Closure of leaking filtering blebs with cyanoacrylate tissue adhesive

Collagen Crosslinking-assisted Treatment of a Bleb Leak: Enhancement of Vascularization around the Bleb

AIM AND OBJECTIVE

To present a case with bleb leakage treated with collagen crosslinking (CXL).

BACKGROUND

Bleb-related complications can cause serious problems even a long time after trabeculectomy. In this case report, we present a relatively unknown treatment method for bleb leakage which might be one of the long-term complications of trabeculectomy.

CASE DESCRIPTION

A 60-year-old male patient was admitted to our clinic with a decrease in his left vision. The patient had a history of left trabeculectomy. The bleb leakage was observed. Autologous blood was injected into the bleb area as the first line of treatment. Collagen crosslinking was applied to the bleb area upon the recurrence of the leakage. In the 1st week after the CXL, CXL was repeated in the bleb area upon the observation that the leakage recurred. It was observed that the leakage did not recur and bleb vascularization was triggered after CXL.

CONCLUSION

Conjunctival CXL might be a non-invasive, viable method in the management of bleb leakage. It might be applied in conjunction with bandage contact lenses for the treatment of late bleb leaks as an alternative treatment method before going into surgical intervention.

CLINICAL SIGNIFICANCE

As a result of conjunctival CXL application, collagen permeability reduction and neovascularization secondary to CXL application might be effective in preventing bleb leakage. However, further studies are needed to prove this.

HOW TO CITE THIS ARTICLE

Aktas Z, Aribas YK, Bilgihan K, et al. Collagen Crosslinking-assisted Treatment of a Bleb Leak: Enhancement of Vascularization around the Bleb. J Curr Glaucoma Pract 2021;15(1):36-39.

Polyethylene Glycol-Based Synthetic Hydrogel Sealant for Filtration Bleb Leaks: An In Vivo and Histologic Study

Purpose

To evaluate the efficacy of polyethylene glycol (PEG)-based synthetic sealant for closing bleb leaks after glaucoma filtration surgery.

Methods

Tube shunt surgery that included implantation of a 22-gauge indwelling catheter and intraoperative mitomycin C was performed in the left eyes of 11 New Zealand white rabbits. Seven days postoperatively, all filtration blebs were perforated with an 18-gauge needle to create a bleb hole. In six rabbits, the holes were covered with the sealant and irradiated with blue-green light for 60 seconds; in the five control rabbits, the holes were untreated. For 3 weeks after the tube shunt surgery, the eyes were checked for bleb leaks, and the intraocular pressure (IOP) was measured in both eyes. Finally, the operated eyes were enucleated for histologic examination.

Results

The bleb leaks stopped in the eyes in which sealant was used and persisted in the other eyes. The sealant preserved the bleb function; the IOPs in these eyes were significantly (P < 0.05) lower than the right eyes that did not undergo surgery. Hematoxylin and eosin staining showed that the holes were closed and covered with conjunctival epithelial cells in the eyes in which sealant was applied; the holes were open in the control eyes. Immunohistochemical staining showed that the bleb holes in which the sealant was applied had fewer inflammatory cells.

Conclusions

The PEG sealant has the potential to seal bleb leaks effectively.

Translational Relevance

Application of the PEG sealant can be used as adjunct therapy for bleb leaks in glaucoma surgery.

Prospective study on a novel treatment for leaking cystic bleb: Efficacy and safety of collagen crosslinking

IMPORTANCE

Management of cystic bleb leak is difficult. It would be essential to look for a method to strengthen the original pathological conjunctiva and reverse bleb leak.

BACKGROUND

To evaluate the long-term efficacy and safety of collagen crosslinking in patients with leaking cystic bleb.

DESIGN

Prospective interventional case series at a university-based hospital.

PARTICIPANTS

Twelve eyes in 12 subjects with late-onset bleb leak from cystic bleb, without indications for prompt surgical interventions were included.

METHODS

The subjects underwent crosslinking with 0.1% riboflavin application to bleb surface, followed by ultraviolet irradiation for 30 minutes. The subjects were followed up at baseline and at 1 week, 1 month, 3 months, 6 months post-treatment and then every 6 months afterwards.

MAIN OUTCOME MEASURES

Interval from treatment to cessation of bleb leak, recurrence rate of bleb leak and side effects of treatment.

RESULTS

The mean follow-up after crosslinking was 29.33 ± 12.45 months. Bleb leak subsided in 11 (92%) of 12 patients after a single session of crosslinking, after 1 to 8 weeks (median 3 weeks). Time to leak cessation was significantly correlated with the number of prior glaucoma interventions (R = .71, P = .014). Bleb wall at 3 months was significantly thicker than at baseline (0.70 ± 0.67 vs 0.81 ± 0.62 mm, P = .008). None of the patients experienced any complications.

CONCLUSIONS AND RELEVANCE

Crosslinking achieves resolution of cystic bleb leak which lasts for at least 12 months, without the need of subsequent surgical interventions. Crosslinking is a simple, non-invasive treatment for bleb leak. It aims to restore the integrity of conjunctiva.

