[Diverse effectiveness of the trabectome for different types of glaucoma]

Recent Advances in the Surgical Management of Glaucoma in Exfoliation Syndrome

Surgical and laser procedures traditionally used in the management of exfoliation glaucoma (XFG) include laser trabeculoplasty, trabeculectomy, and glaucoma drainage implant surgery. Having demonstrated similar safety and efficacy in XFG compared with primary open-angle glaucoma, trabeculectomy remains the most commonly performed surgery in XFG. Recent trends in practice patterns in developed nations demonstrate a shift towards glaucoma drainage implant surgery, which is currently the procedure of choice in XFG for many, particularly in developed nations. In addition, cataract surgery alone may significantly decrease intraocular pressure in patients with XFG, may prevent glaucoma development in patients with exfoliation syndrome, and is recommended to be performed early in the course of the disease. With the relatively recent introduction of nonpenetrating glaucoma surgery and the ongoing evolution of minimally invasive glaucoma surgery, several other surgical procedures have now become part of the glaucoma surgeon's armamentarium when treating XFG, including the Ex-PRESS shunt, deep sclerectomy, viscocanalostomy, Trabectome, as well as angle procedures. These techniques have demonstrated promising results in various types of glaucoma. More research is, however, needed to establish the safety and efficacy of these procedures in XFG.

Long-term follow-up of intraocular pressure and pressure-lowering medication in patients after ab-interno trabeculectomy with the Trabectome

BACKGROUND

The minimally invasive ab-interno trabeculectomy (AIT) via electro-ablation with the Trabectome has been on the European market since 2009. Many studies have proven the safety and efficacy of the procedure. Up until now, studies investigating the long-term effect of AIT have been sparse. In this study, we present long-term results of AIT in patients with primary and secondary open-angle glaucoma.

METHODS

In a retrospective monocentric study, the data of all the patients having undergone the procedure in 2010 at our institution were recorded. Data was collected during routine examinations at our institution. In total, 81 eyes of 74 patients (46 patients with primary open-angle glaucoma (POAG), 28 patients with pseudoexfoliative glaucoma (PEXG)) were included. At every examination, the intraocular pressure (IOP) was measured using Goldmann applanation tonometry and the number of IOP-lowering medication was registered. Statistical analysis was done using the Kaplan-Meier analysis or Dunnett's t test, respectively.

RESULTS

For both groups (POAG and PEXG), we found a significant lowering of the IOP (28% for POAG and 26% for PEXG) and a significant reduction of the number of IOP-lowering medication (32% for POAG and 29% for PEXG) after a median follow-up period of 3.5 years.

CONCLUSION

In patients with open-angle glaucoma and especially pseudoexfoliative glaucoma, ab-interno trabeculectomy is an effective surgical procedure to significantly lower the intraocular pressure on a long-term basis.

[Kahook Dual Blade : An instrument for microincisional trabecular meshwork surgery]

The Kahook Dual Blade (New World Medical, Rancho Cucamonga, CA, USA) is a novel goniotomy instrument for opening Schlemm's canal. Performing the procedure is comparable to the Trabectome (Neomedix, Tustin, CA, USA) under gonioscopic control with the major difference that the trabeculectomy is created by a dual blade instead of electroablation. The currently available clinical data are limited to a small number of retrospective studies with ≤1 year of follow-up. Based on these data and in line with the author's personal experience, the Kahook Dual Blade seems comparable to the Trabectome regarding effectiveness as well as intraoperative and postoperative complications, such as intraocular pressure (IOP) elevation and hyphema.

When Is Evidence Enough Evidence? A Systematic Review and Meta-Analysis of the Trabectome as a Solo Procedure in Patients with Primary Open-Angle Glaucoma

The purpose of this systematic review and meta-analysis was to examine the availability of evidence for one of the earliest available minimally invasive glaucoma surgery (MIGS) procedures, the Trabectome. Various databases were searched up to December 20, 2016, for any published studies assessing the use of the Trabectome as a solo procedure in patients with primary open-angle glaucoma (POAG). The standardized mean differences (SMD) were calculated for the change in intraocular pressure (IOP) and number of glaucoma mediations used at 1-month, 6-month, and 12-month follow-up. After screening, three studies and one abstract with analyzable data were included. The meta-analysis showed statistically significant reductions in IOP and number of glaucoma medications used at all time points. Though the Trabectome as a solo procedure appears to lower IOP and reduces the number of glaucoma medications, more high-quality studies are required to make definitive conclusions. The difficulty of obtaining evidence may be one of the many obstacles that limit a full understanding of the potential safety and/or efficacy benefits compared to standard treatments. The time has come for a thoughtful and integrated approach with stakeholders to determine optimal access to care strategies for our patients.

Long-term Effectiveness of Trabectome (Ab-interno Trabeculectomy) Surgery

Aim

To evaluate the long-term safety and efficacy of ab-interno trabeculectomy with trabectome for the treatment of glaucoma.

Materials and methods

Data collected for 339 eyes which included demographics, intraocular pressure (IOP) measurements using Goldmann applanation tonometry, best-corrected visual acuity (BCVA), visual field results, optic nerve status, gonioscopic findings, prior glaucoma procedures, number of glaucoma medications and pain level. The main data points of interest were preoperative IOP vs. postoperative IOP and BCVA, medication use, pain status, and complications.

Results

Of the 339 eyes that underwent trabectome, we found a statistically significant reduction in IOP (p < 0.01) at final follow-up (average = 18.35 months) of nearly 23%, with a complication rate of 5.86%. Furthermore, this reduction was maintained up to 8 years post procedure. LogMAR visual acuity was significantly improved in 69% of eyes at the final visit (p < 0.05), while only 1.77% of cases saw a significant reduction. Based on these findings, we determined a success rate of around 80% to 100 months following trabectome.

Conclusion

Trabectome is a safe and effective long term for most forms and severities of glaucoma.

How to cite this article

Bendel RE, Patterson MT. Long-term Effectiveness of Trabectome (Ab-interno Trabeculectomy) Surgery. J Curr Glaucoma Pract 2018;12(3):119-124.

Ab interno trabeculectomy: patient selection and perspectives

Ab interno trabeculectomy is one among several recently introduced minimally invasive glaucoma surgeries that avoid a conjunctival incision and full-thickness sclerostomy involved in traditional glaucoma surgery. Ablation of the trabecular meshwork and inner wall of Schlemm's canal is performed in an arcuate fashion via a clear corneal incision, alone or in combination with phacoemulsification cataract surgery. Intraocular pressure reduction following ab interno trabeculectomy is limited by resistance in distal outflow pathways and generally stabilizes in the mid-to-high teens. Relief of medication burden has been demonstrated by some studies. A very low rate of complications, most commonly transient hyphema and intraocular pressure elevations in the immediate postoperative period, have been reported. However, available data are derived from small retrospective and prospective case series. Randomized, controlled trials are needed to better elucidate the potential merits of ab interno trabeculectomy in the combined setting versus phacoemulsification cataract surgery alone and to compare it with other minimally invasive glaucoma surgeries.