Fibrin glue inhibits migration of ocular surface epithelial cells.

PurposeFibrin glue has been used successfully in numerous ophthalmic surgical procedures. Recently, fibrin glue has been used in limbal stem cell transplantation to reduce both operative time and to negate the need for sutures. The aim of this study was to determine the effects of fibrin glue on epithelial cell migration in vitro.MethodsCorneoscleral rims were split to retain the epithelial layer, Bowman's layer, and anterior stroma. Rims were cut into eight equal-sized pieces and were placed directly on culture plates or affixed with fibrin glue. Rims were maintained in culture for 25 days and epithelial cell growth was monitored. Cells were photographed to measure area or growth and immunofluorescence staining of explants for fibrin was performed.ResultsExplants that were glued demonstrated significantly delayed epithelial cell growth and migration as compared with explants without glue. By day 16, all fibrin glue had dissolved and coincided with onset of cell growth from glued explants. Cell growth commenced between days 3 and 4 for control explants without glue and around days 14-16 for explants with fibrin glue.ConclusionsFibrin glue delays epithelial cell migration by acting as a physical barrier and can potentially interfere with explant-derived limbal epithelial cell migration on to the corneal surface. We propose that glue should be used to attach the conjunctival frill of the limbal explant but care should be taken to ensure that the glue does not wrap around the explant if used to secure the explant as well. Strategic use of glue, to attach the recessed conjunctiva, can be advantageous in delaying conjunctival cell migration and reducing the need for sequential sector conjunctival epitheliectomy.

Epidemiological investigation of Pseudomonas aeruginosa isolates from a six-year-long hospital outbreak using high-throughput whole genome sequencing.

Although previous bacterial typing methods have been informative about potential relatedness of isolates collected during outbreaks, next-generation sequencing has emerged as a powerful tool to not only look at similarity between isolates, but also put differences into biological context. In this study, we have investigated the whole genome sequence of five Pseudomonas aeruginosa isolates collected during a persistent six-year outbreak at Nottingham University Hospitals National Health Service (NHS) Trust ­ City Campus, United Kingdom. Sequencing, using both Roche 454 and Illumina, reveals that most of these isolates are closely related. Some regions of difference are noted between this cluster of isolates and previously published genome sequences. These include regions containing prophages and prophage remnants such as the serotype-converting bacteriophage D3 and the cytotoxin-converting phage phi CTX. Additionally, single nucleotide polymorphisms (SNPs) between the genomic sequence data reveal key single base differences that have accumulated during the course of this outbreak, giving insight into the evolution of the outbreak strain. Differentiating SNPs were found within a wide variety of genes, including lasR, nrdG, tadZ, and algB. These have been generated at a rate estimated to be one SNP every four to five months. In conclusion, we demonstrate that the single base resolution of whole genome sequencing is a powerful tool in analysis of outbreak isolates that can not only show strain similarity, but also evolution over time and potential adaptation through gene sequence changes.

Intra-lesional 5 fluorouracil for the management of recurrent pterygium.

AIM: Recurrence is the most common complication arising from pterygium surgery. The aim of this study was to investigate the effectiveness of 5 fluorouracil (5FU) in halting the recurrence of pterygium after surgical excision. METHODS: A retrospective review of patients treated for pterygium recurrence was carried out. Patients with recurrent (secondary) pterygium were treated with multiple weekly intra-lesional injections of 0.1-0.2 ml (2.5-5 mg) 5FU post-operatively depending on the size of the recurrence. The treatment was started within 1 month from the date of recurrence. The time from surgery to start of recurrence, previous treatment modalities, and number of recurrences were documented. The number of injections required to induce arrest of progression and/or regression of vascularity and fleshiness of the pterygium and any complications related to 5FU treatment were examined. RESULTS: Fifteen eyes from 14 patients with recurrent pterygium treated with intra-lesional 5FU injections were analysed. Three of the 15 eyes had undergone a secondary excision and 12 had undergone a primary excision. In all, 93.3% of patients showed regression of the fibrovascular tissue (thickness and vascularity) and arrest of progression following a dose of 0.1-0.2 ml (2.5-5 mg) 5FU. Twelve eyes required three injections or fewer, whereas one patient required eight injections. This beneficial effect was maintained over an average follow-up period of 17 months. No complications from 5FU were observed. CONCLUSION: The use of weekly intra-lesional 5FU injections for the treatment of recurrent pterygium is safe and effective in limiting the progression and inducing the regression of recurrent pterygium. The number of injections can be tailored according to clinical need.