Intraoperative mitomycin versus postoperative 5-fluorouracil in high-risk glaucoma filtering surgery

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.

Effect of mitomycin C and 5-fluorouracil on wound healing in patients undergoing glaucoma surgery: A meta-analysis

Increased intraocular pressure (IOP) is a risk factor for glaucoma. One treatment option is trabeculectomy. Antimetabolic agents are used in the operation to decrease the post-operative scarring of the wound. The two most common medicines are Mitomycin C (MMC) and 5-Fluorouracil (5-FU). The aim of this research is to assess the effect of MMC on post-operation wound healing in comparison with 5-FU in addition to trabeculectomy. Well, we went through four common databases. Our language was limited to English during the study. The last time we looked at the e-databases was August 2023. Case control studies were performed where MMC resulted in better wound healing than 5-FU. Researchers selected a total of 1023 trials and eventually selected six trials for data analysis. Four hundred and ninety one cases of glaucoma were treated with trabeculectomy. Among them, 246 were given MMC and 245 were given 5-FU during operation. Six trials showed that there was no statistical difference between MMC and 5-FU in the incidence of post-operative wound leak in glaucoma patients who received trabeculectomy (OR, 1.21; 95% CI, 0.63-2.30 p = 0.57); Five trials demonstrated that MMC was associated with a reduced risk of post-operative corneal damage compared to 5-FU injection (OR, 0.18; 95% CI, 0.06-0.56 p = 0.003); In both trials, the incidence of post-operative bleeding was not significantly different from that of 5-FU injected in the MMC group (OR, 0.33; 95% CI, 0.05-2.16 p = 0.25). Our results indicate that MMC is superior to 5-FU in the reduction of post-operative corneal injury. Additional comparisons between MMC and 5-FU are required in order to increase the reliability and effectiveness of these findings.

Long-term success after trabeculectomy in open-angle glaucoma: results of a retrospective cohort study

OBJECTIVE

To evaluate the long-term outcomes of trabeculectomy (TE) surgery in a large cohort with a minimum follow-up of 3 years.

DESIGN

Retrospective cohort study.

SETTING

University Eye Hospital, Germany.

PARTICIPANTS

Three hundred and seventy-nine patients with open-angle glaucoma underwent TE with mitomycin C (MMC) between January 2013 and February 2017 with a minimal follow-up of 3 years. Eligible patients were identified via an electronic surgical case register.

INTERVENTIONS

All patients had undergone TE with MMC following a set surgical protocol. To assess the influence of cataract surgery following TE, eyes which underwent cataract surgery at least 6 months after TE were matched 1:3 by sex and age to eyes who did not undergo cataract surgery during the follow-up period.

MAIN OUTCOME MEASURES

Primary outcome was the proportion of surgical success based on intraocular pressure (IOP), surgical complications, the need for revision surgery, loss of light perception and the need for additional pressure-lowering medication.

RESULTS

The mean follow-up time was 6 (±0.8, IQR: 5.4-6.5) years. Seventy-three per cent of eyes achieved qualified surgical success at the last follow-up (IOP≥5 mm Hg and ≤18 mm Hg, without surgical complications or complete loss of vision) but necessitated additional medical therapy, complete surgical success with no additional medical therapy was achieved in 69% of eyes. There was no significant difference in the success probability between eyes that had undergone cataract surgery after TE and those that had not (p=0.45).

CONCLUSIONS

The results demonstrate a high and stable success rate of TE after a mean follow-up time of approximately 6 years, that is, not affected by later cataract surgery.

Racial Disparities Affecting Black Patients in Glaucoma Diagnosis and Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Racial Disparities Affecting Black Patients In Glaucoma Diagnosis And Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Zinc Oxide Tetrapods Modulate Wound Healing and Cytokine Release In Vitro-A New Antiproliferative Substance in Glaucoma Filtering Surgery

Glaucoma filtering surgery is applied to reduce intraocular pressure (IOP) in cases of uncontrolled glaucoma. However, postoperative fibrosis reduces the long-term success of both standard trabeculectomy and microstents. The aim of this study was to test the antiproliferative and anti-inflammatory potential of ZnO-tetrapods (ZnO-T) on human Tenon's fibroblasts (HTFs) for glaucoma surgery. The toxicity of ZnO-T on HTFs was determined using an MTT test. For analysis of fibroblast proliferation, migration, and transdifferentiation, cultures were stained for Ki67, alpha-smooth muscle actin (α-SMA), and p-SMAD. A fully quantitative multiplex ELISA was used to determine the concentrations of different cytokines, platelet-derived growth factor (PDGF), and hepatocyte growth factor (HGF) in culture supernatants with and without previous ZnO-T treatment. Treatment with higher concentrations (10 and 20 µg/mL) was associated with HTF toxicity, as shown in the wound healing assay. Furthermore, the number of Ki67, α-SMA-positive, and pSMAD-positive cells, as well as IL-6 and HGF in supernatants, were significantly reduced following incubation with ZnO-T. In conclusion, we were able to show the antiproliferative and anti-inflammatory potentials of ZnO-T. Therefore, the use of ZnO-T may provide a new approach to reducing postoperative fibrosis in glaucoma filtering surgery.

Comparison of long-term outcomes of trabeculectomy and risk factors for failure in eyes post penetrating keratoplasty or Descemet's stripping endothelial keratoplasty

Purpose:

To evaluate the outcomes of trabeculectomy, graft survival, and risk factors for failure in post penetrating keratoplasty (PK) and Descemet’s stripping endothelial keratoplasty (DSEK) eyes.

Methods:

We reviewed charts of eyes that underwent trabeculectomy for post keratoplasty glaucoma PK [25 eyes] and DSEK [14 eyes] between 1993 and 2019. The demographics, clinical features, and surgical outcomes were evaluated. Success of trabeculectomy was defined as complete when the intraocular pressure (IOP) was >5 and ≤21 mmHg without antiglaucoma medications (AGM) and qualified with AGM. Clear and compact graft was considered for graft success.

Results:

Median (interquartile range [IQR] preoperative IOP in post-PK eyes and post-DSEK eyes was comparable, 32 (28–38) vs. 31.5 (25–36) mmHg, P = 0.38). Median number of preoperative AGMs was comparable (P = 0.78). Median postoperative follow-up was longer in post-PK, compared with post-DSEK, 2.5 (1.3–3.3) vs. 1 (0.3–2.9) years (P = 0.05). Kaplan–Meier survival estimates for complete and qualified success of trabeculectomy at 3 years were 23.7% and 73.3%, respectively, for PK and 45.8% and 71.6%, respectively, for DSEK. Kaplan–Meier survival estimates for graft survival were 91.8% up to 3 years for PK and 100% until 2 years and 77.8% at 3 years for DSEK. Higher IOP prior to trabeculectomy was a risk factor for failure of trabeculectomy (P = 0.03) and older age was a risk factor for graft failure (P = 0.05) in PK eyes. Number of prior corneal surgeries (P = 0.05) was associated with failure of trabeculectomy and graft failure in post-DSEK eyes.

