Mitomycin C versus 5-fluorouracil in high-risk glaucoma filtering surgery. Extended follow-up

Evaluation of Verteporfin as a Novel Antifibrotic Agent in a Rabbit Model of Glaucoma Filtration Surgery: A Pilot Study

Purpose

Verteporfin is a benzoporphyrin derivative which is Food and Drug Administration-approved for treatment of choroidal neovascularization in conjunction with photodynamic therapy. It has been shown to prevent fibrosis and scar formation in several organs and represents a promising novel antifibrotic agent for glaucoma surgery. The goal of this study is to determine the effect of verteporfin on wound healing after glaucoma filtration surgery.

Design

Preclinical study using a rabbit model of glaucoma filtration surgery.

Subjects

Eight New Zealand white rabbits underwent glaucoma filtration surgery in both eyes.

Methods

Eyes were randomized into 4 study groups to receive a postoperative subconjunctival injection of 1 mg/mL verteporfin (n = 4), 0.4 mg/mL mitomycin C (MMC; n = 4), 0.4 mg/mL MMC + 1 mg/mL verteporfin (n = 4), or balanced salt solution (BSS) control (n = 4). Bleb survival, vascularity, and morphology were graded using a standard scale over a 30-day period, and intraocular pressure (IOP) was monitored. At 30 days postoperative or surgical failure, histology was performed to evaluate for inflammation, local toxicity, and scarring.

Main Outcome Measures

The primary outcome measure was bleb survival. Secondary outcome measures were IOP, bleb morphology, and bleb histology.

Results

Compared to BSS control blebs, verteporfin-treated blebs demonstrated a trend toward increased surgical survival (mean 9.8 vs. 7.3 days, log rank P = 0.08). Mitomycin C-treated blebs survived significantly longer than verteporfin-treated blebs (log rank P = 0.009), with all but 1 MMC-treated bleb still surviving at postoperative day 30. There were no significant differences in survival between blebs treated with combination verteporfin + MMC and MMC alone. Mitomycin C-treated blebs were less vascular than verteporfin-treated blebs (mean vascularity score 0.3 ± 0.5 for MMC vs. 1.0 ± 0.0 for verteporfin, P < 0.01). Bleb histology did not reveal any significant toxicity in verteporfin-treated eyes. There were no significant differences in inflammation or scarring across groups.

Conclusions

Although verteporfin remained inferior to MMC with regard to surgical survival, there was a trend toward increased survival compared with BSS control and it had an excellent safety profile. Further studies with variations in verteporfin dosage and/or application frequency are needed to assess whether this may be a useful adjunct to glaucoma surgery.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Wound Modulations in Glaucoma Surgery: A Systematic Review

Excessive fibrosis and resultant poor control of intraocular pressure (IOP) reduce the efficacy of glaucoma surgeries. Historically, corticosteroids and anti-fibrotic agents, such as mitomycin C (MMC) and 5-fluorouracil (5-FU), have been used to mitigate post-surgical fibrosis, but these have unpredictable outcomes. Therefore, there is a need to develop novel treatments which provide increased effectiveness and specificity. This review aims to provide insight into the pathophysiology behind wound healing in glaucoma surgery, as well as the current and promising future wound healing agents that are less toxic and may provide better IOP control.

Wound modulation in glaucoma surgery: The role of anti-scarring agents

Filtration surgery is one of the most frequently performed surgeries in the management of glaucoma, and trabeculectomy is considered the gold standard surgical technique for the same. Though trabeculectomy has been reported to have an excellent initial success rate, about 30% of them fail in 3 years, and nearly 50% of them fail in 5 years. The most significant risk of failure still seems to be wound scarring, especially episcleral fibrosis, leading to bleb failure. As a result, it is essential to explore the role of anti-scarring agents, including mitomycin C, and 5-fluorouracil in wound modulation and improving the bleb survival rate. Since these agents are widely used in trabeculectomy, it is crucial to understand the various modes of application, advantages, and adverse effects of these agents. On an evidence-based approach, all these points have been highlighted in this review article. In addition, the newer agents available for wound modulation and their scope for practical application are discussed.

Surgical Outcomes in Uveitic Glaucoma: Long-Term Evaluation of Trabeculectomy, Non-Penetrating Deep Sclerectomy, Ex-PRESS Shunt and Ahmed Glaucoma Valve. A 3-Year Follow-Up Study

PURPOSE

Uveitis can lead to secondary glaucoma, a condition with challenging management that can carry irreversible visual loss. Filtering surgery has demonstrated a higher failure rate, increased incidence of postoperative complications and reinterventions in uveitic patients. There is no consensus on the optimal surgical approach for uveitic glaucoma (UG) due to limited data comparing various intraocular pressure (IOP)-lowering surgeries. This retrospective cohort aims to assess the clinical outcomes of trabeculectomy (TBT), non-penetrating deep sclerectomy (NPDS), Ex-PRESS shunt and Ahmed glaucoma valve, providing additional insights into the long-term IOP control and safety of filtering surgeries in UG.

METHODS

The filtering surgery was performed on 32 eyes of 27 UG patients. Complete success was defined as IOP ≤ 18 mmHg or a 30% reduction. Qualified success allowed topical hypotensive treatment.

RESULTS

Complete success was 40.63% (13/32) at 12 months and 36.67% (11/30) at 36 months. Qualified success was 84.38% (27/32) at 12 months and 63.33% (19/30) at 36 months. In the survival analysis, both NPDS and Ex-PRESS demonstrated decreased failure rates compared to TBT (NPDS vs TBT: HR = 0.20, p = 0.049; Ex-PRESS vs TBT: HR = 0.28, p = 0.13). One or more reinterventions were required in 34.38% (11/32) of the eyes. NPDS had the lowest incidence of hypotony. Secondary cataract was a common complication in all groups.

CONCLUSION

Various filtering surgeries are safe and effective procedures for lowering IOP and reducing the requirement of topical antihypertensives in UG at 36 months. However, one-third of the patients will require another IOP-lowering procedure.

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.

Limbal Stem Cell Deficiency After Glaucoma Surgery

PURPOSE

To characterize the clinical presentation of limbal stem cell deficiency (LSCD) associated with glaucoma surgeries.

METHODS

This is a retrospective cross-sectional study of patients with LSCD and glaucoma who presented to the Stein Eye Institute at the University of California, Los Angeles, between 2009 and 2018. Patients who underwent trabeculectomy and/or aqueous shunt surgery were included. The severity of LSCD was staged using global consensus guidelines and a clinical scoring system, and basal epithelial cell density was measured by in vivo confocal microscopy. Anatomic locations of glaucoma and non-glaucoma surgeries, locations of LSCD, and severity of LSCD were compared.

RESULTS

Fifty-one eyes of 41 patients with LSCD associated with glaucoma surgery were included in this study. LSCD in these patients uniquely featured sectoral replacement of corneal epithelium by conjunctival epithelium, without corneal neovascularization or pannus. The sites of glaucoma surgery strongly correlated with the locations of LSCD (P = 0.002). There was a trend toward increased severity of LSCD in eyes with 2 or more glaucoma surgeries as compared to eyes with 1 glaucoma surgery, although the difference did not reach statistical significance (P = 0.3). Use of topical glaucoma medications correlated with LSCD severity, while the impact of antimetabolites did not reach statistical significance. The location of glaucoma drainage surgery is correlated with the location of LSCD.

