Anti-VEGF agents with or without antimetabolites in trabeculectomy for glaucoma: a meta-analysis

Treatment Effects in Randomized and Nonrandomized Studies of Pharmacological Interventions: A Meta-Analysis

Importance

Randomized clinical trials (RCTs) are widely regarded as the methodological benchmark for assessing clinical efficacy and safety of health interventions. There is growing interest in using nonrandomized studies to assess efficacy and safety of new drugs.

Objective

To determine how treatment effects for the same drug compare when evaluated in nonrandomized vs randomized studies.

Data Sources

Meta-analyses published between 2009 and 2018 were identified in MEDLINE via PubMed and the Cochrane Database of Systematic Reviews. Data analysis was conducted from October 2019 to July 2024.

Study Selection

Meta-analyses of pharmacological interventions were eligible for inclusion if both randomized and nonrandomized studies contributed to a single meta-analytic estimate.

Data Extraction and Synthesis

For this meta-analysis using a meta-epidemiological framework, separate summary effect size estimates were calculated for nonrandomized and randomized studies within each meta-analysis using a random-effects model and then these estimates were compared. The reporting of this study followed the Guidelines for Reporting Meta-Epidemiological Methodology Research and relevant portions of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guideline.

Main Outcome and Measures

The primary outcome was discrepancies in treatment effects obtained from nonrandomized and randomized studies, as measured by the proportion of meta-analyses where the 2 study types disagreed about the direction or magnitude of effect, disagreed beyond chance about the effect size estimate, and the summary ratio of odds ratios (ROR) obtained from nonrandomized vs randomized studies combined across all meta-analyses.

Results

A total of 346 meta-analyses with 2746 studies were included. Statistical conclusions about drug benefits and harms were different for 130 of 346 meta-analyses (37.6%) when focusing solely on either nonrandomized or randomized studies. Disagreements were beyond chance for 54 meta-analyses (15.6%). Across all meta-analyses, there was no strong evidence of consistent differences in treatment effects obtained from nonrandomized vs randomized studies (summary ROR, 0.95; 95% credible interval [CrI], 0.89-1.02). Compared with experimental nonrandomized studies, randomized studies produced on average a 19% smaller treatment effect (ROR, 0.81; 95% CrI, 0.68-0.97). There was increased heterogeneity in effect size estimates obtained from nonrandomized compared with randomized studies.

Conclusions and Relevance

In this meta-analysis of treatment effects of pharmacological interventions obtained from randomized and nonrandomized studies, there was no overall difference in effect size estimates between study types on average, but nonrandomized studies both overestimated and underestimated treatment effects observed in randomized studies and introduced additional uncertainty. These findings suggest that relying on nonrandomized studies as substitutes for RCTs may introduce additional uncertainty about the therapeutic effects of new drugs.

Management of experimental trabeculectomy filtering blebs via crosslinking of the scleral flap inhibited vascularization

PURPOSE

The aim of this study was to evaluate whether UVA-light-activated riboflavin-induced collagen crosslinking (UVA-CXL) can maintain the function of filtering blebs after trabeculectomy (TRAB) in rabbits.

METHODS

Thirty-six healthy rabbits were randomized to one of the following groups with 12 rabbits in each group: Trabeculectomy group (TRAB group), trabeculectomy combined with CXL group (CXL group), and trabeculectomy combined with MMC group (MMC group). Six rabbits of each group were performed with intraocular pressure (IOP), optical coherence tomography (OCT), and OCT angiography (OCTA). Bleb structure was observed via hematoxylin & eosin (H&E) and Masson staining. Immunohistochemistry, proteomic study, western blot, and tensile test were performed between CXL group and the control. In vitro, cell viability was evaluated by CCK-8 and Calcein/PI staining. TRPV4 and VEGF-a expression levels were measured by Q-PCR. Ca2+ concentration was observed with Fluo-4 AM.

RESULTS

The IOP and bleb median survival day were significantly modified in CXL (5.92 ± 0.32 mmHg and 15.5 days) than TRAB group (7.50 ± 0.43 mmHg and 9 days). The bleb area and height increased. CXL inhibited vascularization, and vascularization peaked at postoperative day (POD) 14 and then decreased gradually. In proteomic analyses, Z disc, actin filament binding, and sarcomere organization were significantly enriched. CXL inhibited scleral stress‒strain in tensile tests. Compared with TRAB group, TRPV4 expression was significantly increased, but VEGF-a and TGF-β1 levels were reduced in the CXL group in western blot. Meanwhile, TRPV4 expression colocalized with CD31. In vitro, CXL inhibited HUVECs cell viability. After CXL, expression level of TRPV4 was increased and calcium influx was activated, but VEGF-a was decreased in HUVECs.

