Clinical experience with N-butyl cyanoacrylate tissue adhesive in fungal keratitis

Outcomes of N-butyl-2-Cyanoacrylate Tissue Adhesive Application in Corneal Perforation Disorders: Consecutive Case Series

INTRODUCTION

The purpose of this study was to report the success and long-term outcomes of cyanoacrylate tissue adhesive (CTA) application in the management of corneal perforation disorders.

METHODS

This retrospective case series describes the profile and outcomes of eyes that underwent CTA for corneal perforation over an 11-year period from January 2009 until January 2020 at a tertiary eye centre in the United Kingdom.

RESULTS

In total, 25 eyes underwent CTA application during the study period. Non-traumatic sterile corneal melt was responsible in more than half of the cases (56.0%; n = 14) followed by infection (32.0%; n = 8) and trauma (12.0%; n = 3). Median size of perforation was 2.0 mm (interquartile range, IQR 1.0-3.0). The most common anatomical location of corneal perforation was central (56.0%; n = 14). Ocular surface disease was seen in almost all eyes except two (92.0%; n = 23) with dry eye disease being the most common (48.0%; n = 12). Amongst 23 eyes that completed follow-up (median 27 months; IQR 9.5-46.5), single CTA application was successful in achieving intact globe in 13 (56.5%) eyes and repeat gluing sealed total of 20 (86.9%) eyes. Survival analysis showed cumulative success of 71.0% and 51.2% at 90 and 250 days, respectively. The CTA was retained in the eyes for median of 94.0 days (IQR 30.0-140.5). A total of five patients developed adverse events, including endophthalmitis (n = 2), following CTA application.

CONCLUSIONS

CTA was highly effective in sealing corneal perforations in acute setting and showed moderate long-term success. However, multiple applications are often required.

Clinical Features, Risk Factors, and Management of Candida Keratitis

BACKGROUND/AIMS

To determine the clinical features, predisposing factors, and management of infectious keratitis caused by Candida spp.

METHODS

Retrospective chart review.

RESULTS

The medical records of 52 patients (54 eyes) with Candida keratitis were available for statistical analysis. Thinning of the corneal stroma was identified in 34 eyes (63.0%), and corneal perforation occurred in 16 eyes (29.6%). Corneal thinning and perforation were more common in Candida albicans compared with non-albicans (P-val < .001, P = .09, respectively). The most common predisposing factors for Candida keratitis were topical steroid use (21 patients, 40.4%), previous corneal transplantation (17 patients, 32.7%), and preexisting ocular surface disease (15 patients, 28.8%). Fourteen eyes (25.9%) required cyanoacrylate glue application and 10 eyes (18.5%) underwent therapeutic penetrating keratoplasty (TPK).

CONCLUSION

Local immunosuppression and ocular surface disease play an important role in Candida keratitis. C. albicans appears to be more invasive compared with non-albicans spp.

Applications of hydrogel materials in different types of corneal wounds

Severe corneal injury can lead to a decrease in light transmission and even blindness. Currently, corneal transplantation has been applied as the primary treatment for corneal blindness; however, the worldwide shortage of suitable corneal donor tissue means that a large proportion of patients have no access to corneal transplants. This situation has contributed to the rapid development of various corneal substitutes. The development and optimization of novel hydrogels that aim to replace partial or full-thickness pathological corneas have advanced in the last decade. Meanwhile, with the help of 3D bioprinting technology, hydrogel materials can be molded to a refined and controllable shape, attracting many scientists to the field of corneal reconstruction research. Although hydrogels are not yet available as a substitute for traditional clinical methods of corneal diseases, their rapid development makes us confident that they will be in the near future. We summarize the application of hydrogel materials for various types of corneal injuries frequently encountered in clinical practice, especially focusing on animal experiments and preclinical studies. Finally, we discuss the development and achievements of 3D bioprinting in the treatment of corneal injury.

Treatment of Non-Infectious Corneal Injury: Review of Diagnostic Agents, Therapeutic Medications, and Future Targets

