Revision of encapsulated blebs after trabeculectomy: Long-term comparison of standard bleb needling and modified needling procedure combined with transconjunctival scleral flap sutures

Intraocular Pressure and Medication Changes Associated with Xen Gel Stent: A Systematic Review of the Literature

The Xen gel stent (Allergan Inc, an AbbVie company; Dublin, Ireland) was conceived as an option for patients requiring modest IOP reduction but for whom trabeculectomy was not yet indicated. As with any glaucoma surgery, establishing criteria for patient selection and identifying factors that contribute to a high likelihood of success are important. To help guide clinical decision-making, a systematic review of published studies on the gel stent was performed, with the goal of understanding postoperative outcomes based on clinical and patient factors. Results were organized around a series of pertinent clinical questions based on scenarios encountered in clinical practice. Criteria for including studies were intentionally broad, with the objective of simulating the diverse population of glaucoma patients encountered in real-world practice. Outcomes for IOP and medication reduction postoperatively were assessed in various analyses, including in eyes with various glaucoma types and severity; in eyes naïve to surgery as well as those with a history of prior incisional glaucoma surgery; and when surgery was performed as a standalone procedure or at the time of cataract surgery. The results of each of the various analyses were consistent in demonstrating that successful gel stent surgery achieved a postoperative IOP of approximately 14.0 mm Hg and reduction to fewer than 1 glaucoma medication. Additional data are shown on outcomes by method of implant (ab interno vs ab externo); intraoperative use of antifibrotics; and rates of needling in published studies.

Influence of Mitomycin C on the Therapeutic Success of Stand-Alone Xen45 Gel Stents and Its Combination with Cataract Surgery in Open-Angle Glaucoma Patients

PURPOSE

Minimally invasive glaucoma surgery (MIGS), like Xen45 gel stents, is known as effective therapy in lowering intraocular pressure (IOP); however, fibrotic reactions are a common problem in postoperative management. It was the aim of this study to investigate the therapeutic success of Xen45 gel stents as a stand-alone technique (Xen) and combined with cataract surgery (XenPhaco), and with antimetabolites (mitomycin C, MMC) in open-angle glaucoma patients.

METHODS

Retrospective analysis was performed of 199 eyes of 177 glaucoma patients of the Department of Ophthalmology, University of Erlangen Nürnberg, and from the Erlangen Glaucoma Registry (NCT00494923; ISSN 2191-5008, CS-2011) who underwent implantation of a Xen45 gel stent. Therapeutic success was defined as IOP reduction of ≥ 20% on the same or less anti-glaucomatous medication after 12 months compared to preoperative and without any additional glaucoma-related surgery (except bleb needling). IOP reduction, reduction in local anti-glaucomatous eye drops, and intra- and postoperative complications were monitored.

RESULTS

Stand-alone Xen45 gel stent: therapeutic success was reached in 39% (-MMC) and 55% (+MMC). Failure rate was 61% (-MMC) and 45% (+MMC). XenPhaco: therapeutic success was achieved in 57% (-MMC) and 46% (+MMC). Failure rate was 43% (-MMC) and 54% (+MMC). Data were not different for group and subgroup analyses (p > 0.05).

CONCLUSIONS

The use of MMC seemed to increase the therapeutic success rate after stand-alone Xen45 gel stent implantation and combined with cataract surgery, yet statistical significant was not reached.

An Ex-Press implant versus trabeculectomy in a fibrotic bleb with late failure after previous trabeculectomy

AIM

To compare the outcome of an Ex-Press implant and subscleral trabeculectomy (SST) in the management of glaucoma after previous trabeculectomy on a fibrotic bleb.

METHODS

This randomized prospective study included 28 eyes from 28 patients (age range: 42-55y) with primary open angle glaucoma (POAG) presented with elevated intraocular pressure (IOP) with fibrotic bleb despite previous SST for more than 4mo. The eyes enrolled in the study were divided into two groups: group I (subjected to Ex-Press implant surgery) and group II [subjected to SST with mitomycin C (MMC)]. The follow-up continued one year after surgery to evaluate IOP, visual acuity (VA), visual field (VF), and postoperative complications.

