[show abstract][hide abstract] ABSTRACT: To evaluate the technique, safety, and efficacy of the retropupillary implantation of iris-claw intraocular lenses in a long-term follow-up study.
This retrospective study included 31 eyes of 31 patients who underwent an Artisan aphakic intraocular lens implantation between January 2006 and February 2011 at the University Hospital Essen, Essen, Germany and at the Zentrum für Augenheilkunde PD Dr Laube, Düsseldorf, Germany. Preoperative data collected included demographics, etiology of aphakia, previous surgeries, preoperative eye pathology, intraocular pressure, clinical signs of endothelial cell loss, and best corrected visual acuity. Operative data and postoperative outcomes included the best corrected visual acuity, lens position, intraocular pressure, pigment dispersion, clinical signs of endothelial cell loss, development of macular edema, and other complications.
Thirty-one patients were included. The mean follow-up was 25.2 months (range: 4-48 months). The mean best corrected visual acuity postoperatively was 0.64 logarithm of the minimum angle of resolution (logMAR) and varied from 0 logMAR to 3 logMAR. Some patients had a low visual acuity preoperatively because of preoperative eye pathologies. In 22 patients the visual acuity improved, in two patients the visual acuity remained unchanged, and seven patients showed a decreased visual acuity. Complications were peaked pupils (n=10) and retinal detachment in one case. Four patients showed an iris atrophy and high intraocular pressure was observed only in one patient. Subluxation of the intraocular lens, endothelial cell loss, and macular edema were not observed.
The presented long-term results demonstrate that retropupillary iris-claw lens implantation is a safe and effective method for the correction of aphakia in patients without capsule support. This surgical procedure has the advantages of a posterior chamber implantation with a low intraoperative and postoperative risk profile.
[show abstract][hide abstract] ABSTRACT: Mooren's ulcer is a severe ulcerative inflammation of the cornea. The exact pathogenesis remains unclear. Therefore many therapies of Mooren's ulcer are recommended in literature. To shed more light on the ongoing question of optimal treatment of severe progressive Mooren's ulcer, we here report on a retrospective case series of patients treated with systemic immunosuppressive therapy and additional amniotic membrane transplantation.
Medical records from seven patients (eleven eyes), 4 male and 3 female, with severe progressive Mooren's ulcer were analysed retrospectively. The mean follow up was 88.4 +/- 80.8 months (range 12-232 month). A HLA-typing was performed in all patients. A systemic immunosuppressive therapy was administered in all patients. The amniotic membrane was transplanted after the base of the ulcer was resected.
Multiple amniotic membrane transplantations were necessary in six patients. The visual outcome of all patients was poor. No patient achieved a visual acuity better than 20/630 Snellen chart. Five patients were positive for HLA-DQ2 and four patients were positive for HLA-DR17(3).
The aggressive and highly inflammatory form of Mooren's ulcer is difficult to treat and the progression of the disease is hard to influence positively even under systemic immunosuppressive therapy. Therefore, the main intention of therapy is to achieve a stable epithelialized corneal surface without the risk of perforation. Amniotic membrane transplantation is not able to cure severe forms of Mooren's ulcer. However it supports the immunosuppressive therapy in acute situations as in critical corneal thinning.
[show abstract][hide abstract] ABSTRACT: The use of cryopreserved amniotic membranes for the treatment of diseases and injuries of the surface of the eye is an established procedure in ophthalmological surgery. Before clinical use of cryopreserved amniotic membranes (AM) a careful testing for microbial contamination is essential to ensure a safe application. In this study the use of the BacT/Alert® test system was evaluated for screening of microbial growth in AMs.
Minced fresh and cryopreserved AMs (approximately 5 × 5 cm in size) were injected with 10 ml of balanced salt solution in separate culture media test bottles and 10 ml of cryopreservation medium bacterial and fungal test strains according to European Union (EU) regulations were applied to test the performance of the system. Approximately 10-100 colony forming units were applied on the samples prior to injection in the corresponding test bottles. Bottles were incubated at 37 °C for 7 days. Positive controls contained only balanced salt solution and the test strains while negative controls contained the test material without microbial test strains.