Ocular adhesives: Design, chemistry, crosslinking mechanisms, and applications

Closure of ocular wounds after an accident or surgery is typically performed by suturing, which is associated with numerous potential complications, including suture breakage, inflammation, secondary neovascularization, erosion to the surface and secondary infection, and astigmatism; for example, more than half of post-corneal transplant infections are due to suture related complications. Tissue adhesives provide promising substitutes for sutures in ophthalmic surgery. Ocular adhesives are not only intended to address the shortcomings of sutures, but also designed to be easy to use, and can potentially minimize post-operative complications. Herein, recent progress in the design, synthesis, and application of ocular adhesives, along with their advantages, limitations, and potential are discussed. This review covers two main classes of ocular adhesives: (1) synthetic adhesives based on cyanoacrylates, polyethylene glycol (PEG), and other synthetic polymers, and (2) adhesives based on naturally derived polymers, such as proteins and polysaccharides. In addition, different technologies to cover and protect ocular wounds such as contact bandage lenses, contact lenses coupled with novel technologies, and decellularized corneas are discussed. Continued advances in this area can help improve both patient satisfaction and clinical outcomes.

Bleb Revision With Temporalis Fascia Autograft

PURPOSE

We report the first description of temporalis fascia autograft to repair a late leakage bleb with scleral defect that occurred long time after trabeculectomy with mitomycin C.

PATIENT

A 65-year-old woman was referred to our hospital with chronic late bleb leakage on her right eye. She had previously undergone a trabeculectomy with mitomycin C 3 years ago for a pigmentary glaucoma. Bleb leakage occurred 1½ year after the initial surgery. She underwent 2 surgical revisions consisting of a conjunctival advancement then an autologous conjunctival with partial scleral grafts without success. The initial best-corrected visual acuity of the right eye was 20/50 (Snellen scale). Slit-lamp examination revealed an avascular filtering bleb with leakage (massive positive Seidel test) and a scleral defect. The anterior chamber was deep and intraocular pressure (IOP) was 9 mm Hg.Faced with the risk of blebitis, endophthalmitis, and with the failure of the previous surgeries announced earlier, a surgical revision with autologous superficial temporalis fascia graft was decided to repair the leaking bleb. After local anesthesia, a sample of superficial temporalis fascia was harvested. The necrotic avascular conjunctiva around the bleb was dissected to separate and excise it from the sclera. The autologous fascia graft was sutured on the scleral defect with 10-0 nylon. Subsequently healthy conjunctiva was sutured above the graft.

RESULTS

No bleb leakage occurred postoperatively, best-corrected visual acuity improved to 20/25, and IOP remained within normal levels 6 months after surgery without IOP-lowering medication.

CONCLUSIONS

Superficial temporalis fascia autograft seems to be an effective, safe, and easy technique for ophthalmologists. It is a new procedure in the management of late-onset bleb leakage.

Collagen crosslinking in the management of leaking cystic blebs: a prospective study

PURPOSE

To evaluate the effectiveness and safety of collagen crosslinking for leaking cystic blebs.

METHODS

A prospective study was conducted on subjects with cystic bleb leaks without indications for urgent surgical intervention. Collagen crosslinking with riboflavin 0.1 % and ultraviolet A irradiation for 30 min was applied to the cystic bleb surface in five patients. Subjects were followed up for at least 20 weeks (mean: 35.5 ± 11.5 weeks) to monitor the length of time to the cessation of bleb leak, as well as visual acuity, intraocular pressure, and the presence of adverse effects arising from the treatment.

RESULTS

Results showed that a single session of collagen crosslinking was effective in stopping cystic bleb leak. In two of the five subjects, the bleb leak subsided 1 week post-treatment, in one patient after 2 weeks, and in the two more complicated cases, after 4 weeks. This effect was maintained for a mean period of 33.5 ± 10.2 weeks after bleb leak cessation. Treatment was effective even in patients with friable conjunctiva following multiple surgical interventions and severe leak, although a longer period was needed for resolution of the bleb leak. The intraocular pressure and visual acuity were largely stable before and after treatment. No side effects or complications arose from this treatment.

CONCLUSIONS

We recommend a trial of collagen crosslinking on leaking cystic blebs without indications for immediate surgical interventions. It is a relatively easy, non-invasive, pain-free, and potential repeatable procedure for treating leaking cystic blebs, with the aim of strengthening the underlying pathological conjunctiva.

Cyanoacrylate tissue glue for wound repair in early posttrabeculectomy conjunctival bleb leak: a case series

We demonstrated a noninvasive management of early bleb leak following trabeculectomy using cyanoacrylate tissue glue (CATG). Three patients who underwent augmented trabeculectomy with mitomycin C with early bleb leak between January 2009 and June 2010 were reviewed. Case 1 and Case 2 exhibited bleb leak on postoperative Day 1 and Case 3 showed leak on follow-up at postoperative Day 7. Case 1 was successfully sealed with CATG at postoperative Day 3, after failed pressure padding and bandage contact lens. Case 2 was successfully sealed with CATG at postoperative Day 3, after failed pressure padding and conjunctiva flap resuturing. In Case 3, the leaking conjunctival flap was managed with combined techniques of resuturing and applying CATG at postoperative Day 9, after failed pressure padding. During leakage, the intraocular pressure was low (6–8 mmHg) in all three cases, with shallow anterior chamber depth and absence of other complications such as choroidal detachment, hypotony maculopathy, or endophthalmitis. Foreign body sensation was the main complaint following the procedure. No clinical allergy reaction was documented. CATG may serve as a potential adjunctive and effective method in the management of posttrabeculectomy early bleb leak.