RESULTS

A significant decrease in IOP was found in both groups with a higher reduction in Ex-Press implant surgery with the mean IOP of 14.50 mm Hg (P=0.001), while the SST group recorded the mean IOP of 16.50 mm Hg (P=0.001) after one year. However, the difference between the two groups in terms of the decrease in IOP was insignificant. Fewer postoperative complications were recorded in the Ex-Press implant surgery and more cases requiring further anti-glaucomatous medications were seen in the SST group. Both groups showed stability in terms of VA and VF.

CONCLUSION

Ex-Press implant surgery and SST with MMC are two surgical alternatives for controlling IOP in late failure that occurs more than 4mo after previous SST with a fibrotic bleb. However, Ex-Press shunt is a safer surgery with fewer complications.

Numerical model to predict and compare the hypotensive efficacy and safety of minimally invasive glaucoma surgery devices

Purpose

To predict and compare the hypotensive efficacy of three minimally-invasive glaucoma surgery (MIGS) implants through a numerical model.

Methods

Post-implant hypotensive efficacy was evaluated by using a numerical model and a computational fluid dynamics simulation. Three different devices were compared: the XEN 45 stent (tube diameter, 45 μm), the XEN 63 stent (63 μm) and the PreserFlo microshunt (70 μm). The influence of the filtration bleb pressure (Bp) and tube diameter, length, and position within the anterior chamber (AC) on intraocular pressure (IOP) were evaluated.

Results

Using baseline IOPs of 25, 30 and 50 mmHg, respectively, the corresponding computed post-implant IOPs for each device were as follows: XEN 45: 17 mmHg (29% decrease), 19 mmHg (45%) and 20 mmHg (59%) respectively; XEN 63: 13 mmHg (48%), 13 mmHg (62%), and 13 mmHg (73%); PreserFlo: 12 mmHg (59%), 13 mmHg (73%) and 13 mmHg (73%). At a baseline IOP of 35 mmHg with an increase in the outflow resistance within the Bp from 5 to 17 mmHg, the hypotensive efficacy for each device was reduced as follows: XEN45: 54% to 37%; XEN 63: 74% to 46%; and PreserFlo: 75% to 47%. The length and the position of the tube in the AC had only a minimal (non-significant) effect on IOP (<0.1 mmHg).

Conclusions

This hydrodynamic/numerical model showed that implant diameter and bleb pressure are the two most pertinent determinants of hypotensive efficacy. In distinction, tube length and position in the AC do not significantly influence IOP.

XEN® Gel Stent in Medically Refractory Open-Angle Glaucoma: Results and Observations After One Year of Use in the United States

Introduction

The purpose of this study was to evaluate intraocular pressure (IOP) lowering and safety of XEN^® stent in medically refractory, progressive, open-angle glaucoma (OAG).

Methods

Forty-seven eyes of 42 patients were treated with XEN^® stent alone or combined with phacoemulsification.

Results

Mean IOP decreased from 22.34 ± 7.34 mmHg to 12.91 ± 4.21, 12.95 ± 4.36, 13.49 ± 3.91, and 13.36 ± 3.63 mmHg at 1, 3, 6, and 12 months (95% confidence interval [CI] [20.24, 24.44], [11.71, 14.12], [11.63, 14.27], [12.36, 14.62], and [12.10, 14.62]), respectively. Mean number of medications decreased from 2.96 ± 1.20 (95% CI [2.62, 3.30]) at baseline to 0.75 ± 1.27 (95% CI [0.31, 1.19]) at 1 year. At 1 year (n = 32), complete success was achieved in 68.8% (n = 22/32) (i.e., IOP reduction ≥ 20% and IOP < 18 mmHg without medication or any secondary glaucoma intervention). Qualified success was achieved in 90.6% (n = 29/32) (i.e., IOP reduction of ≥ 20% and IOP < 18 mmHg with and without medication or any secondary glaucoma intervention). Eleven eyes had not yet reached 12 months. Two patients (three eyes) died before 1 year; one patient (one eye) was lost to follow up. Adverse events: localized choroidal hemorrhage in one eye; hypotony (IOP < 6 mmHg) at day 1 in 10 eyes, with full resolution by 2 weeks. No persistent hypotony or maculopathy occurred. Stent erosion with removal occurred in two eyes. Fourteen eyes (29.8%) underwent needling. One patient required trabeculectomy.

