Bleb Failure Research Articles

Cumulative dissipated energy during phacoemulsification is Associated with bleb failure in eyes with prior trabeculectomy

IntroductionTrabeculectomy is the most effective method of lowering the intraocular pressure (IOP) in patients with open-angle glaucoma refractory to pharmacological treatment or laser trabeculoplasty. Many phakic glaucoma patients later require cataract surgery after trabeculectomy. The purpose of this study is to determine factors that predict bleb failure after phacoemulsification. MethodsThis retrospective, observational study included 33 eyes from 30 patients with open-angle glaucoma who had successful trabeculectomy with mitomycin (MMC) and subsequently underwent uncomplicated cataract surgery by means of clear corneal phacoemulsification performed by a single surgeon between 2006 and 2018. Bleb failure was defined as an eye that required the addition of two or more glaucoma medications or had an IOP > 21 mmHg at any follow-up visit more than one month after surgery. Kaplan-Meier analysis was conducted to visualize bleb survival over the two-year study period. ResultsTen eyes (30.3%) experienced bleb failure, at an average of 325 ± 254 days after phacoemulsification surgery. A further six eyes (18.2%) partially failed over this period. Blebs that remained fully functional (51.5%) two years after phacoemulsification surgery received lower total cumulative dissipated energy (CDE; 12.6 ± 7.2 versus 19.0 ± 7.7, P = 0.027). ConclusionHigher levels of ultrasound energy at the time of cataract surgery, as reflected by CDE, are associated with bleb failure. Removing cataracts at a stage when the lens is less dense so that it will require less total ultrasound energy and allow shorter duration for surgery may benefit eyes with functioning filtering blebs.

Predictive Value of Conjunctival Cytology in Bleb-dependent Glaucoma Surgery.

Metaplasia, chronic inflammation and subconjunctival fibrosis favor failure of bleb-dependent glaucoma surgery. The aim of the study is to identify the patients at a higher risk of post-surgical failure. Prospective, open study, performed in the Glaucoma Unit of the Hospital Universitario Virgen Macarena, from April to November 2021, with a minimum follow-up of one year. 38 eyes with ocular hypertension or chronic open-angle glaucoma were included. All patients underwent preoperative conjunctival sampling in the operating room, under topical or locoregional anesthesia. Sex, age, and laterality; number, type and mean time of preoperative drugs use; type of surgery performed; cytology results and degree of metaplasia; percentage of patients in whom the bleb was closed. Evaluation of potential correlation between bleb closure and any of the other variables. 20 women and 18 men participated, with a mean age of 67 years. The mean number of preoperative hypotensive drugs was 2.7.The mean time of use was 90,97 +/- 48,97 months. Most patients had normal cytology, 8% had inflammatory infiltrate and 21% had squamous metaplasia. When relating bleb failure and cytology, we saw that in those who failed surgery, more than half had cytological alterations. A multiple logistic regression was performed, in which we observed that there was statistically significant association (p = .02) between surgical closure and altered cytology. According to these results, preoperative conjunctival cytology can help predict those cases with a lower probability of surgical success.

Efficacy of Ab Interno Revision for Trabeculectomy Bleb Failure using a Minimally Invasive Approach: A Prospective Study.

Ab interno bleb revision using the Grover and Fellman spatula offers potential benefits in improved intraocular pressure control and spare the conjunctiva for enhanced bleb management. This study aimed to evaluate the safety and effectiveness of Ab-Interno Bleb Revision (AIBR) for treating failed trabeculectomy blebs. This non-comparative case series enrolled glaucoma patients with failed trabeculectomy blebs, who underwent AIBR and were followed up for one year. Eligible patients received subconjunctival Mitomycin C 0.1mL of 0.2mg/mL (20μg) five days before the AIBR, performed using the Grover and Fellman spatula. The primary outcome measures were intraocular pressure (IOP) and the usage of IOP-lowering medications one year after the procedure. Secondary outcomes included the procedure's failure rate and complications. Complete success was defined as achieving an IOP between 5-21mmHg without medication, while qualified success required additional medical treatment. The study comprised 23 eyes from 23 patients, having a mean age of 59.66±14.93 years. Preoperatively, the mean IOP was 23.54±10.7mmHg, and the mean anti-glaucoma medication requirement was 3.99±0.65, both significantly reduced to 15.7±6.9mm Hg (P=0.009) and 1.26±1.2 (P <0.001) at one year, respectively. Overall, 19 eyes (82.6%) achieved success (Complete success: 39.2%, Qualified success: 43.4%), while in 4 (17.4%) patients the procedure failed (IOP >21mmHg). 5 patients had transient hyphema, but there were no sight-threatening complications such as hypotony or choroidal detachment. Ab-Interno Bleb Revision (AIBR) is a safe, effective, and minimally invasive intervention for managing failed trabeculectomy blebs. By eliminating the need to reopen the conjunctiva, this technique offers a promising alternative for the treatment of this challenging condition.