CONCLUSIONS

This study demonstrates that intraoperative UV-RF CXL can significantly improve the success rate of TRAB via inhibiting filtering bleb vascularization. CXL increased sclera stiffness, in turn, induced TRPV4 activation, thus contributing to vascular endothelial cells suppression.

Comparison between Surgical Techniques Used for Revision of the Filter Bleb: A Randomized Controlled Clinical Trial

INTRODUCTION/PURPOSE

The aim of this study was to compare two surgical revision techniques in failed trabeculectomies after 6 months.

METHODS

Patients diagnosed with open-angle glaucoma who underwent trabeculectomy in at least one eye with uncontrolled intraocular pressure (IOP) after trabeculectomy performed at least 6 months before were enrolled in this prospective trial. All participants underwent a complete ophthalmological examination at baseline. Randomization was performed to one eye per patient to double-masked trabeculectomy revision or needling. Patients were examined on the first day, 7 days, 14 days, and then monthly until completing 1 year after surgical intervention. All follow-up visits included the following: patients reported ocular and systemic events, best-corrected visual acuity, IOP, slit-lamp examination, and optic disc evaluation for cup-to-disc ratio. Gonioscopy and stereoscopic optic disc photographs were taken at baseline and 12 months. After 1-year, the IOP and number of medications were compared between the groups. Absolute success criteria in the study were IOP <16 mm Hg, for 2 consecutive measurements without using a hypotensive medication.

RESULTS

Forty patients were included in this study. Among them, 38 completed 1-year follow-up (18 in revision group and 20 in needling group). The age ranged from 21 to 86 years, with a mean of 66.82 ± 13.44. At baseline, the average IOP was 21.64 ± 5.12 mm Hg (range from 14 to 38 mm Hg) in the entire group. All patients were using at least two classes of hypotensive eye drops, and 3 patients were using oral acetazolamide. The mean use of hypotensive eye drop medications was 3.11 ± 0.67 at the baseline for the entire group. In the present study, 58% of the patients presented complete success, 18% qualified success, and 24% failed in both groups. After 1-year treatment, both techniques were similar for IOP parameters and also for number of medications (p = 0.834 and p = 0.433, respectively). Regarding intra- or postoperative complications, one patient in each group needed a new surgical intervention, one in the needling group due to shallow anterior chamber and one in the revision group due to spontaneous Seidel sign, and one patient in the needling group underwent posterior revision due to fail.

CONCLUSIONS

Both techniques were safe and effective for IOP control after 1 year of follow-up in patients who underwent to trabeculectomy more than 6 months before.

A systematic review, meta-analysis, and network analysis of diagnostic microRNAs in glaucoma

Glaucoma is a chronic neurodegenerative process of the optic nerve that is the leading cause of blindness worldwide, and early diagnosis of the disease could greatly affect patients' prognoses. The pathophysiology of glaucoma is complicated by a combination of genetic and epigenetic factors. Deciphering the early diagnostic biomarkers in glaucoma could attenuate the disease's global burden and help us understand the exact mechanisms involved in glaucoma. The microRNAs are members of a larger family of non-coding RNAs that play an essential role in the epigenetic basis of glaucoma. A systematic study and meta-analysis of diagnostic microRNAs in glaucoma, jointly with network analysis of target genes, were carried out on published papers assessing differentially expressed microRNAs in human subjects. In total, 321 articles were found, and, after screening, six studies were eligible for further analysis. 52 differentially expressed microRNAs were found, of which 28 and 24 were up-regulated and down-regulated, respectively. Only 12 microRNAs were qualified for meta-analysis, with overall sensitivity and specificity of 80% and 74%, respectively. Then, using network analysis, it became apparent that the VEGF-A, AKT1, CXCL12, and HRAS genes were the most important targets for the microRNAs. Perturbations in WNT signaling, protein transport, and extracellular matrix organization pathways were discovered to be important in the etiology of glaucoma using the community detection approach. This study tries to uncover the promising microRNAs and their target genes that govern the epigenetics of glaucoma.

Intravitreal anti-vascular endothelial growth factor injections to treat post-trabeculectomy Swan syndrome

Purpose

To report a case of wound neovascularization (Swan syndrome) one year after trabeculectomy favorably treated with two intravitreal ranibizumab injections.

