Biodegradable collagen matrix implant vs mitomycin-C as an adjuvant in trabeculectomy: a 24-month, randomized clinical trial

Clinical Impact of the Use of Ologen in Filtering Surgery Performed in Uncontrolled Glaucoma

Introduction: To compare the efficacy and safety of trabeculectomy with a collagen matrix implant (Ologen®) versus trabeculectomy with mitomycin C (MMC) versus trabeculectomy with both Ologen® and MMC (OLO + MMC). Methods: This non-randomized study included 119 eyes of 101 patients with uncontrolled open-angle glaucoma who underwent trabeculectomy, either alone or combined with phacoemulsification. The data were initially recorded following a standard surgical protocol, using an electronic database with structured fields. The patients were divided into three groups: 44 received trabeculectomy with adjunctive MMC (MMC group), 34 received surgery with Ologen® (OLO group), and 41 received surgery with both Ologen® and MMC (OLO + MMC group). The main outcome measures were the change in intraocular pressure (IOP), change in number of medications needed, complete success rate (defined as IOP ≤ 20 mmHg and at least 20% IOP reduction without hypotensive medications), rate of complications, and rate of postoperative interventions. The follow-up period was 36 months. Results: IOPs significantly decreased (p = 0.01) in all groups across all study visits, decreasing from 19.8 ± 4.6 mmHg to 12.7 ± 4.2 mmHg in the MMC group, from 20.5 ± 4.7 mmHg to 13.9 ± 3.5 mmHg in the OLO group, and from 23.5 ± 6.1 mmHg to 13.1 ± 3.5 mmHg in the OLO + MMC group. After correcting for the baseline IOP, only the first two postoperative visits (first week and first month) showed a significantly greater IOP reduction in the OLO + MMC group. The number of hypotensive medications was significantly reduced from 3.1 ± 0.6 to 0.56 ± 1.1 in the MMC group, from 2.9 ± 0.4 to 0.83 ± 1.1 in the OLO group, and from 3.0 ± 0.6 to 0.45 ± 0.95 in OLO + MMC group, with no statistically significant differences among the groups (p = 0.57). The complete success rates were 63.6% in the MMC group, 67.6% in the OLO group, and 80.5% in the OLO +MMC group, with no statistically significant differences between the groups (p = 0.21). Suture release was significantly more frequent in the MMC group (86.1%) than in the OLO group (62.1%) and in the OLO + MMC group (45.9%; p = 0.02). Bleb needling, with (33.3%; p = 0.005) or without (66.7%; p = 0.0001) 5-fluorouracil injection (5-FU), was significantly more common in the MMC group. The highest complete success rate (61%) was observed in the OLO + MMC group. Conclusions: The use of Ologen® and mitomycin C provided similar surgical IOP reduction in glaucoma surgery compared with either MMC or Ologen® alone, but significantly reduced the need for postoperative interventions.

[Wound healing after trabeculectomy : What and when in postoperative aftercare?]

Excessive wound healing in filtering glaucoma surgery is a key factor for a failed surgery. After the introduction of trabeculectomy in the 1960s many factors associated with an increased fibrotic reaction were recognized and methods were developed to influence postoperative wound healing. These range from the perioperative use of anti-inflammatory drugs and antimetabolites to the use of newer chemical compounds that influence the morphology of postoperative fibroblast growth. In the routine clinical practice, the fine tuning of therapeutic decisions plays a decisive role in the success or failure of filtration surgery.

Device-modified trabeculectomy for glaucoma

BACKGROUND

Glaucoma is an optic neuropathy that leads to visual field defects and vision loss. It is the second leading cause of irreversible blindness in the world. Treatment for glaucoma aims to reduce intraocular pressure (IOP) to slow or prevent further vision loss. IOP can be lowered with medications, laser, or incisional surgery. Trabeculectomy is a surgical approach which lowers IOP by shunting aqueous humor to a subconjunctival bleb. Device-modified trabeculectomy techniques are intended to improve the durability and safety of this bleb-forming surgery. Trabeculectomy-modifying devices include the Ex-PRESS, the XEN Gel Stent, the PreserFlo MicroShunt, as well as antifibrotic materials such as Ologen, amniotic membrane, expanded polytetrafluoroethylene (ePTFE) membrane, Gelfilm and others. However, the comparative effectiveness and safety of these devices are uncertain.

OBJECTIVES

To evaluate the benefits and harms of different devices as adjuncts to trabeculectomy on IOP control in eyes with glaucoma compared to standard trabeculectomy.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search was August 2021.

SELECTION CRITERIA

We included randomized controlled trials in participants with glaucoma comparing device-modified trabeculectomy techniques with standard trabeculectomy. We included studies that used antimetabolites in either or both treatment groups.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. change in IOP and 2. mean postoperative IOP at one year. Our secondary outcomes were 3. mean change in IOP from baseline, 4. mean postoperative IOP at any time point, 5. mean best-corrected visual acuity (BCVA), 6. visual field change, 7. quality of life, 8. proportion of participants who are drop-free at one year, 9. mean number of IOP lowering medications at one year, and 10. proportion of participants with complications.

MAIN RESULTS

Eight studies met our inclusion criteria, of which seven were full-length journal articles and one was a conference abstract. The eight studies included 961 participants with glaucoma, and compared two types of devices implanted during trabeculectomy versus standard trabeculectomy. Seven studies (462 eyes, 434 participants) used the Ex-PRESS, and one study (527 eyes, 527 participants) used the PreserFlo MicroShunt. No studies using the XEN Gel Stent implantation met our criteria. The studies were conducted in North America, Europe, and Africa. Planned follow-up periods ranged from six months to five years. The studies were reported poorly, which limited our ability to judge risk of bias for many domains. None of the studies explicitly masked outcome assessment. We rated seven studies at high risk of detection bias. Low-certainty of evidence from five studies showed that using the Ex-PRESS plus trabeculectomy compared with standard trabeculectomy may be associated with a slightly lower IOP at one year (mean difference (MD) -1.76 mmHg, 95% confidence interval (CI) -2.81 to -0.70; 213 eyes). Moderate-certainty of evidence from one study showed that using the PreserFlo MicroShunt may be associated with a slightly higher IOP than standard trabeculectomy at one year (MD 3.20 mmHg, 95% CI 2.29 to 4.11). Participants who received standard trabeculectomy may have a higher risk of hypotony compared with those who received device-modified trabeculectomy, but the evidence is uncertain (RR 0.73, 95% CI 0.46 to 1.17; I² = 38%; P = 0.14). In the subgroup of participants who received the PreserFlo MicroShunt, there was a lower risk of developing hypotony or shallow anterior chamber compared with those receiving standard trabeculectomy (RR 0.44, 95% CI 0.25 to 0.79; 526 eyes). Device-modified trabeculectomy may lead to less subsequent cataract surgery within one year (RR 0.46, 95% CI 0.27 to 0.80; I² = 0%).

AUTHORS' CONCLUSIONS

Use of an Ex-PRESS plus trabeculectomy may produce greater IOP reduction at one-year follow-up than standard trabeculectomy; however, due to potential biases and imprecision in effect estimates, the certainty of evidence is low. PreserFlo MicroShunt may be inferior to standard trabeculectomy in lowering IOP. However, PreserFlo MicroShunt may prevent postoperative hypotony and bleb leakage. Overall, device-modified trabeculectomy appears associated with a lower risk of cataract surgery within five years compared with standard trabeculectomy. Due to various limitations in the design and conduct of the included studies, the applicability of this evidence synthesis to other populations or settings is uncertain. Further research is needed to determine the effectiveness and safety of other devices in subgroup populations, such as people with different types of glaucoma, of various races and ethnicity, and with different lens types (e.g. phakic, pseudophakic).

