surgeries. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:289-292.].

One-year results of gonioscopy-assisted transluminal trabeculotomy: Evaluation of prognostic factors

PURPOSE

To present the results and complications of gonioscopy-assisted transluminal trabeculotomy in adults with open-angle glaucoma using our different approaches during and after surgery.

METHOD

A retrospective comparative study was designed. Patients with regular 12-month follow-up history were included. Two groups were defined: group 1 comprised patients with open-angle glaucoma who underwent gonioscopy-assisted transluminal trabeculotomy surgery alone; group 2 included patients with open-angle glaucoma who underwent combined gonioscopy-assisted transluminal trabeculotomy and cataract extraction. A 30% reduction in preoperative intraocular pressure or postoperative intraocular pressure below 18 mm Hg was considered as surgical success. The success rate, alteration in intraocular pressure, alteration in best-corrected visual acuity, alteration in the need for antiglaucomatous medications, surgical complications, and the need for additional glaucoma surgery were evaluated and compared between the groups. Multivariate logistic regression analysis was used to show the association between the surgical success and possible prognostic factors.

RESULTS

A total of 37 eyes fulfilled the inclusion criteria and were analyzed in this study. An overall mean decrease in intraocular pressure of 11.3 ± 9.3 mm Hg was shown at 12 months (p < 0.001). The medication-free surgical success rate was 37.8% (14/37), and the surgical success rate with medication was 91.8% (33/37) at 12 months. Surgical outcomes were similar between patients who underwent gonioscopy-assisted transluminal trabeculotomy alone and those who had combined gonioscopy-assisted transluminal trabeculotomy and cataract extraction (p > 0.05). The most common postoperative complication was hyphemia (89.1%). There were no complications that threatened best-corrected visual acuity. Multivariate logistic regression analysis revealed one significant association between the presence of blood in Schlemm's canal and surgical success (odds ratio = 1.47; 95% confidence interval = 1.25-1.68; p = 0.047).

CONCLUSION

This study showed that the gonioscopy-assisted transluminal trabeculotomy procedure is an effective and minimally invasive form of glaucoma surgery. Its effect was related to intraoperative blood in Schlemm's canal.

The Influence of Trabectome Surgery on Corneal Endothelial Cells

PURPOSE

The purpose of this study was to evaluate the influence of trabectome surgery on corneal endothelial cells by site.

METHODS

Retrospective observational study. Trabectome surgeries were performed on 159 eyes of 132 adult Japanese patients. Corneal endothelial cells were measured at the center (C), inferior (I), nasal inferior (NI), nasal superior (NS), superior (S), temporal superior (TS), and temporal inferior (TI) sectors at <1 month preoperatively and 3, 6, 12, 24, and 36 months postoperatively, for changes in corneal endothelial cell density (ECD), coefficient of variation (CV), and incidence of hexagonal cells (6A).

RESULTS

Mean preoperative ECD in all groups were 2401±451 (SD)  cells/mm (C), 2366±450 cells/mm (I), 2397±479 cells/mm (NI), 2476±554 cells/mm (NS), 2493±596 cells/mm (S), 2464±558 cells/mm (TS), and 2329±510 cells/mm (TI). The 12-month postoperative mean ECDs were 2344±480 cells/mm (C), 2312±469 cells/mm (I), 2325±536 cells/mm (NI), 2473±517 cells/mm (NS), 2438±607 cells/mm (S), 2227±578 cells/mm (TS), and 2193±523 cells/mm (TI). There was no change in ECD in all sectors before and after surgery. ECD decreased at the TS and TI in combination with cataract surgery (2620±430 and 2445±384 cells/mm) preoperatively to 2264±501 and 2216±477 cells/mm at 12 months postoperatively. CV and 6A did not change at all sites in all surgical procedures before and after surgery.

CONCLUSIONS

Trabectome surgery involves minimal effects to corneal endothelial cells, although long-term prospective studies with greater sample sizes are necessary to confirm this conclusion.

