Many factors influence the outcome of islet transplantation. As islets in the early posttransplant setting are supplied with oxygen by diffusion only and are in a hypoxic state in the portal system, we tested whether small human islets are superior to large islets both in vitro and in vivo. We assessed insulin secretion of large and small islets and quantified cell death during hypoxic conditions simulating the intraportal transplant environment. In the clinical setting, we analyzed the influence of transplanted islet size on insulin production in patients with type 1 diabetes. Our results provide evidence that small islets are superior to large islets with regard to in vitro insulin secretion and show a higher survival rate during both normoxic and hypoxic culture. Islet volume after 48 h of hypoxic culture decreased to 25% compared with normoxic culture at 24 h due to a preferential loss of large islets. In human islet transplantation, the isolation index (islet volume as expressed in islet equivalents/islet number), or more simply the islet number, proved to be more reliable to predict stimulated C-peptide response compared with islet volume. Thus, islet size seems to be a key factor determining human islet transplantation outcome. Diabetes 56:594 -603, 2007

. Purpose:  To evaluate the relationship between signs and symptoms of dry eye disease (DED) in a clinic‐based population. Methods:  In a retrospective analysis, clinical signs and symptoms were evaluated for 344 subjects (n = 82, normal; n = 263, dry eye), across 11 sites from the EU and United States. Pearson correlations between signs and symptoms (r2) and an independent components analysis (ICA) mixing matrix were derived from the data set. Similar analysis was performed on an independent data set from 200 subjects in a previous study in Munich, Germany. Results:  No correlations above r2 = 0.17 were found between any signs and symptoms, except for corneal and conjunctival staining, which reported an r2 = 0.36. In the multisite study, the average r2 for osmolarity (0.07), tear breakup time (0.12), Schirmer test (0.09), corneal (0.16) and conjunctival staining (0.17), meibomian grading (0.11) and Ocular Surface Disease Index® (0.11) were consistently low. Among patients who showed evidence of DED by consensus of clinical signs, only 57% reported symptoms consistent with a diagnosis of DED. Similar results were observed in the Munich‐based study data set. Each component of the ICA mixing matrix exhibited minimal residual information. Conclusions:  No consistent relationship was found between common signs and symptoms of DED. Each type of measurement provides distinct information about the condition of the ocular surface. These results also demonstrate that symptoms alone are insufficient for the diagnosis and management of DED and argue for a consensus of clinical signs that better reflect all aspects of the disease.

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Purpose: To assess whether Swiss adult citizens diagnosed with keratoconus have the minimal knowledge that a corneal specialist would expect they should have.Methods: Experts defined the "minimal keratoconus knowledge" (MKK) with respect to definition, risk factors, symptoms, and possible treatment options of keratoconus. A survey was performed in 167 patients with keratoconus [mean age 38.8 years (SD 13.9), 77.7% male] in 5 specialized institutions. Of each participant, salient clinical characteristics, highest educational level, paramedical background, and specific health experience with keratoconus in the social surrounding were obtained. We calculated the proportion of MKK and examined whether patients with higher education and greater disease experience would perform better than those from other groups in multivariate analyses.Results: No single citizen reached 100% MKK. The mean MKK was 35.2%, and the range was 0% to 76.2%. Participants with a university degree had only a moderately higher MKK [+8.7% (95% confidence interval: 4.4-13.0); P , 0.001]. Per age decile, the MKK declined by 3.1% (95% confidence interval: 1.2-4.9), P = 0.002. Disease duration, severity of keratoconus in Kmax values, and history of surgical treatment did not significantly increase MKK. Surprisingly, MKK was also lower in patients with a paramedical background [26.3% (214.1 to 1.4); P = 0.107].Conclusions: This sample of Swiss patients with keratoconus did not know more than a third of the MKK. We found a little difference within various subgroups. There is a substantial mismatch between caregivers' expectations of patients' knowledge and patients' active knowledge regarding their condition. This may lead to an inefficient care delivery and misunderstandings.

There is a high variability of osmolarity measurements with the TearLab system. A substantial number of healthy subjects fulfill the DEWS's definition of DED. We propose interpreting the TearLab osmolarity results cautiously and in the context of other established methods.

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Background To assess whether Swiss general ophthalmologists have the minimal keratoconus knowledge that corneal specialists would expect them to have. Methods Corneal specialists defined “minimal keratoconus knowledge” (MKK) with respect to definition, risk factors, symptoms and possible treatment options of keratoconus. A telephone interview survey was conducted among one hundred ophthalmologists (mean age 51.9 years (SD 9.5), 60 % male) from the German-speaking part of Switzerland. For each participant, years of work experience, number of keratoconus patients seen per year and access to a topography device were obtained. We calculated the proportion of MKK and examined in multivariate analyses whether ophthalmologists with access to topography and with greater work experience performed better than other groups. Results No single ophthalmologist had MKK. The mean MKK was 52.0 %, and the range was 28.6–81.0 %. Per 10 years of working in private practice, the MKK decreased by 8.1 % points (95 % CI: -14.2, -2.00; p = 0.01). Only 24 % of participants correctly recalled the definition of keratoconus, 9 % all risk factors, 5 % all symptoms and 20 % all treatment modalities. The MKK values were not associated with the number of keratoconus patients seen per year and the availability of topography to diagnose keratoconus. Conclusions There is a substantial mismatch between corneal specialist’ expectations and general ophthalmologists’ knowledge about keratoconus. The low recall of symptoms and risk factors may explain why ophthalmologists diagnose relatively few cases of keratoconus, resulting in inefficient care delivery and delayed intervention.

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