U C Schaller

Ludwig-Maximilians-University of Munich, München, Bavaria, Germany

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Publications (54)81.7 Total impact

  • Martin M Nentwich, Ulrich C Schaller, Volker Klauss
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    ABSTRACT: In sub-Sahara Africa, the shortage of ophthalmologists is a major obstacle in the struggle of fighting preventable blindness. Migration of well-trained ophthalmologists has an additional negative effect on the low number of caregivers. However, to date, the reasons affecting migration of ophthalmologists have not been completely understood. The present study evaluates reasons reported by ophthalmologists for staying in their current work setting/country and potential reasons why they might consider migrating. In the years 2009-2011, after approval was obtained from the Institutional Review Board, a questionnaire evaluating reasons for and against migration of ophthalmologists was distributed to the participants of 2-week courses in Ethiopia, Cameroon and Kenya providing continuing medical education in the field of ophthalmology. A total of 84 ophthalmologists participated in this survey. The main reasons for staying in their current region/country were good working conditions, commitment to help, possibility of further training, familial ties and general feeling of satisfaction. Professional development elsewhere and better income abroad were named as the main reasons for considering migration. Almost half of the survey participants reported good infrastructure, equipment, and consumables, which is encouraging. Programs aimed at continuing medical education of ophthalmologists to enable professional development may have an appropriate role in the establishment of an ophthalmic infrastructure which can meet patients' needs.
    International Ophthalmology 01/2014;
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    ABSTRACT: To assess quality of life in uveal melanoma patients within the first and second year after CyberKnife radiosurgery. Overall, 91 uveal melanoma patients were evaluated for quality of life through the Short-form (SF-12) Health Survey at baseline and at every follow-up visit over 2 years after CyberKnife radiosurgery. Statistical analysis was carried out using SF Health Outcomes Scoring Software and included subgroup analysis of patients developing secondary glaucoma and of patients maintaining a best corrected visual acuity (BCVA) of the treated eye of 0.5 log(MAR) or better. Analysis of variance, Greenhouse-Geisser correction, Student's t-test, and Fisher's exact test were used to determine statistical significance. Physical Functioning (PF) and Role Physical (RP) showed a significant decrease after CyberKnife radiosurgery, whereas Mental Health (MH) improved (P=0.007, P<0.0001 and P=0.023). MH and Social Functioning (SF) increased significantly (P=0.0003 and 0.026) in the no glaucoma group, MH being higher compared with glaucoma patients (P=0.02). PF and RP were significantly higher in patients with higher BCVA at the second follow-up (P=0.02). RP decreased in patients with BCVA<0.5 log(MAR) (P=0.013). Vitality (VT) increased significantly in patients whose BCVA could be preserved (P=0.031). Neither tumor localization nor size influenced the development of secondary glaucoma or change in BCVA. Although PF and RP decreased over time, MH improved continuously. Prevention of secondary glaucoma has a significant influence on both SF and MH, whereas preservation of BCVA affects VT. Emotional stability throughout follow-up contributes positively toward overall quality of life. CyberKnife radiosurgery may contribute to attenuation of emotional distress in uveal melanoma patients.
    Melanoma research 09/2013; · 2.06 Impact Factor
  • A Klingenstein, A R Haug, C J Zech, U C Schaller
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    ABSTRACT: PURPOSE: To retrospectively evaluate the overall survival, safety, and efficacy of metastatic uveal melanoma patients after radioembolization as salvage therapy. MATERIALS AND METHODS: Thirteen patients were treated with radioembolization of branches of the hepatic artery with resin-based yttrium-90 ((90)Y)-labelled microspheres. Twelve patients underwent a single application, and 1 patient underwent 4 interventions. Dosages from 644 to 2,450 MBq (mean activity 1,780) were applied. Treatment response was evaluated by way of liver magnetic resonance imaging and computed tomography (CT) as well as whole-body fluorodeoxyglucose positron emission tomography (PET)/CT with evaluation of percentage changes in SUV(max) before and at 2-3 months after therapy. Kaplan-Meier analysis was calculated to determine overall survival. RESULTS: Partial remission (PR) was observed in 8 (62 %), stable disease (SD) in 2 (15 %), and progressive disease (PD) in 3 (23 %) patients under terms of standard criteria and PR in 3 (23 %), SD in 3 (23 %), and PD in 7 (54 %) patients according to PET criteria. Neither RECIST nor PET criteria showed a significant difference in predicting overall survival (P = 0.12 and 0.11, respectively). Median survival time after radioembolization was 7 months. No acute toxicity with in-hospital morbidity was observed. One patient developed hepatomegaly, and 1 patient developed gastric ulceration. Throughout follow-up, progression of extrahepatic metastases was observed. CONCLUSION: Radioembolization may be a promising therapy in uveal melanoma patients with predominant hepatic metastases. At first follow-up, we observed PR or SD in 77 % patients under terms of standard criteria with an acceptable toxicity profile.