Comparison of surgical outcomes with and without Ologen collagen matrix augmentation during XEN gel stent implantation

Background

To compare the surgical outcomes and postoperative complications with and without Ologen collagen matrix augmentation during XEN gel stent implantation.

Methods

We retrospectively analyzed patients who underwent XEN gel stent implantation with an ab externo technique. The amount of intraocular pressure (IOP) reduction, percentage of postoperative complications and additional management, and surgical success defined as IOP reduction greater than 20% compared with the preoperative IOP measurement were compared between Ologen-augmented and non-augmented groups. Groups of patients who underwent XEN gel stent implantation alone and combined with phacoemulsification were analyzed separately.

Results

A total 103 eyes of 103 participants were included. Of those, 72 eyes underwent standalone XEN gel stent implantation: 42 eyes with Ologen augmentation (Oloxen group) and 30 eyes without Ologen augmentation (Xen group). Thirty-one eyes underwent XEN gel stent implantation with phacoemulsification: 19 eyes with Ologen augmentation (Phaco-Oloxen group) and 12 eyes without Ologen augmentation (PhacoXen group). The surgical success rate at six months postoperatively was not different between the Oloxen and Xen groups (56.4% vs 43.3%, P > 0.05) or between the Phaco-Oloxen group and PhacoXen group (57.9% vs 41.7%, P > 0.05). The prevalence of postoperative hypotony, 5-fluorouracil injections, use of anti-glaucoma medications, bleb needling, and additional glaucoma surgeries was not different between the Oloxen and Xen groups or between the Phaco-Oloxen and PhacoXen groups when assessed six months postoperatively.

Conclusions

All groups showed significant IOP reduction after XEN gel stent implantation, but there was no significant difference between the Ologen collagen matrix augmented and non-augmented groups in surgical outcomes.

Preliminary results of Preserflo Microshunt versus Preserflo Microshunt and Ologen implantation

PURPOSE

To report preliminary 6-month results on the use of the Preserflo Microshunt implant with and without Ologen in 50 pseudophakic eyes with moderate to advanced primary open-angle glaucoma (POAG).

METHODS

Fifty pseudophakic eyes underwent ab externo Preserflo Microshunt implantation. Data was gathered retrospectively and two groups were then created, group A with application of MMC 0.2 mg/ml and group B with MMC 0.2 mg/ml and Ologen collagen matrix (OCM) implantation. Absolute success was regarded as the percentage of eyes achieving: a) 5 ≤ intraocular pressure (IOP) ≤ 13 mmHg, b) 5 ≤ IOP ≤ 16 mmHg, and c) 5 ≤ IOP ≤ 21 mmHg without additional medication or surgery and qualified success was regarded as the percentage of eyes achieving a) IOP ≤ 13 mmHg, b) IOP ≤ 16 mmHg, and c) IOP ≤ 21 mmHg with or without medication. Evaluation was performed using a log-rank Kaplan-Meier test. A scatterplot analysis presented the treatment effect data of all eyes with a minimum of 20% IOP reduction per case. Failure was defined as requiring additional surgery, IOP greater than 21 mmHg with or without medication and failure to reach 20% IOP reduction.

RESULTS

Mean postoperative IOP was significantly lower in both groups. IOP decreased by 49.06% in group A and by 53.01% in group B at 6 months (P < 0.88), respectively. Medication use was lower in both groups (Wilcoxon test, P < 0.001). The absolute and qualified success rates were not statistically significant between the groups (all P > 0.05). Cumulative IOP results per case were not statistically different in group A compared with group B. One revision surgery in group A (4% failure rate) and three in group B (12% failure rate) were performed.

CONCLUSIONS

Both groups showed equal results in terms of cumulative and mean IOP reduction, medication reduction as well as in absolute and qualified success rates. No significant difference was found in any parameters tested between Preserflo Microshunt with MMC 0.2 mg/ml and with or without OCM implantation at 6 months. Long-term follow-up is required to further evaluate this data.

A Narrative Review of the Complex Relationship between Pregnancy and Eye Changes

Pregnancy is a condition often characterized by changes that occur in different parts of the body. Generally, the eyes suffer several changes during pregnancy that are usually transient but may become permanent at times. This may occur due to the release of placental hormones and those of maternal endocrine glands and fetal adrenal glands. Due to hormonal influences, physiological ocular changes during pregnancy have been shown in Caucasian women, so corneal sensitivity, refractive status, intraocular pressure, and visual acuity may change during pregnancy. Within this review, all studies that referred to physiological aspects and to changes of ocular pathology of pregnancy, the effect of the pregnancy on pre-existing (diabetic retinopathy, neuro-ophthalmic disorders) eye disorders, postpartum ocular changes, the intraocular pressure and the effect of hypotensive ophthalmic medicine during pregnancy, the connection between pregnancy and the neuro-ophthalmic pathology, as well as the role of anesthesia were analyzed.

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.

Outcome of Trabeculectomy with Collagen Matrix Implant versus Mitomycin C in Primary Glaucoma: A Comparative Study

Background:

Glaucoma is a serious vision-threatening condition appropriately called as the silent killer of sight. The effect of postoperative fibrosis on success of filtration surgeries requires modulation of the wound healing process.

Aim:

The aim of the study was to compare trabeculectomy augmented with collagen matrix implant with mitomycin C in primary glaucoma.

Materials and Methods:

This prospective, longitudinal, hospital-based, analytical, and interventional study was conducted on 36 eyes of 36 patients. Group 1 included 18 patients who underwent trabeculectomy combined with subconjunctival collagen matrix implant and Group 2 included 18 patients who underwent trabeculectomy augmented with intraoperative mitomycin C (0.04 mg/ml) for 2 min. Each patient underwent detailed ocular examination and comparison was drawn by recording intraocular pressure (IOP), bleb characteristics, and postoperative complications.

Results:

The cumulative success rates at the end of our study were similar in two groups, 94.44% in Group 1 and 88.89% in Group 2 (P = 1.000). The mean reduction in IOP at 24 weeks in Group 1 was 18.67 ± 7.59 mmHg and in Group 2 was 21.32 ± 5.84 mmHg. The reduction in IOP was similar between the two groups (P = 0.290). The mean fall in IOP was 56.46% in Group 1 and 64.70% in Group 2 at 24 weeks. Mean bleb score in Group 1 was 10.33 ± 1.23 and in Group 2 was 8.89 ± 1.41, and the difference was statistically significant (P = 0.002). Shallow anterior chamber, overfiltration, and hypotony were statistically higher in Group 2 than in Group 1 (P = 0.041, 0.041, and 0.046, respectively).

Conclusion:

Collagen matrix implant as an adjuvant to trabeculectomy is noble, safe, and effective option as compared to mitomycin C.

The clinical and pathogenic spectrum of surgically-induced scleral necrosis: A review

The onset of scleral necrosis after ocular surgery may have catastrophic ocular and systemic consequences. The two most frequent surgeries causing surgically-induced scleral necrosis (SISN) are pterygium excision and cataract extraction. Several pathogenic mechanisms are involved in surgically induced scleral necrosis. All of them are poorly understood. Ocular trauma increasing lytic action of collagenases with subsequent collagen degradation, vascular disruption leading to local ischemia, and immune complex deposition activating the complement system represents some of the events that lead to scleral necrosis. The complex cascade of events involving different pathogenic mechanisms and the patient's abnormal immune response frequently leads to delayed wound healing that predisposes the development of scleral necrosis. The management of SISN ranges from short-term systemic anti-inflammatory drugs to aggressive immunosuppressive therapy and surgical repair. Therefore, before performing any ocular surgery involving the sclera, a thorough ophthalmic and systemic evaluation must be done to identify high-risk patients that may develop SISN.

Estimation of risk-benefit ratio and comparison of post-operative efficacy results between trabeculectomy and canaloplasty

PURPOSE

To estimate a risk-benefit ratio by comparing the efficacy of canaloplasty to trabeculectomy exclusively in pseudophakic eyes with primary open angle glaucoma.

