[Procedural guidelines. Good tissue practice for cornea banks]. / Arbeitsrichtlinien. Gute Fachliche Praxis für Hornhautbanken.

A cornea 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 bank must be present in sufficient numbers and be suitably qualified. A cornea bank must be in possession of appropriate facilities which are suitable for the main purpose of conservation of donor corneas. 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 bank. During conservation a microscopic examination of the endothelial cell layer must be carried out at least once. Measures must be taken to keep the risk of contamination as low as possible. Donor corneal tissue can only be released if defined criteria are fulfilled. Any suspicion of severe undesired reactions and events for the recipient of a corneal transplant must be registered with the authorities. The activities of a cornea bank must maintain and adapt the state-of-the-art with respect to scientific progress.

[Sterility of non-preserved autologous serum drops for treatment of persistent corneal epithelial defects]. / Sterilitätskontrolle von unkonservierten Eigenserumtropfen bei therapieresistenten Hornhautepitheldefekten. Eine prospektive Studie.

PURPOSE: To investigate the sterility of non-preserved autologous serum drops in hospitalized patients with persistent corneal epithelial defects. METHODS: Thirty patients with persistent corneal epithelial defects (aged between 28 and 85, mean 67+/-14 years) were treated with autologous serum drops in five different wards of a university eye hospital between October 2001 and March 2002. After centrifugation of freshly collected autologous blood, the serum was stored in sterile drop bottles at refrigerator temperature (7 degrees C) and applied undiluted every 1 or 2 h up to 7 days. Using blood, chocolate, endo, and Sabouraud agar media, we assessed the sterility of autologous serum drops on the day before application and on the 4th and 7th days. Examinations performed on the 1st and 4th days included 40 autologous serum drops each and on the 7th day 120 samples (40 serum drops, 40 bottle tops, and 40 bottle bottoms). The agar media for bacterial examination were read after 48 h of incubation time, and those for fungal examination were read after 21 days. All patients had received topical autologous serum therapy and prophylactic antibiotic drops for at least 7 days. RESULTS: The time period of autologous serum treatment ranged from 7 to 28 (10+/-5) days. On the 1st and 4th days autologous serum drops were sterile. On the 7th day, 3 of 40 (7.5%) samples were contaminated with Staphylococcus epidermidis. Two of these contaminations were due to a combined serum drop and bottle top contamination (5%). A third case resulted from additional bottle bottom contamination (2.5%). None of the samples examined showed signs of fungal infection. During application of autologous serum as well as during the follow-up period no patient showed any symptoms of ocular infection. CONCLUSIONS: The application of autologous serum has proven to be a practicable therapy in patients with persistent corneal epithelial defects. When the drops are applied by trained personnel, the absence of contamination can be ensured up to the 4th day. By additional application of prophylactic antibiotic drops, infections may be avoided even if refrigerated non-preserved autologous serum is used up to 7 days.

[Vitamins C and E protect cultures of bovine lens epithelium from the damaging effects of blue light (430 nm) and UVA light (300-400 nm)]. / Die Vitamine C und E schützen Kulturen bovinen Linsenepithels vor Schäden durch blaues (430 nm) und UV-A-Licht (300-400 nm).