CONCLUSIONS

LSCD associated with glaucoma surgery has clinical features distinct from LSCD resulting from other etiologies. Further study is required to delineate the full impact of glaucoma surgery on limbal stem cell function and survival.

Targeting the integrated stress response in ophthalmology

Purpose: To summarize the Integrated Stress Response (ISR) in the context of ophthalmology, with special interest on the cornea and anterior segment. Results: The ISR is a powerful and conserved signaling pathway that allows for cells to respond to a diverse array of both intracellular and extracellular stressors. The pathway is classically responsible for coordination of the cellular response to amino acid starvation, ultraviolet light, heme dysregulation, viral infection, and unfolded protein. Under normal circumstances, it is considered pro-survival and a necessary mechanism through which protein translation is controlled. However, in cases of severe or prolonged stress the pathway can promote apoptosis, and loss of normal cellular phenotype. The activation of this pathway culminates in the global inhibition of cap-dependent protein translation and the canonical expression of the activating transcription factor 4 (ATF4). Conclusion:The eye is uniquely exposed to ISR responsive stressors due to its environmental exposure and relative isolation from the circulatory system which are necessary for its function. We will discuss how this pathway is critical for the proper function of the tissue, its role in development, as well as how targeting of the pathway could alleviate key aspects of diverse ophthalmic diseases.

Effect of connective tissue growth factor gene editing using adeno-associated virus-mediated CRISPR-Cas9 on rabbit glaucoma filtering surgery outcomes

Suppressing excessive wound healing responses is critical to ensure surgical success in glaucoma filtration surgery (GFS). Currently used adjunctive materials can lead to side effects due to the nonselectivity in cell inhibition and may require repeated applications. The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system may become a compelling opportunity in glaucoma surgery due to its high selectivity and permanent effect. Connective tissue growth factor (CTGF) is one of the most potent stimulators of tissue fibrosis in the eye. Therefore, we tested the effect of CTGF suppression using the CRISPR-Cas9 system on GFS fibrosis. We used an adeno-associated virus (AAV)-CRISPR-Cas9 system and confirmed successful CTGF suppression was achieved in fibroblasts in vitro through western blot analysis and deep sequencing. In the in vivo intereye-comparison rabbit GFS model, CRISPR-CTGF-treated eyes showed significantly better survival of the surgery site, less subconjunctival fibrosis, limited collagen deposition, and reduced cellularity than untreated eyes. Our results suggest a new possibility of CRISPR-Cas9-mediated CTGF suppression to improve human GFS outcomes.

Learning from the past: Mitomycin C use in trabeculectomy and its application in bleb-forming minimally invasive glaucoma surgery

Trabeculectomy has been performed since the mid-1960s and remains the gold standard for glaucoma surgery. Newer surgical options have evolved, collectively referred to as minimally invasive glaucoma surgeries. Despite producing large intraocular pressure decreases, full-thickness procedures into the subconjunctival space may be limited by fibrosis. Mitomycin C (MMC) and 5-fluorouracil have been in use with trabeculectomy with good evidence of significantly increased success at the cost, however, of an increased risk of complications. Off-label MMC application can be found in almost all clinical trials, including in combination with minimally invasive glaucoma surgeries. We explore current evidence for MMC use in trabeculectomy and how this may differ for minimally invasive glaucoma surgery devices and analyze the range of agents and doses that are used. Although we found that most studies could not show any correlation between MMC dosage and the surgical outcome, the success rates with the Xen® microshunt seemed to be higher when using 20 mcg of MMC than when using 10 mcg. Certain important methodological considerations make this hard to confirm definitively, and other factors such as placement of the device may play a more substantial role. For the PreserFlo® microshunt, preliminary data suggest higher success rates with higher MMC dosage at the cost of higher device-related adverse events and reoperations. Although the ideal dose still needs to be established, it seems very likely that MMC provides significant improvement in outcomes in bleb-forming minimally invasive glaucoma procedures.

Bevacizumab as an Adjunct to Trabeculectomy in Primary Open-Angle Glaucoma: A Randomized Trial

Purpose

To compare the outcomes of trabeculectomy using two different routes of bevacizumab administration as an adjunct in patients with primary open angle glaucoma.

Methods

Prospective, randomized, masked trial that included 180 eyes of 180 patients of documented primary open angle glaucoma were eligible for surgery. Patients were randomized to receive either a single intraoperative dose of subconjunctival bevacizumab (1.25 mg, Group I) or topical bevacizumab (5 mg/ml) for 30 days (Group II). One eye was randomly selected, if both were eligible for surgery. All patients underwent a complete ocular and systemic examination. Bleb morphology was examined and scored as per Moorfields system (MBGS) at 1, 3, 6, 12, 18, and 24 months postoperatively. Visual field, fundus photography, and disc analysis were performed. Outcome measures (at one year) included (1) comparison of bleb morphology in both groups, (2) proportion of patients achieving surgical success, and (3) side effects of treatment.

Results

The groups did not differ with respect to age, sex, and crystalline lens status. Group II patients had significantly lower vascularity scores for central (P=0.042) and peripheral bleb areas (P=0.042) and peripheral bleb areas (P=0.042) and peripheral bleb areas (n = 88) patients achieved average vascular scores of less than 2.5 (P=0.042) and peripheral bleb areas (n = 88) patients achieved average vascular scores of less than 2.5 (vs. 94%; P=0.042) and peripheral bleb areas (

Conclusion

Topical bevacizumab gives a better vascularity profile at one year, but the studied routes appear equally safe and do not seem to affect the outcome in any other way.

Transient Mitomycin C-treatment of human corneal epithelial cells and fibroblasts alters cell migration, cytokine secretion, and matrix accumulation

A single application of Mitomycin C (MMC) is used clinically in ophthalmology to reduce scarring and enhance wound resolution after surgery. Here we show in vitro that a 3-hour MMC treatment of primary and telomerase immortalized human corneal limbal epithelial (HCLE) cells impacts their migration and adhesion. Transient MMC treatment induces HCLE expression of senescence associated secretory factors, cytokine secretion, and deposition of laminin 332 for several days. Transient MMC treatment also reduces migration and deposition of transforming growth factor-β1 (TGFβ1)-stimulated collagen by corneal fibroblasts. Using conditioned media from control and MMC treated cells, we demonstrate that factors secreted by MMC-treated corneal epithelial cells attenuate collagen deposition by HCFs whereas those secreted by MMC-treated HCFs do not. These studies are the first to probe the roles played by corneal epithelial cells in reducing collagen deposition by corneal fibroblasts in response to MMC.

[Trabeculectomy with Ologen® implant and bevacizumab]

BACKGROUND

Trabeculectomy is the most frequent form of glaucoma surgery. Despite the intraoperative use of antimetabolites, such as mitomycin C (MMC) postoperative scarring reactions can cause surgical failure. The subconjunctival placement of an Ologen® implant can avoid wound scarring. The additional application of bevacizumab should reduce angiogenesis and thereby scarring reactions and improve the surgical success rate.