PATIENTS AND METHODS

One hundred four eyes that underwent ab externo canaloplasty and 136 eyes that underwent trabeculectomy with mitomycin C 0.02% and collagen matrix implantation were retrospectively compared. The efficacy was evaluated by evaluating the absolute success rate (5 ⩽ intraocular pressure ⩽ 15 mmHg) and the qualified success rate (intraocular pressure ⩽15 mmHg) using the Kaplan-Meier survival analysis. A meta-analysis to evaluate the relative risk of both procedures in relation to post-operative interventions was performed.

RESULTS

Mean intraocular pressure was significantly lower in both groups. Intraocular pressure decreased by 32.17% in the canaloplasty group and by 55.04% in the trabeculectomy group at 12 months (analysis of variance, p < 0.001). Medication use was lower in both groups (analysis of variance, p < 0.001) by the 12th month. The absolute success rate for canaloplasty was 20.19% of eyes compared to 52.21% of eyes with trabeculectomy (p < 0.0001). The qualified success rate was not statistically different between groups (p = 0.15). The relative risk ratio was not statistically different between groups (relative risk of 0.01 and weight of 49.65% for group A and relative risk of 0.0005 and weight of 50.35% for group B; p = 0.5). The hospitalization length was longer in trabeculectomy-treated patients (t-test, p < 0.0001).

CONCLUSION

The trabeculectomy group showed better results in terms of absolute success rate. However, canaloplasty may provide a better risk-benefit ratio in terms of qualified success rate, hospitalization time, and required post-operative interventions, since canaloplasty yielded equal or superior results compared to trabeculectomy.

Glaucoma in pregnancy: an update

PURPOSE OF REVIEW

Glaucoma management during pregnancy is a complex challenge, which requires balancing the clinical disease of the mother with the potential risks of therapy to the developing child. Because systematic studies are lacking in the pregnant population, this review aims to collect the array of available data from observational studies and case reports to provide the reader with guidance and context for the safety of glaucoma interventions during pregnancy.

RECENT FINDINGS

Surgical glaucoma is a rapidly expanding field with many new technologies and procedures. We review the surgical options for the gravid patient with reference to traditional procedures like trabeculectomy and tube-shunts, and newer MIGS procedures. When indicated, orphan trabeculectomy, or with collagen matrix implant may be a viable solution for severe glaucoma during pregnancy. Newer MIGS procedures such as the gelatin stent may also provide minimally invasive options for pregnant patients. Two new medications, Vyzulta and Rhopressa, were recently released in 2018 and have limited data to support their safety for use during pregnancy.

SUMMARY

The careful consideration of fetal health in the management of glaucoma during pregnancy is best done as a part of a multidisciplinary team including obstetrics and neonatology. When medication is necessary, steps to minimize systemic absorption should be employed. Surgical management should not be excluded for pregnant patients and may be considered before medical management in some cases to prevent fetal exposures and maternal harm.

Phacotrabeculectomy using collagen matrix implant (Ologen® ) versus mitomycin C: a prospective randomized controlled trial

PURPOSE

To compare the efficacy and safety of collagen matrix implant (Ologen^® ; OLO) with mitomycin C (MMC) in phacotrabeculectomy.

METHODS

Prospective, single-centre, nonblinded, randomized controlled trial. A total of 53 eyes of 45 patients were enrolled in the study protocol with 27 eyes randomly assigned to OLO and 26 to MMC. The follow-up was 12 months. The primary outcome measure was mean change from baseline intraocular pressure (IOP) in both groups after 12 months. The secondary outcome measures were cumulative success rates at 12 months with Kaplan-Meier analysis, change in number of medications, change in best corrected visual acuity (BCVA), and bleb morphology assessed using Moorfields Bleb Grading System and anterior segment swept-source optical coherence tomography.

RESULTS

The mean IOP decreased from 26.4 ± 6.1 mmHg to 13.7 ± 3.8 in the OLO group and from 23.4 ± 3.6 mmHg to 13.3 ± 2.8 in the MMC group at 1 year without significant intergroup differences. At 1 year, the overall success rates were 92.6% and 92.3% in the OLO and MMC groups, respectively. There were no significant differences in the overall success rates, BCVA, number of medications, morphology of the filtering blebs and rate of complications at the end of the follow-up.

CONCLUSION

Ologen (OLO) provides similar surgical outcomes in phacotrabeculectomy compared with adjunctive MMC. It may be a new, safe and effective alternative to MMC for combined phacoemulsification and trabeculectomy surgery.

One-Year Results of Stab Incision Glaucoma Surgery and Radiofrequency-Assisted Stab Incision in Management of Open-Angle Glaucoma

PURPOSE

The aim of the study is to evaluate the surgical outcome of stab incision glaucoma surgery (SIGS) and compare it with radiofrequency-assisted stab incision in the treatment of uncontrolled open-angle glaucoma.

PATIENTS AND METHODS

A prospective, interventional study included 50 eyes who were assigned into two equal groups: Group A underwent stab incision procedure with preoperative subconjunctival (SC) mitomycin-C (MMC) and Group B underwent radiofrequency-assisted technique without MMC. Intraoperative and postoperative complications, visual acuity, intraocular pressure (IOP), and bleb status were evaluated up to 12 months.

RESULTS

Mean preoperative IOP in Group A was 26.96 ± 2.42 reduced to 13.43 ± 2.31 while in Group B was 27.20 ± 3.57 reduced to 15.48 ± 3.68 mmHg (P < 0.001) with a mean reduction of 50.61% ± 8.42% and 43.56% ± 12.83%, 12 months postoperatively in Groups A and B, respectively. Non-basal peripheral iridectomy was the most encountered intraoperative complication in 8 eyes (32%) and 9 eyes (36%) and hypotony was the most reported postoperative complication in 5 eyes (20%) and 9 eyes (36%) in Groups A and B, respectively. Flat bleb area had been reported at the end of follow-up time in 3 eyes (13%) and 7 eyes (30%) in Groups A and B, respectively. Complete success rate was 52.2% and 28.6% while qualified success rate was 28.8% and 42.9% in Groups A and B, respectively.

CONCLUSION

SIGS with SC MMC is an effective and safe procedure in IOP lowering, while radiofrequency-assisted stab incision had high incidence of subconjunctival scarring and ostium closure.

Medical Applications of Collagen and Collagen-Based Materials

Collagen and collagen-based materials have been successfully used in medicine for over 50 years. The number of scientific articles about the role of collagen in the construction of scaffolds for tissue engineering has risen precipitously in recent years. The review contains materials about historic and modern applications of collagen in medicine such as soluble collagen injections, solid constructs reconstructed from solution, and decellularized collagen matrices. The analysis of published data proves the efficacy of collagen material in the treatment of chronic wounds, burns, venous and diabetic ulcers, in plastic, reconstructive and general surgery, urology, proctology, gynecology, ophthalmology, otolaryngology, neurosurgery, dentistry, cardiovascular and bone and cartilage surgery, as well as in cosmetology. Further development of collagenoplasty requires addressing the problems of allergic complications, improvement of structure and maximizing therapeutic effects against pathological processes.

Efficacy of collagen matrix implant on adhesions in restrictive strabismus: An experimental study in a rabbit model

PURPOSE

To determine the efficacy of a biodegradable collagen matrix implant (Ologen, Aeon Astron Europe BV, Leiden, the Netherlands) in reducing adhesions in a rabbit model of restrictive strabismus.

METHODS

A prospective, masked-observer, controlled experimental study was performed. Sixty superior rectus muscles of 30 rabbits were resected and Marlex mesh was fixed beneath the resected muscle using nonabsorbable suture. Forty eyes underwent one of two different procedures; the resected muscle was wrapped with preserved human amniotic membrane (AM group) or Ologen (Ologen group). Randomly selected 20 eyes served as controls. Eyes were enucleated at 4 weeks after surgery to measure the severity of adhesion using a push pull gauge. Histopathological examination was performed.

