Subconjunctival bevacizumab to augment trabeculectomy with mitomycin C in the management of failed glaucoma surgery

Intravitreal bevacizumab improves trabeculectomy survival at 12 months: the bevacizumab in trabeculectomy study-a randomised clinical trial

AIMS

To evaluate the effect of an intraoperative dose of intravitreal bevacizumab (Avastin) on surgical success following trabeculectomy with mitomycin-C (MMC) over 12 months.

METHODS

A single centre, parallel, double-blinded randomised, placebo-controlled trial recruiting patients requiring trabeculectomy for progressing glaucoma. Patients were randomised to intravitreal bevacizumab or placebo.

MAIN OUTCOME MEASURE

The primary outcome of treatment success was defined by 'complete success' when intraocular pressure (IOP) remained less than a predefined target IOP without the requirement of topical medication, or 'qualified success' where topical medication was required to meet the predefined target IOP threshold. Secondary outcomes included the need for subsequent IOP-lowering interventions, and structural parameters associated with bleb function.

RESULTS

From 131 patients randomised to bevacizumab (n=65) or placebo (n=66), 128 patients completed 12 months of follow-up (98%). At 12 months, success rates were higher in the bevacizumab group (complete success: 94% vs 83%; p=0.015; qualified success: 98% vs 90%; p=0.033). Within the placebo group, the requirement for topical therapy was higher at 6 months (p=0.045) and 12 months (p=0.045), and the requirement for bleb needling was higher at 1 month (p=0.035). Blebs within the bevacizumab group were larger at 1 month (p<0.001) and demonstrated less vessel inflammation (p<0.0001).

CONCLUSION

Bevacizumab given as a single intravitreal dose during trabeculectomy with MMC resulted in improved surgical success as 12 months. Furthermore, bevacizumab was associated with a significant reduction in the need for additional medication or further surgery to achieve target IOP. Bevacizumab was also associated with larger blebs that were less inflamed and required fewer subsequent interventions.

TRIAL REGISTRATION NUMBER

ACTRN12614000375651.

Trabeculectomy with mitomycin C alone or coupled with intracamerular bevacizumab? A 2-year comparative study

PURPOSE

To compare outcomes of primary trabeculectomy using either mitomycin C (MMC) alone versus MMC augmented with intracamerular bevacizumab in patients with open-angle glaucoma.

METHODS

Retrospective, cohort, two-centre, comparative study. Patients' data were screened between October 2015 and March 2019, with inclusion requiring a minimum follow-up of 24 months. Primary outcome was intraocular pressure (IOP) lowering at 24 months, with surgical success defined with different maximum IOP targets (≤18, ≤16 and ≤14 mm Hg) and at least 30% reduction and higher than 5 mm Hg. Absolute success was achieved if no IOP-lowering medication was needed and a qualified success if otherwise. Safety outcomes were analysed.

RESULTS

A total of 110 eyes underwent trabeculectomy with MMC, 51 of these combined with intracamerular bevacizumab. Both strategies were effective in terms of IOP lowering (baseline vs 2 years postoperatively: 24.4 (8.0) mm Hg vs 12.1 (5.3) mm Hg in the MMC group; 25.1 (8.7) vs 10.8 (3.8) mm Hg in the MMC+bevacizumab group; p<0.001 in both comparisons). The MMC+bevacizumab group had a significant difference towards higher efficacy on absolute success rates at all targets (IOP≤14 or ≤16 or ≤18 mm Hg; p=0.010, p=0.039 and p=0.007, respectively). The large majority (93%) of the MMC+bevacizumab group was drop-free at 24 months, and 41% had IOP below 10 mm Hg. Complication rates were low and similar between groups, with no systemic adverse events.

CONCLUSIONS

Intracamerular bevacizumab in MMC-augmented primary trabeculectomy increases the chances of obtaining low IOP outcomes. This strategy may be useful when planning for surgeries aiming at target pressures in the low teens.

TRIAL REGISTRATION NUMBER

ISRCTN93098069.

In Vitro Study of Combined Application of Bevacizumab and 5-Fluorouracil or Bevacizumab and Mitomycin C to Inhibit Scar Formation in Glaucoma Filtration Surgery

This is an in vitro study conducted to observe the safety and antiscarring effects of combined application of bevacizumab (BVZ) and 5-fluorouracil (5-Fu) or BVZ and mitomycin C (MMC) during glaucoma filtration surgery (GFS). The cytotoxicity of drug combinations in human Tenon's fibroblasts (HTFs) and human umbilical vein endothelial cells (HUVECs) was evaluated. Their effects on the levels of vascular endothelial growth factor (VEGF) in HUVECs, cell proliferation and migration in HTFs, and the expression of collagen type I alpha 1 (Col1A1) gene in HTFs were evaluated. In addition, the effects of combined drugs on VEGF(R) mRNA in HTFs were detected to explore the possible underlying drug mechanisms. The results showed that BVZ combined with 5-Fu demonstrated more significant antiscarring effects than BVZ or 5-Fu alone. However, the inhibitory effects of BVZ combined with MMC were similar to those of MMC alone. The cytotoxicity of the drug combinations was significantly greater than that of single drug, suggesting that combined application of BVZ and antimetabolites after GFS was safer when applied at different sites (such as subconjunctival injection at bilateral sides of the filtering bleb) or at varied time points.