METHODS

This was a retrospective single center study of patients with glaucoma after trabeculectomy with MMC. The operation was carried out either without an Ologen® implant (group 1), or with an Ologen® implant as an bevacizumab depot (group 2) or with an Ologen® implant and intrachamber injection of bevacizumab (group 3). The follow-up postoperative observation of intraocular pressure (IOP), complications, subsequent interventions and antiglaucoma treatment was performed for 12 months.

RESULTS

There were no significant differences between the groups with respect to IOP, complications, subsequent interventions and postoperative antiglaucoma treatment. The highest success rate (IOP after 12 months ≤15 mm Hg without treatment) was in group 1 (77.5%), followed by group 2 with 63.6% and group 3 with 57.1% (p = 0.34, χ²-test).

CONCLUSION

The highest success rate was achieved in group 1 with MMC but without an Ologen® implant or bevacizumab. In this study the additional use of Ologen® implants and bevacizumab in trabeculectomy was found to be a safe operation method but did not provide any additional benefits.

Viscocanalostomy with Mitomycin-C: A Preliminary Study

Purpose

To compare the results of viscocanalostomy with and without mitomycin-C (MMC).

Methods

Retrospective results of 15 standard viscocanalostomy (VCO) operations (Group 1) were compared with the prospective results of 15 VCO operations performed with intraoperative adjunctive MMC (Group 2). MMC (0.2 mg/mL) was applied over and under the superficial scleral flap for 3 minutes in Group 2 before the deep flap was prepared. Each patient was followed up for at least 1 year, and results of examinations in the first 12 months were used in the statistical comparison of the two groups. Surgical success was defined as intraocular pressure (IOP) ≤ 18 mmHg.

Results

Pr eoperative mean intraocular pressures (IOP) in Group 1 and Group 2 wer e 35.3±11.0 and 39.1±8.9, respectively. Mean IOP levels at the 12th month were 14.4±2.6 and 11.9±4.0, respectively, showing a significant decrease in both groups (p<0.001). Postoperative IOP course appeared to be lower in the MMC group, however, the difference was not statistically significant (p=0.554). Complete success rates without medications were 40% in Group 1 and 67% in Group 2. No significant difference was found between the two groups in terms of early and late postoperative complications, pre- and postoperative number of antiglaucoma medications, and surgical success rates at the end of the study period (p>0.05 for all). A significant difference was verified between the two groups of eyes considering the conjunctival bleb types, as low-lying, localized blebs were the most frequent type in Group 1 and thin-walled, avascular blebs were more predominant in the MMC group (p=0.004).

Conclusions

Intraoperative adjunctive MMC use might improve the long-term results of viscocanalostomy by facilitating subconjunctival filtration and might widen the indication range of the technique.

Glaucoma Surgery Outcome in Rwanda

PURPOSE

To assess long-term intraocular pressure (IOP) outcome after adult trabeculectomy surgery in Central Africa.

PATIENTS AND METHODS

All adult glaucoma patients who underwent trabeculectomy surgery in the Kabgayi Eye Unit, Rwanda between August 2003 and March 2008 were invited for a follow-up visit. Surgical and clinical data were collected from medical records. At the study visit, best-corrected visual acuity was measured and Goldmann applanation tonometry and biomicroscopy were done. Good IOP outcome was defined as both an IOP<21 mm Hg and achieving ≥30% reduction from the preoperative IOP. Considering first operated eyes, univariate and multivariate logistic regression was used to investigate risk factors for failure.

RESULTS

Of 163 individuals operated 3 had died, 118 (74%) participated. Preoperatively, the mean IOP was 31 mm Hg (SD=11; range, 12 to 60). At the time of the follow-up study visit the mean postoperative IOP was 13 mm Hg (SD=5; range, 4 to 35). Good IOP outcome was achieved in 132 eyes (84%). Univariate analysis suggested a protective effect against failure of use of antimetabolites [odds ratio (OR)=0.39; 95% confidence interval (CI), 0.14-1.11; P=0.07] and a decrease in success with length of follow-up (OR=3.57; 95% CI, 1.09-12.50; P=0.03). The latter remained borderline significant with multivariate analysis. Seven eyes went from previously better vision (at least hand movements) down to perception of light or no perception of light after trabeculectomy. Particularly a flat anterior chamber in the first postoperative week (OR=0.07; 95% CI, 0.01-0.49; P<0.001) and late hypotony (OR=0.04; 95% CI, 0.002-0.99; P=0.004) were significant risk factors for severe visual loss.

CONCLUSIONS

Trabeculectomy with antimetabolites is one of the best available options for glaucoma management in Africa. However, the IOP control reduced at a follow-up duration beyond 2 years, highlighting the importance of regular long-term follow-up.

Clinical efficacy analysis of Ahmed glaucoma valve implantation in neovascular glaucoma and influencing factors: A STROBE-compliant article

This study aimed to evaluate the efficacy of Ahmed glaucoma valve (AGV) implantation in treating neovascular glaucoma (NVG) and to analyze the factors influencing the surgical success rate.This is a retrospective review of 40 eyes of 40 NVG patients who underwent AGV implantation at Xiangya Hospital of Central South University, China, between January 2014 and December 2016. Pre- and postoperative intraocular pressure (IOP), visual acuity, surgical success rate, medications, and complications were observed. Surgical success criteria were defined as IOP ≤21 and >6 mm Hg with or without additional medications. Kaplan-Meier survival curves and Multivariate cox regression analysis were used to examine success rates and risk factors for surgical outcomes.The mean follow-up period was 8.88 ± 3.12 months (range: 3-17). IOP declined at each visit postoperatively and it was statistically significant (P < .001). An average of 3.55 ± 0.86 drugs was applied preoperatively, while an average of 0.64 ± 0.90 drugs was used postoperatively, with the difference being of statistical significance (P < .05). The complete surgical success rate of 3, 6, and 12 months after the operation was 85%, 75%, and 65%, respectively. Meanwhile, the qualified success rate of 3, 6, and 12 months after the operation was 85%, 80%, and 77.5%, respectively. The multivariate cox regression analysis showed that age (hazard ratio: 3.717, 7.246; 95% confidence interval: 1.149-12.048, 1.349-38.461; P = .028, .021) was influencing factors for complete success rate and qualified success rate among all NVG patients. Gender, previous operation history, primary disease, and preoperative IOP were found to be not significant.AGV implantation is an effective and safe surgical method to treat NVG. Age is an important factor influencing the surgical success rate.

A Pilot Study on Ocular Safety and Efficacy of Infliximab as an Antifibrotic Agent After Experimental Glaucoma Filtration Surgery

Introduction

Tumor necrosis factor-α (TNF-α) is a multifunctional, proinflammatory cytokine that mediates pleiotropic biological functions, especially inflammation and immunoregulation. We hypothesized that blocking TNF-α with a monoclonal antibody would decrease inflammation and subconjunctival scarring in an animal model of experimental filtration surgery.