Conclusions

XEN^® stent is effective and relatively safe surgery for medically refractory, progressive, OAG out to 1 year. Intraocular pressure and medications were significantly reduced.

Two-Year Outcomes of XEN Gel Stent Surgery in Patients with Open-Angle Glaucoma

PURPOSE

To evaluate the 2-year treatment outcomes of the XEN gel stent (Allergan, Inc, Irvine, CA) in glaucoma patients.

DESIGN

Prospective, single-center interventional study.

PARTICIPANTS

One hundred forty-nine eyes of 113 patients with open-angle glaucoma.

METHODS

Consecutive eyes with uncontrolled intraocular pressure (IOP) or signs of disease progression despite medical treatment were included to undergo either standalone XEN implantation or combined XEN implantation plus phacoemulsification surgery, both with mitomycin C injections.

MAIN OUTCOME MEASURES

Primary efficacy outcome was success, defined as complete when the unmedicated IOP was 12 mmHg or less, 15 mmHg or less, or 18 mmHg or less and 20% lower than at baseline over the 2-year period and defined as qualified when the IOP fulfilled the same conditions with fewer medications than at baseline. Secondary measures were mean reduction in IOP and in the number of medications and the rates of reoperations.

RESULTS

One hundred nine eyes (84 patients; mean age, 74.3 years) underwent XEN plus phacoemulsification surgery and 40 eyes (29 patients; mean age, 74.7 years) underwent standalone XEN surgery. Overall, 129 eyes (86.6%; 96 eyes of 75 XEN plus phacoemulsification patients and 33 eyes of 24 XEN standalone surgery patients) completed the study. Mean medicated IOP was 20.0±7.5 mmHg at baseline and 14.1±3.7 mmHg at 2 years (P < 0.01), a 29.3% IOP reduction. Mean number of medications dropped from 2.0±1.3 before surgery to 0.6±0.9 at 2 years (P < 0.001). Complete success was achieved in 18.2% of eyes using the 12 mmHg or less and 20% reduction criteria and in 44.4% using the 15 mmHg or less threshold. Needling with mitomycin C was performed in 58 eyes (45%). In all, 11.4% underwent reoperations.

CONCLUSIONS

After 2 years, XEN gel stent surgery achieved a clinically and statistically significant reduction both in IOP and the number of antiglaucoma medications, while requiring a high rate of needling interventions.

Suture Removal After Trabeculectomy With Fornix-based Conjunctival Flap Leads to Faster Visual Recovery but Not Reduced Astigmatism

PRéCIS:: The closing limbal suture after trabeculectomy with a fornix-based conjunctival flap plays no critical role in the development of corneal astigmatism and intraocular pressure (IOP). A standard removal is not recommended.

PURPOSE

To investigate the effect of removal of the conjunctival suture after trabeculectomy with fornix-based conjunctival flap on corneal astigmatism, visual acuity, and IOP.

METHODS

Eighty-seven cases of trabeculectomy with mitomycin C with a fornix-based conjunctival flap performed in the eyes of 82 patients (5 patients underwent bilateral trabeculectomy) were enrolled in a prospective randomized study. All surgeries were conducted by the same surgeon (J.W.) in the Ophthalmology Department of the University Medical Center of Mainz, Germany. All eyes received a corneal-conjunctival, continuous, mattress, interlocked suture for closing the conjunctiva at the limbus. After randomization, in 46 cases the suture was removed 6 weeks postoperatively; in 41 patients, the suture was left in place. All patients were examined preoperatively, and at 6 weeks, 3 months, 6 months, and 12 months after surgery. Astigmatism was measured using objective refraction and corneal topography, IOP and visual acuity were also assessed. Results were compared using a Wilcoxon test or Mann-Whitney U test for single time-points.

RESULTS

During follow-up, no significant differences between the 2 study groups regarding refractive or topographic values were found. Patients in the suture removal group had a significantly higher visual acuity than controls at 3 months, 6 months, and 1 year after surgery. IOP was similar in both groups throughout the study.

CONCLUSIONS

Removal of the conjunctival suture in trabeculectomy with a fornix-based conjunctival flap leads to a faster rehabilitation of visual acuity but does not significantly affect corneal astigmatism or IOP.