The use of amniotic membrane in ophthalmic surgery and other surgical procedures in the fields of dermatology, plastic surgery, genitourinary medicine and otolaryngology is on the increase. Furthermore, amniotic membrane and its epithelial and mesenchymal cells have broad use in regenerative medicine and hold great promise in anticancer treatment. Amniotic membrane is a rich source of biologically active factors and as such, promotes healing and acts as an effective material for wound dressing. Amniotic membrane supports epithelialization and exhibits anti-fibrotic, anti-inflammatory, anti-angiogenic and anti-microbial features. Placentas utilised in the preparation of amniotic membrane are retrieved from donors undergoing elective caesarean section. Maternal blood must undergo serological screening at the time of donation and, in the absence of advanced diagnostic testing techniques, 6 months postpartum in order to cover the time window for the potential transmission of communicable diseases. Amniotic membrane is prepared by blunt dissection under strict aseptic conditions, then is typically transferred onto a nitrocellulose paper carrier, usually with the epithelial side up, and cut into multiple pieces of different dimensions. Amniotic membrane can be stored under various conditions, most often cryopreserved in glycerol or dimethyl sulfoxide or their mixture with culture medium or buffers. Other preservation methods include lyophilisation and air-drying. In ophthalmology, amniotic membrane is increasingly used for ocular surface reconstruction, including the treatment of persistent epithelial defects and non-healing corneal ulcers, corneal perforations and descemetoceles, bullous keratopathy, as well as corneal disorders with associated limbal stem cell deficiency, pterygium, conjunctival reconstruction, corneoscleral melts and perforations, and glaucoma surgeries.
This report by the European Cornea and Cell Transplantation Registry provides real-world estimates of graft survival and visual acuity in a cohort of 12 913 corneal transplants.
ObjectivesTo assess to which extent the COVID-19 pandemic affected corneal transplantation by virtue of donor selection algorithms in different European countries.DesignSurvey.Setting110 eye banks in 26 European countries.Participants64 eye banks covering 95% of European corneal transplantation activity.InterventionsA questionnaire listing the number of corneas procured and distributed from February to May 2018–2020 was circulated to eye banks.Main outcome measuresThe primary outcome was the number of corneal procurements. Additional outcomes were national algorithms for donor selection, classified according to their stringency (donors with COVID-19 history, suspected for COVID-19, asymptomatic, PCR testing) and the pandemic severity in each country. We calculated Spearman’s correlation coefficient to determine, two by two, the relationship between the 3-month decline in eye banking activity (procurement), the stringency of donor selection algorithm and the grading of pandemic severity (cases and deaths). A partial correlation was run to determine the relationship between decline and stringency while controlling for pandemic severity.ResultsProcurements decreased by 38%, 68% and 41%, respectively, in March, April and May 2020 compared with the mean of the previous 2 years, while grafts decreased, respectively, by 28%, 68% and 56% corresponding to 3866 untreated patients in 3 months. Significant disparities between countries and the decrease in activity correlated with stringency in donor selection independent of pandemic severity.ConclusionsOur data demonstrate significant differences between countries regarding donor screening algorithms based on precautionary principles and, consequently, a decrease in the donor pool, already constrained by a long list of contraindications. Fundamental studies are needed to determine the risk of SARS-CoV-2 transmission by corneal transplantation and guide evidence-based recommendations for donor selection to justify their substantial medical and economic impact.
Methods: Corneal transplant procedures registered in the European Cornea and Cell Transplantation Registry were identified. Preoperative donor and recipient characteristics, indication and reason for transplantation, and surgical techniques were analyzed.Results: A total of 12 913 corneal transplants were identified from 10 European Union MS, the United Kingdom, and Switzerland. Most countries were self-sufficient with regard to donor tissue. Fuchs endothelial corneal dystrophy was the most common indication (41%, n = 5325), followed by regraft (16%, n = 2108), pseudophakic bullous keratopathy (12%, n = 1594), and keratoconus (12%, n = 1506). Descemet stripping automated endothelial keratoplasty (DSAEK, 46%, n = 5918) was the most commonly performed technique, followed by penetrating keratoplasty (30%, n = 3886) and Descemet membrane endothelial keratoplasty (9%, n = 1838). Vision improvement was the main reason for corneal transplantation (90%, n = 11 591). Surgical technique and reason for transplantation differed between indications. Conclusions:This report provides the most comprehensive overview of corneal transplantation practice patterns in Europe to date. Fuchs endothelial dystrophy is the most common indication, vision improvement the leading reason, and DSAEK the predominant technique for corneal transplantation.
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