Ab-Interno Bleb Needling in A Failed Trabeculectomy: A Case Report

Introduction : Trabeculectomy remains a gold standard of glaucoma surgical management despite a steady rate of bleb failure due to conjunctival scarring. In this case, we report a case of a failed trabeculectomy managed with ab-interno bleb needling followed by antimetabolite injection of mitomycin C.&#x0D; Case Illustration : A 18-year-old male patient with a history of blurry vision in his right eye and vision loss in his left eye. The patient had previously undergone cataract surgery due to juvenile cataracts and developed persistent high intraocular pressure (IOP) in both of his eyes. A trabeculectomy was performed on his right eye six months prior to the examination; however, the IOP remained at 22 mmHg. Ocular examination revealed a shallow anterior chamber and flat conjunctival bleb. An ab-interno bleb needling technique was performed followed by antimetabolite injection of mitomycin C under local anesthesia in an operating theatre. Follow-up results showed a significant reduction of IOP on the first day (13.3 mmHg) and a week after surgery (18.5 mmHg), maintained by one anti-glaucoma eye drop.&#x0D; Discussion : Trabeculectomy filtration surgery has a high failure rate in younger patients due to a high risk of conjunctival scarring. The ab-interno needling approach with mitomycin C injection is a novel technique that can be performed and offers the advantage of increasing aqueous outflow through a direct opening of the trabecular meshwork from within the anterior chamber.&#x0D; Conclusion : This technique provides effective management of failed trabeculectomy to achieve intraocular pressure lowering effect and a corresponding decrease in the risk of progressive glaucomatous optic neuropathy.

Bleb vessel density as a predictive factor for surgical revisions after Preserflo Microshunt implantation.

Bleb failure is a common complication after glaucoma filtration surgery. Different bleb classification schemes incorporating filtration bleb vascularization have been proposed, but the reported correlation with intraocular pressure (IOP) has been variable, possibly because of subjective vascularization grading. The purpose of the present study was to evaluate bleb vascularization after Preserflo Microshunt (PM) implantation using anterior segment OCT-angiography (AS-OCTA) as a biomarker for bleb failure. Twenty-three eyes of twenty-three patients underwent PM implantation. Up to 12 months after surgery PM scleral passage-centred AS-OCTA measurements (PLEX Elite 9000) for bleb-vessel density (BVD) determination were performed and IOP as well as necessity for surgical revisions (needling and open revision) were documented. After multi-step image analysis (region of interest definition, artefact removal, binarization, BVD calculation), the predictive value of early postoperative BVD for surgical revisions was assessed using logistic regression modelling. Baseline IOP (23.57 ± 7.75 mmHg) decreased significantly to 8.30 ± 2.12, 9.17 ± 2.33 and 11.70 ± 4.40 mmHg after 1, 2 and 4 week(s), and 13.48 ± 5.83, 11.87 ± 4.49, 12.30 ± 6.65, 11.87 ± 3.11 and 13.05 ± 4.12 mmHg after 2, 3, 6, 9 and 12 month(s), respectively (p < 0.001). Nine patients (39%) needed surgical revisions after a median time of 2 months. Bleb vessel densities at 2 and 4 weeks were significantly associated with future surgical revisions upon logistic regression analysis (2 W/4 W likelihood-ratio test p-value: 0.0244/0.0098; 2 W/4 W area under the receiver operating characteristics curve: 0.796/0.909). Filtration bleb vessel density can be determined using AS-OCTA in the early postoperative period and is predictive for bleb failure after PM implantation.