Conclusion:

Trabeculectomy had moderate qualified success in post-PK and DSEK eyes at 3 years. Higher pretrabeculectomy IOP and higher number of prior corneal surgeries were significantly associated with failure of trabeculectomy in PK and DSEK eyes, respectively.

[Pharmacological modulation of wound healing in glaucoma surgery]

Despite the well-known effectiveness of pharmacological glaucoma therapy, surgical approach remains one of the main treatment options for some forms and stages of the disease. The long-term success of glaucoma surgery depends on the intensity of local wound healing processes at the surgical site. The most common way to influence healing processes in surgical treatment of glaucoma is the use of antimetabolites. However, given the high risk of serious complications associated with their use, the search for new drugs devoid of these disadvantages continues. The aim of this review is to describe the efficacy and safety of both currently used and upcoming pharmacological ways to influence the wound healing process after glaucoma surgery in order to improve the stability of hypotensive effect.

Late-onset Endophthalmitis Caused by Streptococcus Cristatus after Trabeculectomy

Purpose: To report a case of late-onset bleb-associated endophthalmitis caused by <i>streptococcus cristatus</i> (<i>S. cristatus</i>) after trabeculectomy.Case summary: A 59-year-old woman presented with left ocular pain and visual disturbance. She had undergone trabeculectomy of the left eye 2 years ago. At the initial visit, she was only able to count fingers from the left eye. Whitish thin bleb, conjunctival injection, and inflammation were observed in the left anterior chamber, and the fundus could not be visualized. Despite administering topical and systemic antibiotics, the chamber reaction worsened, and hypopyon and inflammatory membrane were noticed the next day. Vitrectomy with phacoemulsification and intravitreal antibiotic injection was performed, and the intravitreal antibiotic injections were repeated over the next two days. Bacterial culture of vitreous fluid showed a growth of <i>S. cristatus</i> 5 days after the surgery, and inflammation improved after 7 days. One month later, she was still only able to count fingers from the left eye, but there were no signs of endophthalmitis.Conclusions: Postoperative endophthalmitis after glaucoma filtering surgeries caused by <i>S. cristatus</i> has not been reported previously from Korea. To the best of our knowledge, this is the first Korean case of late-onset bleb-associated endophthalmitis caused by <i>S. cristatus</i>. If gram-positive cocci are grown in samples from the patients with endophthalmitis after trabeculectomy, resident oral microflora such as <i>S. cristatus</i> should be considered as the causative pathogen.

Assessing safety and success after using bevacizumab, 5-fluorouracil or placebo in primary trabeculectomy. A Prospective Randomized placebo controlled 1-Year Follow-up Study

PURPOSE

The aim of this study was to determine whether glaucoma patients after trabeculectomy could benefit more from subconjunctival injections of bevacizumab than 5-FU or placebo.

METHODS AND RESULTS

Fifty-one eyes of 51 patients were recruited for primary MMC (0.2mg/ml for 1 min) augmented trabeculectomy. 17 patients were randomly assigned to receive 1.25mg (0.05ml) of bevacizumab augmentation, 21 patients were assigned to receive 0.1ml of 50mg/ml 5-FU and 13 patients were assigned to a control group receiving a normal saline injection as a placebo. Initial recruitment included 58 patients, but seven patients had to be excluded from the study for various reasons. Postoperative follow up of IOP and bleb characteristics was carried out at 1 day, 1 week, 3 weeks, 6 weeks, 6 months and 1 year after surgery. All analyses where carried out by two masked clinicians. IOP reduction was statistically significant (P < 0.05) across all three groups between baseline visit and final 1-year postoperative visit. There was no significant difference of the final average IOP values between the three groups. Bleb evaluation was made using the Moorfields bleb grading system (MBGS) after 1 year follow up. Central bleb area was statistically greater in the Bevacizumab group when compared with the 5-FU group but not with the placebo group. The vascularity of the central bleb was significantly different between the groups with the Bevacizumab group showing the least vascularity. Vascularity of the peripheral bleb was also decreased in the Bevacizumab group when compared with the placebo group but not with the 5-FU group.

CONCLUSION

The 12-month IOP results showed no significant differences between the groups of patients after Bevacizumab, 5-FU or placebo to augment primary MMC enhanced trabeculectomy. However, by the analysis of bleb morphology there was a significant difference in terms of central bleb area and vascularity.

Aqueous outflow channels and its lymphatic association: A review

The human eye has a unique immune architecture and behavior. While the conjunctiva is known to have a well-defined lymphatic drainage system, the cornea, sclera, and uveal tissues were historically considered "alymphatic" and thought to be immune privileged. The very fact that the aqueous outflow channels carry a clear fluid (aqueous humor) along the outflow pathway makes it hard to ignore its lymphatic-like characteristics. The development of novel lymphatic lineage markers and expression of these markers in aqueous outflow channels and improved imaging capabilities has sparked a renewed interest in the study of ocular lymphatics. Ophthalmic lymphatic research has had a directional shift over the last decade, offering an exciting new physiological platform that needs further in-depth understanding. The evidence of a presence of distinct lymphatic channels in the human ciliary body is gaining significant traction. The uveolymphatic pathway is an alternative new route for aqueous outflow and adds a new dimension to pathophysiology and management of glaucoma. Developing novel animal models, markers, and non-invasive imaging tools to delineate the core anatomical structure and physiological functions may help pave some crucial pathways to understand disease pathophysiology and help develop novel targeted therapeutic approaches for glaucoma.

Combined Trabeculotomy-Trabeculectomy Versus Trabeculectomy for Treatment of Silicone Oil-induced Ocular Hypertension

PRCIS

Combined trabeculotomy-trabeculectomy (CTT) has a significantly better hypotensive effect than trabeculectomy and a higher success rate in cases of silicone oil-induced ocular hypertension.

PURPOSE

To compare the ocular hypotensive effect of CTT with mitomycin-C (MMC) to that of trabeculectomy with MMC in cases of silicone oil-induced ocular hypertension.

PATIENTS AND METHODS

Thirty eyes of 30 patients with high intraocular pressure (IOP) after vitrectomy and silicone oil injection (followed by silicone oil removal) were randomly allocated to 2 groups in this randomized trial. Group A was composed of 15 cases who underwent combined CTT with MMC while group B cases contained 15 cases undergoing trabeculectomy with MMC. Patients were followed up for 12 months. We included patients above 18 years old, having performed vitrectomy and silicone oil injection followed by oil removal, and having IOP >21 mm Hg uncontrollable by antiglaucoma medications.

RESULTS

The postoperative IOP drop was significantly greater in group A than in group B at all follow up visits (P<0.05). Compared with preoperative IOP, both surgeries produced a significantly lower postoperative IOP at all follow-up visits (P<0.05). For group A, complete success rates (IOP≤21 mm Hg without ocular hypotensive medications) and qualified success rates (IOP≤21 mm Hg with or without ocular hypotensive medications) were both higher than for group B.