Canaloplasty in the Treatment of Open-Angle Glaucoma: A Review of Patient Selection and Outcomes

Canaloplasty is a relatively new non-penetrating surgery for the reduction of intraocular pressure in patients affected by glaucoma. The technique uses a microcatheter to perform a 360 º cannulation of Schlemm’s canal and leaves in place a tension suture providing an inward distension. It aims to restore the physiological outflow pathways of the aqueous humour and is independent of external wound healing. Several studies have shown that canaloplasty is effective in reducing intraocular pressure and has a low rate of complications, especially compared with trabeculectomy, the gold standard for glaucoma surgery. Currently, canaloplasty is indicated in patients with open-angle glaucoma, having a mild to moderate disease, and the combination with cataract phacoemulsification may provide further intraocular pressure reduction. This article reviews canaloplasty indications, results and complications and analyses its outcomes compared with traditional penetrating and non-penetrating techniques.

Canaloplasty versus Viscocanalostomy in Primary Open Angle Glaucoma

INTRODUCTION

The purpose of this study was to compare the efficacy and safety of canaloplasty versus viscocanalostomy in management of uncontrolled primary open angle glaucoma (POAG) with medication.

METHODS

Canaloplasty surgery was applied for thirty eyes of thirty patients (45-55 years) with a mean age of 48 years (Group A) and viscocanalostomy surgery was applied also for thirty eyes of thirty patients (43-54 years) with a mean age of 46 years (group B). All patients were with uncontrolled primary open angle glaucoma by maximally tolerated medical therapy.

RESULTS

Intraocular pressure (IOP) in both surgeries was significantly reduced through follow up period (p < 0.0.001). Complete success was 86.6% in group A and 80% in group B. Visual field deterioration was in 2 cases (6%) in group A and in 4 cases (13%) in group B. Low incidence of postoperative complications was reported as Descemet's membrane detachment (3% in group A and 8% in group B), ocular hypotony (2% in group A and 4% in group B) and hyphema (3% in group A and 5% in group B).

CONCLUSION

Canaloplasty was more effective and safer than viscocanalostomy in management of uncontrolled primary open angle glaucoma (POAG) with medication.

Canaloplasty: Current Value in the Management of Glaucoma

Canaloplasty is a nonpenetrating blebless surgical technique for open-angle glaucoma, in which a flexible microcatheter is inserted within Schlemm's canal for the entire 360 degrees. When the microcatheter exits the opposite end, a 10-0 prolene suture is tied and it is then withdrawn, by pulling microcatheter back through the canal in the opposite direction. Ligation of prolene suture provides tension on the canal and facilitates aqueous outflow. The main advantage of canaloplasty is that this technique avoids the major complications of fistulating surgery related to blebs and hypotony. Currently, canaloplasty is performed in glaucoma patients with early to moderate disease and combination with cataract surgery is a suitable option in patients with clinically significant lens opacities.

Short-term evaluation of Trabectome surgery performed on Japanese patients with open-angle glaucoma

PURPOSE

To evaluate the short-term results of Trabectome surgery performed on Japanese patients.

METHODS

Retrospective observational study. Trabectome surgery was performed on 117 eyes from 101 patients at Kitasato University Hospital from December 2010 to June 2013, involving 48 eyes with primary open-angle glaucoma (POAG), 62 eyes with secondary open-angle glaucoma (SOAG), and 7 eyes with developmental glaucoma. Trabectome surgery alone was performed on 34 phakic eyes (the phakic group) and 35 pseudophakic eyes (the pseudophakic group), and Trabectome surgery combined with phacoemulsification (the combined surgery group) was performed on 48 eyes. The main outcomes assessed were intraocular pressure (IOP), number of IOP-lowering medications, and success probabilities using Kaplan-Meier life-table analyses. Failure risk factors were identified using the Cox proportional hazards ratio.

RESULTS

In all cases, after a mean follow-up of 18.5 ± 13.5 months, IOP was reduced from 31.6 ± 9.9 (SD) mmHg using 5.0 ± 1.7 medications to 16.4 ± 5.4 mmHg using 3.8 ± 1.8 medications. One year after surgery, IOP was reduced from 29.4 ± 7.8 to 16.1 ± 3.8 mmHg in POAG, from 33.6 ± 11.1 to 14.7 ± 2.9 mmHg in SOAG, from 33.0 ± 10.2 to 15.7 ± 3.3 mmHg in the phakic group, from 32.6 ± 9.3 to 15.3 ± 3.0 mmHg in the pseudophakic group, and from 29.9 ± 10.0 to 15.2 ± 3.0 mmHg in the combined surgery group. There were no statistically significant differences in IOP at each measurement point, either between POAG and SOAG or among the three procedure subtypes. The POAG and SOAG success rates at 12 months using postoperative IOP ≤ 21 mmHg and ≥20 % reduction in baseline as criteria were 53.9 and 77.2 %, respectively (p = 0.024, log-rank test). Twenty-one eyes (17.9 %) needed additional trabeculectomy. None of the univariate and multivariate risk factors for failure were detected.