BACKGROUND: In 1992 Radlmaier showed that catalase can protect bovine lens epithelial cultures from blue light. The following experiments have the aim to examine, if vitamin C and E have protective functions, also. MATERIAL AND METHODS: 367 cultures of bovine lens epithelial cells were incubated in Medium 199 added by 20% foetal calf serum FCS, by 125 I.U./ml penicillin, by 125 mg/ml Streptomycin, by 0.31 microgram/ml amphotericin B, by 2% L-Glutamin (200 mM), and by 1.25% Hepesbuffer. The incubation temperature was kept at 36 degrees C at a pCO2 of 5%. In order to avoid secondary morphologic alterations, we experimented only on the second to the third subculture. Light exposure followed three days after addition of the substances such as Cebion 500 (R) ad injection (6 mg/dl) and E-Vicotrat (R) ad injection (0.5 mg/dl). The blue light (420-430 nm, Draeger) was applied in a baby bed at 36 degrees C for four hours (1.1 mW/cm). The UV-A lamp was constructed and described by Heller [7]; at a wave length of 300-400 nm, the irradiation time was 10 minutes at 100 mW/cm2. In morphologic evaluation we looked for criteria such as cell diameter, cellular wall alterations, cellular inclusions and vacuoles. The cell count was done after staining with the vital dye trypan-blue in Neubauer's chamber. In statistic evaluation we used the pair comparison of Tuckey and Kruskall-Wallis-Test. RESULTS: After addition of 0.5 mg/ml vitamin E: In 89 cultures, morphologic evaluation and cell count showed a significant protection against light toxicity: After Uv-A-irradiation we counted 50% more living cells and after blue light 30% more. After addition of 6 mg/ml Cebion vitamin C: Morphologic evaluation and cell count of 223 cultures showed them also to be significantly protected: after irradiation by UV-A we counted 25% more and after exposition to blue light 15% more living cells. CONCLUSION: The demonstrated experiments significantly showed, that vitamin C and vitamin E can protect lens epithelial cultures from toxic stress by blue and by UV-A light and might delay cataract formation in man.

[Interim results from the prospective "Erlanger Non-high-risk Penetrating Keratoplasty Study" in 207 patients]. / Zwischenergebnisse der prospektiven "Erlanger Nicht-Hochrisiko-Keratoplastik-Studie" bei 207 Patienten.

BACKGROUND: Immunologic graft rejection targeted against corneal endothelium is the most frequent cause for graft failure after corneal transplantation. The purpose of this prospective study was to assess the frequency, early symptoms, prophylaxis and therapy monitoring of corneal graft rejection following non-high-risk penetrating keratoplasty (PK). PATIENTS AND METHODS: From February 1997 to May 1999, 237 patients undergoing non-high-risk PK have been enrolled in this prospective study. We evaluated 207 patients (103 female, 113 right eyes, recipient age 54 +/- 20 years, donor age 59 +/- 17 years). In 2 randomized treatment studies we compared the efficacy of postoperative short-term (ST = 6 months) versus long-term (LT = 12 months) topical steroid therapy on the incidence of graft rejection and the effect of high- versus low-dose systemic steroid therapy on the prognosis after a graft rejection. Follow-up examinations included, laser-tyndallometry, corneal topography analysis, endothelial cell count and pachymetry. RESULTS: The main indications for PK were keratoconus (n = 93), endothelial dystrophy Fuchs (n = 52) and bullous keratopathy (n = 35). In 151 (73%) patients, non mechanical trephination with the 193 nm Excimer laser was performed. Up to now, 78 patients were randomized into two groups comparing the postoperative therapy with topical steroids. During follow-up (median: ST: 13.5 months; LT: 12.5 months, maximum 25.3 months) episodes of endothelial graft rejection (3 chronic focal, 8 acute diffuse) showed 11 eyes of 11 patients. Five patients each had short-term and long-term topical steroid treatment. In 1 patient the graft rejection occurred before randomization at 6 months. Six patients with graft rejection episodes underwent a PK only (54% of graft rejections, 4.4% of all patients). In the remaining 5 patients, PK was combined with a lens surgery (46% of graft rejections, 6.9% of all patients). Ten of 11 corneal grafts regained their full function under treatment with systemic and local steroids. CONCLUSION: The frequency of episodes of graft rejection in our study was lower than usually reported in the literature. A good compliance of patients appears to be a major factor for improved prognosis of the graft after PK and in case of graft rejection. Until now no significant differences between short-term or long-term postoperative topical steroid therapy could be detected regarding the incidence of corneal graft rejection.

[Regression analysis of corneal endothelium after nonmechanical penetrating keratoplasty]. / Regressionsverhalten des Hornhautendothels nach nichtmechanischer perforierender Keratoplastik.