Methods

In a randomized, prospective, masked-observer study, 30 New Zealand albino rabbits underwent glaucoma filtration surgery. The animals were allocated to receive either intraoperative application of infliximab (group A) or mitomycin C (MMC) at a concentration of 0.2 mg/ml (group B) or balanced salt solution (BSS, control) (group C). Different infliximab doses, namely 1.0, 2.0, 3.0, 4.0, 5.0 mg in 0.1 ml, were applied. Bleb survival and characteristics were evaluated over a 30-day period. The animals were killed on postoperative day 15 or 30. Histology of the operated eyes was performed to evaluate and grade the amount of scarring in each group. Cellular density was evaluated in each case.

Results

Infliximab did not appear to improve outcomes in this model of glaucoma filtration surgery. Bleb survival was significantly higher in the MMC group compared to the other groups (p < 0.001 for both comparisons). Vascularity was also significantly lower in the MMC group compared to the other groups (p = 0.018 for both comparisons). There was a significant decrease in cellular density in the MMC group compared to the control (p = 0.0352) and the infliximab group (p < 001).

Conclusion

Our results have shown that trabeculectomies in the infliximab group failed faster and displayed more scarring, compared to the control and MMC groups. This outcome suggests that the infliximab doses used in this pilot study resulted in a subconjunctival TNF-α concentration, which acted as a stimulator to fibroblasts.

Histopathologic effects of a low molecular weight heparin on bone healing in rats: a promising adjuvant in dacryocystorhinostomy

AIM

To investigate the effect of short-term prophylactic dose of a low molecular weight heparin (LMWH) drug on the bone healing process in an animal model simulating the osteotomy obtained in dacryocystorhinostomy.

METHODS

Forty male Wistar albino rats were divided into 2 groups. Subcutaneous injections of enoxaparin 1 mg/kg (enoxaparin-treated group) and saline solution (control group) were performed once daily for 4d, beginning on the first preoperative day. The osteotomy was created at the femoral diaphysis in all animals by using a Kirschner wire. Each group was further divided into 2 subgroups depending on the timing of the second operation, 14 or 21d following initial osteotomy. Patent osteotomy area on the second and the third weeks in each group were calculated by using a computer software on digital micrographs.

RESULTS

The patent osteotomy areas at the second and the third weeks were significantly larger in the enoxaparin-treated group than those of the control group (P<0.001 for each time-period). In the control group, the patent osteotomy area at the third week of healing was significantly smaller than that of the second week (P=0.003), whereas there was no significant difference between these two measurements in the enoxaparin-treated group (P=0.185).

CONCLUSION

Short-term administration of enoxaparin resultes in a significant alteration in bone healing at 14 and 21d after injury. LMWHs can be regarded as promising alternative adjuvants in dacryocystorhinostomy after being evaluated with further clinical and animal studies.

Current and Future Techniques in Wound Healing Modulation after Glaucoma Filtering Surgeries

Filtering surgeries are frequently used for controlling intraocular pressure in glaucoma patients. The long-term success of operation is intimately influenced by the process of wound healing at the site of surgery. Indeed, if has not been anticipated and managed accordingly, filtering surgery in high-risk patients could end up in bleb failure. Several strategies have been developed so far to overcome excessive scarring after filtering surgery. The principal step involves meticulous tissue handling and modification of surgical technique, which can minimize the severity of wound healing response at the first place. However, this is usually insufficient, especially in those with high-risk criteria. Thus, several adjuvants have been tried to stifle the exuberant scarring after filtration surgery. Conventionally, corticosteroids and anti-fibrotic agents (including 5-fluorouracil and Mitomycin-C) have been used for over three decades with semi-acceptable outcomes. Blebs and bleb associated complications are catastrophic side effects of anti-fibrotic agents, which occasionally are encountered in a subset of patients. Therefore, research continues to find a safer, yet effective adjuvant for filtering surgery. Recent efforts have primarily focused on selective inhibition of growth factors that promote scarring during wound healing process. Currently, only anti-VEGF agents have gained widespread acceptance to be translated into routine clinical practice. Robust evidence for other agents is still lacking and future confirmative studies are warranted. In this review, we explain the importance of wound healing process during filtering surgery, and describe the conventional as well as potential future adjuvants for filtration surgeries.

Mitomycin C versus 5-Fluorouracil for wound healing in glaucoma surgery

BACKGROUND

Raised intraocular pressure is a risk factor for glaucoma. One treatment option is glaucoma drainage surgery (trabeculectomy). Antimetabolites are used during surgery to reduce postoperative scarring during wound healing. Two agents in common use are mitomycin C (MMC) and 5-Fluorouracil (5-FU).

OBJECTIVES

To assess the effects of MMC compared to 5-FU as an antimetabolite adjunct in trabeculectomy surgery.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015 Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to October 2015), EMBASE (January 1980 to October 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to October 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 2 October 2015.

SELECTION CRITERIA

We included randomised controlled trials where wound healing had been modified with MMC compared to 5-FU.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials and collected data. The primary outcome was failure of a functioning trabeculectomy one year after surgery. Secondary outcomes included mean intraocular pressure at one year. We considered three subgroups: high risk of trabeculectomy failure (people with previous glaucoma surgery, extracapsular cataract surgery, African origin and people with secondary glaucoma or congenital glaucoma); medium risk of trabeculectomy failure (people undergoing trabeculectomy with extracapsular cataract surgery) and low risk of trabeculectomy failure (people who have received no previous surgical eye intervention).

MAIN RESULTS

We identified 11 trials that enrolled 687 eyes of 679 participants. The studies were conducted in the United States, Europe, Asia and Africa. Five studies enrolled participants at low risk of trabeculectomy failure, five studies enrolled participants at high risk of failure, and one study enrolled people with both high and low risk of failure. None of the included trials enrolled participants with combined trabeculectomy/cataract surgery.We considered one study to be at low risk of bias in all domains, six studies to be at high risk of bias in one or more domains, and the remaining four studies to be at an unclear risk of bias in all domains.The risk of failure of trabeculectomy at one year after surgery was less in those participants who received MMC compared to those who received 5-FU, however the confidence intervals were wide and are compatible with no effect (risk ratio (RR) 0.54, 95% confidence interval (CI) 0.30 to 1.00; studies = 11; I(2) = 40%). There was no evidence for any difference between groups at high and low risk of failure (test for subgroup differences P = 0.69).On average, people treated with MMC had lower intraocular pressure at one year (mean difference (MD) -3.05 mmHg, 95% CI -4.60 to -1.50), but the studies were inconsistent (I(2) = 52%). The size of the effect was greater in the high-risk group (MD -4.18 mmHg, 95% CI -6.73 to -1.64) compared to the low-risk group (MD -1.72 mmHg, 95% CI -3.28 to -0.16), but again the test for interaction was not statistically significant (P = 0.11).Similar proportions of eyes treated with MMC lost 2 or more lines of visual acuity one year after surgery compared to 5-FU, but the confidence intervals were wide (RR 1.05, 95% CI 0.54 to 2.06).Adverse events occurred relatively rarely, and estimates of effect were generally imprecise. There was some evidence for less epitheliopathy in the MMC group (RR 0.23, 95% CI 0.11 to 0.47) and less hyphaema in the MMC group (RR 0.62, 95% CI 0.42 to 0.91).None of the studies reported quality of life.Overall, we graded the quality of the evidence as low largely because of risk of bias in the included studies and imprecision in the estimate of effect.