Corneal injuries can occur secondary to traumatic, chemical, inflammatory, metabolic, autoimmune, and iatrogenic causes. Ocular infection may frequently occur concurrent to corneal injury; however, antimicrobial agents are excluded from this present review. While practitioners may primarily rely on clinical examination techniques to assess these injuries, several pharmacological agents, such as fluorescein, lissamine green, and rose bengal, can be used to formulate a diagnosis and develop effective treatment strategies. Practitioners may choose from several analgesic medications to help with patient comfort without risking further injury or delaying ocular healing. Atropine, cyclopentolate, scopolamine, and homatropine are among the most frequently used medications for this purpose. Additional topical analgesic agents may be used judiciously to augment patient comfort to facilitate diagnosis. Steroidal anti-inflammatory agents are frequently used as part of the therapeutic regimen. A variety of commonly used agents, including prednisolone acetate, loteprednol, difluprednate, dexamethasone, fluorometholone, and methylprednisolone are discussed. While these medications are effective for controlling ocular inflammation, side effects, such as elevated intraocular pressure and cataract formation, must be monitored by clinicians. Non-steroidal medications, such as ketorolac, bromfenac, nepafenac, and diclofenac, are additionally used for their efficacy in controlling ocular inflammation without incurring side effects seen with steroids. However, these agents have their own respective side effects, warranting close monitoring by clinicians. Additionally, ophthalmologists routinely employ several agents in an off-label manner for supplementary control of inflammation and treatment of corneal injuries. Patients with corneal injuries not infrequently have significant ocular surface disease, either as a concurrent pathology or as an exacerbation of previously existing disease. Several agents used in the management of ocular surface disease have also been found to be useful as part of the therapeutic armamentarium for treatment of corneal injuries. For example, several antibiotics, such as doxycycline and macrolides, have been used for their anti-inflammatory effects on specific cytokines that are upregulated during acute injuries. There has been a recent wave of interest in amniotic membrane therapies (AMTs), including topical, cryopreserved and dehydrated variants. AMT is particularly effective in ocular injuries with violation of corneal surface integrity due to its ability to promote re-epithelialization of the corneal epithelium. Blood-based therapies, including autologous serum tears, plasma-enriched growth factor eyedrops and autologous blood drops, have additionally been explored in small case series for effectiveness in challenging and recalcitrant cases. Protection of the ocular surface is also a vital component in the treatment of corneal injuries. Temporary protective methods, such as bandage contact lenses and mechanical closure of the eyelids (tarsorrhaphy) can be particularly helpful in selective cases. Glue therapies, including biologic and non-biologic variants, can also be used in cases of severe injury and risk of corneal perforation. Finally, there are a variety of recently introduced and in-development agents that may be used as adjuvant therapies in challenging patient populations. Neurotrophic corneal disease may occur as a result of severe or chronic injury. In such cases, recombinant human nerve growth factor (cenegermin), topical insulin, and several other novel agents may be an alternate and effective option for clinicians to consider.

Fungal keratitis: Mechanisms of infection and management strategies

Fungal corneal ulcers are an uncommon, yet challenging, cause of vision loss. In the United States, geographic location appears to dictate not only the incidence of fungal ulcers, but also the fungal genera most encountered. These patterns of infection can be linked to environmental factors and individual characteristics of fungal organisms. Successful management of fungal ulcers is dependent on an early diagnosis. New diagnostic modalities like confocal microscopy and polymerase chain reaction are being increasingly used to detect and identify infectious organisms. Several novel therapies, including crosslinking and light therapy, are currently being tested as alternatives to conventional antifungal medications. We explore the biology of Candida, Fusarium, and Aspergillus, the three most common genera of fungi causing corneal ulcers in the United States and discuss current treatment regimens for the management of fungal keratitis.

Cyanoacrylate Tissue Adhesive for the Treatment of Corneal Thinning and Perforations: A Multicenter Study

PURPOSE

To examine the outcomes of cyanoacrylate tissue adhesive (CTA) application for impending or frank corneal perforations and assess for predictors of treatment response.

METHODS

A multicenter cohort study was conducted to assess the clinical outcomes of adult patients who underwent CTA gluing for impending or frank corneal perforations between 2013 and 2018. The primary outcome was the proportion of successful CTA applications, defined as tectonic stability of the globe without subsequent keratoplasty (KP). Secondary outcomes included visual acuity and success of subsequent surgical interventions, if performed.

RESULTS

Fifty-three eyes of 52 patients were included in this study [56% women; mean age at presentation 70 ± 13 years; median length of follow-up of 387 days (interquartile range: 191-704)]. Medical comorbidities were present in 62% of patients. The most common etiologies for perforations included infections (43%) and Sjogren disease (9%). Of the CTA-treated eyes, 22% had a complete resolution of the corneal lesion. Fifty-four percent of patients underwent KP. Longer duration of CTA treatment was associated with CTA success (P = 0.04). For patients requiring KP, 71% were successful and 29% failed. There is no significant difference in the median time delay between patients with successful and failed KPs (P = 0.4).

CONCLUSIONS

CTA may be considered a stand-alone treatment for corneal perforations. It yielded a success rate of 22%. Failed CTA treatment occurred quickly, largely because of the severity of presentation. In cases requiring KP, the delay between glue application and surgery did not influence the PK success.