RESULTS

At postoperative week four, the average tensile strength of the myoscleral adhesion was significantly lower in the Ologen group (151.8 ± 42.7 gram force) compared to controls (347.9 ± 68.6 gram force) and AM group (193.0 ± 44.3 gram force) (p < 0.001 and p = 0.045, respectively). Ologen group showed significantly lower degree of acute inflammation, chronic inflammation and rectus muscle fibrosis compared with controls (all p < 0.01). The degree of chronic inflammation was significantly lower in the Ologen group compared with AM group (p = 0.012).

CONCLUSION

Compared to amniotic membrane, Ologen is more effective in reducing mesh-related extraocular muscle adhesions in a rabbit model of restrictive strabismus.

Efficacy of Ologen matrix implant in Ahmed Glaucoma Valve Implantation

To determine the efficacy and safety of the Ologen collagen matrix adjunctive to Ahmed valve surgery. A randomized prospective multicentre clinical trial involving 58 patients that were followed for one year. Conventional surgery with Ahmed valve was performed in 31 eyes (Control group/CG) and in 27 Ologen (Ologen group/OG) was placed over the valve's plate. Baseline data: age, corneal thickness, intraocular pressure(IOP) and antiglaucoma medications.Postoperative data (days 1, 7 and months 1, 3, 6 and 12): IOP, antiglaucoma medications, visual acuity and complications were recorded. Frequency of hypertensive phase, complete and qualified success and survival rate were studied. No differences were found between CG and OG in the baseline data. The only difference between groups was a significantly lower IOP at day 1. No other differences were found in the follow-up between groups. Hypertensive phase (56%CG and 55%OG, p = 0,947), complete success 28,6%CG and 30,4%OG (p = 0,88) and qualified success 96,4% and 95,9%(p = 0,794). Survival rates at 1 year were 76,7%(CG) and 69,2%(OG)(p = 0,531). 38,7% of patients in the CG suffered some complication during follow-up and 61,5% in OG(p = 0,086). Ologen does not increase safety or efficacy in Ahmed valve surgery at one-year follow-up. This is the first study that shows no benefit of Ologen adjunctive to this surgery.

Combined phacoemulsification and viscocanalostomy with Ologen implant versus combined phacoemulsification and viscocanalostomy

BACKGROUND

To study the efficacy of the biodegradable collagen implant Ologen® as an adjuvant in phaco-viscocanalostomy in patients with coexisting cataract and primary open angle glaucoma.

METHODS

This prospective, interventional, randomized clinical study was done at Alpha Vision Center, Zagazig, Egypt. Patients with coexisting cataract and glaucoma were randomized to receive either phaco-viscocanalostomy (Phacovisco group) (39 eyes) or phaco-viscocanalostomy with Ologen® implant (OloPhacovisco group) (40 eyes). Follow-up period was 2 years. Nd:YAG laser goniopuncture was done in cases where the intraocular pressure (IOP) was elevated above 21 mmHg after discontinuation of corticosteroid eye drops at any follow-up visit.

RESULTS

No significant operative or postoperative complications (other than failure) were encountered in either group. At 2 years follow-up, the mean IOP level was statistically significantly decreased in the OloPhacovisco group (p = 0.02) and complete success occurred in 23 eyes (59.0%) in the Phacovisco group and in 32 eyes (80.0%) in the OloPhacovisco group. There was a statistically significant higher success rate regarding complete success in patients that received Ologen® implant (p = 0.04).

CONCLUSIONS

Ologen® implant improved the success rate of phaco-viscocanalostomy. Larger studies with longer follow-up periods may be required to confirm these findings.

TRIAL REGISTRATION

This trial was retrospectively registered on 20/12/2018 under the number ( NCT03782051 ).

[Glaucoma surgery: from traditional filtration techniques to modern principles of bioengineering]

The article reviews the history of glaucoma surgery and analyses the connection between the accumulation of knowledge on glaucoma progression and the emergence of effective surgical treatment methods based on glaucoma pathogenesis. It also describes modern principles of preventing filtering bleb scarring. Particular attention is devoted to biodegradable collagen matrix implants.

Ologen Implantation versus Conjunctival Autograft Transplantation for Treatment of Pterygium

Purpose

To evaluate the effectiveness and safety of Ologen implantation versus conjunctival autograft transplantation for primary pterygium.

Methods

A retrospective case-series analysis. Thirty-one eyes of 29 patients were included in the Ologen group and 42 eyes of 35 patients in the autograft group. The patients were followed up for 1 year and evaluated for slit-lamp biomicroscopy, intraocular pressure, and adverse events. Recurrence rate, complications, and final appearance of the cases were evaluated prospectively.

Result

At 1 year after operation, 2 eyes recurred (6.5%) in the Ologen group and 4 eyes recurred (9.52%) in the autograft group. There was no statistically significant difference between both groups (P=0.157, χ² = 3.781). There was no occurrence of serious complications. Two eyes among the 31 eyes of the Ologen group were conjunctivitis; the incidence of complications was 6.45% (2 eyes). There was conjunctivitis in 3 eyes of the autograft group, 1 eye complicated with symblepharon, and 1 eye with conjunctival granuloma; the incidence of complications was 11.90% (5 eyes), and there was no statistically significant difference between both groups (P=0.094). The conjuntiva was less vascular and inflamed at 1 month postoperatively in the Ologen group than in the autograft group.

Conclusions

Ologen transplantation was technically easier, provided short operative time compared with conjunctival autograft transplantation, and preserved healthy conjunctiva with less complication and less recurrence; it may be a new, safe, and effective alternative for improving the short-term success rate of primary surgery.

Application of biodegradable collagen matrix (Ologen™) implants in Dacryocystorhinostomy surgeries, a randomized clinical study

Background

To introduce and evaluate the application of Ologen implants in external Dacryocystorhinostomy (DCR) Surgeries.

Methods

Prospective comparative randomized study was carried out on 60 patients coming to ophthalmology department, Menoufia University Hospitals. Patients included were suffering from primary acquired nasolacrimal duct obstruction with positive regurge test. Patients were randomly enrolled into two groups using alternating choice technique. Group A included 30 patients who had DCR surgery to treat the obstruction with Silicone tubes. Group B included 30 patients had a Dacryocystorhinostomy with Silicone tubes and Ologen implants.

Results

Success rates as regard to relief of symptomatic epiphora were 86.7% in group A and 96.7% in group B and time of dye clearance test was 4.5 ± 0.6 min in group A and 3.9 ± 0.4 min in group B with p value 0.353 &0.001 consecutively. Apart from immediate mild post operative hemorrhage that was encountered in 2 cases in group B and 1 case in group A, there were no significant complications in both groups.

Conclusion

The current study shows that application of Ologen implants in external DCR surgeries may improve symptomatic epiphora without exposing the patients to more intra-operative or post-operative complications. To the best of our knowledge, the current study is the first one to use Ologen implants in external DCR surgeries. However, the follow-up period was relatively short and the sample size is relatively small and further work is required to verify the effect of Ologen in external DCR surgeries.

Trial registration

Current Controlled Trials PACTR201711002809215, and the date of registration is 29 November 2017. The trial is Retrospectively registered.

Outcome of trabeculectomy with Ologen versus Mitomycin C: A comparative prospective study in Bangladesh

AIMS:

To compare the efficacy and safety of trabeculectomy with Ologen versus Mitomycin C in primary glaucoma.