Observations

A 79-year-old woman under coumadin treatment for atrial fibrillation experienced relapsing decreased vision in her left eye due to vitreous hemorrhage. She had had a past history of ocular hypertension corneal decompensation after phacoemulsification that required a Descemet Membrane Endothelial Keratoplasty and a subsequent trabeculectomy. After clearance of the hemorrhage, examination showed neovascularization not in the retina but surrounding the sclerostomy wound of the trabeculectomy, being diagnosed as a Swan syndrome. After two intravitreal injections of ranibizumab, gonioscopy showed complete resolution of the new vessels. No further recurrences have been reported and IOP has remained controlled without glaucomatous changes 7 months after the last injection. Clinical features and patient characteristics are described.

Conclusion and importance

Anti-vascular endothelial growth factor intravitreal injections may be a good and safe alternative to manage vitreous hemorrhage secondary to wound neovascularization of the trabeculectomy site.

Cross-linked hyaluronic acid viscoelastic scleral implant in trabeculectomy

Purpose:

Patients with glaucoma undergoing trabeculectomy develop bleb cicatrix causing poor postoperative intraocular pressure (IOP) control and low success rates. Several approaches have been explored over the years for better outcomes. This study assesses the safety, efficacy, and outcome of trabeculectomy with HealaFlow^® (Anteis S. A, Geneva, Switzerland), a high-molecular-weight cross-linked hyaluronic acid viscoelastic gel, and comparing it with the antimetabolite Mitomycin-C (MMC).

Methods:

A prospective, interventional, case-controlled study conducted at a tertiary care hospital in Southern India on 60 eyes of patients requiring trabeculectomy divided in two groups – HealaFlow scleral implant and adjuvant low-dose MMC (0.1 mg/mL). Postoperative IOP reduction along with bleb morphology was assessed over follow-up at 1 week, 1 month, 3 months, 6 months, and 12 months.

Results:

Preoperatively IOP in the two groups was statistically similar. Postoperative IOP on day 1 had statistically significant reduction in both groups with greater reduction in MMC group. However, by 12 months, the IOP reduction was statistically similar in both groups, i.e., 46.24% (to 11.04 ± 2.55 mmHg) and 54.47% (to 11.99 ± 3.37 mmHg) in HealaFlow^® group and MMC group, respectively (P > 0.05). The bleb morphologies were similar and complications were seen equally, which resolved by 4 weeks. A complete success rate of 89.29% and a qualified success rate of 10.71% were observed equally in both groups.

Conclusion:

Absorbable biosynthetic cross-linked hyaluronic acid and low-dose MMC are equally safe and efficacious in trabeculectomy with significant IOP reduction and good bleb morphology. Therefore, it is a novel substitute for MMC.

Novel Drug Delivery Systems Fighting Glaucoma: Formulation Obstacles and Solutions

Glaucoma is considered to be one of the biggest health problems in the world. It is the main cause of preventable blindness due to its asymptomatic nature in the early stages on the one hand and patients' non-adherence on the other. There are several approaches in glaucoma treatment, whereby this has to be individually designed for each patient. The first-line treatment is medication therapy. However, taking into account numerous disadvantages of conventional ophthalmic dosage forms, intensive work has been carried out on the development of novel drug delivery systems for glaucoma. This review aims to provide an overview of formulation solutions and strategies in the development of in situ gel systems, nanosystems, ocular inserts, contact lenses, collagen corneal shields, ocular implants, microneedles, and iontophoretic devices. The results of studies confirming the effectiveness of the aforementioned drug delivery systems were also briefly presented.

Personalising surgical treatments for glaucoma patients

Surgical treatments for glaucoma have relied for decades on traditional filtering surgery such as trabeculectomy and, in more challenging cases, tubes. Antifibrotics were introduced to improve surgical success in patients at increased risk of failure but have been shown to be linked to a greater incidence of complications, some being potentially vision-threatening. As our understanding of glaucoma and its early diagnosis have improved, a more individualised management has been suggested. Recently the term "precision medicine" has emerged as a new concept of an individualised approach to disease management incorporating a wide range of individual data in the choice of therapeutic modalities. For glaucoma surgery, this involves evaluation of the right timing, individual risk factors, targeting the correct anatomical and functional outflow pathways and appropriate prevention of scarring. As a consequence, there is an obvious need for better knowledge of anatomical and functional pathways and for more individualised surgical approaches with new, less invasive and safer techniques allowing for earlier intervention. With the recent advent of minimally invasive glaucoma surgery (MIGS) a large number of novel devices have been introduced targeting potential new sites of the outflow pathway for lowering intraocular pressure (IOP). Their popularity is growing in view of the relative surgical simplicity and apparent lack of serious side effects. However, these new surgical techniques are still in an era of early experiences, short follow-up and lack of evidence of their superiority in safety and cost-effectiveness over the traditional methods. Each year several new devices are introduced while others are withdrawn from the market. Glaucoma continues to be the primary cause of irreversible blindness worldwide and access to safe and efficacious treatment is a serious problem, particularly in the emerging world where the burden of glaucoma-related blindness is important and concerning. Early diagnosis, individualised treatment and, very importantly, safe surgical management should be the hallmarks of glaucoma treatment. However, there is still need for a better understanding of the disease, its onset and progression, the functional and structural elements of the outflow pathways in relation to the new devices as well as their long-term IOP-lowering efficacy and safety. This review discusses current knowledge and the future need for personalised glaucoma surgery.

