A case-control study of beneficial and adverse effects of 2-octyl cyanoacrylate tissue adhesive for episcleral explants in retinal detachment surgery

A Comparison between 2-Octyl Cyanoacrylate and Conventional Suturing for the Closure of Epiblepharon Incision Wounds in Children: A Retrospective Case-Control Study

Background: Tissue adhesive has been widely used in ophthalmic surgery for various procedures, proving both effective and safe. However, no studies have compared the surgical efficacy of the tissue adhesive 2-octyl cyanoacrylate (SurgiSeal®) to that of traditional suture closure in Asian children undergoing surgery for lower lid epiblepharon. Methods: This is a single-center retrospective case-control study. Surgical correction for epiblepharon was performed on 22 patients from November 2019 to May 2023. A total of 20 patients who were followed up for at least 1 month were included for analysis. After standardized epiblepharon surgery, group A underwent wound closure with a subcuticular suture and 2-octyl cyanoacrylate, and group B underwent closure with a 6-O fast-absorbing surgical gut suture. Patients were followed up at 1, 4, and 12 weeks post-surgery. Results: A total of 10 patients (20 eyes) underwent skin closure with tissue adhesives (group A), and 10 patients (18 eyes) underwent wound closure using conventional suture material (group B). No significant differences in the sex ratio, mean age at operation, pre- and postoperative best-corrected visual acuity (BCVA), or average surgical time were observed between groups. Both groups exhibited improved postoperative BCVA, with symptom relief and a significant decrease in the severity of keratopathy after surgery. Neither recurrence nor complications were reported during follow-up. The aesthetic results were similar between groups, while caregivers of children in the tissue adhesive group expressed high satisfaction regarding the ease of postoperative care. Conclusions: Successful closure of lower lid epiblepharon surgery wounds in children can be performed using 2-octyl cyanoacrylate (SurgiSeal®). This method is simple, safe, and effective when compared to conventional sutures.

BioAdhere: tailor-made bioadhesives for epiretinal visual prostheses

Introduction: Visual prostheses, i.e. epiretinal stimulating arrays, are a promising therapy in treating retinal dystrophies and degenerations. In the wake of a new generation of devices, an innovative method for epiretinal fixation of stimulator arrays is required. We present the development of tailor-made bioadhesive peptides (peptesives) for fixating epiretinal stimulating arrays omitting the use of traumatic retinal tacks. Materials and methods: Binding motifs on the stimulating array (poly[chloro-p-xylylene] (Parylene C)) and in the extracellular matrix of the retinal surface (collagens I and IV, laminin, fibronectin) were identified. The anchor peptides cecropin A (CecA), KH1, KH2 (author's initials) and osteopontin (OPN) were genetically fused to reporter proteins to assess their binding behavior to coated microtiter plates via fluorescence-based assays. Domain Z (DZ) of staphylococcal protein A was used as a separator to generate a bioadhesive peptide. Following ISO 10993 "biological evaluation of medical materials", direct and non-direct cytotoxicity testing (L-929 and R28 retinal progenitor cells) was performed. Lastly, the fixating capabilities of the peptesives were tested in proof-of-principle experiments. Results: The generation of the bioadhesive peptide required evaluation of the N- and C-anchoring of investigated APs. The YmPh-CecA construct showed the highest activity on Parylene C in comparison with the wildtype phytase without the anchor peptide. eGFP-OPN was binding to all four investigated ECM proteins (collagen I, laminin > collagen IV, fibronectin). The strongest binding to collagen I was observed for eGFP-KH1, while the strongest binding to fibronectin was observed for eGFP-KH2. The selectivity of binding was checked by incubating eGFP-CecA and eGFP-OPN on ECM proteins and on Parylene C, respectively. Direct and non-direct cytotoxicity testing of the peptide cecropin-A-DZ-OPN using L-929 and R28 cells showed good biocompatibility properties. Proof-of-concept experiments in post-mortem rabbit eyes suggested an increased adhesion of CecA-DZ-OPN-coated stimulating arrays. Conclusion: This is the first study to prove the applicability and biocompatibility of peptesives for the fixation of macroscopic objects.