Application of 2-octyl-cyanoacrylate for corneal perforation and glaucoma filtering bleb leak

BACKGROUND

This paper reports on the efficacy of a tissue adhesive, 2-octyl-cyanoacrylate, in the treatment of corneal perforation and glaucoma filtering bleb leak.

METHODS

Two eyes from two patients with corneal perforation or laceration and two eyes from two patients with bleb leak were included. The patients underwent application of 2-octyl-cyanoacrylate onto the perforated or leaking site, and a hydrogel contact lens was applied as a bandage. We also evaluated the in vitro cell toxicity of 2-octyl-cyanoacrylate in HeLa cells.

RESULTS

The two cases of corneal perforation were repaired within 22 days with one application of the tissue adhesive. The two cases of bleb leak were repaired with 2-4 applications of the tissue adhesive over 134 (range 17-134) days). There were no recurrences or adverse effects during a mean follow-up period of 12.7 months. In vitro testing revealed that 2-octyl-cyanoacrylate was markedly toxic to HeLa cells.

CONCLUSION

Four patients with corneal perforation or bleb leak were successfully managed using 2-octyl-cyanoacrylate tissue adhesive. This simple and easy surgical technique may become an alternative therapeutic option for corneal perforation or bleb leak, although several applications of this tissue adhesive may be required. Although 2-octyl-cyanoacrylate was toxic to HeLa cells, no adverse clinical effects were noted using this adhesive.

Interventions for late trabeculectomy bleb leak

BACKGROUND

Late trabeculectomy bleb leaks are a common complication after filtering glaucoma surgery. Although asymptomatic, late bleb leaks may lead to hypotony and are associated with bleb related infections.

OBJECTIVES

To assess the effects of interventions for late trabeculectomy bleb leak.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 7), MEDLINE (January 1946 to July 2012), EMBASE (January 1980 to July 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 18 July 2012.

SELECTION CRITERIA

We included randomised and quasi-randomised trials in which any treatments for eyes with late bleb leak (interventional and non-interventional) were compared with each other.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors when additional information was needed.

MAIN RESULTS

The review included one multicentre trial based in the USA with 30 eyes of 30 participants. The trial compared two surgical procedures (conjunctival advancement and amniotic membrane transplant) to cover a filtering bleb leak. Conjunctival advancement has been shown to be more effective in sealing filtering bleb leaks.

AUTHORS' CONCLUSIONS

Although a variety of treatments have been proposed for bleb leaks, there is no evidence of their comparative effectiveness.The evidence in this review was provided by a single trial that compared two surgical procedures (conjunctival advancement and amniotic membrane transplant). The trial did show a superiority of conjunctival advancement, which was regarded as standard treatment, to amniotic membrane transplantation. There is a need for more randomised trials to validate the findings of this single trial and provide more information on the different types of interventions, especially non-surgical treatments compared to surgical procedures. We recommend that any intervention should be compared to a standard procedure, which is to date conjunctival advancement.

Management of complications in glaucoma surgery

Surgical option for glaucoma is considered when other modalities are not working out to keep the intraocular pressure under control. Since the surgical procedures for glaucoma disrupt the integrity of the globe, they are known to produce various complications. Some of those complications can be vision-threatening. To minimize the morbidity, it is very important that one should know how to prevent them, recognize them and treat them. The objective of this article is to provide insight into some of those complications that will help the ophthalmologists in treating glaucoma patients in their clinical practice.

Corneal lamellar grafting to repair late complications of mitomycin C trabeculectomy

Purpose

To report corneal lamellar grafting to repair the late-onset complications after MMC trabeculectomy.

Methods

Multiple case reports.

Results

A 76-year-old male with primary open-angle glaucoma (POAG) and a 55-year-old male with late developmental glaucoma complicated by bleb leaks from a microhole 10 and eight years after surgery, respectively. Severe ciliochoroidal detachment and a shallow anterior chamber were persistent in one case and bleb-related infection recurred in another. Additionally, a 46-year-old male with POAG had hypotony maculopathy with a giant ischemic bleb 18 months after surgery. Although these patients were quite resistant to medical and surgical treatments, they were successfully treated by corneal lamellar grafting without complications.

Conclusions

Tectonic corneal lamellar grafting is a reliable and final surgical method to improve severe cases of hypotony maculopathy or bleb leak after mitomycin C trabeculectomy.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A hyperdry amniotic membrane patch using a tissue adhesive for corneal perforations and bleb leaks

PURPOSE

To evaluate the efficacy of hyperdry amniotic membrane (AM) patching attached using a tissue adhesive for corneal perforations and glaucoma filtering bleb leaks.

