NF1 mutations in conjunctival melanoma.

BACKGROUND: Conjunctival melanoma is a potentially deadly eye tumour. Despite effective local therapies, tumour recurrence and metastasis remain frequent. The genetics of conjunctival melanomas remain incompletely understood. METHODS: A large cohort of 63 conjunctival melanomas was screened for gene mutations known to be important in other melanoma subtypes by targeted next-generation sequencing. Mutation status was correlated with patient prognosis. RESULTS: Frequent mutations in genes activating the MAP kinase pathway were identified. NF1 mutations were most frequent (n = 21, 33%). Recurrent activating mutations were also identified in BRAF (n = 16, 25%) and RAS genes (n = 12, 19%; 11 NRAS and 1 KRAS). CONCLUSIONS: Similar to cutaneous melanomas, conjunctival melanomas can be grouped genetically into four groups: BRAF-mutated, RAS-mutated, NF1-mutated and triple wild-type melanomas. This genetic classification may be useful for assessment of therapeutic options for patients with metastatic conjunctival melanoma.

Evaluation of a new protocol for sterility controls of corneal culture medium.

Careful testing for microbial contamination is essential for corneal transplants. Sterility tests are performed on the antibiotics containing culture medium leaving the problem that antibiotics might compromise the test results. In this study a protocol for the application of the automated BacT/Alert system for sterility testing of corneal cell culture medium was examined. Corneal culture medium in combination with an antibiotics degrading enzyme were injected in resin containing test bottles of the BacT/Alert system named FA plus (intended for aerobic microorganisms) or FN plus (intended for anaerobic microorganisms) depending on their aerobic or anaerobic nature. Additionally i-FA plus(aerobic test bottle for industrial use) bottles were used. Microbial test strains on the basis of the European Pharmacopaea (Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Candida albicans, Aspergillus brasiliensis and Clostridium sporogenes) with the addition of Propioniobacterium acnes were added to the test bottles. The bottles were incubated at two different temperatures for 14 days. The time to detection (TTD) was monitored for each bottle. Growth of the test strains except European Pharm was detected in the FA and FN Plus bottles. The TTD for the strains was 44 ± 1.5 h (P. aeruginosa), 57.7 ± 2.2 h (B. subtilis), 56 ± 1 h (S. aureus), 26.3 ± 1 h (C. sporogenes), 223 ± 4.6 h (P. acnes), 64.4 ± 10 (C. albicans). A. brasiliensis was detected in i-FA Plus bottles with a TTD of 94.9 ± 3.7 h. The application of BacT/Alert FA Plus and FN Plus resin bottles in combination with a penicillin degrading enzyme is able to detect small scale microbial contamination with different microorganisms in antibiotic containing corneal culture medium. For detection of Aspergillus brasiliensis in the medium the (i-) FA Plus bottles should be used.

[New nanofibrous scaffold for corneal tissue engineering]. / Eine neue Nanofaser-Matrix für den kornealen Gewebeersatz.

BACKGROUND: An estimated 10 million people suffer worldwide from vision loss caused by corneal damage. For the worst cases, the only available treatment is transplantation with human donor corneal tissue. However, in numerous countries there is a considerable shortage of corneal tissue of good quality, leading to various efforts to develop tissue substitutes. The present study aims to introduce a nanofibrous scaffold of poly(glycerol sebacate) PGS as a biodegradable implant, for the corneal tissue engineering. MATERIALS AND METHODS: Nanofibrous scaffolds were produced from PGS and poly(ε-caprolactone) (PCL) by a modified electro-spinning process. The biocompatibility of the material was tested in vitro by colorimetric MTT assay on days 3, 5, and 7 to test the cell viability of human corneal endothelium cells (HCEC). To examine a potential immunological reaction of the scaffolds, samples were exposed to mononuclear cells derived from peripheral blood (PBMCs). After an incubation period of 3 days, supernatants were assayed for apoptotic assessment and immunogenic potentials by annexin V FITC//propidium iodide and flow-cytometric analysis. RESULTS: We could successfully demonstrate that cultivation of HCECs on PGS/PCL scaffolds was possible. Compared to day 3, cell density determined by microplate absorbance was significantly higher after 7 days of cultivation (p < 0.0001). According to the MTT data, none of the samples showed toxicity. Apoptotic assessments by FACS analysis showed that no composition stimulated apoptosis or activated PBMCs occurred. All the compositions were inert for native as well as activated T/B/NK cells and monocytes. It can be concluded that leukocytes and their activity was not affected by the scaffolds. CONCLUSION: A tissue-like scaffold mimicking the human stroma could be developed. The results indicate that PGS/PCL scaffolds could be considered as ideal candidates for corneal tissue engineering as they are biocompatible in contact to corneal endothelial cells and blood cells.