MATERIALS AND METHODS:

This is a prospective study of patients aged 18 years and above, diagnosed with primary glaucoma randomised to having trabeculectomy with Ologen or Mitomycin C. The primary outcome measure was success of trabeculectomy defined as intraocular pressure >5 mmHg but ≤21 mmHg. Complete success was defined as intraocular pressure achieved without anti-glaucoma medication and qualified success was defined as intraocular pressure achieved with additional anti-glaucoma medication.

RESULTS:

At the end of 12 months follow-up, the postoperative mean intraocular pressure in the Ologen group was 12.8 ± 1.6 mmHg and 13.4 ± 2.2 mmHg in the Mitomycin C group. The Ologen group achieved complete success in 86.5% and qualified success in 13.5% of the patients, while the Mitomycin C group achieved complete and qualified success in 85.5% and 14.5%, respectively. There was no statistically significant difference in the success rate of both the groups ( p = 0.57). Furthermore, no significant intraocular pressure difference was noted between the two groups at the end of 12 months follow-up ( p = 0.14).

CONCLUSION:

Trabeculectomy augmented with Ologen appeared to be as successful and safe as trabeculectomy augmented with Mitomycin C, with no reported adverse reaction to Ologen.

Trabeculectomy with Ologen implant versus mitomycin C in congenital glaucoma secondary to Sturge Weber Syndrome

AIM

To compare the efficacy and safety of collagen matrix implant [Ologen (OLO) implant] versus mitomycin C (MMC) with subscleral trabeculectomy (SST) for the surgical treatment of congenital glaucoma (CG) in Sturge-Weber Syndrome (SWS).

METHODS

A prospective comparative randomized study of 20 eyes of 16 patients with CG associated with SWS was divided into two groups. The first group (MMC Group) included 10 eyes that were subjected to SST with MMC. The second group (OLO Group) included 10 eyes that were subjected to trabeculectomy with a collagen matrix implant (OLO implant). Postoperative evaluation included intraocular pressure (IOP) level, bleb evaluation, complications, and the need for further medication or surgical intervention.

RESULTS

The mean preoperative IOP was 29±3.16 mm Hg in MMC and 29.8±3.08 mm Hg in OLO eyes. Mean 12-month percentage reduction in IOP was significant in both groups (57.9% and 56.3%). At the end of the 12 postoperative follow-up month, in the MMC Group, 80% of eyes achieved the complete success, 20% of eyes had qualified success with no failed surgery in comparison to OLO Group which 70% of eyes achieved the complete success, 20% of eyes had qualified success with 10% failed surgery. In terms of complications, the MMC Group had a higher rate of complications than the OLO Group in the form of thin polycystic bleb in 6 eyes (60%), blebitis in only one eye (10%) treated with topical antibiotics, shallow anterior chamber in two eyes (20%).

CONCLUSION

This study proves that the use of a collagen matrix implant yields equally effective results as MMC when combined with trabeculectomy for the treatment of CG in SWS. Furthermore, OLO implantation is safe and has low incidences of complications.

Improving Glaucoma Surgical Outcomes with Adjunct Tools

Conventional glaucoma surgeries, such as trabeculectomy and glaucoma drainage device (GDD) surgery, have been enhanced by surgeons to improve outcome and decrease complications. Over the last two decades, adjuncts, such as collagen matrix implants, fibrin adhesives, and amniotic membrane transplantation (AMT) have been found to be effective in modulating fibrosis and scarring during the wound-healing process, reducing postoperative inflammation, and repairing bleb leakage or conjunctival erosion. The use of these tools provides several advantages when used in trabeculectomy, GDD surgery, and surface reconstruction associated with glaucoma surgery complications. Their use will be discussed in this review. How to cite this article: Lu LJ, Hall L, Liu J. Improving Glaucoma Surgical Outcomes with Adjunct Tools. J Curr Glaucoma Pract 2018;12(1):19-28.

Comparison between Ologen implant and different concentrations of Mitomycin C as an adjuvant to trabeculectomy surgery

CONTEXT:

Trabeculectomy is the most common surgical procedure for treatment of glaucoma. To improve success rates, adjuvants were utilized as Mitomycin C (MMC) and Ologen implant.

AIMS:

This study aims to establish efficacy and safety of Ologen implant versus MMC in trabeculectomy.

SETTING AND DESIGN:

A prospective, comparative clinical study was conducted at the Department of Ophthalmology, Assiut University, between December 2014 and April 2016.

SUBJECTS AND METHODS:

Patients with primary open-angle glaucoma (OAG), primary narrow-angle glaucoma and secondary OAG were assigned equally to trabeculectomy with Ologen, 0.4 mg/mL or 0.2 mg/mL MMC. The study outcome measures were reduction in intra-ocular pressure (IOP), success rates, survival analysis, and rate of complications.

STATISTICAL ANALYSIS USED:

SPSS software Version 17.0 (SPSS, Inc., IL, USA) was utilized.

RESULTS:

Thirty eyes were included in the study. Mean baseline IOP in Ologen, MMC 0.4 and MMC 0.2 groups were 27.43 ± 2.97, 28.4 ± 3.24, and 27.56 ± 2.69 mmHg, respectively. At week 24 follow-up, mean IOP in Ologen, MMC 0.4 and MMC 0.2 groups were 18.55 ± 3.18, 16.2 ± 3.22, and 16.93 ± 3.04 mmHg, respectively. No significant inter-group difference was noticed at any visits. Complete success was achieved in 10%, 40%, and 30%, whereas incomplete success in 70%, 50%, and 60%, respectively in Ologen, MMC 0.4 and MMC 0.2 groups. No treatment group difference was reported by Kaplan–Meier analysis. Shallow anterior chamber occurred more in Ologen and MMC 0.4 groups. A single case of serous choroidal effusion had occurred in MMC 0.4 group.

CONCLUSION:

Ologen implant is a promising alternative to MMC for improving the success rate of trabeculectomy.

Is device-modified trabeculectomy better than classic surgery for treatment of glaucoma?

Several techniques have emerged as complement or replacement for trabeculectomy, the standard surgery for glaucoma. Device-modified trabeculectomy is a recently developed technique whose results compared to the classical technique have not been fully defined. To answer this question, we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We identified eight systematic reviews including 34 studies overall. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. We concluded device-modified trabeculectomy probably leads to greater overall success rate and may decrease intraocular pressure more than classical surgery. In addition, this technique would probably have a better safety profile than standard trabeculectomy.

Collagen matrix vs mitomycin-C in trabeculectomy and combined phacoemulsification and trabeculectomy: a randomized controlled trial

Background

Antifibrotic agents are commonly utilized to enhance the success rates of trabeculectomy. Novel approaches to further improve success rates and reduce the risks of complications are needed. The purpose of this study was to compare intraocular pressure (IOP)-lowering efficacy and safety of trabeculectomy or combined phacoemulsification and trabeculectomy with mitomycin-C (MMC) vs. Collagen Matrix (CM).

Methods

A prospective, multicenter, randomized controlled trial was performed. Ninety-five eyes of 94 patients with uncontrolled glaucoma despite medical therapy, without previous incisional glaucoma surgery underwent trabeculectomy (85 eyes) or combined phacoemulsification and trabeculectomy (10 eyes) and were randomized to MMC or CM. One eye of each subject was analyzed. Patients were followed for 24 months. The criteria for complete success were IOP >5 and ≤21 mmHg with at least a 20% reduction below medicated baseline without additional glaucoma surgery or medications. The main outcome measures were complete success rates at 24 months with Kaplan-Meier analysis and incidence of adverse events.

Results

The baseline IOPs were 20.4 ± 6.0 mmHg and 21.2 ± 6.1 (mean ± standard deviation, p = 0.49) on 3.2 ± 1.1 and 3.1 ± 1.0 medications (p = 0.53) compared to 11.8 ± 5.2 and 12.8 ± 3.7 (p = 0.36) on 0.5 ± 0.8 and 0.6 ± 1.0 medications (p = 0.63) at 2 years in the MMC and CM groups, respectively. Kaplan-Meier analysis demonstrated complete success rates were similar in both groups at 24 months: 38.4 ± 7.6% with MMC and 56.2 ± 7.9% with CM (mean ± standard error, p = 0.112, log rank test); however, a significantly higher incidence of failure due to persistent hypotony was observed with MMC (p = 0.002).