AUTHORS' CONCLUSIONS

We found low-quality evidence that MMC may be more effective in achieving long-term lower intraocular pressure than 5-FU. Further comparative research on MMC and 5-FU is needed to enhance reliability and validity of the results shown in this review. Furthermore, the development of new agents that control postoperative scar tissue formation without side effects would be valuable and is justified by the results of this review.

Role of subconjunctival bevacizumab as an adjuvant to primary trabeculectomy: a prospective randomized comparative 1-year follow-up study

PURPOSE

To compare the safety and efficacy of primary trabeculectomy with adjunctive subconjunctival bevacizumab with that of primary trabeculectomy with mitomycin C (MMC).

MATERIALS AND METHODS

Forty-two patients with primary open-angle glaucoma were studied. Randomly, subject's eyes underwent primary trabeculectomy with either subconjunctival bevacizumab (2.5 mg/0.1 mL) or topical MMC (0.2 mg/mL for 3 min). The intraocular pressure (IOP) was the primary outcome measure. Secondary outcome measures included the corrected distance visual acuity, number of antiglaucoma medications, postoperative interventions and complications, bleb evaluation (on the basis of Moorfields Bleb Grading System), and the percentage of eyes achieving target pressure of 21, 18, 15, and 12 mm Hg at 6 and 12 months postoperatively.

RESULTS

Of the 42 eyes, 21 treated with subconjunctival bevacizumab while 21 were treated with MMC. The mean preoperative IOP in the bevacizumab group improved from 23.9 ± 2.7 mm Hg with 2.6 ± 0.7 antiglaucoma medications to 13.9 ± 2.8 mm Hg with 0.6 ± 0.9 antiglaucoma medications at 12 months (P<0.001 and P<0.001, respectively). The mean preoperative IOP in MMC group improved from 22.9 ± 2.6 mm Hg with 2.7 ± 0.8 antiglaucoma medications to 12.2 ± 3.2 mm Hg with 0.1 ± 0.5 antiglaucoma medications at 12 months (P<0.001 and P<0.001, respectively). At 12 months, 15 of 21 (71%) eyes in the MMC group met a target IOP of 12 mm Hg without antiglaucoma medication while 7 of 21 (33%) eyes in the bevacizumab group did (P=0.02). Encapsulated bleb was seen in 2 (10%) patients in MMC group and in 6 (29%) patients in bevacizumab group (P=0.23).

CONCLUSIONS

Although subconjunctival bevacizumab is effective and safe in primary trabeculectomy, IOP control appears to be superior with MMC, in terms of complete success with a target IOP<12 mm Hg and number of antiglaucoma medications required postoperatively.

Wound Healing Modulation in Glaucoma Filtration Surgery-Conventional Practices and New Perspectives: The Role of Antifibrotic Agents (Part I)

Glaucoma filtration surgery is regularly performed for the treatment of glaucoma and trabeculectomy is often regarded as the ‘gold standard' glaucoma operation. The biggest risk of failure of the operation is bleb scarring. The advent of anti-fibrotic agents, such as mitomycin C (MMC) and 5-fluorouracil (5FU) has vastly prolonged the longevity of the bleb, but concerns remain regarding the potential increase in postoperative complications. More selective therapeutic targets have therefore been explored. One of these is vascular endothelial growth factor (VEGF) inhibition. Vascular endothelial growth factor inhi bition has a role not only in sub conjunctival angiogenesis inhi bition but also it has direct anti-fibrotic properties. Newer phar macological compounds and materials have also been developed in recent years in attempt to modulate the wound healing in different ways after glaucoma surgery. These include physical barriers to scarring and vehicles for sustained release of pharmacological agents, and early promising results have been demonstrated. This two-part review will provide a discussion of the application of anti-fibrotic agents in glaucoma filtration surgery and evaluate the newer agents that have been developed.

How to cite this article: Fan Gaskin JC, Nguyen DQ, Ang GS, O'Connor J, Crowston JG. Wound Healing Modulation in Glaucoma Filtration Surgery–Conventional Practices and New Pers pectives: The Role of Antifibrotic Agents (Part I). J Curr Glaucoma Pract 2014;8(2):37-45.

MicroRNA-542-3p inhibits tumour angiogenesis by targeting angiopoietin-2

Angiopoietin-2 (Angpt2) plays a critical role in angiogenesis and tumour progression. Therapeutic targeting of Angpt2 has been implicated as a promising strategy for cancer treatment. Whereas miRNAs are emerging as important modulators of angiogenesis, regulation of Angpt2 by miRNAs has not been established. Here we firstly report that Ang2 is targeted by a microRNA, miRNA-542-3p, which inhibits tumour progression by impairing Ang2's pro-angiogenic activity. In cultured endothelial cells, miR-542-3p inhibited translation of Angpt2 mRNA by binding to its 3' UTR, and addition of miR-542-3p to cultured endothelial cells attenuated angiogenesis. Administration of miR-542-3p to tumour-bearing mice reduced tumour growth, angiogenesis and metastasis. Furthermore, the level of miR-542-3p in primary breast carcinomas correlated inversely with clinical progression in primary tumour samples from stage III and IV patients. Together, these findings uncover a novel regulatory pathway whereby an anti-angiogenic miR-542-3p directly targets the key angiogenesis-promoting protein Angpt2, suggesting that miR-542-3p may represent a promising target for anti-angiogenic therapy and a potential marker for monitoring disease progression.

Comparison of outcomes of trabeculectomy with mitomycin C vs. ologen implant in primary glaucoma

Purpose:

To compare the safety and efficacy of trabeculectomy with Ologen implant vs. trabeculectomy with Mitomycin C (MMC).

Materials and Methods:

In a prospective, randomized, pilot study, 39 eyes of 33 subjects with medically uncontrolled primary glaucoma, aged 18 years or above underwent trabeculectomy either with MMC (20 eyes) or with Ologen implant (19 eyes). The primary outcome measure was cumulative success probability, defined as complete if the intraocular pressure (IOP) was > 5 and ≤ 21 mm Hg without anti-glaucoma medications or additional surgery and qualified if an IOP was > 5 and ≤ 21 mm Hg with or without anti-glaucoma medications.

Results:

Mean (± standard deviation) follow-up in Ologen group was 19.1 ± 8.1 months, and in MMC group was 18.0 ± 8.4 months. Mean IOP reduction at 6 months was significantly lower (P = 0.01) in the MMC group (11.9 ± 2.9 mm Hg) as compared to Ologen group (14.6 ± 2.7 mm Hg). However, at 12 months (P = 0.81) and 24 months (P = 0.32), the mean IOP was similar between the 2 groups. Complete success probability at the end of 6 months in Ologen group was 100% (95% confidence interval: 59.1 - 99.0) was similar (P = 0.53) to that in MMC group (93.8%, 95% CI: 63.2 - 99.1). The incidences of early post-operative complications were similar in the 2 groups, except hyphema, which was significantly more in Ologen group (P = 0.02).

Conclusion:

In this pilot study, the success of trabeculectomy and complications were similar in both Ologen and MMC groups at the end of 6 months.

Different effects of intravitreally injected ranibizumab and aflibercept on retinal and choroidal tissues of monkey eyes

BACKGROUND

Since there is evidence that the Fc domain of antivascular endothelial growth factor drugs may cause unexpected consequences in retinal and choroidal vessels, the effects of intravitreal ranibizumab and aflibercept on monkey eyes were investigated.