Growth of the test strains was detected in all inoculated samples from non-processed and cryopreserved AM within the 7-day incubation period. In samples of the cryopreservation medium only growth of the fungus Candida albicans could be detected.
The automated BacT/Alert test system is suitable for testing of microbial safety of amniotic membranes but not for testing the cryopreservation medium in clinical practice according to EU regulations.
[show abstract][hide abstract] ABSTRACT: Recent advances in tissue engineering have facilitated the development of new strategies in ocular surface reconstruction. Limitations and possibilities of ex vivo cultivation and limbal epithelium cell culture techniques as well as the short and long-term complications after transplantation of ex vivo expansion of cultivated limbal epithelium for the treatment of limbal stem cell deficiency are summarized in this review.
[show abstract][hide abstract] ABSTRACT: Various ocular surface diseases are caused by loss of corneal epithelial stem cells or dysfunction of the limbal stem cell niche. Besides conventional transplantation of autologous or allogenic limbal tissue, recent advances in tissue engineering have led to the development of new culture and expansion techniques of human limbal stem and progenitor cells (LSPC) as a new strategy to successfully treat limbal stem cell deficiency (LSCD). From a small autologous limbal biopsy with a limited amount of LSPC an epithelium ready for transplantation is achieved. Autologous grafting of cultured limbal epithelium led in most of the treated cases to a successful reconstruction of the corneal surface. Alternative methods which have recently been introduced to treat LSCD use other stem cell sources including the transplantation of oral mucosal epithelium. In this article the challenges and controversies associated with these stem cell culture techniques for ocular surface reconstruction are reviewed.
Der Ophthalmologe 09/2012; 109(9):863-8. · 0.53 Impact Factor
[show abstract][hide abstract] ABSTRACT: Limbal stem cell deficiency results from the loss of tissue regenerating stem and progenitor cells. Corneal epithelial regeneration is maintained by stem and progenitor cells which reside in the schlerocorneal limbus. They possess stem cell characteristics and can be stimulated to proliferate by external signals. The limbus is the stem cell niche for corneal epithelial stem cells and forms a unique microenvironment in which stem cell characteristics are conserved. Regulation of limbal epithelial stem cells is produced by a network of signals within the niche which governs cell fate decisions with regards to proliferation, differentiation or maintenance of a quiescent status.
Der Ophthalmologe 09/2012; 109(9):843-9. · 0.53 Impact Factor
[show abstract][hide abstract] ABSTRACT: Mechanisms that control ocular surface stem cells (SCs) are unclear. Recent studies have shown that several adult SCs express pluripotency markers. Our objective was to analyze the expression of key molecules of pluripotency in human ocular surface tissues as well as in cultivated limbal epithelium.
Four samples of human corneal, limbal and on amniotic membrane cultivated limbal epithelium (HLEC-AM), as well as bulbar and fornical conjunctiva were analyzed. Human embryonic stem (ES) cells and human umbilical vein endothelial cells served as controls. Expression of corneal epithelial differentiation markers (K3, K12, Cx43), putative limbal SC markers (ABCG2, p63, K15), and molecules associated with pluripotency/multipotency (NANOG, OCT4, SOX2, KLF4, KIT, NESTIN, PAX6, NOTCH1) was examined using real-time polymerase chain reaction (PCR) and immunohistochemical staining.
Limbal epithelium showed a significantly (p < 0.05) higher expression of K15, ABCG2, OCT4, SOX2, NESTIN and NOTCH1, but a lower expression of K3 than corneal epithelium. Besides a higher expression of ABCG2 in fornix, the expression of pluripotency markers was similar in both conjunctival regions, although lower than in limbal epithelium. Expression of pluripotency factors in ES cells was significantly higher than in ocular surface SCs, whereas the expression in limbal epithelium was the closest to ES cells. HLEC-AM in comparison to limbal epithelium showed a lower expression of differentiation markers, a similar expression of ABCG2 but a significantly lower expression of pluripotency factors.