PURPOSE: The corneal endothelial cell density is a crucial parameter for the pump function and the transparency of grafts after penetrating keratoplasty (PK). The purpose of this study was to assess corneal endothelial cell density with different regression models after nonmechanical penetrating keratoplasty and to check for differences between diagnoses and two different storage methods. PATIENTS AND METHODS: Two-hundred ninety-six eyes (195 keratoconus, 101 Fuchs' dystrophies, 148 each with short-term preserved and organ-cultured donor corneas) of 268 patients were included in this prospective study. Donor and recipient trephination was performed using nonmechanical trephination technique with the excimer laser 193 nm along metal aperture masks from the epithelial side. The time course of the endothelial cell density (specular microscope EM 1100, TOMEY, Erlangen) after PK was assessed. Endothelial cell density was first analyzed in a cross sectional manner at the 3, 6, 12, 18 and 24 months follow-up and, secondly in a longitudinal manner with linear, polynomial and exponential regression models in the sense of minimizing the residuum (distance between observed and predicted endothelial cell count). The mean donor postmortem time was 10.3 +/- 6.8 hours for short-term-preserved and 19.6 +/- 9.5 hours for organ-cultured corneas (p < 0.0001). The storage time was 63 +/- 49 and 19 +/- 7 days (p < 0.0001), respectively. RESULTS: In a cross section, overall mean endothelial cell density decreased from 2145 +/- 599 cells/mm2 at the 3 months to 1751 +/- 605 cells/mm2 at 2 years follow-up (p > 0.05). Cell density did not differ significantly between different diagnoses or storage methods at any postoperative stage. In a longitudinal section, the linear regression model estimated an annual decrease of 214 cells/mm2. In a polynomial model the decrease expressed by a tangent to the regression line at 24 months was 175 cells/mm2. The exponential regression model yielded a relative decrease of 9.5% annually. The so-called residuum as a measure for the validity of the regression model was maximal in the linear and minimal in the exponential estimate. With keratoconus and short-term preserved donor material the endothelial cell loss was less in the regression analysis. CONCLUSION: During the first two years after nonmechanical trephination in PK, a non-significant decrease in endothelial cell density was observed. The exponential regression model seems to be predestinated for analysis of the time course of corneal endothelium in a longitudinal manner. The annual cell loss ranged around 9.5% without significant differences between diagnoses and storage methods.

[Transplant endothelium and measuring corneal thickness after non-high-risk keratoplasty with briefly or long-term preserved corneal donor tissue]. / Transplantatendothel und Hornhaut-Pachymetrie nach Nicht-Hochrisiko-Keratoplastik mit kurzzeit- oder langzeitkonserviertem Hornhautspendergewebe.

PURPOSE: The corneal endothelial cell density is essential for the pump function and the transparency of grafts after penetrating keratoplasty (PK). The purpose of this study was to assess corneal endothelial cell density after non-high-risk PK and to check for possible correlations with storage parameters of the donor corneas using two different storage methods. PATIENTS AND METHODS: Endothelial cell density (specular microscope EM 1100, TOMEY, Erlangen) and central corneal thickness (ultrasonic pachymetry SP-2000, TOMEY, Erlangen) were assessed 6 weeks, 3, 6, 9 months and one year postoperatively in 168 non-high-risk PKs. Short-term-preserved donor corneas were used in 89 patients, whereas in 79 patients organ-cultured corneas were used. The donor trephination was performed from the epithelial side using an artificial anterior chamber. The postoperative treatment with topical steroids was standardized. The mean donor post-mortem time was 9.6 +/- 8.0 hours for short-term-preserved and 17.6 +/- 10.5 hours for organ-cultured corneas (p < 0.0001). The storage time was 71 +/- 49 and 380 +/- 167 hours (p < 0.0001), respectively. RESULTS: Endothelial cell density did not differ significantly between the two storage methods (p > 0.05). At 6 weeks postoperatively, the mean endothelial cell density was 2042 +/- 675 cells/mm2 for short-term-preserved corneas and 1972 +/- 522 cells/mm2 for organ-cultured corneas (p = 0.7). Endothelial cell density did not decrease significantly (p > 0.05) within the observation period of 12 months in both groups (after 12 months: 1868 +/- 957 cells/mm2 and 1638 +/- 643 cells/mm2, respectively). The mean corneal thickness was 542 +/- 50 microns for short-term-preserved and 541 +/- 55 microns for organ-cultured corneas and remainded unchanged during the follow-up of 12 months (542 +/- 42 microns and 521 +/- 43 microns, respectively). Neither the group of short-term-preserved corneas nor organ-cultured corneas showed a significant correlation between endothelial cell density or central cornea thickness with post-mortem time or with storage time of the donor corneas at any postoperative stage (p > 0.1). CONCLUSION: During the first year after PK, only a small decrease in endothelial cell density was observed in comparison with the 6-weeks finding. The storage method does not seem to affect the short-term changes of endothelial cell density. Further long-term studies are necessary to assess the clinical relevance of these observations.