Corneal transplantation and eye banking practices during COVID-19-related lockdown period in India from a network of tertiary eye care centers

Purpose:

The purpose of this study was to discuss the guidelines and modification of practices with respect to corneal transplantation and eye banking during the COVID-19 pandemic lockdown period and beyond, at a network of tertiary care centers in India.

Methods:

Descriptive study of the challenges faced in eye banking during the lockdown, and practices adopted to overcome the critical aspects in the clinical care of patients who presented with emergency corneal diseases requiring keratoplasty.

Results:

Complete lockdown orders from the Indian government, as a strategy to control the Coronavirus pandemic, resulted in drastic reduction of all types of elective corneal transplants and eye banking activities from March 24, 2020 to May 31, 2020. The sudden cessation of eye banking resulted in an acute demand and supply imbalance of fresh donor corneas for transplants during this time. Our network of eye banks addressed this issue by adopting glycerol preservation of donor corneas, which were subsequently utilized for tectonic penetrating keratoplasty. The donor cornea retrieval was resumed in a strategized manner 3 weeks prior to the date of exit of the lockdown, with modified guidelines on donor suitability, screening, retrieval, processing, and harvesting from various sources. A triage of keratoplasty priority was formulated to tide over the post lockdown shortage of corneas. We performed 31 therapeutic keratoplasties during the nationwide lockdown among our network of tertiary eye care centers.

Conclusion:

The study highlights the approach and strategies to manage and tide over an unprecedented crisis situation faced by corneal surgeons in general and, specifically, the eye banking community.

Surgical alternatives to keratoplasty in microbial keratitis

Penetrating keratoplasty is often required in microbial keratitis not responding to the standard treatments available or the development of complications like corneal perforation. Performing keratoplasty in microbial keratitis has several challenges, the major ones being the availability of donor corneal tissue and the poor success of the corneal graft performed in such a setting. For overcoming these challenges, several alternatives to keratoplasty have been described. Broadly, these options could be categorized into autologous tissues such as conjunctival and tenon tissue, synthetic products like tissue adhesives and therapeutic contact lenses, or biological tissues like amniotic membrane graft. These alternative modalities are not universal. They have their specific indications in microbial keratitis. Most of these alternatives are useful only for small corneal perforations. While autologous tissues are cost-effective and readily available, lack of tectonic support is a significant limitation. Tissue adhesives are excellent alternatives in terms of tectonic support, but surface irregularity and tissue reaction are their potential limitations. The amniotic membrane is useful for small corneal perforations, but availability, cost, and poor tectonic support restrict its use. Herein, we discuss these various alternatives to keratoplasty in microbial keratitis, their indications, advantages, disadvantages, and the various techniques of performing these procedures.

Efficacy of cyanoacrylate tissue adhesive in the management of corneal thinning and perforation due to microbial keratitis

PURPOSE

Report the efficacy of cyanoacrylate tissue adhesive (CTA) application in the management of corneal thinning and perforations associated with microbial keratitis.

METHODS

A retrospective review of consecutive patients who underwent CTA application for corneal thinning and perforation secondary to microbiologically proven infectious keratitis between 2001 and 2018 at a single center. We defined successful CTA application as an intact globe without tectonic surgical intervention.

RESULTS

The cohort included 67 patients, and 37 presented with corneal perforation while 30 had corneal thinning. The perforation/thinning was central/paracentral in 43 eyes and peripheral in 23 eyes. The underlying infectious etiologies were monomicrobial in 42 cases (35 bacterial, 3 fungal, 2 viral, and 2 acanthamoeba cases) and polymicrobial in 25 cases (22 polybacterial cases and 3 cases with a combination of Gram positive bacteria and fungus). The median duration of glue retention was 29 days. The CTA success rate was 73%, 64%, and 44% at 10, 30, and 180 days, respectively. CTA application appears more successful in monomicrobial (vs. polymicrobial) and Gram positive bacterial (vs. Gram negative) keratitis but the differences are statistically non-significant. The location of perforation/thinning and the use of topical corticosteroid were not associated with CTA failure.

CONCLUSION

CTA was moderately effective in restoring globe integrity in severe corneal thinning and perforation secondary to microbial keratitis in the short term. However the majority of patients require tectonic surgical intervention within 6 months. CTA application success is not significantly associated with the location of thinning/perforation or the use of topical corticosteroid.

Outcomes of Cyanoacrylate Tissue Adhesive Application in Corneal Thinning and Perforation

PURPOSE

To report the outcomes of cyanoacrylate tissue adhesive (CTA) application in corneal thinning and perforation.