DESIGN

Prospective, noncomparative, interventional case series.

METHODS

Five eyes of 5 patients (glaucoma bleb leaks, 2 eyes; corneal perforations, 3 eyes) were treated with a single-layer patch of dried AM using a biological tissue adhesive. The dried AM was prepared with consecutive far-infrared rays and microwaves (hyperdry method) and was sterilized by gamma-ray irradiation. The dried AM was cut to the desired size and shape, and the tissue adhesive was applied to the amniotic epithelial side of the dried membrane. After applying the tissue adhesive, the dried membrane with glue applied then was positioned to cover the conjunctival bleb leak site or corneal perforation lesion using forceps. A therapeutic hydrogel contact lens then was installed as a bandage.

RESULTS

Bleb leaks or corneal perforations were repaired successfully within 21 days in all 5 cases. There were no remarkable adverse effects, and there was no recurrence of bleb leak or corneal perforation.

CONCLUSIONS

The hyperdry AM is a useful substrate, and this surgical procedure is a promising method to treat glaucoma filtering bleb leak or corneal perforation, which may result in serious vision-threatening ocular complications.

Fibrin Glue as a Suture Substitute: Histological Evaluation of Trabeculectomy in Rabbit Eyes

PURPOSE

To describe the outcome of the use of fibrin adhesive (Quixil) in penetrating trabeculectomy in a rabbit model.

METHODS

Fibrin adhesive was used experimentally to attach the conjunctiva and the scleral flap in two groups of 17 New Zealand albino adult rabbits (34 eyes). In the first experiment (20 eyes), the fibrin adhesive was used to reattach the tissue after conjunctival peritomy and scleral flap only in 14 eyes (experiment I). In 6 eyes (controls), the conjunctiva was attached with nylon sutures. In the second experiment (14 eyes), the fibrin adhesive was used after conjunctival peritomy, scleral flap, and penetrating trabeculectomy in 8 eyes (experiment II). In a control group of 6 eyes, nylon sutures were used to attach the scleral flap and the conjunctiva after penetrating trabeculectomy. Biomicroscopy and histopathological examinations were performed on postoperative days 1, 3, 7, 14, 21, and 30. Intraocular pressure was measured before and after surgery in the second experiment. Main outcome measures are histological presence of adhesive in the tissue, degree of capillary congestion, inflammatory reaction, collagen density [scar formation] and clinical (IOP measurements before and after surgery, conjunctival chemosis, anterior chamber reaction, presence of filtering bleb and wound leakage).

RESULTS

In experiments I and II, the adhesive was well identified histologically in the tissue as an amorphic eosinophilic substance for up to day 3 and nearly disappeared by day 7. An acute inflammatory reaction was noted for up to 14 days, which converted to chronic inflammation with collagen deposits and scar formation by day 30. Similar inflammatory reaction was observed in the control group. The adhesive had no adverse effects on ocular tissue compared with sutures. One eye in experiment II demonstrated wound dehiscence. Intraocular pressure dropped from 17.35 mmHg preoperatively to 8.28 mmHg on postoperative day 1 in experiment II, and from 17.2 mmHg to 11.5 mmHg in the controls. No significant change in intraocular pressure was noted in experiment I.

CONCLUSIONS

The fibrin adhesive had no adverse effects on ocular tissue compared with sutures. It might serve as an effective substitute for conjunctival and scleral wound closure in trabeculectomy surgery.

Long-term follow up of surgical repair of late bleb leaks after glaucoma filtering surgery

PURPOSE

To study the long-term outcomes of surgical revision of leaking blebs after trabeculectomy and identify possible risk factors for failure.

PATIENT AND METHODS

A retrospective, nonrandomized, noncomparative interventional study of 34 eyes with late bleb leaks after trabeculectomy that underwent bleb excision with conjunctival advancement. The primary outcome measure was successful repair and control of intraocular pressure (IOP). The other measures evaluated included change in visual acuity from baseline and complications such as recurrence of bleb leak, endophthalmitis or the need for additional antiglaucoma medication to control IOP.

RESULTS

After a mean follow up of 36.2+/-23 months, the mean IOP at the last visit was 14.5+/-7.6 mm Hg. IOP in 58.8% of eyes was controlled without medication. Complications included early leaks (7/34), late recurrent or persistent leaks (1/34), and endophthalmitis (1/34). In all, 41.2% patients required additional medication at the last visit. Survival analysis at 22 months the probability of total and qualified success was 52% and 72%, respectively. However, this dropped to 10% and 15%, respectively, at 5 years. The probability of total and qualified success further dropped to 2.5% and 5% at 5 years when the IOP cut-off was lowered from 21 to 15 mm Hg. Cox regression analysis failed to identify risk factors for bleb failure.

CONCLUSIONS

Surgical bleb revision seems to be effective in treating late bleb leaks with few postoperative complications. However, patients should be followed carefully as late failure of bleb function beyond 2 years is a significant possibility.

