Retinal nerve fibre layer thickness profile in normal eyes using third-generation optical coherence tomography

Aims To establish four normal retinal nerve fibre layer (RNFL) thickness radial profiles based on third-generation optical coherence tomography (OCT) and to compare them with previously reported histologic measurements.Methods A total of 20 normal eyes were studied. A circular scan was adjusted to the size of the optic disc and three scans were performed with this radius and every 200 mu m thereafter, up to a distance of 1400 mu m. Four different radial sections (superotemporal, superonasal, inferonasal, and inferotemporal) were studied to establish RNFL thickness OCT profiles. Additionally, two radial scans orientated at 45 and 1351 crossing the optic disc centre were performed in six of 20 eyes, and RNFL thickness was measured at disc margin.Results Quadrant location and distance from disc margin interaction in RNFL thickness was statistically significant (P < 0.001). the RNFL thickness decreased (P < 0.001) as the distance from the disc margin increased for all sections. the measurements automatically generated by the OCT built-in software were thinner (P < 0.001) than histologic ones close to the disc margin.Conclusions Four normal OCT RNFL profiles were established and compared with histological data obtained from the same area. RNFL measurements assessed by OCT 3 were significantly thinner close to the optic disc margin.Hosp Olhos Araraquara, Glaucoma Sect, BR-14802530 Araraquara, SP, BrazilHosp Olhos Araraquara, Retina Diagnost & Treatment Div, BR-14802530 Araraquara, SP, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilUSP, Inst Fis Sao Carlos, Sao Carlos, SP, BrazilUniv So Calif, Doheny Eye Inst, Dept Ophthalmol, Los Angeles, CA USAUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

Septic processes in colonic surgery

USMF “Carol Davila”, Clinica Chirurgie, Spitalul Clinic de Urgență “Bagdasar-Arseni”, Bucureşti, Serviciul de laborator, Spitalul “Bagdasar Arseni”, București, Catedra Informatică, Facultatea de Medicină, București, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Introducere: În studiul prospectiv a 174 pacienți cu media vârstei de 64,3 ani (limite:19-84 ani) au fost operați pentru afecțiuni chirurgicale ale colonului. Material și metoda: Pentru cancer au fost operați 111(63,79%) pacienți: stadiul clinic II(n = 29;27,3%) și stadiul IV(n = 54;31,03 %). Rezultate: S-a intervenit în urgență la 45(25,86%) pacienți pentru semne clinice ale proceselor septice intraperitoneale (n = 15;13,51%) și pentru sindroame ocluzive (n = 30; 27,02%) dintre care ocluzii intestinale (n = 12;19,04%) în patologia netumorală. Pentru afecțiuni netumorale au fost operați 63(36,21%) pacienți pentru: diverticulita colică (n = = 24;13,79%), polipi colici (n = 20;11,60%), volvulus sigmoid (n = 11;6,32 %), rectocolită ulcerohemoragică și purulentă (n=5;2,29%), boala Crohn (n=3;1,72%). Complicațiile postoperatorii au fost reprezentate de manifestările locale și generale ale proceselor septice intraperitoneale (n = 30;17,24%) și complicațiile septice parietale (n=27%;15,81%). Complicațiile postoperatorii mai frecvente în prima săptămână postoperator: hidroelectrolitice (66,66%), a patra decadă postoperator: septice. Au fost efectuate operații în urgență (n=74;44,2%). Operațiile radicale-11,36%. Prezența preoperatorie a sindromului raspunsului inflamator sistemic și evoluția sa postoperatorie a condus la declansarea sindromului de insuficiență multiplă a organelor, factor de predicție a letalitații postoperatorii (p<0,001). S-au înregistrat 37(21,22%) decese postoperatorii. Dezunirea liniei de anastomoza s-a soldat cu mortalitatea de 100 %. Concluzii: Complicațiile septice în chirurgia colonului au valoare predictivă pozitivă de 60 % în producerea deceselor postoperatorii.Introduction: In a prospective study of 174 patients with mean age of 64.3 years (range:19-84 years) were operated for surgical diseases of the colon.Material and methods: For cancer were operated 111(63.79%) patients: clinical stage II (n = 29,27.3%), IV (n = 54,31.03%).Results: We operated in emergency 45(25.86%) patients for clinical signs of intraperitoneal septic processes (n = 15,13.51%) and occlusive syndromes (n = 30,27.02%) from which intestinal occlusion (n = 12,19.04%) with nontumoral pathology. For nontumoral diseases were operated 63(36.21%) patients for: colic diverticulosis (n = 24, 13.79%), colic polyps (n = 20,11.60%), sigmoid volvulus (n = 11,6.32%), ulcerative ulcerohemorrhagic colitis and purulent (n = 5,2.29%), Crohn’s disease (n = 3,1.72%). Postoperative complications were represented by local and general manifestations of septic processes intraperitoneal (n = 30,17.24%) and parietal septic complications (n = 27%, 15.81%).More frequent postoperative complications in the first week after surgery: electrolytes disorders (66.66% ), the fourth decade after surgery: septic complications. Emergency surgery: n = 74,44.2%;11,36% radical operations. This preoperative systemic inflammatory response syndrome and postoperative evolution led to the outbreak of the syndrome multiple organ failure, a predictor of postoperative lethality (p < 0.001). There were 37(21.22%) postoperative deaths. Dehiscence of anastomosis line resulted in 100% mortality.Conclusions: Septic complications of colon surgery were 60% positive predictive value in producing postoperative deaths