Effects of Regorafenib, a Multi-Kinase Inhibitor, on Conjunctival Scarring in a Canine Filtration Surgery Model in Comparison with Mitomycin-C

Regorafenib eye drops were developed for treating age-related macular degeneration. This study aimed to investigate the effects of this multi-kinase inhibitor on intraocular pressure (IOP), bleb formation, and conjunctival changes in a canine filtration surgery model. Glaucoma filtration surgery models were created in 24 eyes of 24 beagles. In experiment 1 (Ex 1), regorafenib eye drops (regorafenib group: n = 6) or a vehicle (control group, n = 6) were instilled twice daily for 4 weeks postoperatively. In experiment 2 (Ex 2), regorafenib eye drops were instilled as in Ex 1 (regorafenib group: n = 6) for 12 weeks while conventional intraoperative mitomycin-C (MMC) was utilized (MMC group: n = 6), In Ex 1, only the regorafenib group showed significant IOP reduction with a significantly higher bleb score. Subconjunctival area, collagen density, vessels, and cells showing proliferation and differentiation were lower in subconjunctival tissue in the regorafenib group. In Ex 2, no significant difference was found in IOP reduction and bleb formation between the regorafenib and MMC groups; bleb walls were significantly thicker and collagen density and vessels were higher in the regorafenib group; and no differences were observed in the above-mentioned cells. Thus, regorafenib might be a better alternative to MMC for creating thicker and less ischemic blebs in glaucoma filtration surgery.

Clinical pharmacology of intravitreal anti-VEGF drugs

Clinical efficacy of intravitreal anti-VEGF drugs has been widely demonstrated in several angiogenesis-driven eye diseases including diabetic macular edema and the neovascular form of age-related macular degeneration. Pegaptanib, ranibizumab, and aflibercept have been approved for use in the eye, whereas bevacizumab is widely used by ophthalmologists to treat patients "off-label". These drugs are active in the nanomolar to picomolar range; however, caution is required when establishing the rank order of affinity and potency due to in vitro inter-experimental variation. Despite the small doses used for eye diseases and the intravitreal route of administration may limit systemic side effects, these drugs can penetrate into blood circulation and alter systemic VEGF with unknown clinical consequences, particularly in vulnerable groups of patients. Clinical pharmacokinetics of ocular anti-VEGF agents should therefore be taken into account when choosing the right drug for the individual patient. The gaps in current understanding that leave open important questions are as follows: (i) uncertainty about which drug should be given first, (ii) how long these drugs can be used safely, and (iii) the choice of the best pharmacological strategy after first-line treatment failure. The current review article, based on the information published in peer-reviewed published papers relevant to anti-VEGF treatments and available on the PubMed database, describes in detail the clinical pharmacology of this class of drugs to provide a sound pharmacological basis for their proper use in ophthalmology clinical practice.

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.

The era of anti-vascular endothelial growth factor (VEGF) drugs in ophthalmology, VEGF and anti-VEGF therapy

Angiogenesis is a clue process for tissue development and function, both in normal and pathological conditions. This process is regulated by multiple molecular systems. One of the most potent is vascular endothelial growth factor (VEGF) and its receptor (VEGFR) system. Members of this family are involved in new vessel formation in embryogenesis and maturation, as well as in reparative or pathological reactions in later stages. They play a substantial role in regeneration, inflammation, wound healing, as well as in cancer pathology. Nowadays it is possible to modulate VEGF-VEGFR interactions in many pathological conditions using anti-VEGF therapy. This therapy has already achieved a grounded position in the management of rheumatological disorders, tumour progression, and metastasis. Such drugs as bevacizumab, ranibizumab, aflibercept, and pegaptanib have also proven to be very effective in the treatment of several ocular diseases, such as age-related macular degeneration (AMD), macular oedema, or proliferative retinopathies and iris neovascularisation. The indications for the application of this therapy in ophthalmology are becoming wider and wider. It may also be used for corneal pathologies and in anti-glaucoma procedures.