Ocular surface sealants and adhesives

Tissue adhesives, both synthetic and biologic, have a long history of use in ophthalmology. Cyanoacrylate-based glues have traditionally been the most widely used glues for various purposes. They have been specially useful for treating corneal perforations and have had significantly improved long-term outcomes. More recently, fibrin-based glues have gained a major role as a suture substitute for attaching biologic tissues and as surface sealants. The literature supports expanded use of fibrin glue in this fashion. Other new agents, such as polyethyelene glycols, have been underutilized and hold promise, especially as surface protectants. Numerous other glues are being developed and show promise as ocular surface sealants and protective membranes. Advances in knowledge about tissue adhesives are leading to more effective and efficient ophthalmic care.

Intraoperative Healon5 injection into blebs for small conjunctival breaks created during trabeculectomy

Leakage from a conjunctival break created during trabeculectomy may cause serious complications such as shallow anterior chamber, hypotony, and a flat bleb in the early postoperative period. Therefore, careful handling of the conjunctiva with a nontoothed forceps is essential. However, thin conjunctiva is susceptible to mechanical injury and is difficult to repair with suturing, especially when the point of leakage is close to the scleral flap. In 3 consecutive cases in which a small break in the thin conjunctiva adjacent to the scleral flap was created during trabeculectomy, sodium hyaluronate 2.3% (Healon5) was intraoperatively injected into the bleb. The break was successfully closed with an intraoperative injection of Healon5 into the bleb. This procedure appears to be a simple, safe, and effective method for closure of a small conjunctival break.

Topical application of autologous serum for the treatment of late-onset aqueous oozing or point-leak through filtering bleb

PURPOSE

To evaluate the efficacy of topical autologous serum application to stop aqueous oozing or point-leak through filtering bleb after trabeculectomy.

PATIENTS AND METHODS

A total of 21 consecutive eyes with oozing and 21 eyes with a point-leak through a functional bleb after trabeculectomy with 5-fluorouracil or mitomycin C were enrolled in this randomized, case-control study. In eyes randomly assigned to the serum group, an antibiotic and the autologous serum, which was sterilely diluted to 20% with physiological saline, were topically applied four times a day for up to 12 weeks. In eyes assigned to the control group, the antibiotic alone was applied according to the same protocol. Intraocular pressure (IOP) and the presence of oozing or a point-leak were tested before and every 2 weeks after starting the treatments.

RESULTS

In the serum and control groups, oozing stopped in 62.5 and 0% of eyes, respectively (P=0.003), and point-leaks stopped in 27.3 and 18.2%, respectively (P>0.9). IOP significantly increased from 10.0+/-3.2 (mean+/-standard deviation) to 11.8+/-3.3 mmHg in eyes in which oozing stopped (P=0.066), and from 11.4+/-2.7 to 15.4+/-2.3 mmHg in eyes in which a point-leak stopped (P=0.042).

CONCLUSIONS

Autologous serum application was significantly effective to stop aqueous oozing but not point-leaks. Stopping oozing or point-leaks was significantly associated with an increase in IOP.

Octyl-2-Cyanoacrylate Tissue Adhesive in External Dacryocystorhinostomy

PURPOSE

To review our experience using octyl-2-cyanoacrylate for closing the cutaneous incision in external dacryocystorhinostomy (DCR).

METHODS

A retrospective review was performed of all cases of external DCR with cyanoacrylate wound closure performed during a 12-month period. At the completion of the DCR, octyl-2-cyanoacrylate was used to close the incision. No subcutaneous sutures were placed to approximate the wound edges. Fifteen seconds of drying time elapsed before a second application of the adhesive was applied. Follow-up consisted of examinations at 1 week, 1 month, and 3 months after surgery.

RESULTS

Twenty-one cases of wound closure using octyl-2-cyanoacrylate in external DCR were performed on 19 patients. Cyanoacrylate was applied to the wound without complications, and all patients had excellent closure of the wound with the cyanoacrylate at the end of the case. No wound infections were noted during the follow-up period. One patient had a wound dehiscence that was treated with forceps debridement of residual cyanoacrylate and reapplication of additional octyl-2-cyanoacrylate. One patient had hypertrophic scar formation that resolved with daily massage. In all patients, the incision was believed to be aesthetically equivalent to the expected appearance of suture closed DCR incisions.

CONCLUSIONS

Closure of the DCR incision with cyanoacrylate is safe, quick, does not compromise wound integrity, and provides an aesthetic result that is equivalent to suture wound closure. Additional benefits could potentially include safer operative environment and postoperative convenience for patient and surgeon.

Surgical Management of Scleral Defects

PURPOSE

To evaluate the results of surgical management of scleral defects using fascia lata, cornea, and sclera as graft materials.

METHODS

The scleral defects of 8 patients were repaired surgically. Six had previous intraocular surgery, 1 had eye trauma, and the other had both intraocular surgery and trauma. Corneoscleral grafts were used in 3 eyes, scleral grafts in 4, and fascia lata was used in 1 eye.

RESULTS

In 7 patients, we achieved the desired cosmetic and tectonic success. During the follow-up period, a recurrent defect was seen in 1 patient, and a second operation was required.