Safety of antivascular endothelial growth factor administration in the ocular anterior segment in pterygium and neovascular glaucoma treatment: Systematic review and meta-analysis

BACKGROUND

Anti-VEGF agents has been widely used in ocular diseases, but its safety for treating anterior segment disorders, the conclusions are controversial.

METHODS

Several major databases, including CENTRAL, MEDLINE, and EMBASE, were searched. Safety data from 18 randomized controlled trials (RCTs) were used to compare anti-VEGF treatment in the ocular anterior segment in pterygium and neovascular glaucoma treatment with placebo/sham treatment for eye diseases. A meta-analysis for adverse events was performed.

RESULTS

Eighteen RCT studies with 955 eyes were included in the meta-analysis. Significant difference in conjunctival disorders (OR: 1.62; 95% CI, 1.01-2.59; P = .05) was noted among the included studies, but not in ocular intolerance (odds ratio [OR]: 0.75; 95% CI, 0.34-1.62; P = .46), corneal disorders (OR: 0.71; 95% CI, 0.37-1.37; P = .31), or the subgroup analysis of conjunctival disorders.

CONCLUSIONS

The administration of anti-VEGF agents in the ocular anterior segment for patients with pterygium and glaucoma was tolerable in tolerance and cornea, but was the risk factor of conjunctival disorders. The healing of corneal epithelium may be delayed in patients with primary corneal epithelial defects after anti-VEGF application. However, due to the limited evidence, further research should be performed on the safety of anti-VEGF administration in patients with different corneal disorders.

First-in-human phase I study of ISTH0036, an antisense oligonucleotide selectively targeting transforming growth factor beta 2 (TGF-β2), in subjects with open-angle glaucoma undergoing glaucoma filtration surgery

Purpose

To evaluate the safety and tolerability of intravitreal ISTH0036, an antisense oligonucleotide selectively targeting transforming growth factor beta 2 (TGF-β2), in patients with primary open angle glaucoma (POAG) undergoing trabeculectomy (TE; glaucoma filtration surgery).

Methods

In this prospective phase I trial glaucoma patients scheduled for TE with mitomycin C (MMC) received a single intravitreal injection of ISTH0036 at the end of surgery in escalating total doses of 6.75 μg, 22.5 μg, 67.5 μg or 225 μg, resulting in calculated intraocular ISTH0036 concentrations in the vitreous humor of approximately 0.3 μM, 1 μM, 3 μM or 10 μM after injection, respectively. Outcomes assessed included: type and frequency of adverse events (AEs), intraocular pressure (IOP), numbers of interventions post trabeculectomy, bleb survival, visual acuity, visual field, electroretinogram (ERG), slit lamp biomicroscopy and optic disc assessment.

Results

In total, 12 patients were treated in the 4 dose groups. Main ocular AEs observed were corneal erosion, corneal epithelium defect, or too high or too low IOP, among others. No AE was reported to be related to ISTH0036. All other safety-related analyses did not reveal any toxicities of concern, either. The mean medicated preoperative IOP at decision time-point for surgery was 27.3 mmHg +/- 12.6 mmHg (SD). Mean IOP (±SD) for dose levels 1, 2, 3, and 4 were at Day 43 9.8 mmHg ± 1.0 mmHg, 11.3 mmHg ± 6.7 mmHg, 5.5 mmHg ± 3.0 mmHg and 7.5 mmHg ± 2.3 mmHg SD; and at Day 85 9.7 mmHg ± 3.3 mmHg, 14.2 mmHg ± 6.5 mmHg, 5.8 mmHg ± 1.8 mmHg and 7.8 mmHg ± 0.6 mmHg, respectively. In contrast to IOP values for dose levels 1 and 2, IOP values for dose levels 3 and 4 persistently remained below 10 mmHg throughout the observation period.

Conclusion

This first-in-human trial demonstrates that intravitreal injection of ISTH0036 at the end of TE is safe. Regarding IOP control, single-dose ISTH0036 administration of 67.5 μg or 225 μg at the time of TE resulted in IOP values persistently < 10 mmHg over the three month postoperative observation period.

