Redefining 3Dimensional placental membrane microarchitecture using multiphoton microscopy and optical clearing

IntroductionRemodeling of human placental membranes (amniochorionic or fetalmembrane) throughout gestation, a necessity to accommodate increasing uterine volume, involves continuous alterations (replacement of cells and remodeling of extracellular matrix). Methodologic limitations have obscured microscopic determination of cellular and layer-level alterations. This study used a combination of advanced imaging by multiphoton autofluorescence microscopy (MPAM) and second harmonic generation (SHG) microscopy along with tissue optical clearing to characterize the 3Dimensional multilayer organization of placental membranes.MethodsPlacental membranes biopsies (6 mm) collected from term, not-in-labor cesarean deliveries (n = 7) were fixed in 10% formalin (native) or treated with 2,2′-thiodiethanol to render them transparent for deeper imaging. Native and cleared tissues were imaged using MPAM (cellular autofluorescence) and SHG (fibrillar collagen). Depth z-stacks captured the amnion epithelium, underlying matrix layers, and in the cleared biopsies, the decidua layer.ResultsMPAM and SHG revealed fetal membrane epithelial topography and collagen organization in multiple matrix layers. Term amnion layers showed epithelial shedding and gaps. Optical clearing provided full-depth imaging with improved visualization of collagen structure, mesenchymal cells in extracellular matrix layers, and decidua morphology. Layer thicknesses measured by imaging corroborated with histology. Mosaic tiling of MPAM/SHG image stacks allowed large area visualization of entire biopsies.ConclusionMPAM-SHG microscopy allowed for study of this multi-layered tissue and revealed shedding, gap formation, and other structural changes. This approach could be used to study structural changes associated with membranes as well as other uterine tissues to better understand events in normal and abnormal parturition.     

In-vitro tomography and non-destructive imaging at depth of pharmaceutical solid dosage forms

Tomographic imaging techniques offer new prospects for a better understanding of the quality, performance and release mechanisms of pharmaceutical solid dosage forms. It is only over the last fifteen years that tomography has been applied for the in-vitro characterisation of dosage forms. This review aims to introduce the concept of tomography in a pharmaceutical context, and describes the current state-of-the-art of the four most promising techniques: X-ray computed microtomography, magnetic resonance imaging, terahertz imaging and optical coherence tomography. The basic working principles of the techniques are introduced and the current pharmaceutical applications of the technologies are discussed, together with a comparison of their specific strengths and weaknesses. Possible future developments in these fields are also discussed.     

红外自发荧光与相干光断层扫描在后极部脉络膜裂伤应用

目的 探讨近红外自发荧光(NIA)联合相干光断层扫描(OCT)检查在视网膜后极部脉络膜裂伤中的应用价值.方法 对2009年2月至2014年4月在河南省立眼科医院确诊为视网膜后极部脉络膜裂伤11例患者进行眼底荧光血管造影(FFA)、NIA和OCT检查,并统计FFA和NIA测量脉络膜裂伤程度结果.结果 8例视网膜后极部脉络膜裂伤未合并视网膜下出血患者FFA与NIA均能从平面显示脉络膜裂伤长度,两组数据比较差异无统计学意义(t =1.06,P=0.31＞0.05).OCT从切面显示脉络膜裂伤及与黄斑中心凹距离.3例视网膜后极部脉络膜裂伤合并视网膜下出血患者NIA和OCT能立体评估和随访视网膜下出血位置及隆起高度的变化.NIA联合OCT检查所需时间约为FFA的35.56％,所需费用为FFA的38.64％.结论 NIA和OCT为无创性检查,两者联合能更简单和经济评估后极部脉络膜裂伤及合并视网膜下出血的患者.     