METHODS

Four cynomolgus monkeys were intravitreally injected with 0.5 mg of ranibizumab and another four with 2 mg of aflibercept. Two untreated monkeys served as controls. Funduscopy, fluorescein angiography (FA), spectral-domain-optical coherence tomography (SD-OCT) and measurement of intraocular pressure (IOP) were performed. The eyes were inspected by light, fluorescence and electron microscopy. The diameter of the choriocapillaris (CC) was measured by morphometry, and the areas of the CC with free haemoglobin, CC fenestrations and endothelial thickness were quantified.

RESULTS

Analysis showed ranibizumab permeated the retina via intercellular clefts, whereas aflibercept was taken up by ganglion cells, cells of the inner and outer retinal layers and the retinal pigment epithelium (RPE). Stasis and haemolysis in the choriocapillaris and choroidal vessels were more frequent after aflibercept treatment, which caused hypertrophy and death of individual RPE cells. The area of the CC was significantly reduced after both drugs compared with controls, but the reduction of the CC endothelium thickness, number of fenestrations and the areas with haemolysis were more pronounced after aflibercept.

CONCLUSIONS

Ranibizumab permeated the retina through intercellular spaces, whereas aflibercept was taken up by neuronal and RPE cells. Aflibercept induced protein complex formation and more haemolysis in the choriocapillaris, leading to individual RPE cell death. The clinical significance and relation of these findings to the Fc domain or to other characteristics of aflibercept remain to be investigated.

Anti-vascular endothelial growth factor for neovascular glaucoma

BACKGROUND

Neovascular glaucoma (NVG) is a potentially blinding secondary glaucoma. It is caused by the formation of abnormal new blood vessels which prevent normal drainage of aqueous from the anterior segment of the eye. Anti-vascular endothelial growth factor (anti-VEGF) agents are specific inhibitors of the primary mediators of neovascularization. Studies have reported the effectiveness of anti-VEGFs for the control of intraocular pressure (IOP) in NVG.

OBJECTIVES

To compare the IOP lowering effects of intraocular anti-VEGF agents to no anti-VEGF treatment, as an adjunct to existing modalities for the treatment of NVG.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 12), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, (January 1950 to January 2013), EMBASE (January 1980 to January 2013), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to January 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov/) and the 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 11 January 2013.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs of people treated with anti-VEGF agents for NVG.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the search results for trials to be included in the review. Discrepancies were resolved by discussion with a third author. Since no trial met our inclusion criteria, no assessment of risk of bias or meta-analysis was undertaken.

MAIN RESULTS

No RCTs were found that met the inclusion criteria for this review. Two RCTs of anti-VEGF agents for treating NVG were not included in the review due to the heterogeneity and uncontrolled assignment of adjunct treatments received by the study participants.

AUTHORS' CONCLUSIONS

Currently available evidence is insufficient to evaluate the effectiveness of anti-VEGF treatments, such as intravitreal ranibizumab or bevacizumab, as an adjunct to conventional treatment in lowering IOP in NVG. Well designed RCTs are needed to address this issue, particularly trials that evaluate long-term (at least six months) benefits and risks since the effects of anti-VEGF agents may be short-term only. An RCT comparing anti-VEGF agents with no anti-VEGF agents taking into account the need for co-interventions, such as panretinal photocoagulation (PRP), glaucoma shunt procedures, cyclodestructive procedures, cataract surgery, and deep vitrectomy, could be of use to investigate the additional beneficial effect of anti-VEGF agents in treating NVG. Since decisions for when and which co-interventions should be used are based on clinical criteria, they would not be appropriate for randomization. However, the design of a study on this topic should aim to balance groups by stratification of co-intervention at time of randomization or by enrolling a sufficient number of participants to conduct subgroup analysis by co-interventions (ideally 15 participants per treatment group for each subgroup). Alternatively, the inclusion criteria for a trial could limit participants to those who receive the same co-intervention.

A FRET-based high throughput screening assay to identify inhibitors of anthrax protective antigen binding to capillary morphogenesis gene 2 protein

Anti-angiogenic therapies are effective for the treatment of cancer, a variety of ocular diseases, and have potential benefits in cardiovascular disease, arthritis, and psoriasis. We have previously shown that anthrax protective antigen (PA), a non-pathogenic component of anthrax toxin, is an inhibitor of angiogenesis, apparently as a result of interaction with the cell surface receptors capillary morphogenesis gene 2 (CMG2) protein and tumor endothelial marker 8 (TEM8). Hence, molecules that bind the anthrax toxin receptors may be effective to slow or halt pathological vascular growth. Here we describe development and testing of an effective homogeneous steady-state fluorescence resonance energy transfer (FRET) high throughput screening assay designed to identify molecules that inhibit binding of PA to CMG2. Molecules identified in the screen can serve as potential lead compounds for the development of anti-angiogenic and anti-anthrax therapies. The assay to screen for inhibitors of this protein–protein interaction is sensitive and robust, with observed Z' values as high as 0.92. Preliminary screens conducted with a library of known bioactive compounds identified tannic acid and cisplatin as inhibitors of the PA-CMG2 interaction. We have confirmed that tannic acid both binds CMG2 and has anti-endothelial properties. In contrast, cisplatin appears to inhibit PA-CMG2 interaction by binding both PA and CMG2, and observed cisplatin anti-angiogenic effects are not mediated by interaction with CMG2. This work represents the first reported high throughput screening assay targeting CMG2 to identify possible inhibitors of both angiogenesis and anthrax intoxication.

Comparison of the outcome of repeat trabeculectomy with adjunctive mitomycin C and initial trabeculectomy

Purpose

To compare the efficacy and safety of repeat and initial trabeculectomy with mitomycine C (MMC).

Methods

Eighty seven patients, who had underwent repeat (repeat group) or initial (initial group) trabeculectomy with MMC, were enrolled in this prospective trial. Postoperative outcome measures included the amount of decrease in intraocular pressure (IOP), the number of anti-glaucoma medications, and the complications. The success of trabeculectomy was defined on the basis of three definitions which were: IOP ≤18 mmHg (definition 1), IOP ≤21 mmHg (definition 2), and the amount of decrease in IOP from baseline ≥30% (definition 3). Success was further defined as "complete" when these criteria were obtained without any anti-glaucoma medications and "qualified" with or without medical therapy and no further surgical procedures.

Results

Fifty nine eyes underwent initial and 28 eyes underwent repeat trabeculectomy. The mean follow-up period was 19.1 ± 5.9 months. Complete success rates were significantly greater in the initial trabeculectomy group (p = 0.02 for definition 1, p = 0.038 for definition 2, p = 0.003 for definition 3). A higher proportion of eyes in the initial group achieved qualified success relative to the group A eyes, but the differences were not statistically significant (p = 0.33 for definition 1, p = 0.99 for definition 2, p = 0.24 for definition 3). The mean number of antiglaucomatous medications at the last examination was 1.2 ± 1.2 in repeat group and 0.7 ± 1.1 in initial group (p = 0.01). The number of complications during the follow up period did not differ significantly between the two groups (p = 0.65).