[Design and preliminary results of the Erlanger non-high-risk penetrating-keratoplasty study]. / Design und erste Ergebnisse der prospektiven "Erlanger Nicht-Hochrisiko-Keratoplastik-Studie".

PURPOSE: The purpose of this prospective study is to examine the non-high-risk penetrating keratoplasty clinically, tyndallometrically and immunological-serologically in order to learn more about the pathogenesis, early symptoms and therapy monitoring of corneal graft rejection. PATIENTS AND METHODS: Since february 1997, patients undergoing non-high-risk-PK have been enrolled in this prospective study. Examinations are done preoperatively and in well-defined postoperative gates (6 weeks, 3 months, 6 months, etc.) and include clinical assessments, corneal topography, laser-tyndallometry, corneal endothelial cell count and corneal pachymetry. Preoperatively as well as at each postoperative examination, 10 ml serum and perioperatively corneoscleral donor tissue are collected and frozen (-80 degrees C) to allow immunological and serological examinations in case of graft rejection later. A relational data base (MS Access) guarantees complete and homognous standardized clinical and serological data. We randomised our patients with respect to duration of topical steroid therapy in standard situations (short-time vs. long-time) as well as for systemic steroid therapy (bolus group vs. tapering group) in case of a graft rejection in 2 treatment groups. RESULTS: Up to March 1998, 99 patients have been enrolled in this prospective study. Our report includes the first consecutive 55 patients (25 female, 30 male, recipient age 56.9 +/- 19.4 years, donor age 57.0 +/- 19.9 years). Up to now (follow-up 2.5 +/- 2.1, maximum of 7.3 months) we did not observe immunologic graft rejections. In one patient a primary graft failure occurred. Laser tyndallometry showed a reduction of blood-aqueous barrier breakdown from 6 weeks postoperatively (9.3 +/- 5.7 photon counts/msec) to 3 months postoperatively (6.8 +/- 3.5 photon counts/msec). CONCLUSION: This prospective randomized clinical and immunological study after non-high-risk-PK is supposed to give more information about pathogenesis, early symptoms and therapy monitoring of graft rejection after elective PK. The concept and design of this study are described. Preliminary data may give significant results in a few years.

Complex wave-field reconstruction by means of the Page distribution function.

The complex amplitude function in the waist of a one-dimensional Hermite-Gaussian model beam is measured by a noniterative method based on the Page distribution function in the two-dimensional spatial-angular phase space. The measurement procedure is realized by an extension of the knife-edge method. The model beam is generated by means of a phase plate in conjunction with a He-Ne laser.

[The presence of aluminum in cerebral vessels in Alzheimer's disease]. / Uber das Vorkommen von Aluminium in Hirngefässen bei Alzheimer-Krankheit.

