Structural Change Can Be Detected in Advanced-Glaucoma Eyes.

PurposeTo compare spectral-domain optical coherence tomography (SD-OCT) standard structural measures and a new three-dimensional (3D) volume optic nerve head (ONH) change detection method for detecting change over time in severely advanced-glaucoma (open-angle glaucoma [OAG]) patients.MethodsThirty-five eyes of 35 patients with very advanced glaucoma (defined as a visual field mean deviation < -21 dB) and 46 eyes of 30 healthy subjects to estimate aging changes were included. Circumpapillary retinal fiber layer thickness (cpRNFL), minimum rim width (MRW), and macular retinal ganglion cell-inner plexiform layer (GCIPL) thicknesses were measured using the San Diego Automated Layer Segmentation Algorithm (SALSA). Progression was defined as structural loss faster than 95th percentile of healthy eyes. Three-dimensional volume ONH change was estimated using the Bayesian-kernel detection scheme (BKDS), which does not require extensive retinal layer segmentation.ResultsThe number of progressing glaucoma eyes identified was highest for 3D volume BKDS (13, 37%), followed by GCPIL (11, 31%), cpRNFL (4, 11%), and MRW (2, 6%). In advanced-OAG eyes, only the mean rate of GCIPL change reached statistical significance, -0.18 μm/y (P = 0.02); the mean rates of cpRNFL and MRW change were not statistically different from zero. In healthy eyes, the mean rates of cpRNFL, MRW, and GCIPL change were significantly different from zero. (all P < 0.001).ConclusionsGanglion cell-inner plexiform layer and 3D volume BKDS show promise for identifying change in severely advanced glaucoma. These results suggest that structural change can be detected in very advanced disease. Longer follow-up is needed to determine whether changes identified are false positives or true progression

Metastase cervicale d’un adenome pleomorphe

Introduction : L’adénome pléomorphe est la tumeur la plus fréquente des glandes salivaires. Malgré son caractère bénin, de rares cas de métastases à distance ont été rapportés, touchant plus fréquemment l’os, les poumons et les ganglions lymphatiques. La localisation sous-cutanée, que nous rapportons dans ce travail, est exceptionnelle.Observation : Il s’agit d’une patiente de 41 ans, qui a eu une parotidectomie exofaciale gauche, par voie de lifting, pour un adénome pléomorphe, et qui a consulté, neuf ans plus tard, pour un nodule sous-cutané cervical moyen gauche. Une exérèse sous anesthésie locale a été réalisée. L’examen histologique de la pièce d’exérèse a conclu à une localisation secondaire d’un adénome pléomorphe. Aucune récidive locale ni à distance n’a été détectée, après trois ans de recul.Conclusion : L’adénome pléomorphe métastasant (APM), décrit depuis 1953, est rare. Aucune particularité clinique ni histologique ne permet de distinguer les formes métastatiques des formes classiques non métastatiques. Le mécanisme exact des métastases reste incertain mais semble être lié à une dissémination intra-vasculaire de cellules tumorales, lors de la manipulation chirurgicale de la tumeur primitive ou des récidives. Si la métastase est accessible, le pronostic est excellent après une exérèse complète.Mots-clés : adénome pléomorphe, métastase, peau, couIntroduction : Pleomorphic adenoma is the most common salivary tumor. Although clinically and histologically known as a benign tumor, there are rare reports of metastasis to distant sites, most commonly in bone, lungs, and lymph nodes. The subcutaneous site,reported in this case, is exceptional.Case-report : A 41 year-old patient, with history of left exofacial parotidectomy with a lifting incision, consulted after nine years for a left cervical subcutaneous nodule. An excision was performed under local anesthesia. The histological exam concluded in a secondary localization of pleomorphic adenoma. No local or distant recurrence was detected after three years.Conclusion : Metastasic pleomorphic adenoma, described since 1953, is uncommon. There are no known clinical or histological features that distinguish metastatic from non metastatic forms. The metastasis mechanism is uncertain, but seems to be related to vascular dissemination of tumoral cells, while surgical manipulation of the primary tumor or the recurrences. If metastasis is accessible, the prognosis is excellent after a complete excision.Keywords : pleomorphic adenoma, metastasis, skin, neck