Human ocular surface epithelial cells and especially limbal epithelial cell express genes are important for pluripotency and may have preserved some common mechanisms with pluripotent SCs.
Current eye research 09/2011; 36(12):1086-97. · 1.51 Impact Factor
[show abstract][hide abstract] ABSTRACT: The cornea is the clear window at the front of the eye and is the eye's main refractive medium. Its transparency is essential for vision. Corneal neovascularisation is a common clinical problem with serious consequences for vision; it can compromise corneal transparency and plays a major role in corneal graft rejection by breaching corneal immune privilege. In this review, we formulate a consensus on the unmet medical needs in the management of corneal neovascularisation and outline a framework for the clinical research that is needed to identify suitable agents to meet these needs.
The British journal of ophthalmology 06/2011; 96(1):3-9. · 2.92 Impact Factor
[show abstract][hide abstract] ABSTRACT: In this article we discuss the complex diagnostic approaches and therapeutic options for the most important conjunctival malignancies. Conjunctival melanoma can be a diagnostic challenge as it can be difficult to distinguish from benign melanocytic conjunctival tumours. Complete surgical excision accompanied by a coherent adjuvant concept is the key for a curative therapy. Moderate and severe conjunctival intraepithelial neoplasias (CIN) are precancerous lesions and can progress to invasive squamous cell carcinoma. The involvement of large parts of the ocular surface can prevent an R 0-resection. Adjuvant therapeutic concepts are therefore especially important to gain tumour control and preserve the function of the affected eye. Lymphomas are the most common malignant primary tumours of the orbit and ocular adnexa. They can present as primary or secondary tumours of the conjunctiva, the lacrimal gland, the orbital fat, the eye lid or the lacrimal sac. The most common manifestation site of ocular MALT lymphoma is the conjunctiva with 20 - 33 % of all epibulbar lymphomas. More than 75 % of ocular lymphoma patients develop only one lymphomatous lesion. Immunophenotyping allows the exact differentiation between the lymphoma entities. Infectious agents (e.g., Chlamydia psittaci) seem to play a role in the pathogenesis. An overview over radiotherapeutic approaches that are conclusively applicable at the conjunctiva completes the article.
Klinische Monatsblätter für Augenheilkunde 04/2011; 228(9):780-92. · 0.70 Impact Factor
[show abstract][hide abstract] ABSTRACT: Amniotic membrane transplantation (AMT) has a long tradition in ophthalmic surgery and has become very popular recently because of newly developed methods of tissue preservation.
We selectively review the literature on recent developments, mechanisms of action, and established indications of AMT in the treatment of various diseases of the ocular surface. We searched the PubMed database for articles that appeared from 1994 to 2009 with the key words "amniotic membrane," "cornea," and/or "conjunctiva."
Amniotic membrane (AM) can function in the eye as a basement membrane substitute or as a temporary graft. It has anti-inflammatory and anti-scarring effects and contains growth factors that promote epithelial wound healing on the surface of the eye. AMT has been found to be a good alternative for corneal and conjunctival reconstruction in many clinical situations, including acute burns, persistent epithelial defects of the cornea, and diseases that cause conjunctival scarring. Nonetheless, there have been no more than a few randomized and controlled trials of AMT to date. Other studies have shown that AM can serve as a culture substrate to expand epithelial progenitor cells for use in ocular surface reconstruction.
AMT is an established technique in the treatment of various diseases of the external eye. In the last few years, AMT has brought about major advances in the reconstructive surgery of the ocular surface.
[show abstract][hide abstract] ABSTRACT: Cryopreserved amniotic membrane (AM) is widely used in ophthalmology because of its anti-angiogenic, anti-inflammatory, and wound healing promoting capabilities. A common method to conserve the tissue is the storage in cryo-medium containing 50% glycerol at -80°C. The aim of this study was to examine the influence of storage time on the sterility as well as the histological and biological properties of cryopreserved AM.