    CardioVascular and Interventional Radiology 04/2012; · 2.09 Impact Factor
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    ABSTRACT: Nilotinib is a second generation tyrosine kinase inhibitor which is used in both first and second line treatment of chronic myeloid leukemia (CML). In the present work, the effects of nilotinib resistance on K562 cells were investigated at the molecular level using Fourier transform infrared (FT-IR) spectroscopy. Human K562 CML cells were exposed to step-wise increasing concentrations of nilotinib, and sub-clones of K562 cells resistant to 50_nM nilotinib were generated and referred to as K562/NIL-50 cells. Antiproliferative effects of nilotinib were determined by XTT cell proliferation assay. Changes in macromolecules in parental and resistant cells were studied by FT-IR spectroscopy. Nilotinib resistance caused significant changes which indicated increases in the level of glycogen and membrane/lipid order. The amount of unsaturated lipids increased in the nilotinib resistant cells indicating lipid peroxidation. The total amount of lipids did not change significantly but the relative proportion of cholesterol and triglycerides altered considerably. Moreover, the transcriptional status decreased but metabolic turn-over increased as revealed by the FT-IR spectra. In addition, changes in the proteome and structural changes in both proteins and the nucleus were observed in the K562/NIL-50 cells. Protein secondary structural analyses revealed that alpha helix structure and random coil structure decreased, however, anti-parallel beta sheet structure, beta sheet structure and turns structure increased. These results indicate that the FT-IR technique provides a method for analyzing drug resistance related structural changes in leukemia and other cancer types.
    Technology in cancer research & treatment 03/2012; 11(5):433-9. · 1.94 Impact Factor
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    ABSTRACT: Purpose of this study is to evaluate radiographic therapy response, clinical outcome and adverse effects of CyberKnife radiosurgery in patients suffering from orbital metastases. Sixteen orbital metastases originating from different solid cancers in fourteen patients were treated by single fraction CyberKnife radiosurgery. Radiographic response and clinical outcome were evaluated. The treated tumor volume ranged from 0.2 to 35 cm(3) (median 2.3 cm(3), mean 7.0 cm(3), SD ± 10.4 cm(3), CI 0.9-9.4 cm(3)). The prescription dose ranged from 16.5-21 Gy (median 18 Gy, mean 18.2 Gy, SD ± 1.2 Gy, CI 17.0-18.4 Gy). A no change situation was observed in nine lesions, partial remission in four as well as complete remission in one metastasis. Tumor growth was stabilized or regressive following CyberKnife therapy in 87% of the cases. Recurrence was observed in two cases (13%). Before therapy, three patients suffered from visual disturbance and five patients reported diplopia. Six patients had no initial symptoms. After therapy, one patient indicated improvement of the present visual deficit and two patients no change. Out of the two patients with persistent diplopia, two reported improvement after therapy and three no change. No progression of symptoms was noted in any of the cases. Fourteen out of sixteen treated lesions were stable or regressive following CyberKnife radiosurgery (87%). As no serious adverse effects were reported in this series, CyberKnife therapy was shown to be of great value for local management of orbital metastases.
    Technology in cancer research & treatment 03/2012; · 1.94 Impact Factor
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    ABSTRACT: The serological marker melanoma inhibitory activity (MIA) has been shown to be significantly higher in the serum of patients suffering from metastatic uveal melanoma than in progression-free patients. The objective of this study was to calculate a meaningful receiver operating characteristic (ROC) curve for MIA based on a large patient collective and to find an appropriate threshold value. MIA tumor marker levels of 503 outpatients suffering from uveal melanoma were evaluated using enzyme-linked immunosorbent assay. Fifty-four patients had confirmed metastases and 449 patients showed no overt metastatic disease at the time the blood sample was taken. ROC analysis was performed and the area under the curve (AUC) was calculated. Metastatic patients showed significantly higher MIA levels (median 11.69 ng/ml) than patients in the group without overt metastatic disease (median 6.97 ng/ml) (the Mann-Whitney test, P<0.001). The AUC was 0.84 (95% confidence interval: 0.76-0.91). The ROC resulting from our study can be applied for test comparison by means of AUC. The AUC value of 0.84 for MIA demonstrates the accurate performance of the test. On the basis of this ROC curve, we propose a MIA threshold value for uveal melanoma patients of 8.3 ng/ml (with a corresponding sensitivity of 82% and specificity of 77%, positive predictive value of 0.30 and negative predictive value of 0.97). In patients with higher MIA serum levels, further diagnostics should be initiated.