Conclusions

Use of the CM implant at the time of trabeculectomy or combined phacoemulsification and trabeculectomy is associated with similar complete success rates compared to adjunctive MMC; however, the risk of persistent hypotony is higher with MMC.

Trial registration

ClinicalTrials.gov registration number NCT01440751.

Registered 9/14/11

Electronic supplementary material

The online version of this article (doi:10.1186/s12886-016-0393-z) contains supplementary material, which is available to authorized users.

The use of collagen matrix (Ologen) as a patch graft in glaucoma tube shunt surgery, a retrospective chart review

Purpose: To determine the safety and efficacy of collagen matrix as a patch graft in glaucoma drainage surgery. Collagen matrix grafts may be advantageous because they do not need to be harvested from human donors.

Methods: An institutional, retrospective review of 43 patients with at least 12 months follow-up status post-glaucoma drainage implant surgery were evaluated for signs of tube erosion after initial placement of collagen matrix patch graft.

Results: Forty-one of 43 eyes (95.3%) required no intervention for patch graft melting with tube erosion. Average time of follow-up was 32 months (range: 12-45). Two cases had tube erosion at 4 months and 26 months post-op requiring tube revision, which was successfully revised with conjunctiva (4 month erosion) and donor sclera (26 month erosion).

Conclusion:  Our results suggest that collagen matrix patch grafts may be used successfully as a patch graft in glaucoma tube shunt surgery, and may be advantageous because they do not have to be harvested from human donors. It is possible that exposure rates may be higher after longer follow-up and with larger numbers of patients. Further research is needed to compare Ologen to traditional graft materials to conclusively determine the safety and efficacy of collagen matrix as a novel patch graft material.

New developments in anterior segment optical coherence tomography for glaucoma

PURPOSE OF REVIEW

The aim of the present review was to summarize the new developments in anterior segment optical coherence tomography (AS-OCT) for glaucoma.

RECENT FINDINGS

Recent years have demonstrated significant advances in the measurement of glaucoma through the use of AS-OCT. Furthermore, a more widespread use of AS-OCT in the clinical study of various glaucomas warrants review, which includes angel assessment, trabecular meshwork and Schlemm's canal assessment, and assessment of the filtering bleb and tube.

SUMMARY

AS-OCT was recently developed and has become a crucial tool in glaucoma clinical practice. AS-OCT is a noncontact imaging device that provides the detailed structure of the anterior part of the eyes. In this review, the author will discuss the various clinical applications of AS-OCT for glaucoma disease, such as angle assessment, trabecular meshwork and Schlemm's canal assessment, or assessment of the filtering bleb and tube.

Trabeculectomy with ologen in secondary glaucomas following failed trabeculectomy with MMC: comparative study

PurposeWe aimed to assess the IOP-lowering effect of trabeculectomy with ologen in refractory secondary glaucoma following failed trabeculectomy with mitomycin C (MMC), and to compare its surgical outcome between open angle (SOAG) and angle closure (SACG) cases.MethodsThis is a prospective interventional comparative study conducted on 40 eyes (40 patients) with medically uncontrolled secondary glaucoma. Patients were divided into group A: 18 eyes (18 patients) with SOAG, and group B: 22 eyes (22 patients) with SACG. All patients underwent trabeculectomy with insertion of ologen implant. Intraocular pressure (IOP) measurement, SITA standard perimetry (Central 24-2), spectral domain optical coherence tomography (OCT) for retinal nerve fiber layer (RNFL) thickness, and anterior segment OCT for bleb morphology, were all done pre- and postoperatively. Primary outcome measures were comparing preoperative to postoperative measurements and also comparing these measurements between SOAG and SACG. All patients were examined up to 1 year.ResultsWhen preoperative IOP was compared with postoperative IOP, in each group, there was a statistically significant difference (P<0.001). IOP percentage difference was statistically insignificantly different between both groups except at 1 month. According to Moorfields bleb grading system; postoperative bleb was better than the bleb of the previously failed trabeculectomy (P<0.001), and there was a significant difference between group A and B regarding bleb area. Total success rate was 100%; in group A, complete success was 100%, while in group B it was 72.7% (P=0.016).ConclusionOur results suggest that Ologen may be a useful alternative to MMC in repeat trabeculectomy.

Stab Incision Glaucoma Surgery: A Modified Guarded Filtration Procedure for Primary Open Angle Glaucoma

Purpose. To describe a modified guarded filtration surgery, stab incision glaucoma surgery (SIGS), for primary open angle glaucoma (POAG). Methods. This prospective, interventional case series included patients with POAG (IOP ≥21 mmHg with glaucomatous visual field defects). After sliding superior conjunctiva down over limbus, 2.8 mm bevel-up keratome was used to create conjunctival entry and superficial corneoscleral tunnel in a single step starting 1.5 mm behind limbus. Lamellar corneoscleral tunnel was carefully dissected 0.5–1 mm into cornea and anterior chamber (AC) was entered. Kelly Descemet's punch (1 mm) was slid along the tunnel into AC to punch internal lip of the tunnel, thereby compromising it. Patency of ostium was assessed by injecting fluid in AC and visualizing leakage from tunnel. Conjunctival incision alone was sutured. Results. Mean preoperative IOP was 27.41 ± 5.54 mmHg and mean postoperative IOP was 16.47 ± 4.81 mmHg (n = 17). Mean reduction in IOP was 38.81 ± 16.55%. There was significant reduction of IOP (p < 0.000). 64.7% had IOP at final follow-up of <18 mmHg without medication and 82.35% had IOP <18 mmHg with ≤2 medications. No sight threatening complications were encountered. Conclusion. Satisfactory IOP control was noted after SIGS in interim follow-up (14.18 ± 1.88 months).

Medium-term Outcomes of Unsutured Scleral Flap Trabeculectomies

PURPOSE

To examine the clinical characteristics and medium-term outcomes of unsutured scleral flap trabeculectomies.

PATIENT AND METHODS

A retrospective review of 45 patients who underwent 50 unsutured scleral flap trabeculectomies by a single ophthalmic surgeon. Information pertaining to each patient's demographic details, preoperative assessment, surgical procedure, and 2 years of postoperative management were obtained.

RESULTS

The average age of patients was 72.4±12.5 (range, 30 to 97) years. The diagnosis was primary open-angle glaucoma in 38 (76.0%) cases. The average preoperative, 1 year postoperative and 2-year postoperative intraocular pressure (with number of topical antiglaucoma medications) were 20.8 (2.5), 13.2 (0.4), and 12.6 mm Hg (0.7), respectively. The procedure performed was a trabeculectomy alone in 32 (64.0%) cases, and combined trabeculectomy and phacoemulsification in 18 (36.0%) cases. Four were performed with mitomycin C. Three procedures (6%) had intraoperative complications (2 iris prolapses, 1 subconjunctival hemorrhage). Seven procedures were complicated by a postoperative choroidal detachment, which were managed conservatively and resolved spontaneously over time. There was 1 case (2%) of postoperative hypotony, which failed to resolve (intraocular pressure of <6 mm Hg for >3 months).

CONCLUSIONS

The majority of unsutured scleral flap trabeculectomies had an acceptable risk profile and resulted in a decrease in the intraocular pressure at 2 years postoperatively.

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.