Une etiologie rare d’une ulceration palatine : la sialometaplasie necrosante

La sialométaplasie nécrosante (SN) est une affection salivaire bénigne et rare, touchant principalement les glandes salivaires palatines et présentant des ressemblances cliniques et histologiques avec les carcinomes orales. Nous rapportons un cas de SN chez une patiente de 73 ans, non tarée, édentée, qui rapporte la notion de prothèse ancienne mal adaptée et qui présente une lésion ulcéro-végétante, bien limitée, douloureuse, palatine gauche, évoluant depuis 3 mois. Le scanner du massif facial a montré un épaississement des parties molles palatines avec un aspect aminci et irrégulier de l’os en regard. Une pathologie maligne à type de carcinome muco-épidermoide a été évoquée. Une exérèse radicale de la lésion a été réalisée et l’examen histologique a conclu à une SN.Mots clés : Sialométaplasie nécrosante; orale; palais; histologieNecrotizing sialometaplasia (NS) is a relatively uncommon benign disease of the salivary glands that most commonly occurs in the palate. It is often confused clinically and histopathologically with malignancies, such as squamous cell carcinoma or mucoepidermoid carcinoma. We report a case of NS in an edentate 73-year-old woman, with no medical history, showed up with a painful, well limited ulcerative lesion on the left palate, reporting its appearance three months ago. Reported also that she had a badly adapted removable denture. CT scan showed a thickening of the palate’s soft tissues with bone irregularity and thinning. A mucoepidermoid carcinoma was suspected. The patient underwent a radical excision of the lesion and histopathological diagnosis of NS was made.Keywords: Necrotizing sialometaplasia; oral; palate; histolog

Retinal Nerve Fiber Layer Features Identified by Unsupervised Machine Learning on Optical Coherence Tomography Scans Predict Glaucoma Progression.

Purpose:To apply computational techniques to wide-angle swept-source optical coherence tomography (SS-OCT) images to identify novel, glaucoma-related structural features and improve detection of glaucoma and prediction of future glaucomatous progression. Methods:Wide-angle SS-OCT, OCT circumpapillary retinal nerve fiber layer (cpRNFL) circle scans spectral-domain (SD)-OCT, standard automated perimetry (SAP), and frequency doubling technology (FDT) visual field tests were completed every 3 months for 2 years from a cohort of 28 healthy participants (56 eyes) and 93 glaucoma participants (179 eyes). RNFL thickness maps were extracted from segmented SS-OCT images and an unsupervised machine learning approach based on principal component analysis (PCA) was used to identify novel structural features. Area under the receiver operating characteristic curve (AUC) was used to assess diagnostic accuracy of RNFL PCA for detecting glaucoma and progression compared to SAP, FDT, and cpRNFL measures. Results:The RNFL PCA features were significantly associated with mean deviation (MD) in both SAP (R2 = 0.49, P < 0.0001) and FDT visual field testing (R2 = 0.48, P < 0.0001), and with mean circumpapillary RNFL thickness (cpRNFLt) from SD-OCT (R2 = 0.58, P < 0.0001). The identified features outperformed each of these measures in detecting glaucoma with an AUC of 0.95 for RNFL PCA compared to an 0.90 for mean cpRNFLt (P = 0.09), 0.86 for SAP MD (P = 0.034), and 0.83 for FDT MD (P = 0.021). Accuracy in predicting progression was also significantly higher for RNFL PCA compared to SAP MD, FDT MD, and mean cpRNFLt (P = 0.046, P = 0.007, and P = 0.044, respectively). Conclusions:A computational approach can identify structural features that improve glaucoma detection and progression prediction

Deep-Layer Microvasculature Dropout by Optical Coherence Tomography Angiography and Microstructure of Parapapillary Atrophy.

Purpose:To investigate the association between the microstructure of β-zone parapapillary atrophy (βPPA) and parapapillary deep-layer microvasculature dropout assessed by optical coherence tomography angiography (OCT-A). Methods:Thirty-seven eyes with βPPA devoid of the Bruch's membrane (BM) (γPPA) ranging between completely absent and discontinuous BM were matched by severity of the visual field (VF) damage with 37 eyes with fully intact BM (βPPA+BM) based on the spectral-domain (SD) OCT imaging. Parapapillary deep-layer microvasculature dropout was defined as a dropout of the microvasculature within choroid or scleral flange in the βPPA on the OCT-A. The widths of βPPA, γPPA, and βPPA+BM were measured on six radial SD-OCT images. Prevalence of the dropout was compared between eyes with and without γPPA. Logistic regression was performed for evaluating association of the dropout with the width of βPPA, γPPA, and βPPA+BM, and the γPPA presence. Results:Eyes with γPPA had significantly higher prevalence of the dropout than did those without γPPA (75.7% versus 40.8%; P = 0.004). In logistic regression, presence and longer width of the γPPA, worse VF mean deviation, and presence of focal lamina cribrosa defects were significantly associated with the dropout (P < 0.05), whereas width of the βPPA and βPPA+BM, axial length, and choroidal thickness were not (P > 0.10). Conclusions:Parapapillary deep-layer microvasculature dropout was associated with the presence and larger width of γPPA, but not with the βPPA+BM width. Presence and width of the exposed scleral flange, rather than the retinal pigmented epithelium atrophy, may be associated with deep-layer microvasculature dropout

Optical Coherence Tomography Angiography Vessel Density in Healthy, Glaucoma Suspect, and Glaucoma Eyes.