近视眼黄斑部神经上皮层厚度变化规律的分析

目的探讨不同度数近视眼黄斑部视网膜神经上皮变化规律。方法 122例近视患者(239只眼),根据等效球镜度数分为低度近视组(≤-3.0 D)、中度近视组(-3.0 D~-6.0 D)、高度近视组(-6.0~-9.0 D)和超高度近视组(>-9.0 D),应用相干光断层扫描(OCT)分析黄斑区视网膜神经上皮层厚度与等效球镜度数及眼轴长度的关系。结果超高近视组距黄斑中心凹颞侧、上方、下方750μm处神经上皮厚度与低度近视组相比均有显著差异(P<0.05);高度近视组上方及下方750μm处神经上皮层厚度亦与低度近视组相比有显著差异(P<0.05),且超高近视组下方750μm处神经上皮厚度较中度近视组亦显著变薄(P<0.05)。黄斑中心凹部及鼻侧、颞侧、上方、下方175μm处视网膜神经上皮厚度与眼轴长呈正相关,而下方750μm处神经上皮厚度与眼轴长呈负相关,差异有显著性(P<0.05)。且各方位厚度分布均是上方视网膜最厚,下方与鼻侧次之,颞侧最薄。结论黄斑部神经上皮的损害随屈光度数增高和眼轴增长而呈区域性萎缩变薄,提示可能出现早期近视性视网膜损害。OCT是为观察此种损害的理想方法。     

光学相干断层成像术观察超声乳化白内障吸除术后黄斑变化

目的　探讨超声乳化白内障吸除术后黄斑形态的变化及其可能的影响因素。方法　对行超声乳化白内障吸除术 ,且术前无合并症、术中无并发症发生的单纯老年性白内障患者 80例 (80只眼 )于术前和术后 1周分别行光学相干断层成像术 (opticalcoherencetomography ,OCT)检查 ;按术中使用的超声能量高低分成 2个组。观察黄斑中心凹视网膜厚度的变化及其与术中超声能量、术后前房炎性反应和视力的关系。结果　 80只眼黄斑中心凹视网膜平均厚度术前为 (14 2 9± 16 7) μm ,术后为 (15 7 9± 36 7) μm ,两者比较差异无显著意义 (P >0 0 5 )。术后 3只眼出现黄斑水肿 ,11只眼出现房水中度闪光 ,黄斑中心凹视网膜平均厚度术前为 (139 9± 11 3) μm ,术后为 (197 6± 36 9) μm ,两者比较差异有显著意义 (t =2 75 1,P <0 0 5 )。低能量组术后黄斑中心凹视网膜平均厚度为 (15 6 2± 18 3) μm ,高能量组为 (172 6± 32 9) μm ,两者比较差异有显著意义 (t=2 4 11,P <0 0 5 )。术后最佳矫正视力与黄斑中心凹视网膜厚度呈负相关性 (r=- 0 82 ,P <0 0 5 )。结论　超声乳化白内障吸除术可导致术眼黄斑中心凹视网膜厚度增加及黄斑水肿 ;术中高超声能量可明显影响术后黄斑中心凹视网膜的形态 ;术后黄斑中心     

非动脉炎性前部缺血性视神经病变光相干断层扫描研究

目的 探讨非动脉炎性前部缺血性视神经病变(non-arteritic anterior ischemic optic neuropathy,NAION)患眼远期视盘周围视网膜神经纤维层(retinal nerve fiber layer,RNFL)厚度及其与视野检查结果的相关性.方法 回顾性病例对照研究.对2007年8月至2009年8月在无锡市,第二人民医院眼科21例单眼发病NAION患者42只眼(21只发病眼为实验组,21只对侧正常眼为对照组)进行了视网膜神经纤维层厚度的光学相干断层扫描(optical coherence tomography,OCT),并检查视野(visual field,VF)、图形视觉诱发电位(pattern-reversal visual evoked potential,P-VEP)等检查.结果 NAION患者RNFL厚度较对照组变薄,上半侧易受累,相应下方视野缺损多见,且视盘非病变区域的RNFL厚度也比正常对照组相应区域变薄.平均RNFL厚度与视野平均缺损有相关性(r=0.38,P ＜0.05).结论 NAION患者远期盘周视神经纤维层厚度变薄,缺血区明显变薄,OCT检查非缺血区的RNFL厚度也变薄,提示NAION的RNFL丢失可能超过了视野检查的视野缺损的范围.NAION患眼盘周RNFL厚度与视野检查结果相关.     