A role for antimetabolites in glaucoma tube surgery: current evidence and future directions

PURPOSE OF REVIEW

Glaucoma is the leading cause of irreversible blindness worldwide. The main treatment modality for glaucoma is the reduction and control of the intraocular pressure (IOP). Glaucoma filtration surgery, including trabeculectomy and/or implantation of a glaucoma drainage device (GDD), is warranted if IOP remains medically uncontrolled. However, postoperative scarring remains a critical determinant of long-term bleb survival and IOP control after drainage surgery. Antimetabolites, such as mitomycin C and 5-fluorouracil, have been used for many years to increase survival time of filtration surgeries by preventing bleb fibrosis and scarring. The aim of this study is to provide an overview of: the current usage of these antimetabolites in GDD, the recent advancements of these antimetabolites in combination with other technologies, and the role of future antimetabolites.

RECENT FINDINGS

Mitomycin C and 5-fluorouracil have been used in GDD and trabeculectomy to prevent the exaggerated cellular reaction that leads to fibrosis. The adjunctive administration of these drugs intraoperatively and postoperatively has resulted in a lower rate of the hypertensive phase, and possibly a better long-term success rate in Ahmed valve surgeries. However, the application of these antimetabolites and their multiple-dosing applications are associated with nonspecific cytotoxicity and potentially severe complications such as bleb leak and conjunctival erosion over the tube. Recent studies are thus focusing on different medications, targeting new molecular pathways, and designing new delivery vehicles to minimize current antimetabolites side-effects and increase their efficacy. Promising results of these studies have led to development of new collaborative medications and advanced drug delivery systems for better modulation of GDD surgeries' predictable outcomes.

SUMMARY

The development of small molecule therapeutics, combination therapies, and innovative drug vehicles to prevent postsurgical fibrosis and achieve better surgical outcome in glaucoma filtration surgeries is promising.

Postoperative management of trabeculectomy and glaucoma drainage implant surgery

PURPOSE OF REVIEW

This article describes important aspects of postoperative management after trabeculectomy and glaucoma drainage implant surgery.

RECENT FINDINGS

Postoperative management of glaucoma drainage implant surgery includes stabilization of intraocular pressure, possible ligature release, and management of complications such as corneal edema, and tube/plate exposure. Postoperative management of trabeculectomy includes evaluation of bleb encapsulation, management of hypotony, and assessment of need for adjuvant therapy. Recent advances in surgical techniques, device/tissue availability, and imaging continue to shape the postoperative course.

SUMMARY

Careful preoperative planning and postoperative care may decrease the likelihood of complications in tube surgery or trabeculectomy.

Conjunctival fibrosis following filtering glaucoma surgery

Despite advances in surgical technique and postoperative care, fibrosis remains the major impediment to a marked reduction of intraocular pressure without the need of additional medication (complete success) following filtering glaucoma surgery. Several aspects specific to filtering surgery may contribute to enhanced fibrosis. Changes in conjunctival tissue structure and composition due to preceding treatments as well as alterations in interstitial fluid flow and content due to aqueous humor efflux may act as important drivers of fibrosis. In light of these pathophysiological considerations, current and possible future strategies to control fibrosis following filtering glaucoma surgery are discussed.

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.

Trabeculectomy with Healaflow versus Trabeculectomy for the Treatment of Glaucoma: A Case-Control Study

Purpose. To compare the outcomes of trabeculectomy with and without Healaflow (Anteis S.A, Geneva, Switzerland), a high molecular weight viscoelastic gel, in patients requiring glaucoma surgery. Methods. This was a retrospective, comparative, interventional case-control study. Forty patients formed two matched study groups and were analyzed (trabeculectomy alone (control) versus trabeculectomy with Healaflow (study)). Results. The postoperative levels of mean IOP were statistically significantly lower (P < 0.05) than preoperatively in both groups, for all time intervals. There was no statistical difference, at the end of the follow-up period, between the two groups in the mean values of the IOP (14.9 ± 3.2 mmHg for the study group versus 14.8 ± 3.3 mmHg for the control group). The number of antiglaucoma drugs used in the study group was reduced from a preoperative mean of 3.4 ± 0.75 to a 6-month postoperative mean of 0.6 ± 0.8 (P < 0.001) and in the control group from 3.6 ± 0.59 to 0.55 ± 0.9 (P < 0.001). Conclusions. Although trabeculectomy with Healaflow appears to be a safe procedure, we failed to identify any significant advantages in the use of Healaflow when compared with trabeculectomy alone, at the end of the 6-month follow-up period.