CONCLUSION

Both surgeries effectively reduce IOP in cases of silicone oil-induced ocular hypertension, but CTT has a significantly better hypotensive effect and a higher success rate on the long-term.

Trabeculectomy with OloGen versus Mitomycin C for the Treatment of Silicone Oil-Induced Glaucoma

AIM

To compare the intraocular pressure-lowering effect and success rate of trabeculectomy with OloGen to that of trabeculectomy with mitomycin C (MMC) in cases of silicone oil-induced glaucoma.

MATERIALS AND METHODS

Forty eyes of forty patients with elevated intraocular pressure (IOP) after vitrectomy and silicone oil injection (followed by silicone oil removal) were assigned to two groups. Group A included 20 cases who underwent trabeculectomy with OloGen, while group B cases contained 20 cases undergoing trabeculectomy with MMC. The follow-up period was 24 months. Patients enrolled had IOP > 21 mmHg despite being on antiglaucoma medications.

RESULTS

The mean postoperative IOP reduction was lower in group A than in group B at all follow-up visits, but this difference was not statistically significant (p > 0.05). Moreover, group A and B patients were found to be similar as regards the need for postoperative antiglaucoma medications on all follow-up visits. The Kaplan-Meier survival analysis curves for the two groups revealed slightly higher success rates in group B than in group A. However, these differences were not statistically significant for both qualified success (IOP ≤ 21 mmHg with or without antiglaucoma medications) and complete success (IOP ≤ 21 mmHg without antiglaucoma medications). There was no significant difference in the postoperative complication rate between the two groups.

CONCLUSION

OloGen implant lowers IOP to a similar extent as MMC when combined with trabeculectomy for the treatment of silicone oil-induced glaucoma, and with comparable success rates. The rate of postoperative complications is similar for OloGen implantation and MMC.

The American Glaucoma Society 100: Articles with Significant Impact on Clinical Glaucoma Care

PURPOSE

To identify 100 articles with significant impact on the clinical care of patients with glaucoma.

DESIGN

Cross-sectional study.

PARTICIPANTS

A total of 108 members of the American Glaucoma Society (AGS) in the original survey and 63 in the follow-up survey.

METHODS

The 100 most frequently cited English-language original articles relevant to glaucoma were identified via a Scopus search. The American Academy of Ophthalmology (AAO) Preferred Practice Pattern Glaucoma Panel selected an additional 100 articles including newer and "classic" papers. An anonymous survey including the list of 200 articles was distributed to the AGS membership. Survey participants were asked to rate the impact of each article on the clinical care of glaucoma patients using a 4-point Likert scale. Survey respondents were able to provide "write-in" suggestions for the AGS 100. A subsequent anonymous follow-up survey was distributed asking participants to use the same Likert scale to rate 31 "write-in" articles suggested in the original survey. The AGS 100 was created by ranking the top 100 articles based on mean Likert scores from the original and follow-up surveys.

MAIN OUTCOME MEASURES

Original English-language articles that have influenced the clinical care of patients with glaucoma.

RESULTS

The mean ± standard deviation Likert score of articles included in the AGS 100 was 2.9 ± 0.3 (range, 2.47-3.69). The median citation number was 345 (range, 11-2426). Publication year ranged from 1965 to 2020. Articles were published in 14 journals, the most common of which were Ophthalmology (42%), American Journal of Ophthalmology (21%), and Archives of Ophthalmology (20%). Forty-eight articles were derived from randomized clinical trials.

CONCLUSIONS

The AGS 100 is a collection of articles judged to have significant clinical impact on glaucoma care. The list will serve as an online educational resource for ophthalmologists in training and in practice.

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.

Comparison of the Efficacy and Safety of Trabeculectomy with Mitomycin C According to Concentration: A Prospective Randomized Clinical Trial

(1) Background: Mitomycin C (MMC) is commonly used during trabeculectomy. However, there is no consensus on which concentration should be used. We aimed to compare the efficacy and safety of 0.2 mg/mL and 0.4 mg/mL of MMC in eyes undergoing trabeculectomy. (2) Methods: Thirty-six eyes (36 glaucoma patients) were randomized to undergo a trabeculectomy with 0.2 mg/mL or 0.4 mg/mL of MMC. The success rate was evaluated according to three criteria: (A) intraocular pressure (IOP) ≤ 18 mmHg and IOP reduction ≥ 20%; (B) IOP ≤ 15 mmHg and IOP reduction ≥ 25%; (C) IOP ≤ 12 mmHg and IOP reduction ≥ 30%. Cox’s proportional hazard model was used to identify the predictive factors for failure. Immunohistochemical procedures for matrix metalloproteinase (MMP) were performed on Tenon’s tissue. Bleb morphology was evaluated. Safety was assessed based on the incidence of complications. (3) Results: Of the 36 eyes, 19 underwent trabeculectomy with 0.2 mg/mL of MMC and 17 with 0.4 mg/mL. The success rates were 75%, 67%, and 47% at 6 months for criteria A, B, and C, respectively. There were no significant differences between the two groups. High MMP-9 staining and low preoperative IOP were associated with failure (hazard ratio (HR), 5.556; p = 0.033, and HR, 0.936; p = 0.033). Complications included hypotony in two eyes (6%), hyphema in one eye (3%), and choroidal detachment in one eye (3%). (4) Conclusions: Trabeculectomy with 0.2 mg/mL and 0.4 mg/mL of MMC showed similar IOP-control effects to those recorded in previous studies, along with a low rate of complications. There was no significant difference in efficacy or safety between the 0.2 mg/mL and 0.4 mg/mL MMC groups.

Outcomes of trabeculectomy with polyvinylpyrrolidone collagen versus mitomycin in primary open angle glaucoma. 36-month follow-up

PURPOSE

Describe and compare the effects of intraoperative application of Polyvinylpyrrolidone Collagen (PVP) versus Mitomycin C (MMC) on the pattern of change in mean IOP reduction and mean number of medications over 36-months follow-up in patients with primary open angle glaucoma (POAG) undergoing trabeculectomy.

METHODS

Prospective, randomized, comparative study. Twenty-six eyes of 26 patients with POAG and no previous incisional glaucoma surgery underwent trabeculectomy and were randomized to PVP or MMC and completed a 36-month follow-up. Main outcome measures were IOP and number of glaucoma medications. Multivariate longitudinal analysis was performed by fitting a linear trend model adjusting for baseline response for the IOP outcome and a log-linear regression model with within-subject associations for the number of hypotensive medications outcome. Sensitivity analysis was performed to assess lower and higher order polynomial trends over time in IOP.