CONCLUSIONS

Trabectome surgery is safe and effective for Japanese patients whose target IOP is 18 mmHg or above. However, it is necessary to carefully consider Trabectome surgery for advanced POAG cases.

Trabeculectomy versus canaloplasty (TVC study) in the treatment of patients with open-angle glaucoma: a prospective randomized clinical trial

Purpose

To compare the outcomes of canaloplasty and trabeculectomy in open‐angle glaucoma.

Methods

This prospective, randomized clinical trial included 62 patients who randomly received trabeculectomy (n = 32) or canaloplasty (n = 30) and were followed up prospectively for 2 years. Primary endpoint was complete (without medication) and qualified success (with or without medication) defined as an intraocular pressure (IOP) of ≤18 mmHg (definition 1) or IOP ≤21 mmHg and ≥20% IOP reduction (definition 2), IOP ≥5 mmHg, no vision loss and no further glaucoma surgery. Secondary endpoints were the absolute IOP reduction, visual acuity, medication, complications and second surgeries.

Results

Surgical treatment significantly reduced IOP in both groups (p < 0.001). Complete success was achieved in 74.2% and 39.1% (definition 1, p = 0.01), and 67.7% and 39.1% (definition 2, p = 0.04) after 2 years in the trabeculectomy and canaloplasty group, respectively. Mean absolute IOP reduction was 10.8 ± 6.9 mmHg in the trabeculectomy and 9.3 ± 5.7 mmHg in the canaloplasty group after 2 years (p = 0.47). Mean IOP was 11.5 ± 3.4 mmHg in the trabeculectomy and 14.4 ± 4.2 mmHg in the canaloplasty group after 2 years. Following trabeculectomy, complications were more frequent including hypotony (37.5%), choroidal detachment (12.5%) and elevated IOP (25.0%).

Conclusions

Trabeculectomy is associated with a stronger IOP reduction and less need for medication at the cost of a higher rate of complications. If target pressure is attainable by moderate IOP reduction, canaloplasty may be considered for its relative ease of postoperative care and lack of complications.

Combined surgery versus cataract surgery alone for eyes with cataract and glaucoma

BACKGROUND

Cataract and glaucoma are leading causes of blindness worldwide, and their co-existence is common in elderly people. Glaucoma surgery can accelerate cataract progression, and performing both surgeries may increase the rate of postoperative complications and compromise the success of either surgery. However, cataract surgery may independently lower intraocular pressure (IOP), which may allow for greater IOP control among patients with co-existing cataract and glaucoma. The decision between undergoing combined glaucoma and cataract surgery versus cataract surgery alone is complex. Therefore, it is important to compare the effectiveness of these two interventions to aid clinicians and patients in choosing the better treatment approach.

OBJECTIVES

To assess the relative effectiveness and safety of combined surgery versus cataract surgery (phacoemulsification) alone for co-existing cataract and glaucoma. The secondary objectives include cost analyses for different surgical techniques for co-existing cataract and glaucoma.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 10), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to October 2014), EMBASE (January 1980 to October 2014), PubMed (January 1948 to October 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to October 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 3 October 2014.We checked the reference lists of the included trials to identify further relevant trials. We used the Science Citation Index to search for references to publications that cited the studies included in the review. We also contacted investigators and experts in the field to identify additional trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of participants who had open-angle, pseudoexfoliative, or pigmentary glaucoma and age-related cataract. The comparison of interest was combined cataract surgery (phacoemulsification) and any type of glaucoma surgery versus cataract surgery (phacoemulsification) alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, collected data, and judged risk of bias for included studies. We used standard methodological procedures expected by the Cochrane Collaboration.