CONCLUSIONS

Surgical techniques using fascia lata, corneal, and scleral grafts are effective for scleral defects.

Severe cough: a cause of late bleb leak

PURPOSE

To highlight coughing as a potential cause for late postoperative trabeculectomy bleb leaks.

METHODS

A retrospective study of 2 patients in whom late bleb leaks developed after a bout of severe coughing. Perioperative 5-fluorouracil was used at the time of the initial filtration procedure for one of the patients, while the second patient had had an ordinary trabeculectomy. Both patients required surgical repair of their bleb leak to manage the resultant hypotony.

RESULTS

Postoperatively, both patients had good intraocular pressure control and maintained their visual fields without topical medications. Both patients demonstrated bleb avascularity after leak repair.

CONCLUSIONS

Trabeculectomy bleb leaks are well recognized. Bleb leaks in the late postoperative period are more common after the perioperative use of antimetabolites, and spontaneous leaks after minimal trauma have been described. The authors describe 2 cases of late spontaneous bleb leaks after severe coughing, both of which responded well to surgical correction. The importance of inquiring about a history of coughing with late bleb leaks in the absence of other causative factors is stressed.

Surgical revision of filtration blebs: a follow-up study

PURPOSE

To assess the clinical outcome of one technique for surgical revision of filtration blebs in terms of bleb function and intraocular pressure control.

METHODS

Retrospective analysis of 36 consecutive cases of leaking, overfiltrating, or oversized blebs treated with bleb excision and conjunctiva and Tenon advancement in a glaucoma referral center between January 1991 and December 1999. Surgical success was defined as a final intraocular pressure between 6 and 22 mm Hg with or without topical antiglaucoma medication, resolution of the bleb leak, hypotony maculopathy and symptoms, and no need for repeat glaucoma surgery.

RESULTS

With a minimum of 12 months and an average of 29.5 months of follow-up, the overall success rate was 86.1%, with 51.6% of patients not requiring medication. In the success group, mean (SD) intraocular pressure was 23.7 (5.9) mm Hg before the original trabeculectomy, 4.3 (3.7) mm Hg prior to revision surgery, and 13.5 (SD 3.8) mm Hg at the last follow-up visit after the revision surgery. Mean number of antiglaucoma medications was 2.1 (range, 1-4) before the original trabeculectomy, none before the revision surgery, and 0.8 (range, 0-3) at the last follow-up visit.

CONCLUSIONS

The surgical revision technique offers a definitive solution for most of these bleb complications and a satisfactory intraocular pressure control in the majority of patients.

Conjunctival advancement versus nonincisional treatment for late-onset glaucoma filtering bleb leaks

OBJECTIVE

To compare the outcomes of conjunctival advancement and nonincisional management of late-onset glaucoma filtering bleb leak.

DESIGN

Retrospective, nonrandomized, comparative interventional trial.

PARTICIPANTS

Fifty-one eyes of 48 persons who underwent management of late-onset glaucoma filtering bleb leak from December 1986 through December 1999 were included. Thirty-seven eyes were included in the nonincisional treatment group (aqueous suppression with lubrication or patching, bandage contact lenses, cyanoacrylate glue, autologous blood injection, or a combination thereof) and 34 eyes were included in the surgical revision group (conjunctival advancement with preservation of the preexisting bleb). Twenty eyes underwent nonincisional treatment before surgical revision and were included in each treatment group.

METHODS

Retrospective chart review of bleb leaks occurring at least 2 months after trabeculectomy. Successful treatment was defined as the resolution of the bleb leak, a final intraocular pressure (IOP) of 21 mmHg or less, and no significant complications such as blebitis, endophthalmitis, or bleb dysesthesia requiring a bleb revision.

MAIN OUTCOME MEASURES

Cumulative success of closure of the filtering bleb leak, complications resulting from the intervention, IOP before and after treatment, and number of glaucoma medications before and after treatment.

RESULTS

The Kaplan-Meier cumulative probability of success at 12 and 24 months were 0.45 and 0.42, respectively, for the nonincisional treatment group and 0.80 and 0.80, respectively, for the surgical revision group. The overall difference between the cumulative success of surgical and nonincisional treatment was statistically significant (P = 0.0001, log-rank test). In the nonincisional treatment group, only 20 of 37 eyes (54%) achieved initial sealing of the bleb leak after the treatment, and of those, almost half (8/20) eventually failed. Reasons for failure included persistent or recurrent leak (n = 21), blebitis or endophthalmitis (n = 6, including 4 with persistent leak), and bleb dysesthesia (n = 2). All eyes in the surgical group achieved closure of the leak, however 7 eventually failed because of leak recurrence (n = 2), elevated IOP (n = 3), or bleb dysesthesia (n = 2), and 11 required additional glaucoma medications.

CONCLUSIONS

Patients with late bleb leaks managed with conjunctival advancement were more likely to have successful outcomes and less likely to have serious intraocular infections than those managed more conservatively.

