Acanthamoeba keratitis – Clinical signs, differential diagnosis and treatment

Purpose: To summarize actual literature data on clinical signs, differential diagnosis, and treatment of acanthamoeba keratitis. Methods: Review of literature. Results: Clinical signs of acanthamoeba keratitis are in early stages grey-dirty epithelium, pseudodendritiformic epitheliopathy, perineuritis, multifocal stromal infiltrates, ring infiltrate and in later stages scleritis, iris atrophy, anterior synechiae, secondary glaucoma, mature cataract, and chorioretinitis. As conservative treatment, we use up to one year triple-topical therapy (polyhexamethylene-biguanide, propamidine-isethionate, neomycin). In therapy resistant cases, surgical treatment options such as corneal cryotherapy, amniotic membrane transplantation, riboflavin-UVA cross-linking, and penetrating keratoplasty are applied. Conclusion: With early diagnosis and conservative or surgical treatment, acanthamoeba keratitis heals in most cases. Keywords: Acanthamoeba, Keratitis, Cornea, Contact len

Ocular Surface Disease Index and Ocular Thermography in Keratoconus Patients

Purpose. Keratoconus (KC) has been defined as a “noninflammatory” corneal disease, but recent studies have noted a potential inflammatory origin. We analysed the Ocular Surface Disease Index (OSDI) and ocular surface temperature (OST) in KC patients compared to controls. Patients and Methods. A total of 179 eyes in 90 patients with KC (topographic keratoconus classification 0-1 to 4, age 36.1 ± 12.5 years, 65.9% males) and 82 eyes in 41 controls (age 36.4 ± 12.8 years, 47.6% males) were examined. The participants completed the OSDI questionnaire and underwent corneal topography, tomography, and thermography. Additional outcome measures were vision- and discomfort-related OSDI subscores and mean OST  at the corneal centre during 10 seconds of sustained eye opening after blinking. Results. The OSDI score (31.4 ± 22.4 vs. 17.5 ± 17.9) and vision- (17.7 ± 14.6 vs. 10.5 ± 13.2) and discomfort-related (14.3 ± 10.7 vs. 9.4 ± 10.5) OSDI subscores were significantly higher in KC patients than in controls (p 0.174, p<0.005), but did not correlate with the central corneal OST (r < 0.001). OST  also did not correlate with the SAI, SRI, and central corneal thickness (r ≥ −0.086). Conclusion. KC patients had increased OSDI scores and vision- and discomfort-related OSDI subscores without an increase in the OST compared to a normal population. OSDI score/subscores weakly correlate with SAI and SRI but do not correlate with OST in KC patients or controls. Vision- and discomfort-related symptoms of KC have to be managed in parallel in ophthalmological practice, but the necessity of anti-inflammatory treatment cannot be verified through ocular thermography

Preliminary interlaboratory trial for ISO/DIS 12010 : determination of short chain polychlorinated alkanes (SCCP) in water

International audienceA first preliminary interlaboratory trial was planned to prepare ISO/DIS 12010: Water quality - determination of short chain polychlorinated alkanes (SCCP) in water - method using GC/MS and electron capture negative ionisation (ECNI). The task was to determine the sum of short chain polychlorinated n-alkanes with carbon chain lengths of C10-C13 and a chlorine content between 49 and 67% in water by GC-ECNI-MS and quantification by multiple linear regression described in ISO/DIS 12010 as the compulsory method. Distributed samples were obtained from a real water extract spiked with a target concentration of 0.4 micro g/mL sum of SCCP, i.e. the environmental quality target level according to the Water Framework Directive. The interlaboratory trial included the calibration, a column chromatographic clean up, a concentration step and an integration of chromatographic unresolved humps as well as the quantification with multiple linear regression. Reproducibility standard deviations between 21.5 and 22.9% were achieved by 17 participating laboratories from four countries. The method outlined no significant difference of the results between the standard solution and a real water matrix extract. On the basis of this succeeded preliminary interlaboratory trial the final interlaboratory trial for validation of ISO 12010 was prepared in autumn 2010

Validation interlaboratory trial for ISO 12010 : water quality-determination of short-chain polychlorinated alkanes (SCCP) in water

International audienceA validation interlaboratory trial was carried out to prepare ISO 12010: Water quality-Determination of short-chain polychlorinated alkanes (SCCP) in water-Method using gas chromatography/mass spectrometry (GC-MS) and electron capture negative ionisation (ECNI). The task was to determine the sum of short-chain polychlorinated n-alkanes with carbon chain lengths of C-10-C-13 and a chlorine content between 49% (g/100 g) and 67% (g/100 g) in water by GC-ECNI-MS. The quantification had to be performed by multiple linear regression as described in ISO/DIS 12010, the compulsory method. Samples distributed were real river samples, and waste water spiked with a target concentration of 0.4 and 0.6 mu g/L for the sum of SCCPs, i.e. a concentration around the environmental quality target level according to the European Water Framework Directive. The different types of water samples tested were surface water with <150 mg/L suspended matter, surface water with 0.5 g/L suspended matter, and filtered waste waster. The interlaboratory trial included the extraction of the water samples, a column chromatographic clean up, a concentration step, and integration of chromatographic unresolved complex mixtures as well as the calibration and quantification by multiple linear regression. The reproducibility standard deviation of the standard concentration was 11.9%. Reproducibility standard deviations of concentrations in the three different water samples between 27.8 and 34.2% were achieved by 10-12 participating laboratories from six countries