A new storage solution for the hypothermic preservation of corneal grafts: an experimental study.

In this experimental study we used for the first time Tiprotec® as a solution for corneal preservation and cold storage. We compared the resultant endothelial cell morphology and viability with this obtained after preservation of the ex-vivo corneas with both usual standard techniques: conventional cold storage (using Eusol-C) and organ culture. This prospective, in vitro, 3-armed parallel study was performed with the use of 90 porcine corneas (examined for their endothelial quality and transparency) randomly selected for preservation in three storage methods (each 30 corneas): organ culture, standard cold storage (Eusol-C) and experimental cold storage (Tiprotec®) Endothelium cell quantity and quality as well as corneal opacification were assessed. The degree of endothelial transparency was significantly reduced over time with all preservation media, without any significant difference among the three groups at any point of time. A reduction in endothelial cell density was also observed with all three preservation media after 30 days of storage without statistically significant differences between groups. The number of hexagonal and pentagonal endothelium cells was significantly reduced overtime in all media with significantly more hexagonal and pentagonal in the organ culture group compared to the cold storage groups. We could show that the cryopreservation medium Tiprotec®, used until now for the preservation of vascular grafts, was of similar quality compared to the medium Eusol-C for the hypothermic storage of corneal tissue for an extended period of time up to 30 days. In comparison to organic culture with culture medium KII, both Tiprotec® and Eusol-C were found less effective in preserving endothelial cell quality, as assessed by the morphometric analysis, and viability, as assessed by the degree of vacuolization at least up to the 30th day of storage. However, both, Tiprotec®- and Eusol-C-preserved corneas demonstrated a certain capacity to recover after their submission in organ culture.

[Diagnosis of Kayser Fleischer Ring: Can Early Diagnosis Improve the Outcome of Wilson's Disease?] / Kayser-Fleischer-Ring ­ kann eine frühe Diagnosestellung den Krankheitsverlauf von Morbus Wilson verbessern?

Wilson's disease is a rare genetic disease of copper metabolism that leads to increased accumulation of copper in the body. Deposits are found mainly in the liver, brain and eye. If left untreated, the disease can lead to movement disorders, personality changes, liver failure and even death. There are many possible differential diagnoses. Diagnosis can only be made through specific test procedures. The ophthalmologist therefore has a special role in the early detection of a Wilson's disease. In our clinic, a 19-year old female patient presented with a faint Kayser-Fleischer corneal ring with otherwise normal ophthalmological findings. The patient had progressive liver failure and received a liver transplant two months after first presentation in the eye clinic. An early ophthalmological co-evaluation with a thorough examination is of great importance for rapid diagnosis. The copper deposits are found in the Descemet membrane and begin in the Schwalbe's line. The so-called Kayser-Fleischer ring can be seen on the Descemet membrane up to 5 mm away from the limbus. Other possible ophthalmological manifestations are chalcosis of the entire Descemet, icterus of the sclera or a sunflower cataract. In the absence of copper deposits in the slit lamp examination, gonioscopy should always be performed if Wilson's disease is suspected. Early diagnosis can protect patients from unnecessary complications and operations. Wilson's disease has a good prognosis if treated.

Donor Cornea Harvest Techniques: Comparison Between Globe Enucleation and In Situ Corneoscleral Disc Excision.

PURPOSE: To compare whole eye enucleation and corneoscleral disc (CD) excision as donor cornea harvesting techniques for possible effects on corneal cultivation and the clinical outcome of the corneal grafts after transplantation in 2929 cases. METHODS: A retrospective analysis was performed on the Hamburg Eye Bank database using comparative statistics. The standard method for donor cornea recovery at the Hamburg Eye Bank changed from enucleation of the whole eye to CD in situ excision in 2008. Corneas recovered between 2003 and 2013 were included in this study. We compared the contamination rate, the endothelial density after retrieval, endothelial cell loss during cultivation, and the clinical outcome (visual acuity, astigmatism, and refraction) of transplanted corneas. RESULTS: Once the retrieval method was changed from whole globe enucleation to in situ CD excision, the donation numbers increased (after several years of constant decrease). Furthermore, we observed slightly lower endothelial cell density after retrieval in corneas obtained by in situ CD excision compared with those from enucleated eyes, whereas endothelial cell loss during cultivation was similar. After changing the recovery procedure to in situ excision, initially a higher rate of contamination was observed, but but it eventually decreased. Finally, the corneas of both groups had a similar clinical outcome. CONCLUSIONS: After a transient technical learning period, in situ CD excision proved to be a method of donor cornea recovery with similar cultivation performance and clinical results compared with whole eye enucleation. It also may have led to higher willingness to donate, possibly because of better acceptance by the relatives of the deceased.

Semi-quantitative assessments of dextran toxicity on corneal endothelium: conceptual design of a predictive algorithm.

Dextran is added to corneal culture medium for at least 8 h prior to transplantation to ensure that the cornea is osmotically dehydrated. It is presumed that dextran has a certain toxic effect on corneal endothelium but the degree and the kinetics of this effect have not been quantified so far. We consider that such data regarding the toxicity of dextran on the corneal endothelium could have an impact on scheduling and logistics of corneal preparation in eye banking. In retrospective statistic analyses, we compared the progress of corneal endothelium (endothelium cell loss per day) of 1334 organ-cultured corneal explants in media with and without dextran. Also, the influence of donor-age, sex and cause of death on the observed dextran-mediated effect on endothelial cell counts was studied. Corneas cultured in dextran-free medium showed a mean endothelium cell count decrease of 0.7% per day. Dextran supplementation led to a mean endothelium cell loss of 2.01% per day; this reflects an increase by the factor of 2.9. The toxic impact of dextran was found to be time dependent; while the prevailing part of the effect was observed within the first 24 h after dextran-addition. Donor age, sex and cause of death did not seem to have an influence on the dextran-mediated toxicity. Based on these findings, we could design an algorithm which approximately describes the kinetics of dextran-toxicity. We reproduced the previously reported toxic effect of dextran on the corneal endothelium in vitro. Additionally, this is the first work that provides an algorithmic instrument for the semi-quantitative calculation of the putative endothelium cell count decrease in dextran containing medium for a given incubation time and could thus influence the time management and planning of corneal transplantations.