Results of open bleb revision as management of primary bleb failure following XEN 45 gel stent and Preserflo™ Microshunt

PurposeThe success of filtering surgery as in XEN-Gel-Stent (XEN) and Preserflo-Microshunt (PF) depends mainly on a functioning bleb. Primary bleb failure (PBF) is not uncommon and can be treated with needling or open bleb revision (OBR). The aim of the study is to compare surgical outcomes of OBR after XEN and PF.MethodsEyes which received OBR as management of PBF following implantation of XEN or PF were retrospectively included. Intraocular pressure (IOP), number of IOP lowering medications (NoM), and success rates (SR) were compared between groups. Complete and qualified success were defined as IOP ≤18mmHg and a reduction of >20%, without and with medications, respectively.Results29 eyes after XEN and 23 eyes after PF were included. Six months following OBR, IOP reduced from 24.2±4.7 to 13.5±4.6 after XEN and from 27.3±8.7 to 15.9±5.8mmHg after PF (both p<0.001). NoM did not change (0.7±1.3 to 0.4±0.8 after XEN and 1.2±1.3 to 1.0±1.5 after PF, p>0.05 for both). Complete SR were higher after XEN than after PF (58.6% vs. 30.4%, p=0.04). Complications were mild and managed mainly conservatively. Additional glaucoma surgery was needed in 17% and 30% of eyes after XEN and PF, respectively (p=0.26).ConclusionAlthough OBR was effective as management of PBF following XEN and PF, SR were higher after XEN than after PF along with comparable safety profile. The change of the surgical approach from ab interno during XEN-Implantation to ab externo during OBR seems to enhance SR compared to PF, where both interventions are done ab externo.

A multicenter phase II study on the safety of rho-kinase inhibitor (ripasudil) with needling for the patients after trabeculectomy

BackgroundThere is no established method of maintaining or reducing intra ocular pressure after the needling procedure for failing blebs post trabeculectomy. Regarding newer antihypertensive medications, ripasudil, which is a rho-associated protein kinase inhibitor ophthalmic solution, was able to prevent excessive scarring in vitro. This study aims to evaluate the safety of glaucoma patients submitted to the needling procedure and administered ripasudil for preventing scarring after the procedure. We also investigate the efficacy of ripasudil after needling for bleb failure through suppression of fibrosis to the bleb. MethodsThis study is a multicenter, open-label, single-arm, phase II trial to evaluate the safety and efficacy of ripasudil in glaucoma patients after the needling procedure. Forty patients who will undergo needling at least 3 months after trabeculectomy will be recruited in Hiroshima university hospital and Hiroshima eye clinic. All the patients will instill ripasudil two times per day for three months after the needling procedure. The primary endpoint is the safety of ripasudil. ConclusionsWe plan to establish the safety of ripasudil and to collect information involving the efficacy of ripasudil widely in this study.

Short-Term Outcomes of Xen-45 Gel Stent Ab Interno Versus Ab Externo Transconjunctival Approaches.

Ab externo transconjunctival placement of the Xen-45 gel stent offers a faster surgical approach and more rapid visual recovery with similar pressure-lowering and complication rates when compared with implantation by the ab interno approach. Compare outcomes of closed conjunctival Xen-45 implantation techniques: ab interno versus ab externo transconjunctival. Single-center, retrospective study of 70 patients undergoing Xen-45 implantation between 2017 and 2020. Group 1 (n=29) had ab interno placement, Group 2 (n=41) had transconjunctival ab externo placement. Primary outcome measures were intraocular pressure (IOP) and medication use. Secondary measures were bleb revision rates, surgical time, time to return to baseline visual acuity, and complication rates. Group 1, preoperative IOP was 22.8±7.5mmHg on 3.8±0.9 IOP-lowering medications and the postoperative IOP at last follow-up was 11.6±2.8mmHg on 1.6±1.3 medications. Group 2, preoperative IOP was 25.6mmHg±7.8mmHg on 3.7±1.1 medications and the postoperative IOP at last follow-up was 12.4±3.6mmHg on 1.5±1.3 medications. There was no difference in postoperative IOP or medications between the 2 groups ( P <0.05). The average surgical time for Group 2 was 25±6.5 minutes to 37±7.3 minutes for Group 1 ( P <0.001). Group 2 showed 88% of patients returning to baseline visual acuity at week 2 compared with 66% in Group 1 ( P <0.05). Bleb revision rates, failure rates, and complication rates were comparable between both groups ( P >0.05). IOP, medication use, complications, bleb revision rates, and failure rates were similar between ab interno and ab externo transconjunctival approaches. The ab externo group had faster surgical times and postoperative visual recovery despite higher number of patients with previous glaucoma procedures.