[Management of Radius-Maumenee syndrome : Treatment with deep sclerectomy, viscocanalostomy and collagen matrix implantation]

We describe the case of an 18-year-old female patient who presented with vasodilation of the episcleral vessels in both eyes. The dilated vessels were more prominent in the right eye and, furthermore, examination of the fundus oculi showed a glaucomatous excavation of the right optic disc. No underlying eye or systemic disease was found as the cause for the vasodilation, therefore, Radius-Maumenee syndrome (idiopathic dilated episcleral vessels with secondary open angle glaucoma) was diagnosed. Radius-Maumenee syndrome is a diagnosis by exclusion. If no underlying disease can be detected primary therapy of the glaucoma is required. Carotid cavernous fistulas as the most common cause for dilated episcleral vessels and elevated episcleral venous pressure should be ruled out. Due to the progression of the excavation and the pathologically elevated intraocular pressure in the right eye of our patient we decided to perform a deep sclerectomy in combination with viscocanalostomy and implantation of a collagen matrix. The operation and postoperative period were free from complications. Two months after the surgical procedure the right eye showed a normalized intraocular pressure of 7 mmHg but no morphological changes in terms of reduction of the vasodilation. In summary, deep sclerectomy in combination with viscocanalostomy and implantation of a collagen matrix showed good results in the reduction of intraocular eye pressure in Radius-Maumenee syndrome.

Device-modified trabeculectomy for glaucoma

BACKGROUND

Glaucoma is an optic neuropathy that leads to vision loss and blindness. It is the second most common cause of irreversible blindness worldwide. The main treatment for glaucoma aims to reduce intraocular pressure (IOP) in order to slow or prevent further vision loss. IOP can be lowered with medications, and laser or incisional surgeries. Trabeculectomy is the most common incisional surgical procedure to treat glaucoma. Device-modified trabeculectomy is intended to improve drainage of the aqueous humor to lower IOP. Trabeculectomy-modifying devices include Ex-PRESS, Ologen, amniotic membrane, expanded polytetrafluoroethylene (E-PTFE) membrane, Gelfilm and others. However, the effectiveness and safety of these devices are uncertain.

OBJECTIVES

To assess the relative effectiveness, primarily with respect to IOP control and safety, of the use of different devices as adjuncts to trabeculectomy compared with standard trabeculectomy in eyes with glaucoma.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2014, Issue 12), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to December 2014), EMBASE (January 1980 to December 2014), PubMed (1948 to December 2014), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to December 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), 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 search for trials. We last searched the electronic databases on 22 December 2014.

SELECTION CRITERIA

We included randomized controlled trials comparing devices used during trabeculectomy with trabeculectomy alone. We also included studies where antimetabolites were used in either or both treatment groups.

DATA COLLECTION AND ANALYSIS

We used standard procedures expected by Cochrane.

MAIN RESULTS

We found 33 studies that met our inclusion criteria, of which 30 were published as full-length journal articles and three as conference abstracts. Only five studies have been registered. The 33 studies included a total of 1542 participants with glaucoma, and compared five types of devices implanted during trabeculectomy versus trabeculectomy alone. Five studies reported the use of Ex-PRESS (386 participants), eight studies reported the use of Ologen (327 participants), 18 studies reported the use of amniotic membrane (726 participants), one study reported the use of E-PTFE (60 participants), and one study reported the use of Gelfilm (43 participants). These studies were conducted in North America, South America, Europe, Asia, and the Middle East. Planned participant follow-up periods ranged from three months to five years. The studies were reported poorly which limited our ability to judge risk of bias for many domains. Only two studies explicitly masked outcome assessment so, we rated 31 studies at high risk of detection bias.Low-quality evidence from three studies showed that use of Ex-PRESS compared with trabeculectomy alone may be associated with a slightly lower IOP at one year (mean difference (MD) -1.58 mm Hg, 95% confidence interval (CI) -2.74 to -0.42; 165 eyes). Cataract surgery and hyphema may be less frequent in the Ex-PRESS group than in the trabeculectomy-alone group (cataract surgery: risk ratio (RR) 0.32, 95% CI 0.14 to 0.74, 3 studies, low-quality evidence; hyphema: RR 0.33, 95% CI 0.12 to 0.94, 4 studies, low-quality evidence). The effect of whether Ex-PRESS prevents hypotony was uncertain (RR 0.92, 95% CI 0.63 to 1.33, 2 studies, very low-quality evidence). All these studies received funding from the device manufacturer.Very low-quality evidence from five studies suggests that use of Ologen compared with trabeculectomy alone is associated with slightly higher IOP at one year (MD 1.40 mm Hg, 95% CI -0.57 to 3.38; 177 eyes). The effect of Ologen on preventing hypotony was uncertain (RR 0.75, 95% CI 0.47 to 1.19, 5 studies, very low-quality evidence). Differences between the two treatment groups for other reported complications also were inconclusive.Low-quality evidence from nine studies suggests that use of amniotic membrane with trabeculectomy may be associated with lower IOP at one year compared with trabeculectomy alone (MD -3.92 mm Hg, 95% CI -5.41 to -2.42; 356 eyes). Low-quality evidence showed that use of amniotic membrane may prevent adverse events and complications, such as hypotony (RR 0.40, 95% CI 0.17 to 0.94, 5 studies, low-quality evidence).The report from the only E-PTFE study (60 eyes) showed no important differences for postoperative IOP at one year (MD -0.44 mm Hg, 95% CI -1.76 to 0.88) between the trabeculectomy + E-PTFE versus the trabeculectomy-alone groups. Hypotony was the only postoperative complication observed less frequently in the E-PTFE group compared to the trabeculectomy-alone group (RR 0.29, 95% CI 0.11 to 0.77).The one Gelfilm study reported uncertainty in the difference in IOP and complication rates between the two groups at one year; no further data were provided in the study report.

AUTHORS' CONCLUSIONS

Overall, the use of devices with standard trabeculectomy may help with greater IOP reduction at one-year follow-up than trabeculectomy alone; however, due to potential biases and imprecision in effect estimates, the quality of evidence is low. When we examined outcomes within subgroups based on the type of device used, our findings suggested that the use of an Ex-PRESS device or an amniotic membrane as an adjunct to trabeculectomy may be slightly more effective in reducing IOP at one year after surgery compared with trabeculectomy alone. The evidence that these devices are as safe as trabeculectomy alone is unclear. Due to various limitations in the design and conduct of the included studies, the applicability of this evidence synthesis to other populations or settings is uncertain. Further research is needed to determine the effectiveness and safety of other devices and in subgroup populations, such as people with different types of glaucoma, of various races and ethnicity, and with different lens types (e.g. phakic, pseudophakic).

Biodegradable collagen matrix (Ologen™) implant and conjunctival autograft for scleral necrosis after pterygium excision: two case reports

BACKGROUND

Scleromalacia, in the form of scleral thinning, melting, and necrosis, is a potentially serious complication of pterygium excision. This study introduces a new biodegradable material, Ologen™ collagen matrix (OCM), to repair scleral thinning as an alternative to preserved scleral tissue, and evaluates the long-term outcomes of OCM for ocular surface reconstruction surgery.

CASE PRESENTATION

Two cases of possibly mitomycin C (MMC)-associated marked scleral thinning after pterygium excision with 0.02 % topical MMC for 2-weeks were included in this study. An OCM graft at the scleral thinning area and conjunctival autograft (CAU) were performed on both patients. The scleral defect size was measured and its margin was marked with a biopsy punch. The margin of the scleral thinning area was trimmed by Vannas scissors and the OCM was cut using a circular-shape biopsy punch of the same size. The OCM was sutured with a recipient scleral wall using 10-0 nylon interrupted sutures. Free CAU was harvested from the superonasal bulbar conjunctiva with a punch biopsy 1-mm larger in diameter than that of the OCM. The previously sutured OCM bed was covered with CAU and the graft was secured with 10-0 nylon interrupted sutures. Both patients were examined periodically for over two years by assessing graft thickness and surface vascularization using a slit lamp biomicroscope. Reepithelialization of the ocular surface was observed within three to six days after surgery. Ocular discomfort and inflammation ceased in both patients as the ocular surface quickly stabilized. The entire graft site remained intact and provided a good healthy ocular surface with fluorescein stain negative intact epithelium and good vascularization of grafted conjunctiva. Epithelial defects and scleral thinning did not recur in either patient over the two year follow-up period.