Morin staining is a specific method by which to detect aluminium in the brain. In cases of Alzheimer disease, aluminium was found to occur in neurons and glial cells, dense cores of senile plaques, primitive plaques, and intracortical congophilic vessels. Findings obtained are likely to suggest concomitant presence of aluminium and amyloid. Aluminium is assumed to have high affinity for amyloid. Aluminium is thus capable of overcoming the blood-brain barrier.

[Experimental animal studies of the caries-protective activity of the anticarious agent Fluorprotektor (author's transl)]. / Tierexperimentelle Studie über die kariesprotektive Aktivität des Präparates Fluorprotektor.

In two caries model experiments on Wistar rats, a significant reduction in caries was observed following local application of Fluorprotektor and Duraphat. There appears to be no difference between the caries-protective properties of these two agents. The accumulation of fluoride in the superficial enamel was tenfold to elevenfold for the two lacquers. Residual Fluorprotektor was found on teeth even after twenty-four days from the application thereto.

[Comparson of occlusal conditions in juveniles from residential areas with different drinking water fluoride contents (author's transl)]. / Vergleich der Okklusionsverhältnisse von Jugendlichen aus Wohngebieten mit untershciedlichem Fluoridgehalt des Trinkwassers.

The investigations reported in this paper were conducted in Karl-Marx-Stadt after 16 years from the introduction of drinking water fluoridation (1.0 ppm F), with a total of 792 randomly selected juveniles (whose average age was 14.9 years) being examined. Serving as a control group were 780 juveniles of the same age (15.4 years). The control persons were from Leipzig (0.2 ppm F). Included in the comparison with metric occlusal traits, use being made in this connection of the method for measuring occlusal traits, which was recommended in 1973 by an F.D.I. commission (COCSTOC-MOT). Despite the considerable reduction of caries in the deciduous dentition and the change in the eruptive behavior of permanent teeth, which is of great importance of the development, of dentition, no systematic differences could be observed between the two groups of subjects. An improvement in the occlusal conditions could not, after consumption of drinking water with an optimum fluoride content, be convincingly demonstrated by means of the epidemiological method used in these investigations.

[Caries prevention by means of aminofluoride after 7 years of collectively conducted oral hygiene]. / Karieshemmung durch Aminfluorid nach 7 Jahren kollektiv angeleiteter Mundhygiene

In the framework of an oral hygiene action (starting with the first year of attendance at school), topically applied amine fluorides (Elmex fluid for supervised toothbrushing at school; Elmex tooth-paste for unsupervised use at home) produced a reduction in caries increase by 36.4% (DMF/T index) or 40.5% (DMF/S index) after 7 years.

[Economic aspects of organized and supervised oral hygiene drives]. / Okonomische Aspekte angeleiteter und überwachter Mundhygiene-Aktionen

The caries reduction of 1.8 tooth surfaces (32,1%) after 5 years of an oral hygiene action using amine fluoride corresponds to a reduction in working time of 0.62 hours; or, on a working time per child basis, to 2.89 hours. The cost of one local application is 0.60 M; 21.60 M must be spent per annum and child. Expressed in terms of working hours, this corresponds to 11.76 M per hour, which is very low in comparison with figures from other countries. It is shown that oral hygiene actions using amine fluoride, supervised by a dental nurse, are collective measures that are economically justifiable.

[Longitudinal studies on the inhibition of caries by amine fluoride within the framework of guided and supervised oral hygiene actions]. / Längsschnittstudien zur Karieshemmung durch Aminfluorid im Rahmen angeleiteter und überwachter Mundhygiene-Aktionen

In a 3-year, 4-year and 5-year studies, the authors tested clinically and radiographically the caries-inhibiting efficiency of topically applied amine fluoride in defined groups (fluoride group with Elmex fluid and Elmex tooth-paste for unsupervised dental and oral hygiene at home, placebo group and control group). After the fifth study year, the caries increment in the children who were 11 years of age at this time had decreased by 30.6% (DMF/T index) and 32.1% (DMF/S index).