TERT promoter mutations in ocular melanoma distinguish between conjunctival and uveal tumours.

BACKGROUND: Recently, activating mutations in the TERT promoter were identified in cutaneous melanoma. We tested a cohort of ocular melanoma samples for similar mutations. METHODS: The TERT promoter region was analysed by Sanger sequencing in 47 uveal (ciliary body or choroidal) melanomas and 38 conjunctival melanomas. RESULTS: Mutations of the TERT promoter were not identified in uveal melanomas, but were detected in 12 (32%) conjunctival melanomas. Mutations had a UV signature and were identical to those found in cutaneous melanoma. CONCLUSION: Mutations of TERT promoter with UV signatures are frequent in conjunctival melanomas and favour a pathogenetic kinship with cutaneous melanomas. Absence of these mutations in uveal melanomas emphasises their genetic distinction from cutaneous and conjunctival melanomas.

[Gene therapy in ophthalmology: state of the art]. / Gentherapie in der Ophthalmologie: Stand der Forschung.

The term "gene therapy" denotes the treatment of diseases or gene deficiencies by introduction of genes into cells. To achieve this goal, vectors are used to transfer the genetic information into the cells. Thus, the protein of interest can be overexpressed or silenced. On account of its easy accessibility, the good compartmentalisation and the separation from the main bloodstream by the blood-retina barrier, the eye represents a very attractive target to treat ocular diseases by gene therapy. In this work, we provide an overview of the progress in ocular gene therapy over the last decade and give an outlook on future developments.

[Topical Mitomycin C as a therapy of conjunctival tumours]. / Topisches Mitomycin C als Therapie konjunktivaler Tumore.

Surgical excision with tumour free margins is the gold standard for squamous cell and melanocytic tumours of the conjunctiva. In cases of diffuse and extensive tumours a complete surgical excision is sometimes not possible. Therefore, alternative or adjuvant therapies are required. Topical chemotherapy with mitomycin C (MMC) is increasingly finding use in clinical practice. MMC has several advantages such as good tolerability and mild side effects. Present studies have shown that mitomycin C is a good option in squamous cell neoplasia of the conjunctiva. However, further multi-centre studies and long-term follow-up are needed.The results in treating melanocytic tumours of the conjunctiva with MMC are less convincing. MMC seems to be an option for the treatment of primary acquired melanosis (PAM); but, if the tumour is suspicious for melanoma primary chemotherapy with MMC is obsolete. In these cases MMC can only be used as an adjuvant therapy, otherwise tumour control is not assured. However, prospective randomized controlled trials are necessary for a final evaluation of MMC therapy in melanocytic tumours of the conjunctiva.

[Aniridia intraocular lenses in eyes with traumatic iris defects]. / Aniridie-Intraokularlinsen bei Augen mit traumatischen Irisdefekten.