RESULTS

The univariate analysis revealed that the mean IOP reduction from baseline to 36 months was 7.62mmHg (3.05; 12.18) in the MMC group and 8.15mmHg (-0.64; 16.95) in the PVP group. Mean percentage IOP reduction from baseline was 37.09% (15.93; 58.17) and 36.08% (5.16; 67.20) in the PVP group. Mean change in number of medications from baseline to 36 months was -0.92 medications (-3.38; +1.54) for the MMC group and -1 medication (-3.12; +1.12) for the PVP group. Both groups had a statistically significant decline in mean IOP over the follow-up period (p<0.001) but there was no discernible difference between the two exposure groups in the rate of change in IOP (p=0.5975). Sensitivity analysis showed that a linear trend model is adequate to describe the IOP reduction over the follow-up period. Both groups had a statistically significant change in the number of hypotensive medications used between baseline and month 36 (p<0.05) but there was no discernible difference between exposure groups (p=0.2917). Both the PVP and MMC groups showed an initial reduction in number of medications until month 12 and a relatively linear increase towards month 36. A longer follow-up may be warranted to reveal differences in the number of medications between the two exposure groups. Postoperative complications were less frequent in the PVP group.

CONCLUSIONS

The use of PVP during trabeculectomy achieves and maintains a statistically significant IOP reduction from baseline to 36 months and decreases the number of glaucoma medications. Secondary outcome measures showed a lower incidence of adverse events in the PVP group.

Surgery for glaucoma in modern corneal graft procedures

Glaucoma is a common cause of vision loss after corneal transplantion and is considered a major risk factor for graft failure. Glaucoma may be present before corneal transplant surgery, or increased intraocular pressure may develop after keratoplasty in up to one-third of patients. Pre-existing glaucoma should be controlled before keratoplasty, either medically or surgically. For postkeratoplasty increase in intraocular pressure; identifying the risk factors allows appropiate follow-up and management. Patients undergoing anterior lamellar keratoplasty may take advantage of reduced rates of postkeratoplasty glaucoma. Glaucoma also complicates eyes with endothelial keratoplasties, mostly related to management of intraocular pressure spikes derived from anterior chamber air bubbles. Nevertheless, the severity is less, and the intraocular pressure is more easily controlled when compared with penetrating keratoplasty. Adequate management of glaucoma that develops before or after keratoplasty may save eyes from irreversible damage to the optic nerve and increase graft survival.

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.

Antimetabolites as an adjunct to dacryocystorhinostomy for nasolacrimal duct obstruction

BACKGROUND

Nasolacrimal duct obstruction (NLDO) is a condition that results in the overflow of tears (epiphora) or infection of the nasolacrimal sac (dacryocystitis). The etiology of acquired NLDO is multifactorial and is not fully understood. Dacryocystorhinostomy (DCR) is the surgical correction of NLDO, which aims to establish a new drainage pathway between the lacrimal sac and the nose. The success of DCR is variable; the most common cause of failure is fibrosis and stenosis of the surgical ostium. Antimetabolites such as mitomycin-C (MMC) and 5-fluorouracil (5-FU) have been shown to be safe and effective in reducing fibrosis and improving clinical outcomes in other ophthalmic surgery settings (e.g. glaucoma and cornea surgery). Application of antimetabolites at the time of DCR has been studied, but the utility of these treatments remains uncertain.

OBJECTIVES

Primary objective: To determine if adjuvant treatment with antimetabolites improves functional success in the setting of DCR compared to DCR alone. Secondary objectives: To determine if anatomic success of DCR is increased with the use of antimetabolites, and if the surgical ostium is larger in participants treated with antimetabolites.

SEARCH METHODS

We searched the Cochrane Register for Controlled Trials (CENTRAL) (which contains the Cochrane Eye and Vision Trials Register) (2019, Issue 9), Ovid MEDLINE, Embase.com, PubMed, LILACS (Latin American and Caribbean Health Sciences Literature database), ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic searches. We last searched the electronic databases on 6 September 2019.

SELECTION CRITERIA

We only included randomized controlled trials. Eligible studies were those that compared the administration of antimetabolites of any dose and concentration versus placebo or another active treatment in participants with NLDO undergoing primary DCR and reoperation. We only included studies that had enrolled adults 18 years or older. We also included studies that used silicone intubation as part of the DCR procedure.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently screened the search results, assessed risk of bias, and extracted data from the included studies using an electronic data collection form.

MAIN RESULTS

We included 31 studies in the review, of which 23 (1309 participants) provided data relating to our primary and secondary outcomes. Many of the 23 studies evaluated functional success, while others also assessed our secondary outcomes of anatomic success or ostium size, or both. Study characteristics Participant characteristics varied across studies, with the age of participants ranging from 30 to 70 years. Participants were predominantly women. These demographics correspond to those most frequently affected by nasolacrimal duct obstruction. Almost all of the studies utilized MMC as the antimetabolite, with only one using 5-FU. We assessed most trials as at unclear risk of bias for most domains. Conflicts of interest were not frequently reported, although the antimetabolites used are generic medications, and studies were not likely to be conducted for financial interest. Findings Twenty studies provided data on the primary outcome of functional success, of which 7 (356 participants) provided data at 6 months and 14 (909 participants) provided data beyond 6 months. At six months, the results showed no evidence of effect of antimetabolite on functional success (risk ratio (RR) 1.12, 95% confidence interval (CI) 0.98 to 1.29; low-certainty evidence). Beyond six months, the results favored the antimetabolite group (RR 1.15, 95% CI 1.07 to 1.25; moderate-certainty evidence). Fourteen studies reported data on the secondary outcome of anatomic success, of which 4 (306 participants) reported data at 6 months and 12 (831 participants) provided data beyond 6 months. Results at six months showed no evidence of effect of antimetabolite on anatomic success (RR 1.02, 95% CI 0.95 to 1.11; low-certainty evidence). Beyond six months, participants in the antimetabolite group were more likely to achieve anatomic success than those receiving DCR alone (RR 1.09, 95% CI 1.04 to 1.15; moderate-certainty evidence). At six months and beyond six months follow-up, two studies reported mean change in ostium size. We did not conduct meta-analysis for the various follow-up periods due to clinical, methodological, and statistical heterogeneity. However, point estimates from these studies at six months consistently favored participants in the antimetabolite group (low-certainty evidence). Beyond six months, while point estimates from one study favored participants in the antimetabolite group, estimates from another study showed no evidence of a difference between the two groups. The certainty of evidence at both time points was low. Adverse events Adverse events were rare. One study reported that one participant in the MMC group experienced delayed wound healing. Other studies reported no significant adverse events related to the application of antimetabolites.

AUTHORS' CONCLUSIONS

There is moderate-certainty evidence that application of antimetabolites at the time of DCR increases functional and anatomic success of DCR when patients are followed for more than six months after surgery, but no evidence of a difference at six months, low-certainty of evidence. There is low-certainty evidence that combining antimetabolite with DCR increases the size of the lacrimal ostium at six months. However, beyond six months, the evidence remain uncertain. Adverse effects of the application of antimetabolites were minimal.