Oral ibuprofen is associated with reduced likelihood of early bleb failure following trabeculectomy in high-risk glaucoma patients.

Individuals prescribed ibuprofen post-trabeculectomy have a better post-operative intraocular pressure control and higher chance of bleb survival despite being at a higher risk of scarring. To investigate the effects of early adjunctive oral ibuprofen treatment on intraocular pressure (IOP) and bleb failure in eyes at high risk of scarring. In these retrospective analyses, 288 eyes of 273 patients (mean±SD age: 68.56±10.47y; 32.60% females) with primary glaucoma who underwent trabeculectomy/phacotrabeculectomy at the Singapore National Eye Centre between April 2020 to April 2021 with a follow-up duration ≥1 year were included. Of these, 77 (26.7%) eyes deemed to be at high risk of scarring were administered oral ibuprofen ≥3 months post-operatively (mean±SD ibuprofen administration duration: 4.08±2.28wk). Participants' IOPs at baseline and at post-operative weeks 1, 2-3; and months 1, 2, 3, 6, and 12 were recorded. Bleb failure was defined as two consecutive IOP readings of >21, >18 and >15mmHg, and/or requiring remedial post-operative laser or surgery. The ibuprofen group experienced significantly greater post-operative IOP reductions at week 1 (mean difference [95% confidence interval]: -2.89 [-5.22, -0.56] mmHg) and month 1 (-2.29 [-4.53, -0.05] mmHg); and substantially lower odds of bleb failure at the >18mmHg (odds ratio [95% confidence interval]: 0.39 [0.20-0.79]) and >15mmHg (0.52 [0.29-0.94]) thresholds, compared to the non-ibuprofen group. No differences in adverse ocular hypotony events were observed. Early adjunctive oral ibuprofen administered to individuals at high risk of post-trabeculectomy scarring is associated with greater IOP reductions and reduced likelihood of bleb failure. Our results suggest that oral NSAIDs may be a safe way of improving trabeculectomy survival in high risk eyes.

Revision of the PRESERFLO® MicroShunt with ologen and mitomycinC

Bleb failure after implantation of filtering stents (e.g. Preserflo Stent) is afrequent challenge in glaucoma surgery that has occurred in recent years. In the following, atechnique for open bleb revision with mitomycin C (0.2 mg/ml) and ologen implantation is presented, which is intended to re-establish the filtration volume lost due to fibrosis and a long-term preservation.

Reoperations for complications within 90 days after gel stent implantation or trabeculectomy

PurposeTo describe reoperations in the operating room for complications that occurred within the first 90 days after gel stent implantation or trabeculectomy at a single institution over 5 years.MethodsIn this retrospective chart review, patients who have undergone gel stent implantation with mitomycin C (MMC) or trabeculectomy with MMC were enrolled. Postoperative complications that required reoperations within the first 90 days were evaluated.ResultsA total of 510 surgeries were performed on 392 patients over a 57-month period by 2 glaucoma surgeons. Of these, 284 were gel stent implantation, and 226 were trabeculectomy. Combined phacoemulsification was performed in 52/284 (18.3%) in the gel stent group and in 26/226 (11.5%) of eyes in the trabeculectomy group (p = 0.03). Reoperations took place in 13/510 (2.5%) eyes, including 4/284 (1.4%) in the gel stent group, 9/226 (4.0%) in the trabeculectomy group (p = 0.07). In the gel stent group, indications for reoperation were bleb failure (2), suprachoroidal hemorrhage (1), bullous keratopathy (1). In the trabeculectomy group, indications for reoperation were bleb failure (3), overfiltration (2), persistent wound leak (2), aqueous misdirection (2).ConclusionsThe rates of reoperation for early postoperative complications after gel stent or trabeculectomy was low and comparable with previous studies. A slightly higher number of reoperations within 90 days was observed in the trabeculectomy group than the gel stent group despite the more significant number of combined procedures in the latter group. Bleb failure was the most common indications for reoperation in both groups. Excessive outflow was a cause of reoperation mostly in the trabeculectomy group.