    Melanoma research 04/2011; 21(4):352-6. · 2.06 Impact Factor
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    ABSTRACT: Metastasis has been reported in the follow-up of up to 50% of uveal melanoma patients. Established oncological diagnostic modalities in tumor follow-up so far have limited sensitivity and specificity. The diagnostic value of combined positron emission tomography (PET)/computed tomography (CT) scans in the follow-up of patients with metastatic uveal melanoma was assessed. Eleven patients with successfully treated and one patient with suspected uveal melanoma underwent combined PET/CT scan. The indication for PET/CT scan was heterogenous and ranged from suspected metastatic choroidal melanoma in conventional imaging (n=3) to exclusion of further organ involvement before local therapy of liver metastases (n=5) and restaging after local or systemic therapy of metastases (n=4). PET/CT scan showed vital metastases from uveal melanoma in all patients (n=12). Ten patients showed vital hepatic metastases (83%), five osseous (42%), four lymphatic (33%), two pulmonary (17%), one adrenal (8%) and one had muscular metastases (8%). Six patients showed multiple organ involvement (50%). In addition, PET/CT scan correctly identified a primary intraocular tumor and ruled out pulmonary metastatic involvement with suspicious intrapulmonary findings in a CT scan and chest X-ray in two patients. It could also confirm an equivocal intrahepatic finding in an MRI scan as a vital metastasis. PET/CT scan is a very sensitive and specific tool for the detection and localization of metastatic disease in patients with uveal melanoma, assessing both anatomical morphology and cell metabolism in one single examination. With novel therapeutic approaches in evolution, PET/CT scanning can be of great importance for therapy planning and monitoring.
    Melanoma research 09/2010; 20(6):511-6. · 2.06 Impact Factor
  • Martin M Nentwich, Matthias Remy, Ulrich C Schaller
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    ABSTRACT: Ocular fat embolism syndrome in the complete absence of any cardiac defects is a rare phenomenon which is not commonly encountered in ophthalmic practice. We present a case of a 16-year-old girl with fat embolism syndrome and involvement of the retina after a tibial fracture without any cardiac defect.
    International Ophthalmology 05/2010; 31(1):15-6.
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    ABSTRACT: A 63-year-old woman presented with a 9-month history of painful amaurosis of the left eye caused by hemophthalmos. She was already undergoing chemotherapy for histopathologically proven liver metastases caused by an assumed melanoma. The location of the primary tumor was unknown. Whole-body FDG-PET/CT staging identified a lesion with characteristically malignant uptake in the region of the left eye as the primary tumor. After enucleation, a primary uveal melanoma was verified that expressed the serological marker melanoma inhibitory activity (MIA). FDG-PET/CT was able to successfully align hepatic metastases due to CUP with local ophthalmologic diagnostic findings and led to a correct diagnosis.
    Der Ophthalmologe 04/2010; 107(10):947-50. · 0.53 Impact Factor
  • Klinische Monatsblätter für Augenheilkunde 03/2010; 227(3):R29-47; quiz R48. · 0.70 Impact Factor
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    ABSTRACT: Clinical differentiation of choroidal pigmented lesions is sometimes difficult. Choroidal melanoma is the most prevalent primary neoplasia among malignant ocular tumors, and metastasis often occurs before the primary tumor is diagnosed. Therefore, early detection is essential. We investigated the imaging properties of clinically diagnosed melanocytic choroidal tumors using a nonmydriatic ultra-wide-field scanning laser ophthalmoscope (SLO) with two laser wavelengths to distinguish benign from malignant lesions. Repeated standardized ultrasound (US) evaluation provided reference standard. In a consecutive series of 49 patients with clinically diagnosed melanocytic choroidal tumors in one eye, 29 had established melanoma (defined by proven growth on repeated US follow-up) and 20 had nevi (defined by no malignancy according to clinical, US, and growth characteristics for at least 2 years). All patients underwent clinical examination, undilated Optomap((R)) (Optos PLC, Dunfermline, Fife, Scotland, UK) imaging, standardized US examination, and standard retinal photography. Measurements of the tumor base using the Optomap software were compared with US B-scan measurements. Imaging characteristics from the SLO images were correlated with the structural findings in the two patient groups. Measurements of tumor base correlated well between SLO and US with r = 0.61 (T-direction) and r = 0.51 (L-direction). On SLO imaging, typical malignant lesions appeared dark on the red laser channel and bright on the green laser channel. Based on those simple binary characteristics, a sensitivity of 76% at a specificity of 70% was obtained for a correct classification of lesions. When analogous to clinical examination lesion size, margin touching the optic disc, and existence of subretinal fluid were additionally considered, 90% sensitivity at 82% specificity was obtained. In this first, limited series, nonmydriatic SLO imaging with two laser wavelengths permitted to differentiate malignant ocular tumors from nonmalignant lesions with high diagnostic accuracy. Additional parameters may further enhance diagnostic properties, but larger patient series are required to validate our findings and prove the diagnostic properties.