PurposeThe purpose of this study was to compare retinal nerve fiber layer (RNFL) thickness and optical coherence tomography angiography (OCT-A) retinal vasculature measurements in healthy, glaucoma suspect, and glaucoma patients.MethodsTwo hundred sixty-one eyes of 164 healthy, glaucoma suspect, and open-angle glaucoma (OAG) participants from the Diagnostic Innovations in Glaucoma Study with good quality OCT-A images were included. Retinal vasculature information was summarized as a vessel density map and as vessel density (%), which is the proportion of flowing vessel area over the total area evaluated. Two vessel density measurements extracted from the RNFL were analyzed: (1) circumpapillary vessel density (cpVD) measured in a 750-μm-wide elliptical annulus around the disc and (2) whole image vessel density (wiVD) measured over the entire image. Areas under the receiver operating characteristic curves (AUROC) were used to evaluate diagnostic accuracy.ResultsAge-adjusted mean vessel density was significantly lower in OAG eyes compared with glaucoma suspects and healthy eyes. (cpVD: 55.1 ± 7%, 60.3 ± 5%, and 64.2 ± 3%, respectively; P < 0.001; and wiVD: 46.2 ± 6%, 51.3 ± 5%, and 56.6 ± 3%, respectively; P < 0.001). For differentiating between glaucoma and healthy eyes, the age-adjusted AUROC was highest for wiVD (0.94), followed by RNFL thickness (0.92) and cpVD (0.83). The AUROCs for differentiating between healthy and glaucoma suspect eyes were highest for wiVD (0.70), followed by cpVD (0.65) and RNFL thickness (0.65).ConclusionsOptical coherence tomography angiography vessel density had similar diagnostic accuracy to RNFL thickness measurements for differentiating between healthy and glaucoma eyes. These results suggest that OCT-A measurements reflect damage to tissues relevant to the pathophysiology of OAG

Manganese pigmented anodized copper as solar selective absorber

The study concerns the optical and structural properties of layers obtained by a new efficient surface treatment totally free of chromium species. The process is made up of an anodic oxidation of copper in an alkaline solution followed by an alkaline potassium permanganate dipping post-treatment. Coatings, obtained at the lab and pilot scales, are stable up to 220 °C in air and vacuum, present low emissivity (0.14 at 70 °C) and high solar absorptivity (0.96), i.e. a suitable thermal efficiency (0.84 at 70 °C)

Control of Local Mass Transfer in the Separated and Reattaching Flow by a Periodic Forcing

A numerical study based on the Large Eddy Simulation (LES) methodology was made of mass transfer in locally forced turbulent separated and reattaching flow over a backward facing step. The local forcing was given to the flow by a sinusoidally blowing /suction of the fluid into a separated shear layer. The Reynolds number was fixed at 33000 and Schmidt number at 1. The forcing frequency was varied in the range 0 St 2, where St is the Strouhal number of forcing. The obtained results revealed the existence of an optimum forcing frequency value, St = 0.25, in terms of the reduced reattachment length. At this frequency the mass transfer is significantly enhanced in the recirculation zone. The influence of the frequency and the amplitude of forcing, in the maximum mass transfer positions and the maximum Sherwood number, are analyzed

Macular Ganglion Cell Inner Plexiform Layer Thickness in Glaucomatous Eyes with Localized Retinal Nerve Fiber Layer Defects

Purpose: To investigate macular ganglion cell–inner plexiform layer (mGCIPL) thickness in glaucomatous eyes with visible localized retinal nerve fiber layer (RNFL) defects on stereophotographs. Methods: 112 healthy and 149 glaucomatous eyes from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES) subjects had standard automated perimetry (SAP), optical coherence tomography (OCT) imaging of the macula and optic nerve head, and stereoscopic optic disc photography. Masked observers identified localized RNFL defects by grading of stereophotographs. Result: 47 eyes had visible localized RNFL defects on stereophotographs. Eyes with visible localized RNFL defects had significantly thinner mGCIPL thickness compared to healthy eyes (68.3 ± 11.4 μm versus 79.2 ± 6.6 μm respectively, P<0.001) and similar mGCIPL thickness to glaucomatous eyes without localized RNFL defects (68.6 ± 11.2 μm, P = 1.000). The average mGCIPL thickness in eyes with RNFL defects was 14% less than similarly aged healthy controls. For 29 eyes with a visible RNFL defect in just one hemiretina (superior or inferior) mGCIPL was thinnest in the same hemiretina in 26 eyes (90%). Eyes with inferior-temporal RNFL defects also had significantly thinner inferior-temporal mGCIPL (P<0.001) and inferior mGCIPL (P = 0.030) compared to glaucomatous eyes without a visible RNFL defect. Conclusion: The current study indicates that presence of a localized RNFL defect is likely to indicate significant macular damage, particularly in the region of the macular that topographically corresponds to the location of the RNFL defect