MAIN RESULTS

We included nine RCTs, with a total of 655 participants (657 eyes), and follow-up periods ranging from 12 to 30 months. Seven trials were conducted in Europe, one in Canada and South Africa, and one in the United States. We graded the overall quality of the evidence as low due to observed inconsistency in study results, imprecision in effect estimates, and risks of bias in the included studies.Glaucoma surgery type varied among the studies: three studies used trabeculectomy, three studies used iStent® implants, one study used trabeculotomy, and two studies used trabecular aspiration. All of these studies found a statistically significant greater decrease in mean IOP postoperatively in the combined surgery group compared with cataract surgery alone; the mean difference (MD) was -1.62 mmHg (95% confidence interval (CI) -2.61 to -0.64; 489 eyes) among six studies with data at one year follow-up. No study reported the proportion of participants with a reduction in the number of medications used after surgery, but two studies found the mean number of medications used postoperatively at one year was about one less in the combined surgery group than the cataract surgery alone group (MD -0.69, 95% CI -1.28 to -0.10; 301 eyes). Five studies showed that participants in the combined surgery group were about 50% less likely compared with the cataract surgery alone group to use one or more IOP-lowering medications one year postoperatively (risk ratio (RR) 0.47, 95% CI 0.28 to 0.80; 453 eyes). None of the studies reported the mean change in visual acuity or visual fields. However, six studies reported no significant differences in visual acuity and two studies reported no significant differences in visual fields between the two intervention groups postoperatively (data not analyzable). The effect of combined surgery versus cataract surgery alone on the need for reoperation to control IOP at one year was uncertain (RR 1.13, 95% CI 0.15 to 8.25; 382 eyes). Also uncertain was whether eyes in the combined surgery group required more interventions for surgical complications than those in the cataract surgery alone group (RR 1.06, 95% CI 0.34 to 3.35; 382 eyes). No study reported any vision-related quality of life data or cost outcome. Complications were reported at 12 months (two studies), 12 to 18 months (one study), and two years (four studies) after surgery. Due to the small number of events reported across studies and treatment groups, the difference between groups was uncertain for all reported adverse events.

AUTHORS' CONCLUSIONS

There is low quality evidence that combined cataract and glaucoma surgery may result in better IOP control at one year compared with cataract surgery alone. The evidence was uncertain in terms of complications from the surgeries. Furthermore, this Cochrane review has highlighted the lack of data regarding important measures of the patient experience, such as visual field tests, quality of life measurements, and economic outcomes after surgery, and long-term outcomes (five years or more). Additional high-quality RCTs measuring clinically meaningful and patient-important outcomes are required to provide evidence to support treatment recommendations.

Episcleral venous fluid wave: intraoperative evidence for patency of the conventional outflow system

PURPOSE

To report the observation of a perilimbal and/or episcleral vessel fluid wave seen during trabectome surgery, newly termed episcleral venous fluid wave.

PATIENTS AND METHODS

In 4 consecutive patients undergoing phaco-trabectome surgery, the authors observed the nasal perilimbal and episcleral collector vessels for an anticipated wave of fluid adjacent to the trabeculotomy site. The wave of fluid was elicited during the irrigation and aspiration phase of cataract surgery at the time of low intraocular pressure with no infusion (foot pedal position 0) to maximum irrigation (foot pedal position 2), creating a maximal pressure gradient for balanced salt solution (BSS) to surge into the anterior chamber and potentially out of the newly cleaved canal venous collector system.

RESULTS

During the anterior chamber surge of BSS, the authors observed in 4 cases, 2 types of fluid waves, one episcleral and sectorial in distribution and the other through the perilimbal conjunctival vessels. There was a correlation between the location of retrograde reflux of blood into the anterior chamber during the low-pressure phase and a wave of BSS into the immediate adjacent collector.

CONCLUSIONS

The authors believe the fluid wave signifies intraoperative structural patency of the conventional outflow system from the anterior chamber to the episcleral and conjunctival distal collectors. The fluid wave is a sign that the collector system is at least anatomically functional, however, not necessarily physiologically functional. The presence or absence of a fluid wave may better explain canal-based surgical outcomes and could be a prognostic indicator for success after a trabectome surgery.

Intraindividual comparison of Canaloplasty versus trabeculectomy with mitomycin C in a single-surgeon series

PURPOSE

To compare the safety, efficacy, and postoperative management of canaloplasty in one eye versus trabeculectomy with mitomycin C in the contralateral eye in patients with open-angle glaucoma.

METHODS

This study was a consecutive case series of 30 eyes of 15 patients who had prior trabeculectomy with mitomycin C (group II) and later were treated with canaloplasty (group I) in the fellow eye. Primary outcome measures included intraocular pressure (IOP) and glaucoma medication after 6- and 12-month follow-up. Secondary outcome measures were number of postoperative interventions, hospitalization, and follow-up visits.