    Clinical Ophthalmology 01/2010; 4:829-36.
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    Kernt Marcus, Ulrich C Schaller, Stumpf Carmen, al et
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    ABSTRACT: Marcus Kernt, Ulrich C Schaller, Carmen Stumpf, Michael W Ulbig, Anselm Kampik, Aljoscha S NeubauerDepartment of Ophthalmology, Ludwig-Maximilians-University, Munich, GermanyPurpose: Clinical differentiation of choroidal pigmented lesions is sometimes difficult. ­Choroidal melanoma is the most prevalent primary neoplasia among malignant ocular tumors, and metastasis often occurs before the primary tumor is diagnosed. Therefore, early detection is essential. We investigated the imaging properties of clinically diagnosed melanocytic choroidal tumors using a nonmydriatic ultra-wide-field scanning laser ophthalmoscope (SLO) with two laser wavelengths to distinguish benign from malignant lesions. Repeated standardized ultrasound (US) evaluation provided reference standard.Methods: In a consecutive series of 49 patients with clinically diagnosed melanocytic ­choroidal tumors in one eye, 29 had established melanoma (defined by proven growth on repeated US follow-up) and 20 had nevi (defined by no malignancy according to clinical, US, and growth ­characteristics for at least 2 years). All patients underwent clinical examination, undilated Optomap? (Optos PLC, Dunfermline, Fife, Scotland, UK) imaging, standardized US ­examination, and standard retinal photography. Measurements of the tumor base using the Optomap software were compared with US B-scan measurements. Imaging characteristics from the SLO images were correlated with the structural findings in the two patient groups.Results: Measurements of tumor base correlated well between SLO and US with r = 0.61 (T-direction) and r = 0.51 (L-direction). On SLO imaging, typical malignant lesions appeared dark on the red laser channel and bright on the green laser channel. Based on those simple binary characteristics, a sensitivity of 76% at a specificity of 70% was obtained for a correct classification of lesions. When analogous to clinical examination lesion size, margin touching the optic disc, and existence of subretinal fluid were additionally considered, 90% sensitivity at 82% specificity was obtained.Conclusions: In this first, limited series, nonmydriatic SLO imaging with two laser wavelengths permitted to differentiate malignant ocular tumors from nonmalignant lesions with high ­diagnostic accuracy. Additional parameters may further enhance diagnostic properties, but larger patient series are required to validate our findings and prove the diagnostic properties.Keywords: choroidal melanoma, nevus, imaging, ultra-wide-field scanning laser ophthal­moscopy
    Clinical Ophthalmology. 01/2010;
  • Klinische Monatsblatter Fur Augenheilkunde - KLIN MONATSBL AUGENHEILK. 01/2010; 227(03).
  • M M Nentwich, U C Schaller, V Klauss
    Klinische Monatsblätter für Augenheilkunde 10/2009; 226(10):R155-69; quiz R170-1. · 0.70 Impact Factor
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    ABSTRACT: Evaluation of the protein osteopontin (OPN) as a potential new marker in comparison to melanoma inhibitory activity (MIA) for screening and detection of metastatic uveal melanoma. Plasma levels of 32 patients with uveal melanoma were analyzed for OPN and MIA by enzyme-linked immunosorbent assay (ELISA). Fourteen of these patients had clinically detectable liver metastases. Median plasma concentration of OPN in patients with metastatic disease was 152.01 ng/ml compared to 47.39 ng/ml in patients without clinically detectable metastases (p < 0.001). The difference between the median MIA plasma levels in patients with (13.11 ng/ml) and patients without (5.64 ng/ml) metastatic disease was also statistically significant (p < 0.001). No correlation could be found between MIA or OPN levels and tumor height in patients without clinically detectable metastases. The proteins MIA and OPN seem to be promising tumor markers for the metastasis screening in patients with uveal melanoma.