The use of autologous fibrinogen concentrate in treating ocular hypotony after glaucoma filtration surgery

Antimetabolite therapy with 5-fluouracil (5-FU) or mitomycin-C (MMC) has significantly improved the success rate of glaucoma filtration surgery. However, in some eyes, when filtration is excessive, persistent hypotony may develop. In this study, we describe the experience of using autologous fibrinogen concentrate (AFC) to treat patients with persistent hypotony after glaucoma filtration surgery. Among seven MMC-augmented trabeculectomy patients who developed persistent postoperative hypotony, the effects of AFC intrableb injections were evaluated. Under a microscope, 0.2 ml AFC and bovine thrombin were injected into the blebs of the patients from both sides of the filtering blebs. Postoperative best-corrected visual acuity, anterior chamber status, intraocular pressure (IOP) and fundus examination were followed and compared with those preoperative. On the second day, the mean IOP of seven eyes elevated from preoperative 3.4 +/- 2.1 mmHg to 12.6 +/- 4.2 mmHg, and the anterior chamber became deep without obvious inflammatory response. Within two weeks, macular edema and visual acuity were noted to improve in six eyes (85.7%). In addition, after a mean follow-up of 25 months, the trabeculectomy procedure remained successful in all eyes. AFC appears to be safe and effective in the treatment of ocular hypotony after glaucoma filtration surgery.

Autologous blood injection for late-onset filtering bleb leak

PURPOSE

To report the outcomes of autologous blood injections for late-onset filtering bleb leak.

METHODS

Retrospective chart review of all eyes that had autologous blood injection(s) for filtering bleb leak occurring at least 2 months after trabeculectomy at the Indiana University Medical Center. Successful treatment was defined as resolution of the bleb leak and no need for additional glaucoma medications. Failure was defined as a persistent bleb leak, intraocular pressure greater than 21 mm Hg, or the occurrence of a vision-threatening event related to the procedure.

RESULTS

Thirty-two eyes of 31 patients had autologous blood injection for filtering bleb leak and were followed for a mean of 4.9 months (SD, 9.2; range, 1 to 37 months). Twenty-three eyes (72%) were outright failures because of persistence of the leak. Nine eyes (28%) had an initially successful outcome, but the success rate decreased over time as bleb leaks recurred in three of the nine eyes at 5, 6, and 37 months. No patient characteristics correlated with outcome. Mean intraocular pressure increased from pretreatment to final examination (4.5 to 6.5 mm Hg, P =.003). Mean logarithm of minimal angle of resolution (logMAR) vision remained unchanged from pretreatment to final examination (P =.55). Blood seepage into the anterior chamber after autologous blood injection was common but transient.

CONCLUSIONS

Autologous blood injection is of limited success in treating late-onset filtering bleb leak.

The surgical management of leaking filtering blebs

Leaking blebs may be encountered in the early postoperative period, or months to years after filtering surgery. Early postoperative bleb leaks are most often related to surgical trauma to the conjunctiva and can be avoided by careful surgical technique. Spontaneous late bleb leaks occur more frequently in glaucoma filtering surgery following adjunctive use of antimetabolites and full-thickness procedures. As we endeavor to achieve better long-term success with filtering surgery, antimetabolites have gained increasing popularity. With this change in clinical practice, a higher rate of bleb leaks is being recognized. These leaks may be uncomplicated or may be associated with sight-threatening complications such as endophthalmitis. The plethora of treatment options for bleb leaks described in the literature reflects the widespread nature of this problem. It also reflects the failure of any one particular approach not only to resolve bleb leaks but also to prevent their recurrence. This paper reviews the contemporary surgical management of leaking blebs and formulates a practical approach to their management.

Control of intraocular pressure after trabeculectomy

Control of intraocular pressure (IOP) is the goal of trabeculectomy, and pursuit of this goal does not end with the completion of the surgical procedure. Proper postoperative management of the trabeculectomy patient requires an understanding of possible events that alter IOP and knowledge of the treatments to control IOP. Recent changes in surgical technique, including the use of antimetabolites, have provided new challenges in the postoperative management of trabeculectomy patients. Interventions are described to restore the flow of aqueous to the filtering bleb in the early postoperative period, to manage flat anterior chambers with both high and low intraocular pressures, to manage a failing filtering bleb, and to manage hypotony. Herein we discuss current methods for controlling IOP in the postoperative period.

Dysfunctional filtering blebs

Guarded filtration surgery, is commonly used to control the intraocular pressure (IOP) in glaucomatous patients. Filtration surgery lowers the IOP by creating a fistula between the inner compartments of the eye and the subconjunctival space (i.e., filtering bleb). There are several options to improve the function of filtering blebs and to prevent their failure. However, improvement of IOP control after guarded filtration procedures is associated with a higher frequency of bleb-related complications. Early (e.g., bleb leak, excessive filtration, flat anterior chamber, filtration failure) and late (e.g., bleb leak, excessive filtration and hypotony, symptomatic blebs, bleb encapsulation, filtration failure, bleb infection) complications associated with filtering procedures should be managed adequately to prevent further problems. Techniques to improve the function of filtering blebs and to treat postoperative complications have progressed over the past decade.