Conclusions

Repeat trabeculectomy with MMC has high success and low complication rates in patients with previously failed trabeculectomy in spite of the need of higher number of anti-glaucoma medications.

Mitomycin-C needle bleb revision in congenital glaucoma

Purpose and Settings:

This study was designed to evaluate the efficacy and safety of mitomycin-C (MMC) augmented needling procedure in the management of failed bleb after trabeculectomy in congenital glaucoma. This study was carried out at Ain Shams University Hospital.

Patients and Methods:

A retrospective study was carried on 30 eyes of 25 patients with congenital glaucoma with bleb failure after trabeculectomy. The mean age of the subjects was 7.3 ± 3.4 years (range, 1–12 years). Under general anesthesia, needling procedure was performed with adjunctive use of a mixture of 0.1 mL of MMC (0.04 mg/mL) and 0.2 mL of lidocaine 1% injected subconjunctivally. Needling was performed with a 30-gauge needle to dissect the areas of subconjunctival fibrosis and re-establish aqueous outflow.

Results:

Follow-up ranged from 6 to 20 months (mean, 9.23 ± 5.25 months). One needling revision was performed in 22 eyes (73.3%) and eight eyes (26.7%) received two needle revisions. The mean intraocular pressure (IOP) decreased from 26.9 ± 2.85 mmHg (range, 21–34 mmHg) before surgery to 15.63 ± 3.15 mmHg (range, 10–24 mmHg) at last follow-up. Complications included significant subconjunctival hemorrhage in six eyes, intraoperative bleb leak in two eyes, choroidal detachment in one eye, and minimal hyphema in one eye.

Conclusion:

MMC needle bleb revision appears to be an effective method to revive failed filtration surgery after trabeculectomy in patients with congenital glaucoma. This technique is effective in reducing IOP with preservation of the remaining conjunctiva for further surgery.

Topical treatment options for conjunctival neoplasms

Topical therapies offer a nonsurgical method for treating conjunctival tumors by delivering high drug concentrations to the ocular surface. Over the past ten years, topical agents have been used by investigators to treat various premalignant and malignant lesions of the conjunctiva, such as primary acquired melanosis with atypia, conjunctival melanoma, squamous intraepithelial neoplasia and squamous cell carcinoma of the conjunctiva, and pagetoid spread of the conjunctiva arising from sebaceous cell carcinoma. Despite the enthusiasm generated by the success of these agents, there are unanswered questions regarding the clinical efficacy of this new nonsurgical approach, and whether a single topical agent can achieve cure rates comparable with traditional therapies. Furthermore, the long-term consequences of prolonged courses of topical chemotherapeutic drugs on the ocular surface are unknown, and the ideal regimen for each of these agents is still being refined. In this review, we present specific guidelines for treating both melanocytic and squamous neoplasms of the conjunctiva, utilizing the available data in the literature as well as our own clinical experience at the Memorial Sloan-Kettering Cancer Center.

Utilizing targeted gene therapy with nanoparticles binding alpha v beta 3 for imaging and treating choroidal neovascularization

Purpose

The integrin αvβ3 is differentially expressed on neovascular endothelial cells. We investigated whether a novel intravenously injectable αvβ3 integrin-ligand coupled nanoparticle (NP) can target choroidal neovascular membranes (CNV) for imaging and targeted gene therapy.

Methods

CNV lesions were induced in rats using laser photocoagulation. The utility of NP for in vivo imaging and gene delivery was evaluated by coupling the NP with a green fluorescing protein plasmid (NP-GFPg). Rhodamine labeling (Rd-NP) was used to localize NP in choroidal flatmounts. Rd-NP-GFPg particles were injected intravenously on weeks 1, 2, or 3. In the treatment arm, rats received NP containing a dominant negative Raf mutant gene (NP-ATPμ-Raf) on days 1, 3, and 5. The change in CNV size and leakage, and TUNEL positive cells were quantified.

Results

GFP plasmid expression was seen in vivo up to 3 days after injection of Rd-NP-GFPg. Choroidal flatmounts confirmed the localization of the NP and the expression of GFP plasmid in the CNV. Treating the CNV with NP-ATPμ-Raf decreased the CNV size by 42% (P<0.001). OCT analysis revealed that the reduction of CNV size started on day 5 and reached statistical significance by day 7. Fluorescein angiography grading showed significantly less leakage in the treated CNV (P<0.001). There were significantly more apoptotic (TUNEL-positive) nuclei in the treated CNV.

Conclusion

Systemic administration of αvβ3 targeted NP can be used to label the abnormal blood vessels of CNV for imaging. Targeted gene delivery with NP-ATPμ-Raf leads to a reduction in size and leakage of the CNV by induction of apoptosis in the CNV.

Use of Ultrasound Biomicroscopy to Predict Long-Term Outcome of Sub-Tenon Needle Revision of Failed Trabeculectomy Blebs: A Pilot Study

Purpose.

To evaluate the role of ultrasound biomicroscopy (UBM) in predicting the long-term outcome of sub-Tenon needling revision of failed trabeculectomy blebs.

Methods.

Adult patients with a failed trabeculectomy bleb and unsatisfactory intraocular pressure (IOP) control were recruited. The aqueous flow under the partial thickness scleral flap was looked for and the blebs classified on UBM as scleral route patent (SRP) or scleral route occluded (SRO). All blebs underwent needling revision with injection of 5 mg/0.1 mL 5-fluorouracil. Survival of the revision procedure at the end of 2 years follow-up with regards to the baseline UBM characterization of the bleb was noted. Successful outcome was defined as IOP <22.0 mmHg and/or 30% reduction of baseline IOP with or without medication.

Results.

A total of 13 eyes had SRP and 5 eyes had SRO blebs on UBM. Only SRP blebs survived the needling procedure by the end of 2 years. Of the 13 SRP blebs, 10 blebs survived (76.9%). Needling had failed in all 5 SRO blebs. The overall success rate was 55.6 % at 2 years. There was no difference in age, IOP, and time from initial trabeculectomy between the failed and successful group. The outcome correlated significantly to the patency of the scleral route assessed by UBM (p=0.07).

Conclusions.

Ultrasound biomicroscopy characterization of failed blebs appears to help in predicting the outcome of needle revision. In SRO blebs, it may be better to plan a full bleb revision rather than needling alone. Ultrasound biomicroscopy may help in avoiding an unnecessary needling procedure in SRO blebs where it is likely to fail.

Trabeculectomy versus Ahmed Glaucoma Valve implantation in neovascular glaucoma

Purpose:

To compare surgical outcomes in neovascular glaucoma patients who underwent trabeculectomy with mitomycin C versus Ahmed Glaucoma Valve implantation.

Patients and methods:

This was a retrospective comparative case series. We reviewed 40 eyes of 39 patients with underlying diagnosis of neovascular glaucoma, divided into two groups: Ahmed Glaucoma Valve (N = 20) and trabeculectomy with mitomycin C (N = 20). Surgical success was defined as 6 mm Hg ≤ intraocular pressure ≤21 mm Hg, with or without the use of glaucoma medications, with no further glaucoma surgery, and light perception or better vision. Early postoperative hypotony was defined as intraocular pressure <5 mm Hg during the first postoperative week.