    Ophthalmologica 03/2009; 223(4):239-43. · 1.41 Impact Factor
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    ABSTRACT: To determine whether a patient's age, gender, local or systemic risk factors affect the rate of preoperative bacterial contamination. Consecutive 1,474 patients undergoing intraocular surgery were enrolled in this prospective masked study. Past medical history was noted and examinations were performed. The patients were divided into four groups: a control group (without local or systemic risk factors), those with local risk factors (chronic use of topical medications, contact lens wear, blepharitis, chronic eyelid or conjunctival inflammation), those with systemic risk factors (immunosuppression, diabetes, autoimmune conditions, and asthma), and those with both. Conjunctival cultures were obtained before surgery. Among the 1,474 patients, 914 bacteria were isolated from 214 (14.9%) patients. Advanced age was associated with a higher rate of positive conjunctival cultures (p<0.005). No statistical difference was found with regard to gender (p=0.7173). Among the 282 patients in the control group, 14 (5%) had a positive conjunctival culture. Compared to the control group, positive conjunctival cultures were found in 118 out of 503 patients (23.5%) with local risk factors (p<0.0001), 65 out of 545 patients (11.9%) with systemic risk factors (p=0.0019), and 22 out of 144 (15.3%) with both (p=0.0006). Two patients developed postoperative endophthalmitis (0.14%), one with both local risk and systemic factors and the other with a systemic risk factor. Patients with local or systemic risk factors or advanced age were found to have a higher rate of bacterial conjunctival contamination before intraocular surgery.
    European journal of ophthalmology 01/2009; 19(5):717-22. · 0.91 Impact Factor
  • M. Nentwich, U. Schaller, V. Klauß
    Klinische Monatsblatter Fur Augenheilkunde - KLIN MONATSBL AUGENHEILK. 01/2009; 226(09).
  • M. Nentwich, U. Schaller, V. Klauß
    Klinische Monatsblatter Fur Augenheilkunde - KLIN MONATSBL AUGENHEILK. 01/2009; 226(10).
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    ABSTRACT: To analyze the feasibility and safety of frameless, image-guided robotic radiosurgery against uveal melanoma, we developed a streamlined procedure that is completed within 3 hours under retrobulbar anesthesia without immobilization. Twenty patients (10 men and 10 women) with medium (3-5-mm prominence) and large (>5-mm prominence) unilateral uveal melanomas were treated with a frameless robotic radiosurgery system. Median age was 61 years (range 32-78 years). All patients underwent a single-session procedure beginning with retrobulbar anaesthesia, followed by computerized tomography (CT) scanning that was used in the generation of a treatment plan, and then the delivery of a radiosurgical tumor dose between 18 and 22 Gy to the 70% isodose line. Three-dimensional treatment planning was aimed at securing the optical lens and the optic disc as much as possible. Follow-up occurred at 3, 6, 12, and 18 months after the radiosurgery with clinical, ultrasound, and CT studies. We were able to treat all patients in the frameless setup within 3 hours. In five patients with lateral and dorsal tumors, the dose to the optic lens could be kept below 2 Gy. The clinical response was evaluated for the first seven patients treated with a follow-up of at least 6 months. No local recurrences occurred with any of the clinically evaluated patients for a mean 13-month follow-up (range 6-22 months). Maximum median apical tumor height according to standardized A-scan ultrasound evaluations decreased from 7.7 to 5.6 mm (p < 0.1). The median reflectivity increased from 41% to 70% (p < 0.01). None of the patients developed a secondary glaucoma during the short-term follow-up period. Frameless, single-session, image-guided robotic radiosurgery is a feasible, safe and comfortable treatment option for patients with uveal melanoma. Longer follow-up and analysis of a larger patient series is required for definitive clinical recommendations.
    Technology in cancer research & treatment 11/2008; 7(5):369-74. · 1.94 Impact Factor
  • Archives of neurology 09/2008; 65(8):1124-5. · 7.58 Impact Factor

Publication Stats

279 Citations
81.70 Total Impact Points

Institutions

  • 2000–2012
    • Ludwig-Maximilians-University of Munich
      • Eye Clinic
      München, Bavaria, Germany
  • 2008
    • Cyberknife Center Munich
      Münchenbernsdorf, Thuringia, Germany
  • 2000–2002
    • University Hospital München
      München, Bavaria, Germany