Fixation of the craniofacial skeleton with butyl-2-cyanoacrylate and its effects on histotoxicity and healing

Butyl-2-cyanoacrylate is an easily applied, biocompatible, bioresorbable polymer glue that provides an alternative to conventional rigid fixation techniques. Our aim was to determine if cyanoacrylate fixation of the bone flap in a rabbit craniotomy model provides the healing and strength afforded by plate and screw fixation. We also investigated the inflammatory responses of adjacent tissues including the scalp, cranium, and brain. A unilateral parietal bone flap was elevated in 33 adult New Zealand rabbits. The bone was fixed in position with cyanoacrylate (n = 13), fixed with a microplate and screws (n = 14), or was replaced without fixation (sham-control, n = 6). Normal scar formation and no residual polymer were found in scalp specimens. Neuropathologic analysis identified the presence of residual polymer on the surface of 2 of the 13 rabbit brains. Histopathologic analysis of the bone flap-to-skull interface revealed no difference in the degree but rather in the quality of inflammation and healing between the plate and screw and polymer fixation groups. Microdensitometric analysis of the bone gap revealed nearly equivalent bone density in the cyanoacrylate and plated groups, tending to less density in the sham group (p = 0.11 and 0.09, respectively). An additional study focusing on neurotoxicity was performed in 20 adult rabbits with 3-week and 11-week recovery periods and similarly found the absence of a marked inflammatory response to the polymer. In conclusion, bone healing and soft-tissue inflammation were comparable between cyanoacrylate and plate and screw fixation groups. Although butyl-2-cyanoacrylate glue fixation may provide a reasonable alternative to hardware fixation, further investigations are necessary to identify its ideal utilization.

Butyl-2-cyanoacrylate fixation of mandibular osteotomies

Butyl-2-cyanoacrylate is an easily applied, bioresorbable, noninfective glue that may provide an alternative to conventional craniofacial fixation techniques. Recent studies have demonstrated that the healing and strength of glue fixation of bone fragments in the craniofacial skeleton is equivalent to that of plate and screw fixation. We sought to determine if this glue could also provide strength and healing in a more stressed environment, that of the mandible. Fourteen New Zealand White rabbits underwent mandibular osteotomies at the angle. The osteotomy was fixed with either a microplate (n = 4) or glue (n = 10). Mandibles were assessed 10 weeks postoperatively and classified according to bone healing, condylar morphology, and dental morphology. Callus and nonunion were more prevalent in the glued group, whereas condylar resorption was similar in both experimental groups. Despite the poor bony healing in the glued group, the teeth did not decay but modified their standard form to meet the demands of the anatomic deformity. Butyl-2-cyanoacrylate does not offer the biomechanical stability afforded by plates and screws in bone subject to large forces.

Management of bleb leaks after glaucoma filtering surgery. Use of autologous fibrin tissue glue as an alternative

PURPOSE

To study the nature of bleb leaks after contemporary glaucoma filtering surgery as well as to evaluate various treatment modalities, including autologous fibrin tissue glue (AFTG) prepared in a modified manner.

METHODS

Patients who presented to a Glaucoma Service during a 1-year period with a postoperative bleb leak were studied. Evaluation of various treatment modalities, including AFTG, was performed.

RESULTS

Thirty-five episodes of bleb leaks were encountered in 25 eyes of 22 patients in a 1-year period. There was no statistically significant association between late or early leaks and the age or the race of the patient, previous eye surgery, or the use of antimetabolites at the time of filtering surgery. Eleven (31.4%) of the leaks were refractory to nonsurgical treatment modalities, 8 or them being of the late type. Successful healing of the leaks was obtained in 9 of the 12 episodes in which AFTG was used. However, there were no statistically significant differences between AFTG and the other treatment modalities.

CONCLUSION

Bleb leaks are a common complication of contemporary glaucoma filtering surgery. Various nonsurgical and surgical modalities can be used in the treatment. In early as well as late bleb leaks, AFTG offers an alternative nonsurgical treatment and is at least as efficacious and may, in some ways, be superior to other nonsurgical modalities of treatment.

Free conjunctival patch for repair of persistent late bleb leak

In four patients, we repaired leaking blebs by using a new technique of excision of the cystic bleb and replacement with free conjunctival autograft. The leaks were repaired successfully, and bleb function was maintained in all four patients. This technique should be considered when surgical management of a leaking bleb is indicated.

Cryotherapy to close a corneal subepithelial aqueous track after trabeculectomy

After filtering surgery for primary open-angle glaucoma in a 64-year-old man, a persistent wound leak was encountered from the fornix-based conjunctival flap. Cyanoacrylate adhesive was applied but was unsuccessful in sealing the leak. The limbal margin was sutured with 10/0 nylon. One week later a corneal subepithelial fistulous track developed from the edge of the bleb and extended across the cornea towards the inferonasal limbus. The inferior end of the track leaked aqueous. Further surgery was performed to refashion the conjunctival bleb, ablate the fistula at its origin and re-form the anterior chamber. The track recurred 16 days later. The upper cornea was then treated with cryotherapy, which successfully closed the track with maintenance of a functional bleb (ocular pressure 6 mmHg). A faint asymptomatic subepithelial scar persisted.