Amniotic membrane from different donors was stored in cell culture media containing 50% glycerol for different time periods, on average 4 months (group 1), 15 months (group 2), and 24 months (group 3), at -80°C. Samples of the tissue and cryo-medium were examined for bacterial and fungal contamination. Tissue samples were incubated in 0.5 ml/cm(2) serum-free medium at 37°C. The medium was changed after 1, 2, and 3 days. The proteins released by AM were TCA-precipitated and the presence of the proteins TIMP-1 and IL-1ra was analyzed using Western blotting and semi quantified by means of image analysis. Integrity of the amniotic epithelium and the basement membrane components collagen IV, collagen VII, laminin, laminin 5, and fibronectin were examined by haematoxylin eosin stain and immunohistochemistry in cryosections of AM.
None of the examined samples showed bacterial or fungal contamination. The soluble proteins TIMP-1 and IL-1ra were found in all samples of medium incubated for all time periods. The examined proteins were detectable after one-day incubation but the staining signal diminished significantly in the second and third wash after 48 hr and 72 hr. Differences in the intensity of the Western blot signal between the three particular groups were statistically not significant. The epithelia of all samples were intact. The basement membranes of all samples showed a similar distribution of collagen IV, collagen VII, laminin, laminin 5, and fibronectin.
Long-term storage of amniotic membrane in cell culture media with 50% glycerol does not significantly impair sterility, histology, or biological properties of AM.
Current eye research 03/2011; 36(3):247-55. · 1.51 Impact Factor
[show abstract][hide abstract] ABSTRACT: In this study the clinical outcome of ex vivo expansion of autologous limbal epithelial cells on intact amniotic membranes (AM) for ocular surface reconstruction in limbal stem cell deficiency (LSCD) was investigated.
A total of 30 eyes in 28 patients (22 male and 6 female) with total (n=18) or partial (n=12) LSCD were treated by transplantation of autologous limbal epithelial cells after expansion on intact AM. The causes of LSCD in the patients were chemical and thermal burns (n=16), pterygium (n=9), tumor excision (n=2), perforating injury, mitomycin C-induced LSCD and epidermolysis bullosa (each n=1). Only eyes with a follow-up time of at least 9 months were included in the analysis. The main outcome criteria were restoration of ocular surface integrity and improvement of visual acuity (VA).
The mean follow-up time was 28.9±15.5 months. An entirely stable corneal surface was reconstructed in 23 (76.7%) eyes. Visual acuity increased significantly in 21 (70%) eyes, was stable in 8 (26.7%) eyes and decreased in 1 (3.3%) eye. The mean visual acuity increased significantly (p<0.0001) from a preoperative value of 1.58±0.97 LogMAR to 0.6±0.49 LogMAR.
Transplantation of limbal epithelium cultivated on intact AM restores a stable corneal surface and results in a significant increase in visual acuity in most cases of LSCD. Autologous transplantation of cultivated limbal epithelium showed an excellent prognosis and outcome after long-term follow-up.
Der Ophthalmologe 12/2010; 107(12):1133-8. · 0.53 Impact Factor
[show abstract][hide abstract] ABSTRACT: A cornea/tissue bank must have an organizational structure in which responsibility and authority to issue directives are clearly defined. It must also use a documented quality management system on the basis of good practice procedures which is maintained to the current standards. The personnel of a cornea/tissue bank must be present in sufficient numbers and be suitably qualified. A cornea/tissue bank must be in possession of appropriate facilities which are suitable for the main purpose of preparation of cryopreserved human amniotic membranes from donor placentas. All equipment must be designed and maintained corresponding to the intended purpose. Deviations from the stipulated quality and safety standards must give rise to documented investigations which include decisions on options for correctional and preventive measures. Acquisition of donors and tissue sampling must be strictly controlled and documented. This also applies to entry of donor tissue in the cornea/tissue bank. Cryopreserved human amniotic membranes can only be preserved from donors undergoing caesarean section and who did not present any known infection of the abdominal cavity or any systemic blood borne infection. Contamination of media used for cryopreservation of donor placenta must be ruled out at least once. Measures must be taken to keep the risk of contamination as low as possible. Cryopreserved human amniotic membranes from donor placentas can only be released if defined criteria are fulfilled. Any suspicion of severe undesired reactions and events for the recipient of an amniotic membrane transplant must be registered with the authorities. The activities of a cornea/tissue bank must maintain and adapt to the state-of-the-art with respect to scientific progress.