BACKGROUND: Globe injuries frequently are the cause of permanent loss of visual function. Especially ruptures of the globe have a 50 times lower chance of achieving a final visual acuity better than 20/200 as compared to contusions of the globe. Besides injury to the retina and choroids, injury of the iris-lens diaphragm plays an important role for visual rehabilitation (10% iris defects and 1% aniridia after blunt trauma). Against this background the surgical results after implantation of aniridia intraocular lenses were investigated. PATIENTS AND METHODS: Eleven patients (41.9+/-19.6 years of age) after globe injury (three ruptures of the globe, eight penetrating injuries with trauma of the iris) were implanted with an aniridia IOL. RESULTS: The implantation of an aniridia IOL was performed on average 1.0+/-0.6 years (range: 0.4-2.3 years) after the primary injury. In ten eyes an aniridia IOL model HMK ANI 2 (Ophtec/Polytech) was implanted and in one eye an aniridia IOL model 67 (Morcher). Most patients were very satisfied with the results achieved (average corrected visual acuity 0.48; 0.05-1.0). Of the operated eyes, 63% reached a visual acuity > or = 0.4. All patients noticed a significant reduction in glare disability as compared to the preoperative condition. The incidence of secondary glaucoma remained unchanged after the secondary implantation. One patient demonstrated retinal detachment 3 months after receiving the secondary implant, which was successfully treated with vitrectomy and gas tamponade. CONCLUSIONS: The implantation of aniridia IOLs seems to be a beneficial therapeutic option in post-traumatic eyes with partial or complete aniridia and aphakia with good visual recovery. During the postoperative follow-up special attention must be paid to sufficient regulation of intraocular pressure and to the retinal situation.

[Good practice procedures for acquisition and preparation of cryopreserved human amniotic membranes from donor placentas]. / Gute fachliche Praxis zur Gewinnung und Herstellung von kryokonservierter humaner Amnionmembran aus Spenderplazenta.

Within the framework of obtaining a valid authorization for tissue preparation of cryopreserved human amniotic membranes at the Paul Ehrlich Institute, pursuant to § 21a paragraph 1 of the German Medicines Act (AMG), parts of the existing good practice procedures for acquisition of cryopreserved human amniotic membranes from donor placentas were reviewed and supplemented by new knowledge. The present good practice procedures were formulated in cooperation with members of the section for tissue transplantation and biotechnology of the German Ophthalmological Society. The current revised version is presented in this article.

[Ocular graft versus host disease : Corneal complications]. / Okuläre Graft-versus-Host-Disease : Korneale Komplikationen.

BACKGROUND: Ocular graft-versus-host disease (GvHD) following allogeneic blood stem cell transplantation leads to immunologically induced alterations in many ocular tissues, particularly at the ocular surface. Within the framework of the main topic, this article focuses primarily on corneal complications in chronic ocular GvHD. OBJECTIVE: This article aims to promote understanding of the influencing factors, diagnostics, and therapeutic options pertaining to corneal complications in ocular GvHD. Furthermore, the possibilities for prevention are discussed. MATERIALS AND METHODS: This analysis is based on a literature review as well as on data from the Ophthalmology Clinic at the University Hospital Essen. RESULTS: Corneal complications often occur secondarily in ocular GvHD, as a consequence of severe inflammatory alterations of the conjunctiva or eyelid. Spontaneous corneal perforations associated with only mild symptoms are less common during the course of disease. From the ophthalmologist's perspective, it is important that the inflammatory activity of all the different ocular tissues is considered. Treatment may follow a stepwise scheme that includes substitution, immunosuppression, and surgical rehabilitation. CONCLUSION: Systematic diagnosis of ocular GvHD helps to prevent corneal complications or support early therapeutic intervention. An interdisciplinary approach to diagnosis and treatment planning is recommended, in order to optimize local and systemic immunosuppressive therapy.

[Clinical, morphological and molecular biological characteristics of the aging eye]. / Klinische, morphologische und molekularbiologische Charakteristika des alternden Auges.

BACKGROUND: The physiological aging of the eye is associated with loss of visual function. Age-related changes of the eye can result in ophthalmological diseases. The aim of this article is to display morphological, histological and molecular biological alterations of the aging eye. MATERIAL AND METHODS: A web-based search and review of the literature for aging of the visual system including cornea, lens, vitreous humor, retina, retinal pigment epithelium (RPE), choroidea and optic nerve were carried out. The most important results related to morphological, histological and molecular biological changes are summarized. RESULTS: Age-related, morphological alterations can be found in preretinal structures, e. g. cornea, lens and vitreous humor, as well as neuronal structures, such as the retina. In addition to negligible clinical signs of the aging eye, there are clinically relevant changes which can develop into pathological ophthalmological diseases. These transitions from age-related alterations to relevant ophthalmological diseases, e. g. age-related macular degeneration and glaucoma are continuous. CONCLUSION: An understanding of aging could provide predictive factors to detect the conversion of physiological aging into pathological conditions. The derivation of physiological markers or new approaches to detection and treatment of disease-related entities associated with the risk factor aging are desirable. Translational approaches in clinical and basic science are necessary to provide new therapeutic options for relevant ophthalmological diseases in the future.