RESULTS

Mean preoperative IOP±SD was 26.73±6.4 mm Hg in group I and 26.3±10.9 mm Hg in group II (P=0.9), which decreased to 13.21±2.83 mm Hg for canaloplasty (P<0.0001) and 11.64±5.2 mm Hg for trabeculectomy (P<0.0005) including 3 patients with hypotony at 12 months. Glaucoma medication decreased from 2.5 in group I and 2.7 in group II to no medication in group I and 0.36±0.74 supplemental medication in group II 12 months postoperatively (P<0.0001). Best corrected visual acuity (±SD) was logMAR 0.06±0.09 (group I) and 0.28±0.56 (group II) before and logMAR 0.07±0.09 (group I) and 0.31±0.58 (group II) after surgery. In group I, 2 interventions were necessary. In group II, 8 eyes needed 112 interventions for filtering bleb management. Although canaloplasty took significantly longer to perform, trabeculectomy group required a longer initial postoperative hospitalization (mean 10.4 vs. 5.4 d, P<0.0001) and more postoperative follow-up visits (mean 3.9 vs. 8.5, P<0.001).

CONCLUSIONS

Canaloplasty and trabeculectomy were both effective in lowering IOP. However, less follow-up visits and significantly fewer complications and interventions were favorable for canaloplasty.

Gonioscopy-assisted transluminal trabeculotomy, ab interno trabeculotomy: technique report and preliminary results

PURPOSE

To introduce a minimally invasive, ab interno approach to a circumferential 360-degree trabeculotomy and to report the preliminary results.

DESIGN

Retrospective, noncomparative cases series.

PARTICIPANTS

Eighty-five eyes of 85 consecutive patients who sought treatment at Glaucoma Associates of Texas with uncontrolled open-angle glaucoma and underwent gonioscopy-assisted transluminal trabeculotomy (GATT) for whom there was at least 6 months of follow-up data.

METHODS

Retrospective chart review of patients who underwent GATT by 4 of the authors (D.S.G., D.G.G., O.S., R.L.F.) between October 2011 and October 2012. The surgery was performed in adults with various open-angle glaucomas.

MAIN OUTCOME MEASURES

Intraocular pressure (IOP), glaucoma medications, visual acuity, and intraoperative as well as postoperative complications.

RESULTS

Eighty-five patients with an age range of 24 to 88 years underwent GATT with at least 6 months of follow-up. In 57 patients with primary open-angle glaucoma, the IOP decreased by 7.7 mmHg (standard deviation [SD], 6.2 mm Hg; 30.0% [SD, 22.7%]) with an average decrease in glaucoma medications of 0.9 (SD, 1.3) at 6 months. In this group, the IOP decreased by 11.1 mmHg (SD, 6.1 mmHg; 39.8% [SD, 16.0%]) with 1.1 fewer glaucoma medications at 12 months. In the secondary glaucoma group of 28 patients, IOP decreased by 17.2 mmHg (SD, 10.8 mmHg; 52.7% [SD, 15.8%]) with an average of 2.2 fewer glaucoma medications at 6 months. In this group, the IOP decreased by 19.9 mmHg (SD, 10.2 mmHg; 56.8% [SD, 17.4%]) with an average of 1.9 fewer medications (SD, 2.1) at 12 months. Treatment was considered to have failed in 9% (8/85) of patients because of the need for further glaucoma surgery. The cumulative proportion of failure at 1 year ranged from 0.1 to 0.32, depending on the group. Lens status or concurrent cataract surgery did not have a statistically significant effect on IOP in eyes that underwent GATT at either 6 or 12 months (P > 0.35). The most common complication was transient hyphema, seen in 30% of patients at the 1-week visit.

CONCLUSIONS

The preliminary results and safety profile for GATT, a minimally invasive circumferential trabeculotomy, are promising and at least equivalent to previously published results for ab externo trabeculotomy.

Recent clinical pearls from clinical trials in glaucoma

PURPOSE OF REVIEW

Over the past several years, numerous clinical trials in glaucoma have contributed to our understanding of the medical and surgical treatment of the disease. The goal of this review is to summarize the findings and conclusions of what the authors feel are the key clinical trials in glaucoma.