Treatment outcomes of Mitomycin‐C (MMC) augmented bleb needling in failing trabeculectomy blebs in NHS Tayside

AbstractPurposeTrabeculectomy is the gold standard surgical option in managing glaucoma when intraocular pressure (IOP) is uncontrolled with topical anti‐hypertensive. Bleb failure is not uncommon in trabeculectomy. Bleb needling is a relatively straightforward procedure that can be conducted to re‐establish flow from the trabeculectomy.1,2 We aim to investigate treatment outcomes of MMC augmented needling of failing trabeculectomy blebs in NHS Tayside.MethodsRetrospective cohort study was performed by reviewing clinical notes of all MMC‐augmented bleb needling procedure after trabeculectomy performed in NHS Tayside from May 2012 to June 2016, patients were identified from surgical records. Data were analysed using IBM® SPSS software and R software (R Foundation for Statistical Computing, Vienna, Austria).Results111 patients were identified, 34 excluded as they were lost to follo‐ ups or did not have clinical notes.86 eyes (77 patients) were included in this study. Median number of months between index filtration surgery and the first needling was 23 months. Mean IOP was reduced by 32.6% by the end of Year 1 (23.94 vs 16.14) and 40.4% by the end of Year 3 (23.94 vs 14.28).This was statistically significant at the 0.05 level.28 eyes (32.6%) required further surgical procedures to control IOP (repeat trabeculectomy, glaucoma drainage device, cyclodiode). 9 eyes (10.5%) had complications related to needling with 3 hyphema, 2 post‐operative needling spike,and 1 each had bleb leak, aqueous misdirection, choroidal effusion and hypotony respectively.ConclusionsBleb needling is a safe procedure that can be carried out re‐establish flow in failing trabeculectomy to achieve satisfactory control.Bibliography1. Lin S, Byles D, Smith M. Long‐term outcome of mitomycin C‐augmented needle revision of trabeculectomy blebs for late trabeculectomy failure. Eye. 2018;32(12):1893‐1899.2. Panarelli J, Vinod K, Huang G, Sidoti P. Transconjunctival Revision With Mitomycin‐C Following Failed Trabeculectomy. Journal of Glaucoma. 2016;25(7):618‐622.

Outcomes of bleb revision with ologen following filtering glaucoma surgery.

This study reports long-term outcomes of bleb revision with ologen™ Collagen Matrix (Aeon Astron Europe BV, the Netherlands) for the surgical management of various bleb-related issues including persistent bleb leaks with or without associated hypotony, bleb dysesthesia, overhanging blebs, or hypotony after filtering glaucoma surgery. A retrospective chart review was performed for patients who underwent ologen bleb revision from 2012 to 2019 at Glaucoma Associates of Texas. The study included 23 eyes of 22 patients undergoing bleb revision with the ologen implant. Mean age was 74.0 ± 11.3 years, 16 (69.6%) were female, and 13 (56.5%) were White. Indications for bleb revision included bleb leak (78.3%), dysesthesia (13.0%), and hypotony from an overfiltering bleb (8.7%). Mean preoperative intraocular pressure was 6.8 ± 4.1 mmHg and the number of medications was 0.3 ± 0.9. Median follow-up was 24 months (range: 12-84 months); all patients had at least 12 months of follow-up. At 1 year, mean intraocular pressure was 10.9 ± 4.6 mmHg on 0.2 ± 0.5 medications, and at last follow-up, mean intraocular pressure was 10.4 ± 3.6 mmHg on 0.3 ± 0.7 medications. Bleb morphology remained low, diffuse, and posterior. One patient developed kissing choroidal effusions requiring surgical drainage with subsequent stabilization of intraocular pressure and bleb function, and three patients required additional surgery due to persistent leaks or bleb failure; there were no other vision-threatening complications. Use of the ologen implant during surgical bleb revision is a useful surgical technique that confers long-term improvements in bleb morphology and stability of function.

Anterior segment imaging in minimally invasive glaucoma surgery - A systematic review.