[Adjuvant topical interferon-alpha-2b treatment in epithelial tumors of the ocular surface]. / Adjuvante topische Interferon-alpha-2b-Therapie bei epithelialen Tumoren der Augenoberfläche.

PURPOSE: The aim of this study was to evaluate the role of topical interferon-alpha-2b in the adjuvant treatment of corneal and conjunctival tumors. METHOD: In this noncomparative, prospective, interventional case series, five patients with histologically proven conjunctival intraepithelial neoplasia (CIN) after primary excision and amniotic membrane transplantation were treated with interferon (IFN)-alpha-2b eye drops five times daily over a period of 6 weeks (1 million IU/ml Intron A, Schering). An in situ hybridization technique was used to detect human papillomavirus (HPV) in all specimens. Frequent follow-up was undertaken clinically and photographically for evidence of tumor recurrence. RESULTS: In the follow-up period (13.2+/-4,97 months) no clinical evidence of recurrence with only limited treatment side effects such as mild conjunctival hyperemia were recorded after 6 weeks of interferon. In one CIN specimen HPV 16/18 could be detected. CONCLUSIONS: The combination of excisional biopsy and topical interferon-alpha-2b application seems to be an effective and safe treatment for conjunctival intraepithelial neoplasias. Therefore, we prefer this combined treatment to topical interferon-alpha-2b treatment alone, more destructive approaches such as radiation and cryotherapy, or treatment with antimetabolites such as 5-fluorouracil or mitomycin C.

[Analysis of ocular surface alterations following proton beam radiation in eyes with conjunctival malignant melanoma]. / Analyse der okulären Oberfläche nach Protonenbestrahlung bei malignem Melanom der Bindehaut.

BACKGROUND: In cases of large, diffuse or multilocular growth pattern of conjunctival melanoma, proton beam irradiation can serve as an alternative therapy to exenteration. In extended tumours, ocular surface problems can result after therapy. In this study we examined ocular surface integrity of ten patients who underwent proton beam radiation between 1996 and 2002. METHODS: The patients were examined during their follow-up. Eight of the ten cases who underwent proton radiotherapy were recurrent tumours, which were previously treated with other adjuvant therapies. We performed a standard ophthalmological examination and detailed tear film diagnostics. RESULTS: The follow-up was 17-87 months (mean: 40.9+/-20.1). In six cases more than 50% of the upper and lower eyelids were included in the radiation field. All of these cases showed moderate to severe sicca symptoms. The impression cytology revealed squamous metaplasia of conjunctival cells in nine of ten cases. CONCLUSIONS: Squamous metaplasia of conjunctival epithelia indicates a radiogenic, persisting disturbance of differentiation of the conjunctival epithelial cells. The tear film instability correlates with the loss of mucin-secreting goblet cells and meibomian gland dysfunction.

[Long-term results of autologous transplantation of limbal epithelium cultivated ex vivo for limbal stem cell deficiency]. / Langzeitergebnisse zur autologen Transplantation von ex vivo kultiviertem Limbusepithel bei limbaler Stammzellinsuffizienz.

OBJECTIVE: This study reports the long-term clinical outcome of autologous limbal epithelial cells cultivated ex vivo on intact amniotic membranes (AM) for ocular surface reconstruction in limbal stem cell deficiency (LSCD). PATIENTS AND METHODS: A total of 61 eyes from 57 patients (46 males and 11 females) with LSCD were treated by transplantation of autologous limbal epithelial cells cultivated on intact AM. The etiology of the LSCD was chemical and thermal burns (n = 34), recurrent or primary large-sized pterygium (n = 12), mitomycin C and tumor excision-induced LSCD (n = 9), severe infectious keratitis (n = 3), perforating injury, epidermolysis bullosa and contact lens-associated keratopathy (each n = 1). Only eyes with a follow-up time of at least 12 months were included in the analysis. The main outcome end points were restoration of ocular surface integrity and improvement of visual acuity (VA). RESULTS: The mean follow-up time was 50.8 ± 32.7 months. An entirely stable corneal surface was reconstructed in 46 (75.4%) eyes. Visual acuity significantly increased in 40 (65.6 %) eyes, was stable in 12 (19.7%) eyes and decreased in 9 eyes (14.8%). The mean visual acuity significantly increased (p < 0.0001) from 1.4 ± 0.91 LogMAR preoperatively to 0.8± 0.67 LogMAR postoperatively. CONCLUSION: Transplantation of limbal epithelium cultivated ex vivo on intact AM leads to restoration of a stable corneal surface and resulted in a significant increase of visual acuity in most cases of LSCD. Autologous transplantation of cultivated limbal epithelium showed an excellent prognosis and outcome after long-term follow-up.