The effects of ocular magnification on Spectralis spectral domain optical coherence tomography scan length

Purpose The purpose of this study was to assess the effects of incorporating individual ocular biometry measures of corneal curvature, refractive error, and axial length on scan length obtained using Spectralis spectral domain optical coherence tomography (SD-OCT). Methods Two SD-OCT scans were acquired for 50 eyes of 50 healthy participants, first using the Spectralis default keratometry (K) setting followed by incorporating individual mean-K values. Resulting scan lengths were compared to predicted scan lengths produced by image simulation software, based on individual ocular biometry measures including axial length. Results Axial length varied from 21.41 to 29.04 mm. Spectralis SD-OCT scan lengths obtained with default-K ranged from 5.7 to 7.3 mm, and with mean-K from 5.6 to 7.6 mm. We report a stronger correlation of simulated scan lengths incorporating the subject’s mean-K value (ρ = 0.926, P < 0.0005) compared to Spectralis default settings (ρ = 0.663, P < 0.0005). Conclusions Ocular magnification appears to be better accounted for when individual mean-K values are incorporated into Spectralis SD-OCT scan acquisition versus using the device’s default-K setting. This must be considered when taking area measurements and lateral measurements parallel to the retinal surface

Repeatability of Foveal Measurements Using Spectralis Optical Coherence Tomography Segmentation Software

PURPOSE: To investigate repeatability and reproducibility of thickness of eight individual retinal layers at axial and lateral foveal locations, as well as foveal width, measured from Spectralis spectral domain optical coherence tomography (SD-OCT) scans using newly available retinal layer segmentation software. METHODS: High-resolution SD-OCT scans were acquired for 40 eyes of 40 young healthy volunteers. Two scans were obtained in a single visit for each participant. Using new Spectralis segmentation software, two investigators independently obtained thickness of each of eight individual retinal layers at 0°, 2° and 5° eccentricities nasal and temporal to foveal centre, as well as foveal width measurements. Bland-Altman Coefficient of Repeatability (CoR) was calculated for inter-investigator and inter-scan agreement of all retinal measurements. Spearman's ρ indicated correlation of manually located central retinal thickness (RT0) with automated minimum foveal thickness (MFT) measurements. In addition, we investigated nasal-temporal symmetry of individual retinal layer thickness within the foveal pit. RESULTS: Inter-scan CoR values ranged from 3.1μm for axial retinal nerve fibre layer thickness to 15.0μm for the ganglion cell layer at 5° eccentricity. Mean foveal width was 2550μm ± 322μm with a CoR of 13μm for inter-investigator and 40μm for inter-scan agreement. Correlation of RT0 and MFT was very good (ρ = 0.97, P 0.05); however this symmetry could not be found at 5° eccentricity. CONCLUSIONS: We demonstrate excellent repeatability and reproducibility of each of eight individual retinal layer thickness measurements within the fovea as well as foveal width using Spectralis SD-OCT segmentation software in a young, healthy cohort. Thickness of all individual retinal layers were symmetrical at 2°, but not at 5° eccentricity away from the fovea

Influence of Elemental Iodine on Imidazolium-Based Ionic Liquids: Solution and Solid-State Effects

Ionic liquids doped with I-2, usually resulting in the formation of polyiodide anions, are extensively used as electrolytes and in iodination reactions. Herein, NMR spectroscopy and single-crystal X-ray diffraction were used to rationalize the structures of imidazolium-based polyiodide ionic liquids in the liquid and solid states. Combined, these studies show that extensive interactions between the imidazolium cation and the resulting polyiodide anion are present, which have the net effect of lengthening, polarizing, and weakening the I-I bonds in the anion. This bond weakening rationalizes the high conductivity and reactivity of ionic liquids doped with I-2

