Transplanting embryonic stem cells onto damaged human corneal endothelium

AIM To investigate whether human embryonic stem cells(hESCs) could be made to attach, grow and differentiate on a human Descemet's membrane(DM).METHODS Spontaneously differentiated hESCs were transferred onto a human corneal button with the endothelial layer removed using ocular sticks. The cells were cultured on a DM for up to 15 d. The genetically engineered hESC line expressed green fluorescent protein, which facilitated identification during the culture experiments, tissue preparation, and analysis. To detect any differentiation into human corneal endothelial-like cells, we analysed the transplanted cells by immunohistochemistry using specific antibodies.RESULTS We found transplanted cells form a single layer of cells with a hexagonal shape in the periphery of the DM. The majority of the cells were negative for octamer-binding transcription factor 4 but positive for paired box 6 protein, sodium potassium adenosine triphosphatase(NaKATPase), and Zona Occludens protein 1. In four of the 18 trials, the transplanted cells were found to express CK3, which indicates that the stem cells differentiated into corneal epithelial cells in these cases. CONCLUSION It is possible to get cells originating from hESCs to become established on a human DM, where they grow and differentiate into corneal endothelial-like cells in vitro.

The European registry of quality outcomes for cataract and refractive surgery(EUREQUO):a database study of trends in volumes,surgical techniques and outcomes of refractive surgery

Background:A European web-based registry for refractive surgery was established in 2008;The European Registry of Quality Outcomes for Cataract and Refractive Surgery(EUREQUO).The aim of the registry was to improve treatment and standards of care for refractive surgery.Further aims were to offer a tool for benchmarking by establishing a reference database and for surgeons to enter and analyze their own outcomes.The purpose of this study was to characterize the registry and analyze the data collected during its first decade.Methods:The characteristics of the web-based registry are described.Data collected from February 4^(th) 2004 until June 30th 2014 are included in the analysis.The database is analyzed in terms of surgical technique,indications for surgery,complications,and refractive and visual outcomes.Results:Data have been reported from 47 centers in 14 countries until mid-2014.About 4,000 procedures were reported annually.The most frequent procedure was laser-assisted in-situ keratomileusis(LASIK)with 11697 reported surgeries.Over time in the database,LASIK declined(p<0.001)while photorefractive keratectomy(PRK)and refractive lens exchange(RLE)increased(p<0.001 for both procedures).The indications for surgery,in terms of preoperative refraction and age,were stable over time,for all types of procedures.Surgical complications were reported infrequently and with a well-known relationship to the type of surgical procedure.The reported refractive outcomes were good.The visual outcomes indicate a significant increase of visual acuity after high myopia treatment by phakic intraocular lens in the anterior(phakic IOL AC)and the posterior(phakic IOL PC)chamber and a poorer visual outcome,after both myopia and hyperopia treatment,by epithelial LASIK(Epi-LASIK).Conclusions:We describe the establishment of a European registry for refractive surgery.The database increases at a rate of approximately 4000 refractive procedures per year.The most frequent procedure is LASIK,but both PRK and RLE are an increasing part of the reported procedures.The indications for surgery have been stable over time.Surgical complications and visual outcome vary,depending on the type of surgery.