E-journal of Surface Science and Nanotechnology最新文献

Introduction: Peripheral nerve sheath tumours are neurogenic neoplasms that arise from the nerve sheath which are not within the central nervous system. While most of these lesions may be benign, some of them may undergo malignant transformation, establishing why it is imperative for ultrasound practitioners to familiarise themselves with ultrasound presentations of this lesion to facilitate early and effective diagnosis, which would in turn positively impact patient management.

Case report: We present an incidental finding of a thrombus-mimicking peripheral nerve sheath tumour in a female patient who came to the ultrasound department for a left leg deep vein thrombosis scan.

Discussion: This case study demonstrates a peripheral nerve sheath tumour which by virtue of its location (very closely adjacent the deep calf veins) and appearance (incompressible, heterogeneous, minimal colour flow), mimicked a deep calf vein thrombus on ultrasound. Careful surveillance of the area on ultrasound revealed the lesion was distinct from the calf vasculature, and further imaging was advised. A magnetic resonance imaging was conducted confirming the diagnosis of a peripheral nerve sheath tumour.

Conclusion: In addition to assessing the lower limb venous system during deep venous thrombosis scans, sonographers should be mindful that other soft tissue lesions such as peripheral nerve sheath tumour may be present with symptoms that mimic those of a thrombotic leg, and therefore check to exclude or confirm the presence of any adjacent soft tissue lesions, especially at the symptomatic site indicated by the patient.

Purpose: The aim of this study was to assess the difference in treatment success after phototherapeutic keratectomy (PTK) for Salzmann's nodular degeneration (SND) using two excimer lasers with different specifications.

Patients and methods: 272 PTK procedures, which had been performed on 246 eyes with SND from 181 patients, were retrospectively examined in the period from 2007 to 2017. Until 2014 the excimer laser MEL70 (Carl Zeiss Meditec Vertriebsgesellschaft mbH, Oberkochen, Germany) was used for PTK following manual pannectomy, and after 2014 the excimer laser Amaris 750S (Schwind eye-tech-solutions GmbH, Kleinostheim, Germany) was used. Treatment success was assessed on basis of visual acuity, refraction, and astigmatism, as well as pachymetry and endothelial cell count, recorded at the following time points: T1 = preoperative, T2 = 6-week follow-up, T3 = 6-month follow-up. The Wilcoxon-Mann-Whitney U test and the chi-square test with a significance level of 5% were used to compare the data.

Results: A significantly higher improvement of 0.17 ± 0.33 logMAR could be shown for visual acuity in the Schwind group (p < 0.013) after 6 months. In the Zeiss group, visual acuity improved by only 0.11 ± 0.36 (logMAR p < 0.057). Regarding refraction, a significant reduction of the spherical equivalent (SEQ) (p < 0.001) by 3.35 ± 2.76 diopters (D) after 6 months could only be shown for the Schwind group. SEQ did not change significantly in the Zeiss group (p < 0.676). The topographic astigmatism was significantly improved after 6 months in both study groups, by 1.73 ± 1.99 D in the Schwind group (p < 0.001) and by 1.99 ± 2.21 D in the Zeiss group (p < 0.0001). Haze had to be treated in 12.7% of the cases in the Schwind group and in 16.2% of the cases in the Zeiss group. No endothelial cell damage was found in either group.

Conclusions: In both study groups, the patients with SND clearly benefited from PTK. However, a significantly higher advantage for visual acuity and refraction was shown for the Schwind group compared with the Zeiss group. In contrast to the usual hyperopic effect of PTK in other diagnoses, PTK in SND showed a "myopic shift", which can be explained by the often midperipheral SND nodes and the associated asymmetric tear film pooling prior to surgery.