Der Ophthalmologe 11/2010; 107(11):1020-31. · 0.53 Impact Factor
[show abstract][hide abstract] ABSTRACT: To analyse the expression of melanoma chondroitin sulfate proteoglycan (MCSP) and the preferentially expressed antigen of melanoma (PRAME) in conjunctival melanoma (CoM), lymph node (LN) metastases of cutaneous melanoma (CM) and conjunctival nevi (CoN) by immunohistology.
Immunohistology was performed in 70 samples of CoM, 25 of LN metastases of CM and 12 of CoN, and assessed by an immunoreactive score (0-12 points). Statistical analysis was performed to disclose relevant differences in the expression pattern. The diagnostic value of the markers was tested by receiver operating characteristics (ROC) analysis.
MCSP and PRAME were expressed at significantly higher levels in CoM and LN metastases of CM than in CoN (p<0.0001). Within CoM, an MCSP expression <9.0 points meant higher risk for recurrences (Cox HR=3.1) and a shorter recurrence-free survival (p=0.002) than an MCSP expression >9.0 points. ROC analysis showed an area under the curve of 91.3% for MCSP (p=0.0002) and 93.8% for PRAME (p<0.0001).
MCSP and PRAME are differentially expressed in conjunctival melanomas and nevi. MCSP might have an impact on the risk for recurrence in being inversely correlated to the event. Both markers have high potential to discriminate CoM from CoN. The results indicate that immunohistological characteristics gain relevance in the assessment of CoM.
The British journal of ophthalmology 10/2010; 94(10):1322-7. · 2.92 Impact Factor
[show abstract][hide abstract] ABSTRACT: Severe infectious corneal ulceration such as herpetic stromal keratitis commonly causes loss of vision and may lead to blindness. Treatment depending on the underlying disease includes antimicrobial medication and the development of surgical strategies to restore the integrity of the corneal ocular surface. Ulcerative herpetic stromal keratitis and/or neurotrophic keratopathy with the risk of corneal perforation are still clinically challenging conditions in ophthalmic surgery of the ocular surface. Since the introduction of newly developed preservation methods, amniotic membrane (AM) functioning as a basement membrane substitute has gained widespread popularity in ocular surface reconstruction. Various ways of clinical application such as the use of AM as a graft, patch or culture substrate and carrier system to expand ocular surface epithelia have been recently reported. In this article, the basis and clinical application of amniotic membrane transplantation for the management of corneal infections with Herpes simplex and Herpes zoster virus are reviewed.
Klinische Monatsblätter für Augenheilkunde 05/2010; 227(5):393-9. · 0.70 Impact Factor
[show abstract][hide abstract] ABSTRACT: To report a case of partial limbal stem cell deficiency (LSCD) caused by epidermolysis bullosa dystrophica mutilans Hallopeau-Siemens treated by transplantation of autologous ex vivo expanded limbal epithelium.
Review of the clinical findings of an 11.5-year-old boy with unilateral LSCD and epidermolysis bullosa dystrophica who underwent ocular surface reconstruction in the right eye with autologous on intact human amniotic membrane cultivated limbal epithelial cells.