CONCLUSION

For treatment of a possibly MMC-associated scleral necrosis following the surgical excision of the pterygium, an OCM graft with CAU is highly recommended for good clinical outcomes and low recurrence rates. With the clinical results of this study, the new biodegradable Ologen™ collagen matrix qualifies as an alternative treatment to scleral tissue for ocular surface reconstruction.

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.

A nanopore membrane regulator device for laser modulated flow after glaucoma surgery

Glaucoma, the second most common cause of blindness in the world, is a multifactorial disease with several risk factors, of which intraocular pressure (IOP) is a primary contributing factor. Filtration surgery is one of the most effective means to significantly lower IOP compared to medical or laser treatments, and it is typically reserved for advanced disease. However, there are high rates of postoperative complications associated with the procedure, often from over- or under-filtration. To address these problems, the glaucoma drainage device regulator (GDDR) implant was developed to allow post-operative control of aqueous flow and IOP. The device, a tube with a nanopore membrane, is placed beneath the scleral flap. Postoperatively, the membrane surface can be ruptured with a laser to augment flow through the system. This feature allows adjustable control of aqueous flow and diminishes the risk of hypotony in the early postoperative period.

Biodegradable 3D-Porous Collagen Matrix (Ologen) Compared with Mitomycin C for Treatment of Primary Open-Angle Glaucoma: Results at 5 Years

Purpose. To evaluate the effectiveness and safety of the Ologen as an aid for trabeculectomy performed for primary open-angle glaucoma compared with mitomycin C. Methods. In this prospective, randomized, parallel assignment, comparative study, 31 eyes of 21 primary open-angle glaucoma patients were allocated for trabeculectomy with the Ologen implant; another 32 eyes of 23 patients were treated with trabeculectomy augmented with mitomycin C. The patients were followed up for 5 years and evaluated for intraocular pressure, rate of success, status of the bleb, and adverse events. Result. The mean postoperative intraocular pressure was statistically different at 3 m, 6 m, 1 y, 3 y, and 5 y follow-up. The rates of both complete success (P = 0.017) and overall success (P = 0.031) in the Ologen group were significantly higher than those in the mitomycin C group. The difference of the bleb extent and vascularity was statistically significant in both groups. There was no significant difference in postoperative complication. Conclusions. Ologen provides higher rates of surgical success compared with mitomycin C for patients with primary open-angle glaucoma undergoing trabeculectomy. It may be a new, safe, simple, and effective therapeutic approach for treating primary open-angle glaucoma.

Using a collagen matrix implant (Ologen) versus mitomycin-C as a wound healing modulator in trabeculectomy with the Ex-PRESS mini glaucoma device: a 12-month retrospective review

PURPOSE

To compare outcomes between patients undergoing trabeculectomy with an Ex-PRESS mini glaucoma device using mitomycin-C (MMC) to those undergoing the same procedure using a subconjunctival collagen matrix implant (Ologen).

MATERIALS AND METHODS

All patients underwent a trabeculectomy using an Ex-PRESS shunt. A total of 49 eyes of 37 patients received Ologen, and 50 eyes of 48 patients received MMC. Postoperative data were reviewed over 12 months. Outcomes included mean intraocular pressure (IOP), rate of success in achieving a target IOP (with and without antiglaucoma medications), number of medications used, and rates of complications/reoperations.

RESULTS

The mean preoperative IOP was 24.98 mm Hg for the MMC group, and 23.24 mm Hg for the Ologen group (P=0.3). At 12 months postoperatively, the mean IOP was 12.1 mm Hg for the MMC group, and 13.12 mm Hg for the Ologen group (P=0.34). At 12 months, the rate of achieving an IOP≤21 mm Hg off medications (unqualified success) was 84% for the MMC group, and 86% for the Ologen group. There was no statistically significant difference between either group for the rates of achieving a specified postoperative IOP either with (qualified success) or without medications. There was no statistically significant difference between the 2 groups in the mean number of postoperative medications required. Both groups had similar rates of complications, and 1 patient in the MMC group lost light perception after a suprachoroidal hemorrhage.

CONCLUSIONS

Our results suggest that ologen provides similar rates of surgical success as MMC for patients undergoing a filtering procedure using an Ex-PRESS mini glaucoma device.

Achieving Target Pressures with Combined Surgery: Primary Patchless Ahmed Valve Combined with Phacoemulsification vs Primary Phacotrabeculectomy

PURPOSE

To evaluate the ability of phacoemulsification combined with either primary trabeculectomy (PT) or primary Ahmed glaucoma valve implantation (PAVI) to achieve target intraocular pressures (TIOP) in adults with primary open angle glaucoma.

MATERIALS AND METHODS

Chart review of 214 adult patients operated between January 2002 and June 2008 with a minimum follow-up of 6 months. Group 1 comprised 181 eyes of 166 patients undergoing PT while group 2 included 50 eyes of 49 patients in combination with primary AVI. Target lOPs were pre-determined for each patient and success was defined as an IOP at or lower than target with or without medications. An IOP above target, loss of light perception or need for additional procedures to lower IOP were considered a failure.

RESULTS

Mean preoperative IOP was 17.2 mm Hg in group 1 and 17.3 in group 2. Mean postoperative IOPs were 10.2 and 9.2 on day 1, 12.2 and 11.6 at year 1, and 10.7 in both groups at year 5. Survival rates in groups 1 and 2 were 96.7 vs 96% at 6 months, 89 vs 96% at 12 months, 83.5 vs 96% at 24 months and 79.4 vs 89.1% at 36, 48 and 72 months. Transient bleb leaks were more frequent in group 1 (26 eyes, 14.4 vs 0%, p = 0.001) and transient choroidal detachments were more frequent in group 2 (7 eyes, 3.9 vs 6 eyes, 12%, p = 0.038).

CONCLUSION

Midterm results for achieving target pressures using combined phacoemulsification with either PT or PAVI are comparable. The profile of complications is different for the two procedures. How to cite this article: Albis-Donado O, Sánchez-Noguera CC, Cárdenas-Gómez L, Castañeda-Diez R, Thomas R, Gil-Carrasco F. Achieving Target Pressures with Combined Surgery: Primary Patchless Ahmed Valve Combined with Phacoemulsification vs Primary Phacotrabeculectomy. J Curr Glaucoma Pract 2015;9(1):6-11.

Biodegradable Collagen Implants in Trabeculectomy

Subconjunctival and subscleral fibrosis are the major causes of failure of filtering surgery. Antiproliferative agents have been successfully used to improve the long-term success of this surgery. Recent advancement in the field of glaucoma surgery has been the use of bioengineered, biodegradable, porous collagen-glycosaminoglycan matrix implant in the subconjunctival and/or subscleral space to modify the wound-healing process and reduce scar formation, hence improving the surgical success without the need for anti-fibrotic agents. Biodegradable, collagen implants have shown favorable results when used with deep sclerectomy. There have been variable results regarding the success of trabeculectomy when combined with these implants. These implants also decrease the dose of mitomycin C required with trabeculectomy and hence, decrease the side effect associated with these drugs. The use of the biodegradable implants in glaucoma surgery is still evolving and further studies are needed to find the appropriate surgical technique, the ideal size and site of placement and determine their long-term impact on trabeculectomy outcomes and complications. How to cite this article: Ichhpujani P, Dada T, Bhartiya S. Biodegradable Collagen Implants in Trabeculectomy. J Curr Glaucoma Pract 2015;9(1):24-27.