RECENT FINDINGS

One of the major findings of Low-Pressure Glaucoma Treatment study was that patients randomized to the brimonidine group were statistically less likely to have progressive visual field loss than those randomized to the timolol group, even though there was no significant difference between the intraocular pressure (IOP)-lowering effect of these two drugs. The Ocular Hypertension Treatment Study has effectively demonstrated that patients with ocular hypertension should be risk stratified prior to initiation of treatment and that it appears to be relatively safe to delay treatment in low-risk patients. The 3-year canaloplasty study demonstrates the long-term safety and efficacy of this surgery. However, it also demonstrates that canaloplasty can deliver a modest IOP reduction and therefore is likely more suited for patients with mild damage and a higher target IOP. The 1-year results from the Ahmed Baerveldt Comparison Study do not demonstrate a clear superiority of one implant over the other. These findings are consistent with prior retrospective studies in the literature.

SUMMARY

These four studies have furthered our understanding of the field of glaucoma and provided key insights into the medical and surgical management of patients with this complex disease.

[Canaloplasty : a new alternative in non-penetrating glaucoma surgery]

BACKGROUND

Canaloplasty provides a new option in non-penetrating glaucoma surgery. The aim of this study is to examine its early postsurgical safety and efficacy.

PATIENTS AND METHODS

This was a retrospective study of canaloplasties performed at our institution in 2009 (n=46, 13 of which were combined with cataract surgery). The mean follow-up was 6.0±3.4 months. The most important parameters examined were intraocular pressure (IOP), number of topical medications, postoperative complications, and required additional surgery.

RESULTS

Mean presurgical IOP: 18.2±5.8 mmHg on a mean of 2.3±1.2 applied topical medications. Mean postsurgical IOP: 12.3±5.1 mmHg at 3 months, 11.7±3.0 mmHg at 6 months, and 12.6±2.4 mmHg at 12 months. Number of postsurgical medications: 0.8±1.1 at 3 months, 1.2±1.3 at 6 months, and 1.0±1.1 at 12 months. The most frequent postoperative complications were transient hypotension (32.6%), bleb leakage (26.1%), and microhyphema (23.9%). Revision surgery was required in 8.7% of all patients.

CONCLUSIONS

Canaloplasty showed a good IOP-reducing effect. Complications occurred mostly temporarily and were of a controllable nature.

Primary lens extraction for glaucoma management: A review article

Recently, primary lens extraction alone gained more acceptance as an alternative surgical approach for glaucoma management. This view was supported by the advances in phacoemulsification and intraocular lenses with greater safety and visual recovery, in addition to a substantial reduction of intraocular pressure and deepening of the anterior chamber and filtration angle. The decrease in IOP after cataract surgery in primary open-angle glaucoma (POAG) is mild, less predictable, related to baseline levels, and may return to presurgical values after an initial period of reduction. Therefore, the IOP-lowering effect of primary cataract extraction in POAG may be insufficient to achieve adequate IOP control. The IOP reduction after lens extraction is consistently greater in eyes with primary angle closure glaucoma (PACG) than in eyes with POAG. Primary lens extraction in acute PACG eliminates, or at least, reduces the risk of recurrence of acute attacks and deepens the anterior chamber and widens the angle which reduces the risk of progression of peripheral anterior synechiae and development of chronic PACG. Primary lens extraction may be more preferable to glaucoma incisional surgery in mild to moderate PACG eyes with appositional angle closure. The decision to do lens extraction as a primary treatment for glaucoma should be individualized based upon several factors other than the effect on IOP. These factors include patients' characteristics, surgeons' skills and preferences, status of glaucoma control, type of cataract and intraocular lens implanted, and potential harm of laser treatment for late capsular opacification and fibrosis.

A review of canaloplasty

Canaloplasty is a method of lowering intraocular pressure (IOP) by which a flexible, beacon-tipped microcatheter equipped with an ophthalmic viscosurgical device (OVD) delivery system is used to catheterize and introduce a suture into Schlemm's canal. Ligation of this suture provides tension on the canal and facilitates aqueous outflow. Canaloplasty is designed to be a blebless procedure that requires no antifibrotic agents and has been shown to safely and effectively lower IOP in patients with open-angle glaucoma (OAG) with minimal complications. Most importantly, no bleb-related adverse events are associated with this procedure. When contemplating surgical management of OAG, canaloplasty may be considered.

Three-year canaloplasty outcomes for the treatment of open-angle glaucoma: European study results

BACKGROUND

To report 3-year results investigating the safety and efficacy of canaloplasty, a procedure involving circumferential viscodilation of Schlemm's canal and tensioning of the inner canal wall to treat open-angle glaucoma.