Results:

The average follow-up was 31 months (range 6–87 months) for the Ahmed Glaucoma Valve group and 25 months (6–77 months) for the trabeculectomy group. Although the mean number of postoperative intraocular pressure-lowering medications was significantly higher in the trabeculectomy group compared with the Ahmed Glaucoma Valve group at 3 and 6 month time points, there was no statistically significant difference at any other time point. There was no statistically significant difference between both groups in postoperative visual acuity and intraocular pressure. Success was 70% and 65% at 1 year and 60% and 55% at 2 years after Ahmed Glaucoma Valve and trabeculectomy, respectively. Kaplan–Meier survival curve analysis showed no significant difference in success between the two groups (P = 0.815). Hyphema was the most common complication in both groups.

Conclusion:

We found similar results after trabeculectomy with mitomycin C and Ahmed Glaucoma Valve implantation in eyes with neovascular glaucoma.

Effect of excision of avascular bleb and advancement of adjacent conjunctiva for treatment of hypotony

PURPOSE

To evaluate the efficacy of excision of avascular bleb and advancement of adjacent conjunctiva (EBAC) for treatment of hypotony after trabeculectomy with mitomycin C (MMC).

METHODS

Fifteen patients (17 eyes) who received EBAC for correction of hypotony between September 1996 and October 2008 were reviewed retrospectively. The main outcomes were intraocular pressure (IOP) and postoperative complications.

RESULTS

Hypotony (IOP <6 mmHg) of eight eyes (47.1%, seven patients) was caused by bleb perforation. Of these, two eyes (two patients) had a history of trauma. Hypotony appeared at 33.9+/-30.8 months, and EBAC was performed at 48.2+/-35.3 months after trabeculectomy with MMC. The mean follow-up period was 38.3+/-29.8 months. The qualified success rate of EBAC was 100% at 51 months after EBAC, and the complete success rate of EBAC was 76.5% at six months and 70.6% at 51 months, as determined by Kaplan-Meier analysis. Post-EBAC complications included blepharoptosis in four eyes (23.5%) and bleb perforation in one (5.9%). The blepharoptosis resolved within one month after EBAC in two patients. However, in the other patients, mild blepharoptosis remained at 17 and 22 months postoperatively.

CONCLUSIONS

EBAC was found to be an effective method for treatment of hypotony after trabeculectomy with MMC, and postoperative blepharoptosis was a major complication.

Aberrant wound-healing response in mitomycin C-treated leaking blebs: a histopathologic study

OBJECTIVE

To characterize histopathologic features of leaking mitomycin C-treated blebs and aberrant wound healing that may lead to persistent conjunctival thinning and leakage.

METHODS

Forty mitomycin C-treated filtering blebs excised for persistent leaks from 40 patients were examined histopathologically using hematoxylin-eosin, periodic acid-Schiff, Masson trichrome, and Alcian blue histochemical stains.

RESULTS

Ninety percent of the leaking blebs contained epithelial-stromal domes with areas of acellular stroma covered by attenuated epithelium. Seventy-five percent of the blebs demonstrated varying degrees of fibrovascular repair growing from the bleb margin, either beneath or interdigitating with the acellular zone. A novel observation in 65% of specimens was Alcian blue-positive myxoid stroma at the interface between the fibrovascular proliferation and the epithelial-stromal dome. The association between the presence of fibrovascular proliferation and Alcian blue-staining myxoid stroma was significant by Fisher exact test (P = .002).

CONCLUSIONS

A desirable filtration bleb requires a sufficient reparative fibrovascular response to maintain an epithelial-stromal barrier to prevent leakage. Fibroblasts must lay down a continuous collagen-rich fibrous layer, rather than merely myxoid stroma, beneath the conjunctival epithelium to promote bleb stability. Surgical techniques and postsurgical care should aim to attain this desired outcome.

Filtering Bleb Evaluation with Slit-Lamp–Adapted 1310-nm Optical Coherence Tomography

PURPOSE

Investigation of slit-lamp-adapted 1310-nm optical coherence tomography (OCT) as an in vivo imaging device in the postoperative course of glaucoma surgery.

METHODS

Postoperative images of filtering blebs and deep sclerectomies and their healing processes were qualitatively evaluated with a slit-lamp-adapted anterior segment OCT (AS-OCT; Heidelberg Engineering, Heidelberg, Germany) in 28 patients. Ophthalmologic examinations included slit-lamp examination, applanation tonometry, and slit-lamp photography. The OCT scans were qualitatively correlated with the morphologic and functional outcome of the filtering bleb.

RESULTS

1310-nm OCT was able to demonstrate the internal structure and the dimensions of filtering blebs, as well as the scleral flap and the deep sclerectomy location including Descemet membrane. Functioning filtering blebs showed a low OCT signal, small fluid-filled cysts, superficial microcystic layer, and a slack internal texture. High internal reflectivity indicated an earlier scarring of the filtering bleb. Nonfunctioning filtering blebs delivered a high OCT signal, no or few cysts, and a dense internal texture. These different OCT patterns correlated with the clinical outcome.

CONCLUSIONS

Slit-lamp-adapted 1310-nm OCT allowed the noncontact observation and documentation of the postoperative healing course of filtering blebs after glaucoma surgery. Internal structures of the filtering bleb and deep sclerectomies could be visualized. Functioning and dysfunctioning filtering blebs delivered different OCT pattern and correlated with the clinical outcome. This could be a new way to assess the postoperative healing process with the possibility of earlier intervention in cases of impending scarring.

Trabeculectomy with mitomycin C for neovascular glaucoma: prognostic factors for surgical failure

PURPOSE

To evaluate the prognostic factors for surgical outcomes of trabeculectomy with mitomycin C (MMC) for neovascular glaucoma (NVG).

DESIGN

Retrospective cohort study.

METHODS

We reviewed the medical records of 101 patients (101 eyes) with NVG treated at Kumamoto University Hospital. The primary endpoint was persistent intraocular pressure > or = 22 mm Hg, deterioration of visual acuity to no light perception, and additional glaucoma procedures. Multivariate analysis was performed using the Cox proportional hazards model.

RESULTS

The mean follow-up period was 29.3 months (range, 0.5 to 142.3 months). The probability of success 1, 2, and 5 years after trabeculectomy was 62.6%, 58.2%, and 51.7%, respectively. The multivariate model showed that younger age (relative risk [RR], 0.96/year; P = .0007) and previous vitrectomy (RR, 1.62; P = .02) were prognostic factors for surgical failure among all NVG patients. Additionally, an eye with unremoved proliferative membrane and/or unrepaired retinal detachment (RD) after vitrectomy (RR, 1.59; P = .05) was a probable prognostic factor in a subgroup of 66 eyes with previous vitrectomy, and having a fellow eye with NVG (RR, 1.73; P = .003) was a significant prognostic factor in 82 eyes with NVG attributable to diabetic retinopathy.

CONCLUSIONS

The prognostic factors for surgical failure of trabeculectomy with MMC for NVG were younger age and previous vitrectomy in all NVG patients, and having a fellow eye with NVG in patients with disease caused by diabetic retinopathy. Persistent proliferative membrane and/or RD after vitrectomy might contribute to poorer outcomes of trabeculectomy.