Endoscopic Endonasal Transsphenoidal Approach in the Management of Sellar and Parasellar Lesions: and Standard Surgical Technique (Part I)

Transsphenoidal approaches have been used for a century for the resection of pituitary and other sellar tumors. In the past decade, however, the endoscopic endonasal transsphenoidal approach has been proposed as a minimally invasive procedure for the treatment of pathologies of the sellar region. This procedure introduces various advantages compared with the transsphenoidal microsurgical approach, such as an improved vision of the surgical field, less traumatism of the nasal structures and reduced complications. Patients’ quick recovery, short hospital stays and minimal postoperative discomfort have been observed. More recently, the standard endoscopic endonasal technique has been extended to provide access to parasellar lesions. This expansion carries significant potential for the resection of skull base lesions. In this article, the authors review the indications of the endoscopic endonasal transsphenoidal approach and define the main phases of the standard surgical technique. Preoperative evaluation, equipment, preoperative and postoperative care are presented. Endoscopic endonasal technique is a safe and effective method for removal of most sellar and some parasellar masses, providing more complete lesion excision and reducing complications

Endoscopic endonasal transsphenoidal approach in the management of sellar and parasellar lesions: Alternative surgical techniques, results, complications (Part II)

The endoscopic endonasal transsphenoidal approach is a minimally invasive surgical technique for the removal of sellar and parasellar lesions. It allows panoramic vision of the surgical target and surrounding structures, with minimal trauma and a low complication rate. The procedure has been gaining in popularity in recent years. There are now surgical instruments intentionally conceived to respond to the specific characteristics of the neuroendoscopy.&nbsp;The widespread use of the endoscope in transsphenoidal surgery has recently contributed to the extension of the approach superior, inferior or lateral. This expansion carries significant potential for the resection of skull base lesions. For selected patients, the various techniques of the endoscopic endonasal transsphenoidal approach are valid alternatives to transcranial approaches. Macroadenomas, suprasellar or even intraventricular craniopharyngiomas, tuberculum sellae or even planum sphenoidale meningiomas and clival tumors become accessible for removal via an endoscopic approach.&nbsp;The authors review the main alternative surgical techniques of the endoscopic endonasal transsphenoidal approach. They also present the results and the complications of the endoscopic transsphenoidal surgery. Due to an improvement and refinement of the surgical procedures, the endoscopic endonasal transsphenoidal approach can be considered a good choice for the excision of the sellar and parasellar lesions

Integration and fusion of standard automated perimetry and optical coherence tomography data for improved automated glaucoma diagnostics

<p>Abstract</p> <p>Background</p> <p>The performance of glaucoma diagnostic systems could be conceivably improved by the integration of functional and structural test measurements that provide relevant and complementary information for reaching a diagnosis. The purpose of this study was to investigate the performance of data fusion methods and techniques for simple combination of Standard Automated Perimetry (SAP) and Optical Coherence Tomography (OCT) data for the diagnosis of glaucoma using Artificial Neural Networks (ANNs).</p> <p>Methods</p> <p>Humphrey 24-2 SITA standard SAP and StratusOCT tests were prospectively collected from a randomly selected population of 125 healthy persons and 135 patients with glaucomatous optic nerve heads and used as input for the ANNs. We tested commercially available standard parameters as well as novel ones (fused OCT and SAP data) that exploit the spatial relationship between visual field areas and sectors of the OCT peripapillary scan circle. We evaluated the performance of these SAP and OCT derived parameters both separately and in combination.</p> <p>Results</p> <p>The diagnostic accuracy from a combination of fused SAP and OCT data (95.39%) was higher than that of the best conventional parameters of either instrument, i.e. SAP Glaucoma Hemifield Test (p < 0.001) and OCT Retinal Nerve Fiber Layer Thickness ≥ 1 quadrant (p = 0.031). Fused OCT and combined fused OCT and SAP data provided similar Area under the Receiver Operating Characteristic Curve (AROC) values of 0.978 that were significantly larger (p = 0.047) compared to ANNs using SAP parameters alone (AROC = 0.945). On the other hand, ANNs based on the OCT parameters (AROC = 0.970) did not perform significantly worse than the ANNs based on the fused or combined forms of input data. The use of fused input increased the number of tests that were correctly classified by both SAP and OCT based ANNs.</p> <p>Conclusions</p> <p>Compared to the use of SAP parameters, input from the combination of fused OCT and SAP parameters, and from fused OCT data, significantly increased the performance of ANNs. Integrating parameters by including a priori relevant information through data fusion may improve ANN classification accuracy compared to currently available methods.</p