Innovations and adaptations in trabeculectomy

PURPOSE OF REVIEW

This article examines the current literature reporting updates on trabeculectomy techniques, complications, and cost-effectiveness.

RECENT FINDINGS

Trabeculectomy continues to be the standard for glaucoma surgery when a low intraocular pressure is required. Recent publications describe technique modifications that successfully increase efficacy and lower complications. There is also an ongoing effort to define the role of trabeculectomy in the management of glaucoma from a cost and public health standpoint.

SUMMARY

The current literature continues to support the use of trabeculectomy as a method of lowering intraocular pressure in glaucoma management. Efficacy has been improved by ongoing surgical innovation, and reported complication rates are lower than those previously noted. Trabeculectomy has a favorable cost-benefit profile when compared with medical therapy or other surgical techniques. In spite of these ongoing changes, trabeculectomy appears to be decreasing in frequency in favor of newer surgeries and medications.

The Effects of Bevacizumab in Augmenting Trabeculectomy for Glaucoma: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The aim of the study was to assess the effects of bevacizumab in augmenting trabeculectomy for glaucoma. We searched the databases of Cochrane Library, PubMed, Embase, CNKI, and VIP. All the databases were retrieved from the time databases established to September, 2015. The keywords we used were as follows: "bevacizumab," "anti-VEGF," "avastin," "trabeculectomy," "glaucoma," and so on. We used a method of the freedom word search and the MeSH search combined, which was recommended by Cochrane Systematic Review Manual 5.1.2. Randomized controlled trails (RCTs) of frequently used bevacizumab in trabeculectomy for glaucoma were included. Study selection, data extraction, quality assessment, and data analysis were performed according to the Cochrane standards. Eight randomized controlled trails involving 212 eyes in the experimental (bevacizumab or bevacizumab + mitomycin C) groups and 214 eyes in the control (mitomycin C or placebo) groups were selected. Compared with placebo, bevacizumab significantly increased the complete success rate [OR = 2.79, 95%CI, (1.47, 5.29), P = 0.002], what else, bevacizumab also significantly decreased the intraocular pressure (IOP) [MD = 3.07, 95% CI, (0.87, 5.27), P = 0.006] at the 6-month after trabeculectomy and the number of antiglaucoma medications [MD = 1.23, 95% CI, (0.66, 1.80), P < 0.0001]. Additionally, it also increased the risk of bleb leak [OR = 5.24, 95% CI, (1.30, 21.10), P = 0.02]. When compared with mitomycin C (MMC), bevacizumab significantly increased the rate of encysted blebs [OR = 4.62, 95% CI, (1.02, 20.91), P = 0.05]. However, there was no significantly difference between the bevacizumab + MMC groups and MMC groups whatever the items were. Bevacizumab was an effective way in trabeculectomy concerning the complete success rate, IOP, and anti-glaucoma medications reduction when compared with placebo; however, it increased the risk of bleb leakage. And it significantly increased the rate of encysted blebs compared with MMC.

Anti-vascular endothelial growth factor for control of wound healing in glaucoma surgery

BACKGROUND

Trabeculectomy is performed as a treatment for glaucoma to lower intraocular pressure (IOP). The surgical procedure involves creating a channel through the wall of the eye. However scarring during wound healing can block this channel which will lead to the operation failing. Anti-vascular endothelial growth factor (VEGF) agents have been proposed to slow down healing response and scar formation.

OBJECTIVES

To assess the effectiveness of anti-VEGF therapies administered by subconjunctival injection for the outcome of trabeculectomy at 12 months follow-up and to examine the balance of benefit and harms when compared to any other anti-scarring agents or no additional anti-scarring agents.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2015, Issue 10), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to November 2015), EMBASE (January 1980 to November 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), 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 12 November 2015.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of anti-VEGF therapies administered by subconjunctival injection compared to any other anti-scarring agents or no additional anti-scarring agents (no treatment or placebo) in trabeculectomy surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcome was successful trabeculectomy at 12 months after surgery which was defined as achieving a target IOP (usually no more than 21 mm Hg) without any additional intervention. Other outcomes included: qualified success (achieving target IOP with or without additional intervention), mean IOP and adverse events.