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

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

Comparison of the effect of mitomycin C and bevacizumab-methylcellulose mixture on combined phacoemulsification and non-penetrating deep sclerectomy surgery on the intraocular pressure (a clinical trial study)

PURPOSE

Comparison of the effect of mitomycin C (MMC) versus bevacizumab-methylcellulose mixture (BMM) on combined phacoemulsification and non-penetrating deep sclerectomy surgery on the intraocular pressure in patients with open-angle glaucoma was made.

METHODS

The current study is a controlled, randomized, double-blind clinical trial. Thirty-eight patients were enrolled, with a total of 40 eyes, and underwent a combined phacoemulsification and non-penetrating deep sclerectomy surgery from 2016 to 2017. MMC with concentration of 0.2 mg/mL for 2 min was used for 20 eyes before separating the scleral flap, and 0.3 mL of BMM (bevacizumab 1.25 mg incorporated into 2% methylcellulose) was injected subconjunctivally following surgery. The success rate of surgery was categorized as complete, relative and failure. Fisher's exact, Mann-Whitney U and Chi-square tests were employed to data analysis. A p value < 0.05 was supposed significant.

RESULTS

Patients had the same distribution in terms of age, sex, type of glaucoma and type of cataract. Patients were followed up for a mean of 6 months. The mean intraocular pressure before surgery in the MMC group was 24.85 ± 2.83 mmHg with 3.2 ± 0.523 anti-glaucoma drugs, which reached 13.75 ± 3.552 mmHg with 0.15 ± 0.489 anti-glaucoma drugs at the latest visit. The average intraocular pressure before surgery in the BMM group was 24.45 ± 2.48 mmHg with 2.9 ± 0.641 anti-glaucoma drugs, which reached 15.40 ± 3.267 mmHg with 0.25 ± 0.55 anti-glaucoma drug at the last follow-up. The intraocular pressure was notably lower in the MMC group than BMM group 6 months after surgery. There was not a significant difference from the aspect of success rate and failure rate among the two groups at the 6-month follow-up (p = 0.135).

DISCUSSION

Based on the results of this study, MMC and bevacizumab-methylcellulose both seem to be effective in the success of combined phacoemulsification and non-penetrating deep sclerectomy surgery, but MMC decreases intraocular pressure in patients at 6 months post-surgery.

Effect of Lignocaine Concentration on Human Fibroblasts Growth in Eyes Undergoing Trabeculectomy: An in vitro Study

Purpose

To evaluate the effect of lignocaine on growth and apoptosis indication of primary human Tenon's capsule fibroblast (HTFs) in an in vitro model.

Patients and Methods

Tenon's capsule tissue obtained from patients undergoing trabeculectomy were grown in cell culture medium. The effect of different concentrations of lignocaine (0.5, 1.0, 1.5, and 2%) on the morphology and growth of the fibroblasts was studied using microscopy, cell viability, and proliferation assay, and apoptosis was detected using the FITC Annexin V Apoptosis Kit.

Results

Morphological changes similar to those of apoptotic cells, including cytoplasmic vacuolation, shrinkage, and rounding were visualized in the cells treated with concentrations greater than 1.0% (i.e., 1.5, 2.0%). Though proliferation inhibition was found with all four concentrations (0.5–2.0%), the viability of cells decreased from 1.0% lignocaine.

Conclusion

0.5% lignocaine prevents proliferation of fibroblasts without causing apoptosis in vitro.

Combined Application of Bevacizumab and Mitomycin C or Bevacizumab and 5-Fluorouracil in Experimental Glaucoma Filtration Surgery

The present study aimed at observing the effect of a single subconjunctival injection of bevacizumab (BVZ) combined with 5-fluorouracil (5-Fu) or mitomycin C (MMC) on the antiscarring effect of glaucoma filtration surgery (GFS). The inhibitory effect of combined BVZ and 5-Fu in retinal pigment epithelial cells on vascular endothelial growth factor (VEGF) levels was demonstrated through in vitro experiments. Combined BVZ and 5-Fu and combined BVZ and MMC inhibited cell cycle, induced apoptosis, and inhibited human umbilical vein endothelial cell migration. Also, the cytotoxicity of combined BVZ and 5-Fu was lower. In animal experiments, the observation of filtering bleb survival, hematoxylin and eosin and Masson staining of filtering bleb scars, and mRNA expression levels of fibrosis markers in filtering blebs showed that combined BVZ and 5-Fu had a better antiscarring effect compared with single drugs; however, the antiscarring effect of combined BVZ and MMC was not significantly different from MMC. Therefore, the findings of this study provided more reference for the clinical use of adjuncts to inhibit scarring after GFS and helped understand the regulatory effect of combined anti-VEGF antibody BVZ and antimetabolites on wound healing more comprehensively.

Conjunctival Fibrosis after Application of Mitomycin C: An Animal Experimental Study

Mitomycin C (MMC) is widely used as an antimetabolite to minimize scarring of filtering blebs. Its effectiveness has been demonstrated in several clinical studies. The drug's mechanism of action is attributed to its antiproliferative effect on the subconjunctival cells, reducing the wound healing response. We placed sponges soaked with various concentrations of MMC, from 0.05 to 1.0 mg/ml, under the conjunctiva of 18 rabbits. Four weeks later, there was marked concentration-dependent scarring of the substantia proppria of the conjunctiva. Macrophages were more numerous in treated eyes, as determined by immunohistochemistry. The reason for MMC-related fibrosis in this animal model is not clear but may be related to the substances toxic effects. Whether it is only present in rabbits remains to be clarified.

Long-Term Effects of Postoperative Subconjunctival Injections of Mitomycin-C in the Rabbit Eye

Aim

Single or multiple subconjunctival injections of mitomycin-C (MMC) may offer one way of establishing the total dosage of MMC more accurately. The method also allows re-applications later postoperatively. In this experimental, randomized prospective study we compared the effects of a single intraoperative application of MMC at the filtering site and a single postoperative subconjunctival injection of the drug.

Methods

The left eyes of 32 pigmented rabbits were divided into two groups. In the first group we applied MMC intraoperatively (10) with a 4×1 mm surgical sponge soaked in a MMC solution (0.5 mg/ml). In the second group we injected 0.4 ml of the same solution subconjunctivally (SC) immediately after (conjunctival) suture. Post-operative evaluation was carried out every day during the first week, then every three days until day 58. Survival analyses were done for intraocular pressure (IOP) and bleb failure. Log-rank tests were used to compare survival differences between the groups.

Results

The IO group showed longer survival parameters than the SC group (p<0.05), both in the control of IOP and as regards blebs. The histological persistence of fistulas was similar. The IO group, however, had a higher incidence of undesirable side effects.

Conclusions

Our findings suggest IO application of MMC is more effective in reducing fibroblast ingrowth. However, subconjunctival application offers certain advantages such as the possibility of repeating the treatment postoperatively and, therefore, using a smaller initial dose.