METHODS

A retrospective interventional case series of 137 patients receiving CTA for corneal thinning and perforation in 140 eyes between 2001 and 2018 at a single center was reviewed. Success rate and factors associated with glue failure were analyzed.

RESULTS

Median age of the cohort was 63 years and 69 (50%) were women. One hundred fifteen patients (84%) had at least 1 systemic condition, 46 (34%) had autoimmune diseases. Eighty-nine eyes (64%) presented with perforation and 51 (36%) with thinning. The perforation/thinning was central/paracentral in 82 eyes (59%) and peripheral in 57 eyes (41%). Median size of perforation was 3.1 mm. Causes of perforation and thinning were microbial infection in 75 (55%), sterile melt in 49 (35%), laceration in 10, and keratoprosthesis melt in 8 eyes. Median glue retention was 58 days. Success rate of glue application (defined as intact globe without surgical intervention) was 72%, 61%, and 46% at 10, 30, and 90 days after glue application, respectively. Larger size of perforation/thinning, perforation (vs. thinning), and single glue application (vs. multiple) were correlated with higher failure rate. Systemic conditions, use of topical corticosteroid, etiologies, and location of perforation/thinning were not significantly correlated with glue failure.

CONCLUSIONS

CTA application was moderately effective in stabilizing corneal perforation and thinning in the very short-term. Multiple applications are often required. Maintenance of globe integrity after glue application decreases with time and the need for surgical intervention remains high.

Surgical management of corneal infections

PURPOSE OF REVIEW

The purpose of this review is to discuss the options for, and recent developments in, the surgical treatment of corneal infections. Although the mainstay of treatment of corneal infections is topical antimicrobial agents, surgical intervention may be necessary in a number of cases. These include advanced disease at presentation, resistant infections, and progressive ulceration despite appropriate treatment. Prompt and appropriate treatment can make the difference between a good outcome and loss of vision or the eye.

RECENT FINDINGS

There are a number of surgical therapies available for corneal infections. Preferred therapeutic modalities differ based on the size, causation, and location of the infection but consist of either replacement of the infected tissue or structural support of the tissue to allow healing. Although there are no completely novel therapies that have been developed recently, there have been incremental improvements in the existing treatment modalities making them more effective, easier, and safer.

SUMMARY

Several options are available for surgically managing corneal infections. Ophthalmologists should select the optimal procedure based on the individual patient's situation.

VIDEO ABSTRACT

http://links.lww.com/COOP/A20.

Creation of a uniform pleural defect model for the study of lung sealants

OBJECTIVE

Animal models are indispensable for the development of new therapeutic methods for the closure of alveolar air leakage. However, it is difficult to create a uniform pleural defect model. The purpose of this study was to establish an appropriate animal model for assessing the efficacy and histotoxicity of synthetic sealants for lung surgery.

METHODS

Nine beagle dogs were used to evaluate the pleural defect model in comparison with conventional resection procedures. A donut-shaped silicon ring with an inner diameter of 15 mm was placed on the pleura, and 0.1 mL of cyanoacrylate was dropped into the ring. A pleural defect was created by sliding a microtome blade just beneath the polymerized cyanoacrylate. Hemostasis was performed by pressure with a sponge.

RESULTS

Morphologically, round areas of the pleura were uniformly resected with our procedure. The resected tissue consisted of pleura and thin underlying lung parenchyma. Among the results from 3 surgeons, there were no significant differences in the mean time required for hemostasis (P = .69), the mean thickness of the resected tissue (P = .13), and the mean amount of air leakage from the resected area (P = .19). No penetration of cyanoacrylate into the lung parenchyma was evidenced by immunofluorescence microscopy. Histologically, when the pleura was resected without using cyanoacrylate, a thick fibrocellular layer extended to the lung parenchyma. Furthermore, severe fibrosis was observed when electrocautery was used for hemostasis. However, when the pleura was resected using cyanoacrylate, the normal alveolar structure was preserved.

CONCLUSIONS

Our uniform pleural defect model using cyanoacrylate may be feasible for the evaluation of synthetic sealants for alveolar air leakage.

Penetrating keratoplasty for corneal perforations in fungal keratitis

PURPOSE

To evaluate the complications and therapeutic effects of penetrating keratoplasty (PKP) in the treatment of corneal perforations in fungal keratitis.

METHODS

The medical records of patients who underwent PKP for corneal perforations in fungal keratitis at Shandong Eye Institute from January 1999 to December 2004 were retrospectively reviewed.