Twenty-eight months after reconstruction, the corneal surface is clear, smooth, and stable showing no signs of LSCD recurrence. Three subconjunctival bevacizumab (Avastin) injections reduced the recurrent growth of symblepharon and corneal vascularization. The visual acuity has increased from hand motion to 20/50.
Autologous transplantation of cultivated human limbal epithelial cells on intact human amniotic membrane can be a safe and effective method for corneal surface reconstruction in LSCD caused by recessive epidermolysis bullosa dystrophica.
[show abstract][hide abstract] ABSTRACT: In chronic GVHD after BMT, the conjunctiva represents a target organ. GVHD can lead to severe inflammation and dry-eye syndrome (sicca syndrome). The molecular mechanisms are largely unknown. We examined the expression of chemokines in the conjunctiva in cases of chronic GVHD. In this study, we included 10 patients with chronic GVHD and 10 healthy controls. Clinical data were collected and tear film analysis and conjunctival cytology were carried out. Conjunctival biopsies were taken from all participants. Gene expression profiles of chemokines and their corresponding receptors were evaluated by means of quantitative real-time PCR. Chemokine protein expression was analysed by immunohistochemical analyses. Expressions of the Th1-associated chemokines, chemokine (C-X-C motif) ligand (CXCL) 9 (Mig), CXCL10 (IP-10), and their receptor chemokine (C-X-C motif) receptor 3 (CXCR3) were significantly increased in GVHD patients. Immunohistochemical analysis confirmed marked expression of the inflammatory CXCR3 ligands. A total of six patients had a moderate or severe sicca syndrome. Impression cytology revealed a mild keratinisation, moderate keratinisation or severe squamous metaplasia in three patients, respectively. Chronic GVHD of the conjunctiva is characterised by the expression of Th1-associated chemokines. Taken together, our results confirm that the conjunctiva is a target organ in this T cell-mediated process and add to molecular understanding of conjunctival GVHD.
Bone marrow transplantation 02/2010; 45(8):1340-6. · 3.00 Impact Factor
[show abstract][hide abstract] ABSTRACT: Limbal stem cell deficiency (LSCD) leads to growth of abnormal fibro-vascular pannus tissue onto the corneal surface as well as chronic inflammation and impaired vision. Our aim was to investigate the clinical outcome of ocular surface reconstruction in LSCD using limbal epithelial cells expanded on amniotic membrane (AM).
Forty-four eyes of 38 patients (27 male, 11 female) with total (n = 32) or partial (n = 12) LSCD were treated by transplantation of autologous (n = 30) or allogeneic (n = 14) limbal epithelial cells expanded on intact AM. LSCD was caused by chemical and thermal burns (n = 22), pterygium (n = 9), congenital aniridia (n = 6), tumor excision (n = 2), perforating eye injury, mitomycin C, epidermolysis bullosa, bilateral graft-versus-host disease and chlamydial conjunctivitis (each n = 1).
Mean follow-up time was 28.5 +/- 14.9 months. The corneal surface could be reconstructed to full stability in 30 (68%), and clear central cornea was achieved in 37 (84%) eyes. Grafting was significantly more successful in eyes treated by autologous than by allogeneic transplantation (76.7 vs. 50%, p < 0.05). The corneal surface could be successfully restored in 10 (83.3%) eyes with partial LSCD and in 20 (63.3%) eyes with total LSCD. Visual acuity (VA) increased significantly in 32 (73%) eyes, was stable in 10 (23%) eyes and decreased in 2 (4%) eyes. Mean VA increased significantly (p < 0.0001), from preoperative 1.7 +/- 0.9 log MAR (20/1,000) to 0.9 +/- 0.7 log-MAR (20/160). VA increased significantly after both autologous (p < 0.0001) and allogeneic transplantation (p < 0.005).
In most patients with LSCD, transplantation of limbal epithelium cultivated on intact AM restores the corneal surface and results in significantly increased VA.