Minimally invasive glaucoma surgery (MIGS) has grown in popularity over the past decade. This systematic review explores the peri-operative and intraoperative application of anterior segment imaging to maximize the efficacy and safety of MIGS. A review of the PubMed, EMBASE and CINAHL databases was conducted, with inclusion criteria restricted to MIGS that had received United States Food and Drug Administration (FDA) premarket approval, FDA 510(K) premarket notification, or were listed as a class 1 device exempt from FDA approval or notification. 21 manuscripts from 21 unique studies were identified pertaining to MIGS devices including the XEN Gel Stent, Trabectome, iStent Inject, 1st-generation iStent and the Kahook Dual Blade (KDB). Anterior segment imaging modalities included anterior segment optical coherence tomography (AS-OCT), ultrasound biomicroscopy (UBM), aqueous angiography, OCT volumetric scans and invivo confocal microscopy. Identification and evaluation of aqueous outflow pathways before and after MIGS have potential for improving patient preoperative patient selection and postoperative outcomes. Intraoperative imaging potentially provides the resolution needed for good visualization of angle anatomy and accurate evaluation of surgical endpoints in angle-based MIGS. Anterior segment imaging has been used to identify procedural complications, provide objective information on implant location in relation to surrounding anatomy, assess the post-implantation structural impact of MIGS devices and manage bleb failure and scarring. Technical difficulties in incorporating imaging modalities into the surgical microscope, variable quality of images and optical interference from ocular structures or surgical instruments are remaining barriers, which discourage the widespread clinical use of this technology.

Post trabeculectomy situations: Hypotony

Hypotony, characterized by a low intraocular pressure <6.5 mm Hg or <5 mm Hg with possible clinical complications, can lead to dreaded complications, posttrabeculectomy. It leads to a breakdown of blood-aqueous barrier, leading to an inflammatory cascade, scarring, and bleb failure, in the long term. It also predisposes to blebitis and other hypotony-related complications. Identifying the cause of hypotony, such as bleb leak or overfiltration, is vital to addressing the underlying cause. It can be managed conservatively with pressure patching, and medically with steroids or cycloplegics, or would require surgical bleb revision, depending on the cause and extend of underlying damage. In this article, we review the definition, pathophysiology, risk factors for hypotony, and posttrabeculectomy and identify the various possibilities, and their respective management strategies.

Factors affecting the early and mid-term success of needling for early failure of filtering bleb.

Purpose:The purpose of this study is to evaluate the factors affecting the success of needling surgery for early filtering bleb failure after trabeculectomy.Methods:Patients who underwent a single needling surgery within 3 months after trabeculectomy were retrospectively evaluated. Glaucoma type, intraocular pressure (IOP), and medical treatments before trabeculectomy; the presence of hypotony after trabeculectomy; bleb type; IOP before needling; lens status; complications; IOP after 1, 6, and 12 months; and medical treatments after needling were recorded. Risk factors were evaluated for complete success at 1, 6, and 12 months after needling.Results:Thirty-three eyes of 33 patients were analyzed. The mean IOP after needling at 1, 6, and 12 months was 16.09 ± 3.70, 15.64 ± 2.68, and 15.79 ± 2.61 mmHg, respectively. The mean age of the patients was 53.97 (25–79) years. The mean IOP after needling at 1, 6, and 12 months was 16.09 ± 3.70, 15.64 ± 2.68, and 15.79 ± 2.61 mmHg, respectively. The pre-needling IOP and IOP decrease on the first day affected the complete and qualified success at 1, 6, and 12 months, but the glaucoma type, presence of hypotony after trabeculectomy, lens status, interval between trabeculectomy and needling, and bleb type were not found to affect success. In the receiver operating curve analysis, the pre-needling IOP value was found to be significant in determining complete success. Complete success at 1 month was more likely when the pre-needling IOP cutoff value was <24.5 mmHg.Conclusion:According to the results of single needling surgery performed within 3 months after trabeculectomy, the pre-needling IOP and IOP decrease with needling were found to be factors affecting success. Regardless of the time between the primary trabeculectomy and needling, effective needling will be successful before the IOP rises to high levels. Keeping the IOP at low values with medical treatment until the needling process is performed will have a positive effect on success.

Retrobulbar tube shunt: anterior chamber to back of the eye (A2B) efficacy in glaucomatous eyes with uncontrolled IOP.