RESULTS

Fifty-two patients (52 eyes) were included in this study. Twenty eyes (38.5%) had graft rejection after primary PKP, 12 of which were medically treated, and 8 underwent secondary PKP with 4 acquiring clear grafts. Fungal infection recurred in 8 eyes (15.4%), 3 of which were controlled with antifungal agents, 3 were treated with secondary PKP, and 2 were enucleated. Ten eyes (19.2%) with complicated cataract underwent intraoperative or postoperative extracapsular cataract extraction. Seven eyes (13.5%) with secondary glaucoma were cured. Graft ulcer occurred in 5 eyes (9.6%), 3 of which were cured with amniotic membrane transplantation and 2 with medications. Forty-four grafts (84.6%) remained clear at final follow-up, and 46 eyes (88.5%) had improved visual acuity.

CONCLUSION

Although many complications may occur, therapeutic PKP seems to be effective in the treatment of fungal keratitis with corneal perforation.

A comparison of three methods of wound closure following arthroplasty

We carried out a blinded prospective randomised controlled trial comparing 2-octylcyanoacrylate (OCA), subcuticular suture (monocryl) and skin staples for skin closure following total hip and total knee arthroplasty. We included 102 hip replacements and 85 of the knee.

OCA was associated with less wound discharge in the first 24 hours for both the hip and the knee. However, with total knee replacement there was a trend for a more prolonged wound discharge with OCA. With total hip replacement there was no significant difference between the groups for either early or late complications. Closure of the wound with skin staples was significantly faster than with OCA or suture. There was no significant difference in the length of stay in hospital, Hollander wound evaluation score (cosmesis) or patient satisfaction between the groups at six weeks for either hips or knees.

We consider that skin staples are the skin closure of choice for both hip and knee replacements.

The effectiveness of isobutyl cyanoacrylate tissue adhesive for the treatment of corneal perforations

PURPOSE

To study the results of treatment of corneal perforations with isobutyl cyanoacrylate tissue adhesive.

DESIGN

Retrospective case series.

METHODS

The charts of 20 patients (22 eyes) with corneal perforation <or=3 mm in size treated with isobutyl cyanoacrylate tissue adhesive were reviewed for etiology of perforation, visual outcome, and complications.

RESULTS

Nine of the 22 eyes (40.9%) healed with application of adhesive alone. The mean interval of time needed for healing was 33.4 days. Visual acuity improved in seven eyes (77.8%) and remained stable in two (22.2%). Seven eyes (31.8%) proceeded to penetrating keratoplasty (PK) with the adhesive in place. Of these, visual acuity improved in five (71.4%), remained stable in one (14.3%), and decreased in one (14.3%). Six eyes (27.3%) required more than one application of adhesive.

CONCLUSIONS

Isobutyl cyanoacrylate tissue adhesive is highly effective at treating corneal perforations. Approximately half of the perforations <or=3 mm healed and visual acuity improved in most of these eyes.

Antifungal therapy for keratomycoses

Keratomycoses have recently emerged as an important cause of ocular morbidity, especially in third-world countries. Available antifungal agents are limited in their efficacy, due to limited penetration into the cornea, the fungistatic nature and the development of drug resistance. Effective usage of the available drugs is hampered by the inefficiency of currently available antibiotic sensitivity tests for fungal organisms. There is also limited knowledge regarding the ideal combination(s) of antifungal agents, including issues of synergism and antagonism. Despite these problems, recent publications indicate encouraging outcomes in the treatment of a large series of fungal keratitis. Advances include better drug formulations, new agents and novel methods of drug delivery into the eye. As our ability to deal with advanced fungal keratitis remains limited, the importance of early diagnosis has been stressed and molecular biological techniques may play an important role in the future. This article summarises the important new advances in these areas in the past 2 years and provides guidelines for the management of these serious corneal infections.

Fungal keratitis

PURPOSE OF REVIEW

Throughout the world, fungal keratitis is a leading cause of ocular morbidity. The purpose of this review is to discuss the recently published literature in relation to the epidemiology, etiology, diagnosis, and therapy of fungal keratitis.

RECENT FINDINGS

Globally, the incidence of keratomycoses and systemic mycoses is rising. Current therapies are often ineffective. Ongoing research toward rapid diagnosis and specific drug therapy could minimize the morbidity caused by this preventable disease. New antifungal drugs, including voriconazole, have been applied recently for the treatment of keratomycosis.

SUMMARY

The incidence of fungal keratitis is on the rise in the densely populated continents of Asia and Africa. Filamentous fungi are the most frequently reported pathogens. Polyene antifungal antibiotics, the first-line therapy in fungal keratitis, are not effective in severe keratomycosis. Imidazole derivatives such as voriconazole and echinocandin may be the better choice in the future.