黄斑裂孔的光学相干断层成像分析

目的 探讨黄斑裂孔的光学相干断层成像（ｏｐｔｉｃａｌ ｃｏｈｅｒｅｎｃｅ ｔｏｍｏｇｒａｐｈｙ,ＯＣＴ）特征及ＯＣＴ临床应用价值。方法 １９９８年９～１２月临床诊断为黄斑裂孔者共３５例（３８只眼）。经双眼散瞳后进行ＯＣＴ检查,对获取的图像进行分析和测量。结果 １例（１只眼）ＯＣＴ显示为玻璃牵引：１例（１只眼）为黄斑前膜所致的性裂孔：３３例（３６只眼）为黄斑裂孔,其中３例累及双眼。３６只眼中,板层黄     

光凝对糖尿病视网膜病变黄斑区视网膜厚度的早期影响

目的 探讨视网膜光凝术对糖尿病视网膜病变(diabetic retinopathy, DR)黄斑区视网膜厚度的早期影响。 方法 应用Zeiss-Humphrey光学相干断层扫描成像仪观察和定量分析21例30只眼 Ⅲ～Ⅳ 期DR患者视网膜光凝术前、术后第3天和第7天的黄斑中心凹和距离黄斑中心凹750 μm处神经上皮厚度和色素上皮厚度的改变。 结果 光凝术后第3天，黄斑中心凹神经上皮厚度较术前显著增加，其变化值与年龄、血糖、DR病程呈显著的正相关，术后第7天恢复至术前水平；距黄斑中心凹750 μm处的神经上皮厚度和色素上皮厚度无显著改变。 结论 视网膜光凝术能够引起DR眼术后早期的黄斑水肿或使原有的黄斑水肿加重，表现为黄斑中心凹神经上皮厚度的增加，老龄、血糖水平高、DR病程长可能加重术后黄斑水肿的程度。 (中华眼底病杂志, 2002, 18:031-33)     

Optical aberrations in the mouse eye

PURPOSE: The mouse eye is a widely used model for retinal disease and has potential to become a model for myopia. Studies of retinal disease will benefit from imaging the fundus in vivo. Experimental models of myopia often rely on manipulation of the visual experience. In both cases, knowledge of the optical quality of the eye, and in particular, the retinal image quality degradation imposed by the ocular aberrations is essential. In this study, we measured the ocular aberrations in the wild type mouse. METHODS: Twelve eyes from six four-week old black C57BL/6 wild type mice were studied. Measurements were done on awake animals, one being also measured under anesthesia for comparative purposes. Ocular aberrations were measured using a custom-built Hartmann-Shack system (using 680-nm illumination). Wave aberrations are reported up to fourth order Zernike polynomials. Spherical equivalent and astigmatism were obtained from the 2nd order Zernike terms. Modulation Transfer Functions (MTF) were estimated for the best focus, and through-focus, to estimate depth-of-focus. All reported data were for 1.5-mm pupils. RESULTS: Hartmann-Shack refractions were consistently hyperopic (10.12+/-1.41 D, mean and standard deviation) and astigmatism was present in many of the eyes (3.64+/-3.70 D, on average). Spherical aberration was positive in all eyes (0.15+/-0.07 microm) and coma terms RMS were significantly high compared to other Zernike terms (0.10+/-0.03 microm). MTFs estimated from wave aberrations show a modulation of 0.4 at 2c/deg, for best focus (and 0.15 without cancelling the measured defocus). For that spatial frequency, depth-of-focus estimated from through-focus modulation data using the Rayleigh criterion was 6D. Aberrations in the eye of one anesthetized mouse were higher than in the same eye of the awake animal. CONCLUSIONS: Hyperopic refractions in the mouse eye are consistent with previous retinoscopic data. The optics of the mouse eye is far from being diffraction-limited at 1.5-mm pupil, with significant amounts of spherical aberration and coma. However, estimates of MTFs from wave aberrations are higher than previously reported using a double-pass technique, resulting in smaller depth-of-field predictions. Despite the large degradation imposed by the aberrations these are lower than the amount of aberrations typically corrected by available correction techniques (i.e., adaptive optics). On the other hand, aberrations do not seem to be the limiting factor in the mouse spatial resolution. While the mouse optics are much more degraded than in other experimental models of myopia, its tolerance to large amounts of defocus does not seem to be determined entirely by the ocular aberrations.