The purpose of this study is to examine the efficacy and safety of a commercial model of the retrobulbar shunt, anterior chamber to back of the eye (A2B), in lowering intraocular pressure (IOP) and medication requirements after the failure of all other IOP-lowering therapies, including trabeculectomy with antimetabolites and tube shunt procedures. This is a single-site, prospective, nonrandomized concept study. Patients with prior failed tube shunts, or moderate to severe glaucoma refractory to treatment, were included. All subjects underwent A2B shunt implantation. Each subject's IOP and number of medications were assessed from baseline at each time interval using paired t tests. Primary outcome measures were IOP and glaucoma medication use pre- and postoperatively. Complete success is defined as (1) IOP ≤ 21mmHg; (2) IOP reduction from baseline of ≥ 20%; (3) no reoperation for glaucoma; (4) no loss of light perception vision; (5) no chronic hypotony defined as IOP ≤ 5mmHg; and (6) no use of supplemental glaucoma medication. "Qualified success" required satisfaction of the same criteria as "complete success" but with the use of supplemental glaucoma medication at 6months. Nineteen eyes of 19 patients (mean age 39.5 ± 6.4) were followed for 6months. The mean IOP (mmHg±SEM) at 6months dropped from baseline of 35.3 ± 2.3 to 18.5 ± 1.1(- 16.8, - 47%; p < 0.0001). The mean number of glaucoma medications (±SEM) at 30, 90, and 180days decreased from a baseline of 2.4 ± 0.3 to < 0.3 at each interval (p < 0.0002). The complete and qualified success rates at 6months were 46.6% (7/15) and 66.6% (11/15), respectively. The mean number of prior incisional glaucoma surgeries was 3.2. The percent of patients that had previously failed sub-Tenon tube shunt surgeries was 79%. The A2B shunt is an effective rescue therapy in patients that have failed other IOP-lowering procedures. By shunting aqueous humor into the retrobulbar space, IOP and number of glaucoma medications required were substantially reduced for the 6-month postoperative assessment interval. The intrinsic properties of the retrobulbar space may limit the risk of fibrosis, the principal cause of bleb failure.

Needling after XEN gel implant: What's the efficacy? A 1-year analysis.

To analyse the long-term efficacy and safety of bleb needling in glaucoma patients previously submitted to XEN implantation. Retrospective, observational study. Charts from patients who underwent XEN gel implant surgery between October 2015 and December 2017 were reviewed. Needling protocol involves use of Mitomycin C 0.2 mg/mL in an operating room. Primary outcome was defined as intraocular pressure (IOP) lowering efficacy at 12 months post-operative. Complete success was defined as a decrease in IOP > 20% and overall value <18 mmHg. Secondary outcomes included safety parameters (both intra and post-operative). Exploratory analysis of predictive factors for success were performed. Statistical analysis was performed using SPSS version 24. About 94 charts were reviewed, with 18 patients (19%) having undergone needle revision. This salvage procedure was performed after 3.3 ± 3.4 months, achieving a mean IOP reduction of 8.3 ± 8.4 mmHg at 12 months after the procedure (pre-needling: 24.0 ± 5.2 mmHg vs 12th month: 13.5 ± 5.9 mmHg, p < 0.0001). Accordingly, success was achieved in 72% (complete success in 61% of cases). Among predictive factors, there was a higher tendency for success in patients on two types of medications or fewer pre-operatively, cases of standalone XEN surgery and patients with a higher IOP difference pre-needling - day 1. No vision-threatening complications were recorded. XEN salvage procedure with mitomycin C is a valid option in early bleb failure. This single intervention had a long-lasting effect on bleb survival, with almost two-thirds achieving long term significant drop-free IOP reduction.

Two-year outcomes of minimally invasive XEN Gel Stent implantation in primary open-angle and pseudoexfoliation glaucoma.

PurposeThe aim of this study was to evaluate the efficacy of XEN® Gel Stent implantation in the treatment of primary open‐angle glaucoma (POAG) and pseudoexfoliation glaucoma (XFG) regarding the reduction of intraocular pressure (IOP) and number of IOP‐lowering medications over 2 years.MethodsIn this retrospective, observational, single‐centre study, patients with POAG or XFG underwent implantation of the XEN® Gel Stent with or without combined phacoemulsification. Changes in mean IOP, mean number of IOP‐lowering medications, number of postoperative interventions, complete or qualified surgical success rate (defined as IOP < 18 mmHg without or with IOP‐lowering medication, respectively) and complete surgical failure rate (defined as the necessity of a glaucoma‐related secondary surgical intervention or loss of light perception) were assessed 12 months (12M) and 24 months (24M) postoperatively.ResultsSeventy‐nine eyes of 63 patients with open‐angle glaucoma were included in the study (71% POAG, 29% XFG). Before surgery, mean IOP was 23.4 ± 7.9 mmHg. IOP was 14.6 ± 3.6 mmHg 12 months postoperatively (−31% from baseline, 95% CI −42% to −20%, n = 30, p < 0.001) and 14.8 ± 4.4 mmHg 24 months postoperatively (−29% from baseline, 95% CI −30% to −41%, n = 28, p < 0.001). Mean number of IOP‐lowering medications was significantly reduced from 2.7 ± 1.1 before surgery to 1.0 ± 1.2 (−69%, 95% CI −89% to 46%, p < 0.001) 12 months after surgery and 1.0 ± 1.2 (−64%, 95% CI −91% to −36%, p < 0.001) at 24 months after surgery. Complete surgical success was achieved in 39% (12M) and 34% (24M) of patients and qualified success in 29% (12M) and 27% (24M). 13 (16%) eyes were classified as complete surgical failure. In 62% of the patients needling procedures had to be performed.ConclusionThe XEN® Gel Stent is an efficacious minimal invasive glaucoma surgery for primary open‐angle and pseudoexfoliation glaucoma, resulting in significant reduction of IOP and a reduction in glaucoma medications from baseline in two‐third of treated patients with 2‐year follow‐up. Frequent follow‐up examinations were mandatory to identify early and late bleb failure and additional needling procedures were necessary to reestablish aqueous flow.