[show abstract][hide abstract] ABSTRACT: Eine Hornhautbank/Gewebebank muss über eine Organisationsstruktur verfügen, in der Verantwortlichkeiten und Weisungsbefugnisse
eindeutig definiert sind. Sie muss ein dokumentiertes Qualitätsmanagementsystem nach den Grundsätzen der „guten fachlichen
Praxis“ verwenden und dieses auf dem neuesten Stand halten. Das Personal der Hornhautbank/Gewebebank muss in ausreichender
Anzahl vorhanden und qualifiziert sein. Eine Hornhautbank/Gewebebank muss über geeignete Einrichtungen verfügen, die dem Zweck
der Gewinnung von kryokonservierter humaner Amnionmembran aus Spenderplazenta entsprechen. Sämtliche Ausrüstungen müssen entsprechend
ihres Verwendungszwecks gestaltet und gewartet werden. Abweichungen von den vorgeschriebenen Qualitäts- und Sicherheitsstandards
müssen zu dokumentierten Untersuchungen führen, die eine Entscheidung über mögliche Korrektur- und Präventivmaßnahmen einschließen.
Spendergewinnung und Gewebeentnahme müssen streng kontrolliert und dokumentiert werden. Dasselbe gilt für den Eingang der
Spendergewebe in der Hornhautbank/Gewebebank. Die Gewinnung einer kryokonservierten humanen Amnionmembran kann nur erfolgen,
wenn bei der Spenderin eine Sectio caesarea erfolgte und keine bekannte Infektion des physiologischerweise keimarmen Bauchraums
oder gar systemische Infektionen (Sepsis) vorliegen. Bei der Präparation/Konservierung ist mindestens eine Sterilitätsprüfung
einer Plazentaprobe im Konservierungsmittel durchzuführen. Es sind Maßnahmen zu ergreifen, um das Kontaminationsrisiko so
gering wie möglich zu halten. Die humane Amnionmembran, kryokonserviert, aus Spenderplazenta darf erst freigegeben werden,
wenn sie festgelegte Anforderungen erfüllt. Der Verdacht auf schwerwiegende unerwünschte Reaktionen und schwerwiegende Zwischenfälle
beim Empfänger eines Amnionmembrantransplantats ist der zuständigen Behörde zu melden. Die Tätigkeiten der Hornhautbank/Gewebebank
sind zeitnah an den wissenschaftlichen Fortschritt anzupassen.
A cornea/tissue bank must have an organizational structure in which responsibility and authority to issue directives are clearly
defined. It must also use a documented quality management system on the basis of good practice procedures which is maintained
to the current standards. The personnel of a cornea/tissue bank must be present in sufficient numbers and be suitably qualified.
A cornea/tissue bank must be in possession of appropriate facilities which are suitable for the main purpose of preparation
of cryopreserved human amniotic membranes from donor placentas. All equipment must be designed and maintained corresponding
to the intended purpose. Deviations from the stipulated quality and safety standards must give rise to documented investigations
which include decisions on options for correctional and preventive measures. Acquisition of donors and tissue sampling must
be strictly controlled and documented. This also applies to entry of donor tissue in the cornea/tissue bank. Cryopreserved
human amniotic membranes can only be preserved from donors undergoing caesarean section and who did not present any known
infection of the abdominal cavity or any systemic blood borne infection. Contamination of media used for cryopreservation
of donor placenta must be ruled out at least once. Measures must be taken to keep the risk of contamination as low as possible.
Cryopreserved human amniotic membranes from donor placentas can only be released if defined criteria are fulfilled. Any suspicion
of severe undesired reactions and events for the recipient of an amniotic membrane transplant must be registered with the
authorities. The activities of a cornea/tissue bank must maintain and adapt to the state-of-the-art with respect to scientific
SchlüsselworteGewebebanken-Amnionmembran-Spenderplazenta-Kryokonservierung-Gute fachliche Praxis
KeywordsTissue banks-Amniotic membrane-Donor placenta-Cryopreservation-Good practice procedures
Der Ophthalmologe 01/2010; 107(11):1020-1031. · 0.53 Impact Factor