Adenoviral p53 gene transfer inhibits human Tenon's capsule fibroblast proliferation.

BACKGROUND/AIM: Although antiproliferative drugs have been used successfully to prevent scarring after filtration surgery in patients with glaucoma, complications associated with their use (such as hypotony or endophthalmitis) energise the search for an alternative treatment. Single application of beta radiation leads to long term growth arrest and expression of p53 in human Tenon's capsule fibroblasts (hTf). The authors assume that the activation of p53 is one of the cellular triggers. Their aim was to analyse the effect of p53 overexpression on hTf and to determine which pathways are involved. METHODS: A recombinant adenoviral vector (rAd.p53) containing transgenes encoding for human p53 and green fluorescent protein (GFP) was used to induce overexpression of p53 in hTF and a control vector (rAd.GFP). Transgene expression was detected by western blot (p53 and p21WAF-1/Cip1). Cell proliferation and viability were investigated using cell counts, 5'-bromodeoxyuridine incorporation (BrdU assay) and tetrazolium reduction (MTT assay). RESULTS: Infection of hTf with rAd.p53 resulted in significant inhibition of cell proliferation, DNA synthesis, and metabolic activity in vitro. Western blot showed increased levels of p53 and p21WAF-1/Cip1 in rAd.p53 infected cells, but not in rAd.GFP and uninfected cells. Apoptosis was excluded with flow cytometry. CONCLUSIONS: Adenoviral p53 gene transfer leads to significant growth inhibition in hTf. P53 induces p21(WAF-1/Cip1) expression and does not cause apoptosis in hTf in vitro. p53 as an antiproliferative drug has the potential to replace mitomycin C and 5-fluorouracil in glaucoma surgery.

[Do antisense oligonucleotides improve viral immunopathology?]. / Verbessern Antisense-Oligonukleotide die virale Immunpathologie? Lokale Gabe gegen TNF-alpha-mRNA bei experimenteller Herpeskeratitis.

BACKGROUND: Tumor necrosis factor (TNF)-alpha as a proinflammatory cytokine is of great importance during the development of herpes simplex virus-1 keratitis (HSK). In this study the local administration of antisense oligonucleotides (ASON) targeting TNF-alpha was examined for its usefulness in ameliorating this disease. METHODS: Uptake and efficacy of the oligonucleotides were studied in vitro by fluorescence microscopy and flow cytometry. Substance- and sequence-specific influences on the development of HSK were scrutinized in an animal model. RESULTS: Quick and stable uptake of FITC-labeled ASON by isolated spleen and lymph node cells was proved. The production of TNF-alpha by these cells after stimulation with HSV antigen or concanavalin A (ConA) was clearly downregulated after addition of ASON. In vivo, incidence and development of HSK were ameliorated after subepithelial corneal injection of ASON targeting TNF-alpha. When buffer and control oligonucleotides were given, no significant influence on the disease was found. CONCLUSION: The ASON effectively reduced TNF-alpha secretion in vitro and suppressed the development of experimental HSK in vivo.

[Operative therapy and irradiation of conjunctival melanoma]. / Operative Therapie und Bestrahlung konjunktivaler Melanome.