Low-Dosage Mitomycin C as an Adjunct to Trabeculectomy. A Prospective Controlled Study

PURPOSE

To assess the advantages and adverse effects of intraoperative low-dose Mitomycin C in filtering glaucoma surgery.

METHODS

Sixty eyes of 48 patients undergoing surgery for uncontrolled glaucoma were randomized to two groups: one underwent standard trabeculectomy, the other had trabeculectomy with intraoperative application of 0.1 mg/ml mitomycin C. Follow-up was at least one year.

RESULTS

The success rate (IOP < 18 mmHg) was 96.6% in the mitomycin C group and 73.3% in the control group. Mean IOP at one year of successful cases was 11.1 +/- 3.1 mmHg in the mitomycin C group and 16.4 +/- 6.1 mmHg in controls (p < 0.0001). Two patients in the mitomycin C group (6.6%) and six (20%) in the control group needed antiglaucomatous drugs to keep IOP below 18 mmHg.

CONCLUSIONS

Mitomycin C is a useful adjunct to glaucoma surgery. Adverse effects at the dosage used are mainly due to hypotony and are preventable with two-layer suture. Low-dose mitomycin C may be useful in standard primary trabeculectomy.

Clinical Evaluation of the Effect of Mitomycin-C in Re-Operation for Primary Open Angle Glaucoma

The aim of the study was to evaluate the effect of mitomycin-C (MMC) in a second antiglaucoma operation after failure of the first operation. We assessed 46 patients (26 male, 20 female, mean age 64.2 years) with high intraocular pressure (IOP) (mean 32.4 +/- 5.2 mmHg) despite previous trabeculectomy (Tr-Ec) one to three years earlier and topical or systemic medical treatment. All patients underwent a second Tr-Ec and were randomly divided into two groups: group A, 24 patients, underwent a second Tr-Ec with MMC and group B, 22 patients, also underwent a second Tr-Ec but without MMC. Postoperative complications included: shallow anterior chamber (duration > 1 week), group A 29.2%, group B 13.6%; chroidal effusion, group A 8.3%, group B 0%; cystic degeneration of conjunctiva, group A 16.6%, group B 4.5%; transient maculopathy, group A 12.5%, group B 0%. IOP control (< or = 20 mmHg after 18 months) was: group A 20 patients (83.3%) with mean 12.5 +/- 3.2 mmHg and group B 13 patients (63.6%) with mean 19.6 +/- 6.1 mmHg. In conclusion, the use of MMC in re-operation for primary open-angle glaucoma is associated with a higher rate of and more severe postoperative complications than Tr-Ec alone. However, it achieves significantly lower IOP in a larger number of patients.

Relationship between age and surgical success after trabeculectomy with adjunctive mitomycin C

PURPOSE

To investigate whether there is any effect of age on bleb morphology and surgical success after trabeculectomy with adjunctive Mitomycin C (MMC).

METHODS

A total 143 eyes of 123 patients were divided into two groups: group 1 ( ≤ 60 years old, n = 85) and group 2 ( > 60 years old, n = 58). Kaplan-Meier survival curve analysis was used to assess long-term surgical success according to "complete success" (intraocular pressure (IOP) reduction ≥ 30% without medications) and "qualified success" criteria (IOP reduction ≥ 30%, with or without medications) between the two groups. Cox proportional hazard models were used to examine the factors associated with surgical success. Bleb morphology was evaluated by height, extent and vascularity at postoperative 1 month, 3 months, 6 months, and 12 months.

RESULTS

The younger-age group (group 1) showed significantly better results, in terms of both complete success and qualified success, than did the older-age group (group 2) (p < 0.001 and p = 0.01, respectively). Age and preoperative anti-glaucoma medications were the factors related to complete success (p = 0.001). Also, there were significant differences in height, extent and vascularity of bleb between the two groups (p = 0.038, p = 0.002 and p = 0.006, respectively).

CONCLUSION

The long-term surgical outcome after trabeculectomy with MMC was better in the younger-age group than in the older-age group. Specifically, the younger-age group showed a more prominent and more localized bleb with less vascularity.

Glaucoma after corneal replacement

Glaucoma is a well-known complication after corneal transplantation surgery. Traditional corneal transplantation surgery, specifically penetrating keratoplasty, has been slowly replaced by the advent of new corneal transplantation procedures: primarily lamellar keratoplasties. There has also been an emergence of keratoprosthesis implants for eyes that are high risk of failure with penetrating keratoplasty. Consequently, there are different rates of glaucoma, pathogenesis, and potential treatment in the form of medical, laser, or surgical therapy.

Evaluation of a photocrosslinkable hydroxyethyl chitosan hydrogel as a potential drug release system for glaucoma surgery

Hydroxyethyl chitosan (HECTS) is a critical derivative of chitosan that has been widely used as biomedical materials due to great water-solubility and excellent biocompatibility. Here, photosensitive hydroxyethyl chitosan was synthesized by introducing azide group on NH2 of HECTS (HECTS-AZ), afterwards FTIR and ¹H NMR spectra were detected to confirm the formation of HECTS-AZ. The solution of HECTS-AZ can achieve a sol-gel transition through UV irradiation for 30 s. The evaluation of biocompability and biodegradability in vivo was conducted in rats, visual and pathological examinations exhibited the HECTS-AZ has excellent biocompability and degradation time of the hydrogel is more than 14 weeks. Furthermore, HECTS-AZ hydrogel as an ocular drug delivery system loading heparin was prepared to implant under sclera of rabbit after glaucoma filtration surgery (GFS). The experimental results demonstrated the heparin loaded hydrogel can effectively maintain filtration bleb and lowing intraocular pressure (IOP) after GFS for prolonged time. Besides, obvious inflammatory reactions and side effects have not been observed in ocular during the experimental period. In conclusion, the HECTS-AZ hydrogel is a potential drug delivery device for the treatment of glaucoma and other ocular diseases.

Deep sclerectomy for uveitic glaucoma: long-term outcomes

PurposeTo report long-term outcomes of deep sclerectomy (DS) in eyes with raised intraocular pressure (IOP) and glaucoma secondary to uveitis.Patients and methodsRetrospective consecutive case series of 43 eyes of 43 patients with uveitic glaucoma. Mitomycin C (MMC) 0.2-0.4 mg/ml was applied sub-conjunctivally prior to scleral flap dissection for 2-3 min in 35 eyes (81%). Combined phacoemulsification and DS was done in 4 cases (9%).ResultsMean follow-up was 68.5±33.5 months. In total, 23 eyes (53.5%) had previous intraocular surgery. Pre-operative IOP was 33.6±12.0 mm Hg. Mean IOP at one, three and five years after surgery was 15.5±5.0 mm Hg, 16.9±6.7 mm Hg and 16.4±5.2 mm Hg, respectively.The probability of IOP <22 and <19 mm Hg was 69 and 62% at 3 years and 60 and 51% at 5 years, respectively. This included eyes that had undergone needle revision and/or laser goniopuncture within that period but had not needed glaucoma medication or further glaucoma procedures. The overall number of glaucoma medications decreased from 3.0±1.2 to 0.8±1.2 by last follow-up (P<0.001). Serious complications included hypotony with macular folds in two eyes and occlusion of the trabeculo-Descemet's membrane (TDM) by iris in two eyes. Recurrence of uveitis was observed in 16 eyes. Seven eyes (16.3%) had subsequent procedures including trabeculectomy with MMC in one eye, DS with MMC in two eyes and Baerveldt tube implantation in five eyes.ConclusionsDS is a safe and effective procedure to lower IOP in uveitic glaucoma. However, as with other glaucoma procedures, a significant proportion of patients will require another IOP-lowering procedure in the long-term.