Does bleb needling augmented by mitomycin C or 5‐fluorouracil share similar efficacy with no antimetabolites?

Dear Editor, We have read the article entitled ‘Needling after trabeculectomy - does augmentation by anti-metabolites provide better outcomes and is Mitomycin C better than 5-Fluoruracil? A systematic review with network meta-analyses’ (Halili et al. 2020) with great interest. The authors had concluded no significant difference in the efficacy of using either mitomycin C (MMC), 5-fluorouracil (5-Fu) or no antimetabolites for bleb needling after trabeculectomy, which most doctors may disagree according to the clinical practice. However, there are a few points that need to be clarified before we can state that MMC or 5-Fu application does not outweigh those without antimetabolite usage. One included article retrospectively compared 26 eyes that underwent needling revisions for trabeculectomy failure (Fagerli, et al. 2003). On the one hand, as the individual data presented in this article, four patients had multiple times of needling after the original trabeculectomy. They received the injection of MMC and 5-Fu subsequently. Instead of excluding these cases or analysing them separately, they had abruptly allocated these cases to the MMC group with the presumption that MMC had a more potent effect than 5-Fu. For the current meta-analysis, the inclusion of these inaccurate data reduced the credibility of comparison. On the other hand, the no antimetabolite group in this article had only three cases. In the current meta-analysis, the authors directly compared 13 cases in the MMC group and 10 cases in the 5-Fu group with the 3 cases without antimetabolite application, as Fagerli et al. did in his article. Comparison between small sample sizes data may lead to considerable bias, to a certain degree. As the random effect model was used, it increased the weight of studies with small sample sizes, which magnified its influence on the meta-analysis results. Therefore, ambiguous application of medication and small sample may lower the value of comparison with the inclusion of this article. Another included research focused on topical application of MMC with microsponge before needling revision (Ghoneim & Abd El Hameed 2011). Compared with no antimetabolite group, topical use of MMC brought about significant efficacy in bleb needling. Based on the study design, although the concentration of MMC can be predetermined, the exposure time will be short as irrigation with the balanced salt solution before needling will wash out the antimetabolites. The doses of MMC were therefore inaccurate, as well. In comparison, for the other articles included, antimetabolite augmentation was accomplished by subconjunctival injection of fixed doses within the study. The duration of the antimetabolic effect was prolonged. Though mentioned in the meta-analysis, such difference in drug administration may introduce inaccuracy in assessing MMC’s antifibrotic impact. Selection bias was seen in the included studies. In retrospective studies, patients were selected for antimetabolite injection based on the severity of bleb failure and the judgement from glaucoma specialists (Fagerli et al. 2003; Kim et al. 2019). Under this consideration, those tend to suffer needling failure may be alleviated by antimetabolites and reach similar IOP control and success rate as those only receive needling and have lower chances of failure. The selection bias may hide the potential difference. For the current meta-analysis, all the studies included for the direct comparison of MMC/5-Fu with no antimetabolites were not robust enough to come up with the conclusion. For this reason, we cannot reasonably compare the application of antimetabolites based on the included studies. To sum up, we thought it with low credibility for the comparison of with/without antimetabolites in the current meta-analysis. In agreement with the authors, we call for more extensive randomized studies on this topic.