BACKGROUND: Radiotherapy of conjunctival melanoma has gained in importance in recent years compared to less invasive therapeutic approaches. This is due to the high recurrence rates achieved by omitting adjuvant therapy and to the increasing availability of suitable radiotherapeutic methods, so that tumors formerly not amenable to organ-preserving therapy can now be treated. OBJECTIVE: This article presents the current radiotherapeutic options for conjunctival melanoma. The aim is to describe the diagnostic and therapeutic strategies and the course of therapy of malignant conjunctival melanoma. It is the authors' intention to justify the necessity of the adjuvant therapy of conjunctival melanoma and to emphasize the need for interdisciplinary cooperation during the course of tumor therapy. METHODS: The article is based on results published in the literature as well as on data collected and experience gained in our centre.

Effect of PDGF-AB heterodimer on a corneal epithelial cell line.

Exposure of cells of a rabbit corneal epithelial cell line (SIRC) to platelet-derived growth factor-AB heterodimer (PDGF-AB) resulted in a rapid and transient elevation of cytosolic free calcium concentration with a maximum at 2 to 3 min after stimulation. The kinetics of the calcium response were dose-dependent, e.g., higher concentrations of PDGF-AB caused a faster rise in cytosolic free calcium concentration. Maximum response was achieved with 10 ng/ml PDGF; higher concentrations up to 100 ng/ml did not further enhance cytosolic free calcium concentration. The ED50 was calculated to be 5 ng/ml PDGF-AB. After complexing extracellular calcium, PDGF-AB still caused a significant rise in cytosolic free calcium concentration indicating a mobilization of calcium from intracellular stores. This rise, however, was less pronounced than in the presence of extracellular calcium. The elevation in cytosolic free calcium concentration was not accompanied by an increased mitotic or proliferative activity of the cells as checked by [3H]thymidine incorporation and counting of cell numbers after 3 days of continuous incubation with various concentrations of PDGF-AB or by alterations in cell size and cell volume. In contrast, alterations in cell shape with a remarkable amount of rounded and partially detached SIRC cells after addition of PDGF-AB were observed within 24 h. Moreover, PDGF-AB caused a reversible distortion of cytoskeletal components such as actin-containing microfilament bundles, microtubules, and vimentin filaments. The results suggest that PDGF-AB may act only as a competence factor for the stimulation of SIRC cells via modification of the intracellular calcium homeostasis.

A rabbit corneal epithelial cell line expresses functional platelet-derived growth factor beta-type receptors.

Platelet-derived growth factor (PDGF) is a family of three isoforms termed PDGF-AA, PDGF-AB, or PDGF-BB that induce proliferation in various mesenchymal cells. A rabbit corneal epithelial cell line (SIRC) was chosen to study the effects of the three isoforms of PDGF. These cells express approximately 43,000 PDGF beta-type receptors and less than 2800 alpha-type receptors on their surface. Thus, only PDGF-BB and -AB led to a transient dose-dependent rise in cytosolic free calcium with an effective dose for 50% of cells of 5 ng/ml. The PDGF-induced calcium signal is largely independent of the presence of extracellular calcium.

Relevance of host-derived and bacterial factors in Pseudomonas aeruginosa corneal infections.

Two pathogenic mechanisms of Pseudomonas aeruginosa corneal infections are discussed, one involving bacterial exoenzymes, the other involving polymorphonuclear leukocyte (PMN)-derived lysosomal enzymes. The objective of the present study was (1) to show the relative importance of the two mechanisms and (2) to evaluate the effect of active immunization against P. aeruginosa exoenzymes on ocular damage. Rabbits were immunized against P. aeruginosa alkaline protease (AP) or elastase (Ela) and challenged with the respective enzymes. Corneal damage was studied by light photography (LP). In another group, rabbits were immunized against AP, Ela and exotoxin A (ExoA) and challenged with P. aeruginosa strains PA01 or PA103. Corneal damage was studied with LP, light microscopy, and electron microscopy. Immunized animals were totally protected against intracorneal inoculation of P. aeruginosa proteases. Twelve hr and 24 hr after challenge with whole bacteria, immunized rabbits revealed less corneal damage than non-immunized animals. However, after 48 hr corneal damage (ie severe corneal ulceration) was comparable in both groups. The study suggests that corneal damage involving lysosomal enzymes from stimulated PMN is more important after bacterial infection than direct damage by P. aeruginosa exoenzymes.