METHODS

This was a prospective, multi-center, interventional study of 109 eyes of 109 adult, open-angle glaucoma patients undergoing canaloplasty or combined cataract-canaloplasty surgery. Qualifying preoperative intraocular pressures (IOP) were at least 16 mmHg with historical IOPs of at least 21 mmHg with or without medical therapy. A flexible microcatheter was used to viscodilate the full circumference of the canal and to place a trabecular tensioning suture. Primary outcome measures included IOP, glaucoma medication usage, and adverse events.

RESULTS

Eyes with canaloplasty showed a mean baseline IOP of 23.0 ± 4.3 mmHg and mean glaucoma medication usage of 1.9 ± 0.7 medications, which decreased to a mean IOP of 15.1 ± 3.1 mmHg on 0.9 ± 0.9 medications at 3 years postoperatively. Eyes with combined cataract-canaloplasty surgery showed a mean baseline IOP of 24.3 ± 6.0 mmHg on 1.5 ± 1.2 medications, which decreased to a mean IOP of 13.8 ± 3.2 mmHg on 0.5 ± 0.7 medications at 3 years. Intraocular pressure and medication use results for all study eyes were significantly decreased from baseline (p <0.00001) at all intervals. Late postoperative complications included cataracts (19.1%) and transient IOP elevation (1.8%).

CONCLUSIONS

Canaloplasty demonstrated significant and sustained IOP reductions accompanied by an excellent short- and long-term safety profile in adult patients with open-angle glaucoma.

A history of the surgical management of glaucoma

Many new surgeries have been devised since 1856, when von Graefe discovered that iridectomy is an effective surgical method for acute glaucoma treatment. Two years later, De Wecker presented sclerotomy as a procedure for chronic glaucoma. In 1900, internal filtration (cyclodialysis) was developed. In 1932, ciliodestruction was suggested. The four approaches, relief of pupillary block, external filtration, internal filtration, and ciliodestruction, are still the basic techniques of glaucoma surgeries over 100 years later. There have been two basic approaches to lowering eye pressure surgically: increase outflow and decrease inflow of aqueous humor. Although the majority of surgeries used nowadays were introduced in the 1960s, their roots can be traced to the work of surgeons in the 19th century. Trabeculectomy, in use since the mid-1960s, is the most effective glaucoma surgery in terms of intraocular pressure reduction but carries its own limitations. Non-penetrating glaucoma surgeries emerged at the same time trabeculectomy was presented, but they are not used as commonly as trabeculectomy. Molteno introduced the first effective shunt and followed by others. Since 1995, the majority of new surgeries have consisted of new implantable devices including SOLX, iStent, and Ex-PRESS shunt. This article will review the history of glaucoma surgery and describe the fundamentals of different glaucoma procedures.

Surgical management of glaucoma: an Indian perspective

Glaucoma is a serious sight-threatening disorder aptly named the Silent thief of sight. India, being the second most populous country in the world, has about 20% of the world glaucoma population. The complex geographical and socioeconomic architecture and the economic extremes have a profound effect on its health system. The present times are abundant with fresh developments in the field of glaucoma. Though newer modalities are present in India, they are not ample and are unequally distributed. Adherence and persistence with medical therapy is an issue owing to a multitude of factors. In such a setting, most of the ophthalmologists find themselves performing glaucoma surgeries quite often. In the present era, there are a number of new surgeries to choose from, especially procedures which are nonpenetrating and blebless. Faced with a spectrum of surgeries from shunts to canal surgeries and trabecular bypass devices, the surgeon is often in a dilemma. Still, trabeculectomy remains the gold standard with an increasing trend toward glaucoma drainage devices. The new procedures and devices are worth exploring but await long-term results, good training of surgeons and cost effectiveness.

Canaloplasty using iTrack 250 Microcatheter with Suture Tensioning on Schlemm's Canal

Open angle glaucoma (OAG) necessitating surgery has traditionally been treated with filtering procedures using antifibrotics. Unfortunately, such filtering procedures are not without the risk of postsurgical complications. Increasing interest in blebless surgery has led to innovative surgical procedures aimed at rejuvenating the natural trabeculo canalicular outflow pathway. Circumferential catheterization with suture tensioning of Schlemm's canal has emerged as a safe and effective way to surgically treat OAG.