The Effect of Adjuvant Intracameral Triamcinolone Acetonide on the Surgical Results of Trabeculectomy with Mitomycin C

OBJECTIVES

To evaluate the effect of adjuvant intracameral triamcinolone acetonide (TA) on the surgical results of trabeculectomy with mitomycin C.

MATERIALS AND METHODS

All consecutive trabeculectomy cases performed in the glaucoma clinic between July 2012 and December 2013 were retrospectively reviewed from the patient charts. Only those with follow-up of 12 months or longer were included. Patients with intraoperative intracameral TA (study group, n=19) were compared to those without TA (control group, n=21) in terms of surgical success, intraocular pressure (IOP) change, medication use and complications.

RESULTS

Forty eyes of 31 patients (21 male/10 female, mean age 64.2±13.8 years) were included in the study. The mean follow-up period was 20.9±5.1 months and 20.7±6.7 months in the study and control groups, respectively (p=0.830). Baseline IOP was 26.4±9.9 and 25.2±7.6 mmHg (p=0.979), and final IOP was 12.7±2.6 and 13.6±3 mmHg in both groups respectively (p=0.226). At the final follow-up, complete success was observed in 68.4% and 52.4% of the study and control groups (p=0.349) and anti-glaucoma medication was used by 31.6% (mean number of medications: 0.79±1.2) and 47.6% (mean number of medications: 1.33±1.7), respectively (p>0.05). Bleb encapsulation, leakage, suture-lysis and hypotony rates were similar in both groups (for all, p>0.05). Cataract progression was noted in six (35.3%) and in five (26.3%) of the phakic eyes in the study and control groups, respectively (p=0.720).

CONCLUSION

When used intracamerally, TA did not increase the complication rate in trabeculectomy surgery. Although the group that received TA showed lower IOP levels, use of fewer medications and fewer eyes requiring medication, the differences did not reach significance.

Same-site Trabeculectomy Revision for Failed Trabeculectomy: Outcomes and Risk Factors for Failure

PURPOSE

To evaluate long-term tonometric outcomes of same-site trabeculectomy revision with mitomycin C (MMC) after failure of an initial trabeculectomy, and to identify risk factors for failure in patients with open-angle glaucoma.

DESIGN

Retrospective cohort study.

METHODS

One-hundred and seventeen patients (130 eyes) with primary open-angle, pseudoexfoliation, or pigmentary glaucoma, who failed a first trabeculectomy and who were ≥40 years of age at the time of same-site trabeculectomy revision, were included. Three levels of success criteria were defined: (A) intraocular pressure (IOP) ≤18 mm Hg and IOP reduction of 20%; (B) IOP ≤15 mm Hg and IOP reduction of 25%; and (C) IOP ≤12 mm Hg and IOP reduction of 30%. The primary outcome was the qualified Kaplan-Meier success rate (with or without medications) for each criterion. Cox multivariate regression analysis was used to identify risk factors for failure.

RESULTS

The success rates (± standard error) at the first, third, and fifth years of follow-up for criterion A were 69.7% (± 4.1%), 58.2% (± 4.6%), and 51.1% (± 5.0%); for criterion B these were 60.9% (± 4.4%), 47.8% (± 4.7%), and 44.0 (± 4.8%); and for criterion C, 44.6% (± 4.5%), 29.7% (± 4.4%), and 25.8% (± 4.3%). Mean follow-up was 5.2 (± 3.6) years. A time interval between the first and the same-site trabeculectomy revision of <3 years, worse baseline visual acuity, and dyslipidemia were significant risk factors for failure.

CONCLUSIONS

Given the long-term tonometric success rates along with significant medication reduction, same-site trabeculectomy revision with MMC should be considered as a viable option to achieve reasonable IOP targets after a first failed trabeculectomy in open-angle glaucoma patients.

Biodegradable collagen matrix implant versus mitomycin-C in trabeculectomy: five-year follow-up

Background

Clinical studies comparing trabeculectomy augmented with Ologen implant (OLO) versus trabeculectomy plus mitomycin-C (MMC) show contradictory results. To obtain long-term data, we report an extended 5-year follow-up trial evaluating the safety and efficacy of OLO as adjuvant compared to low-dosage MMC in trabeculectomy.

Methods

Forty glaucoma patients (40 eyes) assigned to trabeculectomy with MMC or Ologen. Primary outcome: target IOP at ≤21, ≤17 and ≤15 mmHg; complete and qualified success endpoint rates. Secondary outcomes: visual acuity (VA), mean deviation (MD), bleb evaluation, according to Moorfields Bleb Grading System (MBGS); spectral domain OCT (SD-OCT) bleb examination; number of glaucoma medications; frequency of postoperative complications.

Results

The mean preoperative IOP was 26.7(±5.2) in MMC and 27.3(±6.0) in OLO eyes. Mean 60-month percentage reduction in IOP was significant in both groups [40.9 (±14.2) and 42.1(±13.3) P = 0.01], with an endpoint value of 15.2 (±3.2) and 15.8 (±2.3) mmHg in MMC and OLO, respectively. Complete success rates at ≤ 21 mmHg target IOP were 65 % and 70 %, at ≤17 mm Hg 60 % and 55 %, and at the ≤15 mm Hg target IOP 35 % and 45 % in MMC and OLO, respectively.

The Kaplan–Meier curves did not differ both for complete and qualified success at any target IOP, with no significant endpoint intergroup difference at ≤ 15 mm Hg (log-rank P = 0.595).The intergroup MBGS scores differed due to reduced central and peripheral vascularity in MMC group (P = 0.027; P = 0.041).

SD-OCT analysis denied differences in bleb height between MMC vs OLO (140.5 ± 20.3 μ vs 129.2 ± 19.3 μ respectively; P =0.079).

Mean antiglaucoma medications were significantly reduced (P < 0.0005) from 2.5 (±0.3) to 1.2 (±0.4) in MMC and from 2.6 (±0.2) to 1.4 (±0.3) in OLO group, with no intergroup differences (P = 0.08).

Six (30 %) cystic thin avascular blebs without oozing were recorded in the MMC group and 2 (10 %) in the OLO group, without intergroup difference (P = 0.235).

Conclusions

Our extended follow-up results confirm that Ologen implant yields efficacy and long-term success rates quite similar to MMC, with at least equivalent safety.