MAIN RESULTS

We included five RCTs (175 participants, 177 eyes) that met the inclusion criteria in this review.One trial conducted in Iran (37 participants, 37 eyes) compared anti-VEGF (bevacizumab 0.2 mg) versus control (sham injection) in people with refractory glaucoma. We judged this study to be at low risk of bias.The primary outcome of this review was not reported; mean IOP at three months was 15.1 mm Hg (standard deviation 1.0) in both anti-VEGF and control groups.Four trials compared anti-VEGF to mitomycin C (MMC) (138 particpants, 140 eyes). These studies were conducted in India, Iran, Turkey and the USA. The anti-VEGF agent used in these four trials was bevacizumab 2.5 mg (two trials), bevacizumab 1.25 mg three times and ranibizumab 0.5 mg. Two trials were at high risk of bias in two domains and one trial was at high risk of bias in four domains.Only one of these trials reported the primary outcome of this review (42 participants, 42 eyes). Low quality evidence from this trial showed that people receiving bevacizumab 2.5 mg during primary trabeculectomy were less likely to achieve complete success at 12 months compared to people receiving MMC but the confidence interval (CI) was wide and compatible with increased chance of complete success for anti-VEGF (risk ratio (RR) 0.71, 95% CI 0.46 to 1.08), Assuming that approximately 81% of people receiving MMC achieve complete success, the anticipated success using anti-VEGF agents would be between 37.2% and 87.4%. The same trial suggested no evidence for any difference in qualified success between bevacizumab and MMC (RR 1.00, 95% CI 0.87 to 1.14, moderate quality evidence). Two trials of primary trabeculectomy provided data on mean IOP at 12 months; one trial of bevacizumab 2.5 mg and one trial of ranibizumab 0.5 mg. Mean IOP was 1.86 mm Hg higher (95% CI 0.15 to 3.57) in the anti-VEGF groups compared to the MMC groups (66 people, low quality evidence). Data were reported on wound leak, hypotony, shallow anterior chamber and endophthalmitis, but these events occurred rarely and currently there are not enough data available to detect any differences, if any, between the two treatments.

AUTHORS' CONCLUSIONS

The evidence is currently of low quality which is insufficient to refute or support anti-VEGF subconjunctival injection for control of wound healing in glaucoma surgery. The effect on IOP control of anti-VEGF agents in glaucoma patients undergoing trabeculectomy is still uncertain, compared to MMC.Further RCTs of anti-VEGF subconjunctival injection in glaucoma surgery are required, particularly compared to sham treatment with at least 12 months follow-up.

Evaluation the adjunctive use of combined bevacizumab and mitomycinc to trabeculectomy in management of recurrent pediatric glaucoma

PURPOSETO evaluate the efficacy and safety of combined bevacizumab-mitomycin c (MMC) in recurrent cases of pediatric glaucoma.METHODSA prospective non-masked controlled study that included bilateral cases of 12 patients (24 eyes) with recurrent (had previous glaucoma surgery before) pediatric glaucoma. One eye in each patient (12 eyes) was assigned to trabeculectomy operation with combined application of MMC (0.4 mg/ml for 3 min) under and around the scleral flap before trabeculectomy and bevacizumab (avastin) (2.5 mg in 0.2 ml) injected subconjunctivally around the bleb after completing the surgery (group I). The other eye of each patient (12 eyes) was assigned to trabeculectomy operation with application of MMC (0.4 mg/ml for 3 min) only (group II). The mean follow-up period was 13±1 months.ResultsThe mean age was 2.16±1.5 (range 7 months to 4.1 years). No significant difference in preoperative intraoperative pressure (IOP) was observed between the groups (P>0.05). Recurrent primary congenital glaucoma represents 66.7% of the cases. Other cases included were recurrent aphakic and pseudophakic glaucoma 25% and recurrent post uveitic glaucoma 8.3%. The mean IOP was 12.1±4.2, 12.6±5.4, and 12.8±5.2 mm Hg in group I at 3, 6, and 12 months, respectively, and was 12.8±5.3, 13.7±6.7 and 15.6±5.9 mm Hg in group II at 3, 6, and 12 months, respectively. There was a statistically significant difference in the mean IOP between the studied groups at the 1-year follow-up visit (P<0.05). In addition, group I showed a higher statistically significant difference in absolute and total success (75 and 91.7%, respectively) compared with group II (58.3 and 75%, respectively) (P<0.05). The encountered complications included mild hyphema, which occurred in 8.33% in group 1, wound leakage, which occurred in 8.33% in each group, and shallow anterior chamber (AC), which occurred in 16.7% in each group and was the most common encountered complication in the study. One case of shallow AC in group I led to choroidal effusion (8.33%). One case in group II developed late bleb-related endophthalmitis after 3 months, which resulted in phthisis bulbi (8.33%).ConclusionThe additive effect of subconjunctival bevacizumab to MMC-augmented trabeculectomy in the case of recurrent pediatric glaucoma was beneficial in improving the success rate. Better IOP control and prolonging the bleb survivalvia reducing the long-term need of using anti-glaucoma drugs postoperatively without adding complications had also been achieved with this technique. This offers a promising alternative for the treatment of this type of glaucoma.