Electronic supplementary material

The online version of this article (doi:10.1186/s12886-016-0198-0) contains supplementary material, which is available to authorized users.

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.

Comparison between the EX-PRESS P-50 implant and trabeculectomy in patients with open-angle glaucoma

Purpose

To evaluate the EX-PRESS P-50 implant compared to standard trabeculectomy (TBC).

Methods

Single-center prospective randomized study; 20 eyes of 20 patients were treated with the EX-PRESS P-50 implant, and 20 eyes of 20 patients with TBC, over a 19-month period. Records of all patients were reviewed and compared. Success was defined as intraocular pressure (IOP) <21 and >5 mmHg or a decrease of 30% of IOP. Failure was defined as >21 mmHg or decline in visual acuity. Statistical analysis was made with Student’s t-test and χ² test analyzed with SPSS version 13.0.

Results

The average follow-up was 8.6 months (±4.9 months) for the EX-PRESS P-50 group and 9.6 months (±5.3 months) for the TBC group. The postoperative visual acuity and IOP were not significantly different. We report more complications in the EX-PRESS P-50 group. At 3, 6, and 12 months follow-up, the control group was found to be free of complications, whereas multiple complications were observed in the EX-PRESS P-50 group at 3 and 6 months follow-up. We found no differences in either group with respect to success.

Conclusion

Both procedures are equally effective for the treatment of glaucoma, with 80% success in the EX-PRESS P-50 group and 72.7% in the control group.

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.

A review of the efficacy of mitomycin C in glaucoma filtration surgery

The success of trabeculectomy, which is considered the gold standard in the surgical treatment of glaucoma, depends on the wound healing response. The introduction of antiproliferative agents such as mitomycin C (MMC) has increased the success rates of trabeculectomy. However, complications due to these agents can be challenging to manage. Hence, it is important to determine the most efficacious dose and duration of exposure. Multiple studies suggest that many factors, including but not limited to MMC preparation, different concentrations, different exposure times, and method of application may affect success rate, and these factors were reviewed in this article. We concluded that lower concentrations of MMC that are prepared and applied in a standardized fashion, such as that using the Mitosol(®) kit (for 2-3 minutes) during trabeculectomy, could potentially provide trabeculectomy success rates similar to that reported with off-label preparations, and that such a treatment regime could result in in lower complication rates than higher doses of MMC.

23-gauge transconjunctival vitrectomy in eyes with pre-existing functioning filtering blebs

Background

We investigated the outcome of 23-gauge transconjunctival pars plana vitrectomy (23G PPV) for the treatment of vitreoretinal disorder in patients with prior trabeculectomy.

Methods

We retrospectively reviewed medical records of 23G PPV in 11 eyes that had functioning filtering blebs after trabeculectomy. The main outcome measures were the visual acuity, intraocular pressure (IOP) and subconjunctival fluid height in bleb by anterior segment optical coherence tomography (OCT) before and after the surgery.

Results

Eyes that had 23G PPV showed improvement of visual acuity after the surgery (P =0.003). Mean IOP was 13.82 mmHg before 23G PPV and 15.82 mmHg at 6 months postoperatively, which was statistically insignificant (P = 0.758). The bleb was observed before and after surgery using anterior segment OCT, and the difference in subconjunctival fluid was not statistically significant (P =0.172).

Conclusions

23G PPV did not adversely affect bleb function in eyes with prior trabeculectomy.

Rho kinase inhibitor AMA0526 improves surgical outcome in a rabbit model of glaucoma filtration surgery

PURPOSE

First, to elucidate the effect of Rho kinase inhibitor, AMA0526, on Human Tenon Fibroblast (HTF) proliferation and transdifferentiation to myofibroblasts. Second, the effects of ROCK inhibition on the wound healing process and surgical outcome were investigated in a rabbit model of glaucoma filtration surgery.

METHODS

After exposure of HTF to AMA0526 (0.1-25 μM), a water-soluble tetrazolium salt-1 assay and caspase 3/7 activity assay were used to assess its effect on cell proliferation and to elucidate any toxic effects, respectively. Immunohistochemistry of α-smooth muscle actin expression was used to investigate fibroblast-to-myofibroblast differentiation induced by transforming growth factor-beta 1 (TGF-β1) in the presence or absence of the ROCK inhibitor. The effect of topical treatment was studied in a rabbit model of glaucoma filtration surgery. Treatment outcome was studied by performing intraocular pressure (IOP) measurements and clinical investigation of the bleb area and survival. Immunohistological analysis for inflammation (CD45), angiogenesis (CD31), and collagen I was performed at day 8, 14, and 30 after surgery (n=5/time point). Separate control groups treated with vehicle were used as control.

RESULTS

In vitro results showed that AMA0526 dose dependently inhibited proliferation of HTF (P<0.05) without the induction of caspase 3/7 activity. Incubation of HTF with the AMA0526 inhibited TGF-β1 induced fibroblast-to-myofibroblast differentiation. In the rabbit model, topical treatment significantly improved surgical outcome. Compared to vehicle-treated eyes, AMA0526 resulted in increased bleb area (P<0.0001) and prolonged survival (P=0.0025). IOP remained significantly lower throughout the course of the experiment in the AMA0526 group (P<0.0001). Histological evaluation revealed that blebs treated with the ROCK inhibitor were characterized by reduced inflammation, angiogenesis, and collagen deposition at the site of filtration surgery (P<0.05).

CONCLUSIONS

AMA0526 had profound effects on HTF proliferation and myofibroblast transition and improved glaucoma filtration surgery outcome by interfering at different levels of the wound healing process. Therefore, these data indicate that ROCK inhibitors may be considered as more physiological agents which specifically target the wound healing process to improve the outcome of glaucoma surgery.

Modulation of wound healing in glaucoma surgery

Glaucoma is a neurodegenerative disease and is the second most important cause of irreversible blindness. Filtration surgery remains the most effective therapy to reduce intraocular pressure in glaucoma patients. The main determinant of long-term surgical success is the healing response. Excessive postoperative wound healing with subsequent fibrosis may lead to obstruction of the created channel which frequently results in early surgical failure and consequent progression of visual field loss. Preoperative use of antimitotics, such as mitomycin-C and 5-fluorouracyl, effectively improves surgery outcome. However, the use of these nonspecific antiproliferative agents can be associated with severe side effects. This review provides an overview of the most important efforts that have been made to explore novel, more specific, and safer agents to prevent glaucoma filtration failure and improve surgery outcome.

The use of mitomycin C in pediatric airway surgery: does it work?

PURPOSE OF REVIEW

To describe the efficacy of mitomycin C in combating airway stenosis.

RECENT FINDINGS

Recent publications discussing mitomycin C utility have not altered the mixed results previously established by prospective trials.

SUMMARY

Mitomycin C has been used for the past 16 years to inhibit pediatric airway fibroblast proliferation. Its benefit remains more hypothetical than proven and its future role remains uncertain.